外文资料翻译(变频调速)
变频调速的工作原理
变频调速的工作原理
变频调速（Variable Frequency Drive,VFD）是一种用于调节电
动机转速的技术。
其工作原理基于改变电机输入电压频率来控制其转速。
变频调速主要由变频器（Inverter）和电动机两部分组成。
变
频器通过将输入电源的交流电转换为直流电，然后再将直流电通过逆变电路转换为可调频率的交流电输出给电动机。
电动机则根据所提供的频率进行运转。
当变频器的输出频率增加时，电动机的转速也相应增加。
因此，通过控制变频器输出的频率，我们就能实现对电动机转速的调节。
变频器中的控制电路可以通过监测电动机运行状态，收集反馈信号，并根据预设的转速要求进行调整。
通过比较预设转速与实际转速之间的差异，控制电路可以自动调整变频器的输出频率，从而实现对电动机转速的精确控制。
在变频调速过程中，我们可以通过调整变频器的输出频率来实现不同转速的控制。
例如，当我们需要电动机运行在低速状态时，可以降低变频器的输出频率；当需要电动机运行在高速状态时，可以增加变频器的输出频率。
变频调速技术的应用广泛，可以用于工业生产线、空调系统、泵站、机械设备等领域。
通过实现电动机的精确调速，可以提高设备的效率和运行稳定性，同时节约能源和减少设备的损耗。
变频调速的原理及应用教案
变频调速的原理及应用教案变频调速（Variable Frequency Drive，简称VFD）是一种电气设备，用于控制电机的转速和运行。
它通过改变电机的供电频率和电压来调节电机的转速。
以下是一个关于变频调速原理及应用的教案。
一、教学目标：1. 了解变频调速的原理；2. 掌握变频调速的应用范围和优势；3. 能够解释变频调速与传统调速方式的区别；4. 能够应用变频调速解决实际工程问题。
二、教学内容：1. 变频调速的原理1.1 变频调速的基本原理变频调速的基本原理是通过改变电源的频率和电压来改变电机的转速。
变频器将电网的交流电转换为直流电，然后再将直流电转换为可调频率和可调电压的交流电，供给电机。
通过改变输出电压的频率和幅值，可以调整电机的转速。
1.2 变频调速的控制方法变频调速的控制方法主要有开环控制和闭环控制两种。
开环控制是根据负载要求预先设定电机的转速，而闭环控制则通过传感器对电机的运行状态进行监测，并根据监测结果调整电机的输出转速。
2. 变频调速的应用2.1 工业领域在工业领域中，变频调速被广泛应用于各种需要控制转速的设备，如风机、泵、压缩机等。
通过调节设备的转速，可以实现能量的节约和运行效率的提高。
2.2 电梯电梯是另一个应用变频调速的领域。
通过变频调速可以实现电梯的平稳运行和快速响应，提升乘客的舒适度和安全性。
2.3 交通运输在交通运输领域，变频调速被广泛应用于地铁、电车和高速列车等。
通过调节电机的转速，可以实现车辆的平稳起动和制动控制。
三、教学方法：1. 学生讨论法：教师提出问题，学生进行小组讨论，然后在班内进行展示和讨论。
2. 实例分析法：通过实际工程案例，引导学生分析和解决问题，提高理论知识与实践能力的结合。
四、教学过程：1. 引入（10分钟）引入话题，向学生介绍变频调速的应用领域和优势。
2. 知识讲解（30分钟）2.1 讲解变频调速的基本原理和控制方法。
2.2 结合实例，展示变频调速在工程中的应用和效果。
变频器外文翻译文献
变频器外文翻译文献(文档含中英文对照即英文原文和中文翻译)外文:Converter reference design(1)Converter Selection:Selection to determine the frequency converter when the following points:1) The purpose of a variable frequency; constant pressure to control or constant current control.2) the load converter types such as leaves or pump volume pumps, with special attention to load the performance curve, the performance curve of the decision of the ways and means.3) the frequency converter and load matchingVoltage match: a rated voltage converter with a rated voltage line with the load. Current matches: ordinary pump, the rated current inverter and motor rated current match. For special load such as deep-water pumps, and so on need to refer to the electrical performance parameters to determine the most current inverter current and Guozainengli.Torque match: in this case constant torque load or slow down when the device may have occurred.4) the use of high-speed motor drive inverter, because of the high-speed motor, anti-small, high harmonics lead to increased output current value increases. So for high-speed motor inverter Selection, its capacity to be slightly larger than the ordinary motor selection.5) If the frequency converter to a long cable run, this time to take measures to curb the long cable to the impact of capacitive coupling, inadequate efforts to avoid converter, so in this case, the drive to enlarge the capacity of a file or the converter Output installed output reactor.6) For the application of some special occasions, such as high temperatures, high altitude, at this time would cause the down converter capacity, the drive to enlarge the capacity of a block.(2) inverter control schematic design:1) First confirmation of the installation environment ConverterOperating temperature: high-power converter is the internal electronic components, vulnerable to the effects of temperature, product general requirementsfor 0 ~ 55 ℃, but in order to ensure the safe, reliable, the use of room to be taken into account, the best control in 40 ℃below. In the control box, the converter box should generally be installed in the upper and strictly comply with the Manual of installation requirements, absolutely not be allowed to heating elements or components easily fever close to the converter installed at the bottom.Ambient temperature: the temperature is too high and large temperature changes, within easy converter there is dew, the insulation properties will be greatly reduced,or even short-circuit caused the accident. When necessary, to be added to the desiccant in the box and heater. In water treatment, generally heavier than water vapor, if the temperature changes, then this problem would be more prominent.Corrosive gases: the use of the environment if the corrosive gas concentrations, will not only lead corrosion of components, printed circuit boards, but it will also accelerate the aging of plastic devices, reducing insulation properties.Vibration and shock: the control cabinet with converter by vibration and mechanical shocks will cause electrical connection is bad. Huaian thermoelectric there such a problem. Apart from raising the control cabinet at this time of the mechanical strength, vibration and shock away from the source, we must also use seismic rubber pad fixed within and outside the control cabinet, such as electromagnetic switches have a vibration components. Equipment operation after a period of time and should conduct inspections and maintenance.Electromagnetic interference: Inverter at work due to rectification and frequency, produce around a lot of electromagnetic interference, these high-frequency electromagnetic waves in the vicinity of the instrument, apparatus, a certain interference. Therefore, the cabinet instrumentation and electronic systems, it should be optional metal, shielding the inverter instrument interference. All the components should be reliable grounding, in addition, the electrical components, equipment andinstrumentation should use the connectivity between the shielding control cables, and the shield should be grounded. If handled properly electromagnetic interference, often cause the entire system does not work, leading to the control unit failure or damage.2) Drives and determine the distance between the electrical cables and wiring methodsDrives and motor the short distance should be as much as possible. This reduces the capacitance of the cable, reducing the emission source of interference.Control cables optional shielded cable, power cable or optional shielding from the cable converter to use all the threads of the electrical shield.Electric cables should be independent of the other cable alignment, the minimum distance of 500 mm. At the same time should avoid the electrical cables and other long-running cable lines, in order to reduce the output voltage inverter rapid changes in the electromagnetic interference. If the control cables and power cables cross, as far as possible so that they cross the 90-degree angle. Converter and analog signals on the line and back to the main line of separation of alignment, even in the case also in the control cabinet.And the analog signal converter line the best choice of unshielded twisted pair, shielded power cables selection of the three-core cable (its specifications than ordinary electrical cables in the files) or to comply with the user manual converter.3) inverter control schematicsMain circuit: the role of reactor is to prevent the high-frequency converter harmonic power through the input circuit to return to the grid by the impact of other electronic devices, in accordance with the capacity size converter to decide whether to increase reactor; filter Converter is installed in the output, the output of high-frequency converter to reduce harmonics, when the electrical inverter to the longer distance, we should install filters. Although the frequency converter itself has all kinds of protection, but the lack of protection is not perfect, the main circuit breaker played overload, lack the same protection, selection, in accordance with the capacity to choose the frequency converter. Converter itself can be used to replace thermal overload protection relay.Control loop: the frequency with the frequency manually switch to the failure frequency can be manually cut-operation, not because of output voltage, frequency and frequency-be interlocked.4) Inverter groundingInverter correct grounding is to improve the system stability, the ability to inhibit an important means of noise. Inverter grounding resistance grounding terminal of the smaller the better, the grounding wire cross-section of not less than 4 mm, the length of not more than 5 m. Inverter should be grounded and power equipment to the sites separately, not in total. The shield signal converter from one end of the grounding end, the other floating air. Inverter and control of electrical between the same counter.(3) Inverter Control DesignConverter should be installed in the control cabinet internal control counters in the design should pay attention to the following issues1) heat: Inverter fever is the internal loss. In the frequency converter in the main part of the loss mainly to the main circuit, or about 98 percent, accounting for 2% of control circuits. In order to ensure reliable operation of the normal inverter, Thermal must inverter are usually used for cooling fan; converter fan of the contents of the converter box can be removed internal heat, if the fan does not work, should immediately stop inverter Operation; the high-power inverter also need to increase control Guishang fan, Control of the wind, to design a reasonable, all outlet into the net to set up dust, exhaust open, to avoid over the counter in a swirl, in a fixed location dust Accumulation, according to the statement converter ventilation fans to select the match, fans installed to the attention of earthquake problems.2) the problem of electromagnetic interferenceConverter in its work due to rectification and frequency, produce around a lot of electromagnetic interference, these high-frequency electromagnetic waves in the vicinity of the instrument, apparatus, a certain interference, and will produce high harmonics, the high harmonics will be available for adoption Xinhua loop into the whole power supply network, thus affecting other instruments. If the power inverter system as a whole lot of more than 25 percent, to be considered the anti-jammingmeasures to control supply.When the system in the high-frequency welding machine such as the impact load, electroplating power, the converter itself will appear as interference protection, to consider the whole system of power quality problems.3) protection issues need to pay attention to the following pointsWaterproof anti-condensation: If the converter on the scene, the need to pay attention to the frequency converter Guishang not have the flange or other pipeline leak, the inverter can not be near the water splash, sum up the scene OEM Switchgear Kits & level of security to IP43 above.BOOT: All outlet into the net to set up dust debris into the barrier floc, dust network should be designed to be removable, to facilitate the clean-up, maintenance. Dust of the grid network in accordance with the specific circumstances at the scene determined that dust around the net and Control Department to handle the combination of tight.Anti-corrosive gases: the chemical industry in this relatively Most of this can be on the frequency counters in the control room.(4) converter cable normsSignal lines and power lines must be separately alignment: the use of analog signal converter for remote control, in order to reduce the analog converter and other equipment from the interference, please control signal converter line with the strong electric circuit (H Circuit-and-loop) separate alignment. Distance should be 30 cm above. Even in the control cabinet, the same connection to maintain such a standard. The signal converter and the control should not be longer than the road back to 50 m. Signal lines and power lines must be placed in different metal pipe or metal hose internal: connect PLC and the signal converter if not placed in metal tubes, Drives and vulnerable to external interference equipment; because the converter No built-in the reactor, so the converter input and output level of external power line will have a very strong interference, placing the signal lines of metal or metal hose has to be extended to the inverter control terminal, to ensure that the signal Line and the complete separation of power lines.1) analog control signal line should use two-strands shielding line, cable specifications for 0.75 mm2. When the wiring must pay attention to, to the extent possible, the cable Baoxian short (5-7 mm or so), while Bao Xian after the shield should wrap insulating tape to prevent shielding lines and other equipment contact with the introduction of interference.2) To improve the simple wiring and reliability, signal recommend the use of online video pressure bar.(5) converter and the operation of the relevant parameters setInverter setting parameters, the parameters of each have a certain range of options, often encountered in the use of individual set of parameters for misconduct, leading converter does not work phenomenon.Control: that is, speed control, transferred from the control, PID control or other means. To take control, according to the general control precision, the need for static or dynamic identification.Running a minimum of: that is, the minimum speed motor running, the motor running at low speed, its poor performance cooling, electrical long run on low speed, it can cause burning motor. And at low speed, the cable will increase in the current, cable will lead to fever.The maximum operating frequency: the general maximum frequency converter to 60 Hz, and some even to 400 Hz, high-frequency will enable high-speed motor operation, which the ordinary motor, its bearings can not be over-speed long run, whether the motor rotor To be capable of such a centrifugal force.Carrier frequency: the higher the carrier frequency setting its high harmonics greater weight, and the length of cable, the electrical heating, cable converter fever fever and other factors are closely related.Electrical parameters: the frequency converter to set parameters of the motor power, current, voltage, speed, maximum frequency, these parameters can be directly in the motor nameplate.FH: In a frequency point, there may be a resonance phenomenon, particularly in the relatively high when the entire device in control of the compressor, thecompressor to avoid the surge point.(6) common fault analysis1) flow failure: over-current fault can be divided into acceleration, deceleration, constant speed over-current. May be due to the increase in frequency converter too little time to slow down, load mutations, the unequal distribution of load, output short-circuit, and other causes. At this time can be extended by the general acceleration and deceleration time, reduce the load of mutations, plus braking energy components, load distribution design, the lines to be checked. If off-load converter ora failure that has been Central converter inverter circuits, to be replaced converter.2) overload fault: overload fault, including frequency and overload the electrical overload. May be accelerated their time is too short, too low voltage power grids, Fuzaiguochong and other causes. General can be accelerated through the extension of time to extend the braking time, such as check-voltage power grid. Fuzaiguochong, selected motor and inverter can not drag the load, but also may be due to poor machinery lubrication caused. If the former is the need to replace high-power motors and inverter, if the latter will have to carry out maintenance on production machinery.3) under-voltage: the importation of some of the power inverter that there are problems, need to check before you can run.变频器设计使用参考（1）变频器选型：变频器选型时要确定以下几点：1) 采用变频的目的；恒压控制或恒流控制等。
中英文对照变频调速
变频调速The speed of standard induction motors can be controlled by variation of the frequency of the voltage applied to the motor. Due to flux saturation problems with induction motors, the voltage applied to the motor must alter with the frequency. The induction motor is a pseudo synchronous machine and so behaves as a speed source. The running speed is set by the frequency applied to it and is independent of load torque provided the motor is not over loaded.标准的感应电动机可通过改变施加到电动机上的频率和电压控制电动机的旋转速度。
由于感应电动机存在磁饱和的问题，施加在电动机上的电压必须随频率的变化而变。
感应电动机是准同步电动机，因此是速度的来源。
在电动机没有过载的情况下，电动机的旋转速度是由施加在其上的频率决定的，而不是由负载转矩决定的。
1．Vector drives have a mathematical model of the drive in software and by measuring the current vectors in relation to the applied voltage, they are able to maintain a constant field at all frequencies below the line frequency. These drives need to be tuned to the motor and typically include a self tuning algorithm that is enabled at commissioning to determine the component values for the mathematical model. If the motor is replaced, the drive needs to be retuned to learn the characteristics of the new motors.1. 矢量驱动装置建有软件化的驱动数学模型。
Application of Frequency Control System PLC(PLC变频调速系统应用研究) 外文翻译
Application of Frequency Control System PLC Abstract: This paper introduces the principle of frequency control heating system, focuses on the structural features of PLC control system, and system hardware and software design.Key words:programmable controller, frequency control, VVVF, heating system.One, IntroductionWith the rapid development of the information age, environmental protection, water and energy saving is no longer a regional topic. According to national statistics from related departments, AC motors, pumps and load for 40% of the country's total power consumption, so large a wide range of pumps and machinery is one of the key areas of energy efficiency. As environmental issues become increasingly accepted by the people in major cities is gradually heating the dispersion of the original into a central heating system. By the microcontroller and relays and other control system composed of short life, system failure rate, is bound by a simple function to the computer, and flexible, the advantages of universal set of one of the devices replaced. The current PLC electrical control system has become the most widely used heart devices. It not only can implement complex logic control, but also to complete the order or timing of various closed-loop control and high reliability, good stability, strong anti-interference, in the harsh environment a long time,uninterrupted operation, and programming Simple, easy maintenance, and is equipped with various communication interfaces and module processing, can be easily connected at all levels.Two, and SelectionIndoor heating, in order to make heating pipe without air, we must maintain a pipeline pressure of the water, or heating system does not work. We use PLC, accompanied by different functions of sensor, according to the pressure of the pipeline, through the inverter to control the pump speed, so that the pipeline pressure is always maintained at the appropriate range, and coupled with over-current, over voltage, overload, without water overpressure protection device set. System has two sets of the same device, to achieve a preparation for one. In addition, PLC by expanding the I / O interface for monitoring, control and communications functions. Control Principle 3The system is PLC real-time device monitoring system. 20 Circulating water pumps, 16 sets of constant pressure up water pumps to PLC's time from the stop control, including the standby pump (pump, constant pressure up water pumps) in the time switch, pump the front of the flow signal detection and alarm, pump overload short-circuit fault alarm.The 36 pump electrical control and protection devices were installed in 7 surface counters, the following detailed description of the first cabinet of the control surface and the initial component selection. Principles of theremaining cabinet features side with the first cabinet.The first control object surface power distribution equipment, including two 2.2 kW pumps and constant pressure up 3 sets of circulating water pump. Pump up work as a set pressure value with a comparison to PID regulator output, and drive up constant pressure water pump work. PLC time to under two pump switch, the specific process for the first frequency converter soft stop, stop receiving the transducer signal the end of the pump disconnect contactor current work, while spare pump contactor to connect operations then start the inverter, the switch to complete the work of the main standby pump. The switching time can be set as needed (using programming device or laptop to the PLC within the original set of switching time parameter changes). Two pump contactor for electrical interlocking. PLC detect the switching state of all contacts.Because the inverter has a short circuit, overload protection, so when the current inverter driven pump failure occurs when the converter will automatically cut off a power supply circuit, into the protection of the state and the output alarm signal. PLC on the alarm signal detection, and then to spare pump input. Specific process for the PLC after the first alarm signal is detected off the current pump contactor, after the inverter reset, and then connected back-pump contactor, start to run back-pump inverter. While the output of the pump failure alarm signal.The cabinet also includes 3 sets of 30 kW pump, a dual-use equipment forthe work, carried out by the PLC according to the time the rotation of 3 water pumps working switch. As the circulating pump is not controlled by inverter, the PLC only need 3 sets of pumps were on time and the disconnect contactor can be connected to operate. Electrical protection components used GV3, GV2 motor protection switch. Motor protection switch with release of the indicator, when the water pump short circuit, overload, etc. for release when the motor protector to protect and output alarm signal, PLC to detect the signal to cut off the pump and standby pump contactor contactor connected, run the standby pump. Pump failure alarm also issued instructions. PLC simultaneous detection of all the pump contactor switch state.All circulating pumps are installed in the outlet water flow sensors, PLC to detect the flow sensor output signal, to determine whether the water pump starts output, and normal work instructions or abnormal alarm indicator. Two constant pressure water pump up a public water sensor works ibid. The system has a number of electric control valve, its distribution by the supply control cabinet, operation control of its installation in control cabinet from the surface of the instrument weather compensator control. PLC to control its power circuit. When the electric control valve corresponding to one or a few circulating pump shut down or failure, the electric control valve will not be able to open.System Settings manual automatic conversion selector switch. PLC willswitch the state of the real-time detection, when you select manual functions, PLC only for signal detection, fault alarm and power supply circuit with the electric valve interlock. All pumps switches and switch start-stop converter installed in the control cabinet by the manual button control panel. When you select automatic state of all control and alarm by the PLC to complete.Overall system diagram in Figure 3-1.Fore, hardware4.1 System block diagramPLC not only to control the circulating pump starts and stops, but also indirectly control up constant pressure from the pump stop working and the alarm output. Following a heat transfer station on the structure of explanation, several other similar basic structure, heat transfer station. Assumption P1, P2, P3 for the 3 sets of circulating pump, P4, P5 up to 2 sets of constant pressure pumps, P6 alarm output for the PLC, then the heat stops the hardware shown in Figure 4-1 to connect.4.2 The job description of all hardwareIn addition to the sensors, other hardware are all installed in a distribution cabinet.(1) converterCounters on each side by the constant pressure pump direct control inverter, inverter installed in the control cabinet, two public a constant pressure water pump converter, two pump electrical interlock. Start-stop control of the inverter is divided into manual and PLC control. There is one pressure sensor transducer input signal (feedback amount), all the way potentiometer signal (reference volume), three-way switch volume (two-way road from the stop signal and reset signal). There are two output signal (along fault protection alarm signal, lower than 5Hz run signal). Inverter parking parking are soft, manual control to stop when the counter has two buttons, one for the sub-contactor off button, a soft-stop button for the inverter. Note that because of the frequency converter soft parking parking are located, so when the manual stop button should press the soft-stop, soft stop and then disconnect the contactor end (this time fromthe actual case may be). Inverter fault reset signal is also equipped with manual and automatic two-way input.(2) Each side cabinet has a weather compensator to require distribution N = 250 W 230 VAC, the input from the external sensor input, output control electric control valve. Weather compensator to counter installation, including the sensor input and control output needs, including a total of 27 secondary terminals. Climate compensator with alarm, alarm lamp power distribution cabinet left.(3) flow switchPump starts the flow switch to detect whether there is any water after the pipe through, if the pump is running for the dual purpose of a front-end equipment is installed on each pump a flow sensor, a total of three. Or one of two pumps with a total installed equipment is a flow sensor. Specific process is: PLC after the start of a pump, after some delay (this delay can be set based on experience), PLC will detect the pump flow sensor output signal, if the signal indicative of the water flow is determined PLC pump failure, resulting in failure alarm signal, while the pump power and the standby pump pump put into operation.When the pipeline pressure tends to set the value of converter operating frequency is low, then the pump speed is very low, the flow switch may also issue non-flow signals. This is not failure, PLC will detect low-frequency transducer output signal to different (less than 5 Hz the waywhen the inverter output signal).(4) 24 hours under normal conditions and automatically switch the water pump, standby pump to run.(5) manual and automatic selection switchEach side cabinets are equipped with a manual / automatic transfer switch, the switch to a three selector switch, installed in the secondary control loop.1 to select Auto,2 to select Manual, 0 for the power left vacant.Select a button to manually power off, manual / automatic instructions breaker pull, PLC test the relay state, the implementation of control procedures, from the PLC to control all the water pump starts and stops and switching, including the frequency converter from the stop and alarm. Select 2 for the manual, then manually / automatically disconnect relay instructions, PLC detect the state of the relay, the implementation of manual procedures. PLC was detected only alarm. At this point all the counter control buttons by hand through the counter on the buttons and switches and switch starts and stops pumps, including the frequency converter from the stop. Note that the PLC in manual mode is still in working condition.Select 0 for the vacant state, now part of the counter button manual control circuit is cut off, can not control the device. Manual / Auto disconnect relay instructions. The PLC signal is detected at this time and when you select Manual as the PLC to perform manual procedures. Fault alarm.(6) supply water solenoid valve cabinets on each side there is a replenishment valve require distribution N = 100 W 220 VAC (7 号cabinet for the two), solenoid valves supply water from the corresponding box of the float switch to control. Replenishment box has two float switches, one at a high, a bit at the bottom. By two different water levels in the different relay contact output, through the intermediate relay to control the electromagnetic valve for starting, stopping and ultra-underground water level alarm. The device also has a set of solenoid valve manually switch the button, installing and counter. Choice through a two-phase control switch and float switch. Select Manual when the water level alarm is also low. Five,System SoftwarePLC software is modular programming system by manual operation module, the module automatically and fault diagnosis and alarm output module and other components.(1) Manual operation modulesAccording to system requirements, the system is run manually, PLC circuit protection only to receive the signal and the sensor signals, and thus judge the work of running the pump in case of failure, the output alarm signal. Chart 5-1 is a flowchart of this module.(2) the module automaticallyAccording to system requirements, the system is running automatically, PLC to complete the work are: to receive the signal circuit protection; to receive the sensor signal; time work in order to switch pumps and backup pumps; in case of failure, the output alarm signal. Figure 5-2 is a flowchart of this module.(3) fault diagnosis and alarm output moduleIn the fault diagnosis and alarm output module, the procedure receives the signal and sensor signal circuit protection, under certain conditions, diagnostic results obtained. If there is no fault, then the process to continue; if there is fault, the output alarm signal, notify the staff for processing. Specific fault are:a. The work of the pump over-current protection signal is valid;b. Working pump starts, the detector can not detect water flow (constant pressure water pump up the work in the frequency converter does not applywhen the ultra-low frequency);c. Pump water up to the constant pressure of reservoir water level is low;d. Other failure.Six, ConclusionThe system is simple, reliable, easy to maintain, is convenient for people living in the PLC in a successful application. PLC frequency current heating system used in the South of use in Urumqi, more than a year without trouble, and compact, precise movement, is an ideal heating system.PLC变频调速系统应用研究论文摘要:本文介绍了变频调速供暖系统的原理，重点介绍了PLC控制系统的结构特点，以及系统硬件和软件设计方法。
外文翻译---PLC变频调速的网络反馈系统的实现
Realization of Neural Network Inverse System with PLC in Variable Frequency Speed-Regulating System Abstract. The variable frequency speed-regulating system which consists of an induction motor and a general inverter, and controlled by PLC is widely used in industrial field. .However, for the multivariable, nonlinear and strongly coupled induction motor, the control performance is not good enough to meet the needs of speed-regulating. The mathematic model of the variable frequency speed-regulating system in vector control mode is presented and its reversibility has been proved. By constructing a neural network inverse system and combining it with the variable frequency speed-regulating system, a pseudo-linear system is completed, and then a linear close-loop adjustor is designed to get high performance. Using PLC, a neural network inverse system can be realized in actural system. The results of experiments have shown that the performances of variable frequency speed-regulating system can be improved greatly and the practicability of neural network inverse control was testified.1.IntroductionIn recent years, with power electronic technology, microelectronic technology and modern control theory infiltrating into AC electric driving system, inverters have been widely used in speed-regulating of AC motor. The variable frequency speed-regulating system which consists of an induction motor and a general inverter is used to take the place of DC speed-regulating system. Because of terrible environment and severe disturbance in industrial field, the choice of controller is an important problem. In reference [1][2][3], Neural network inverse control was realized by using industrial control computer and several data acquisition cards. The advantages of industrial control computer are high computation speed, great memory capacity and good compatibility with other software etc. But industrial control computer also has some disadvantages in industrial application such as instability and fallibility and worse communication ability. PLC control system is special designed for industrial environment application, and its stability and reliability are good. PLCcontrol system can be easily integrated into field bus control system with the high ability of communication configuration, so it is wildly used in recent years, and deeply welcomed. Since the system composed of normal inverter and induction motor is a complicated nonlinear system, traditional PID control strategy could not meet the requirement for further control. Therefore, how to enhance control performance of this system is very urgent.The neural network inverse system [4][5] is a novel control method in recent years. The basic idea is that: for a given system, an inverse system of the original system is created by a dynamic neural network, and the combination system of inverse and object is transformed into a kind of decoupling standardized system with linear relationship. Subsequently, a linear close-loop regulator can be designed to achieve high control performance. The advantage of this method is easily to be realized in engineering. The linearization and decoupling control of normal nonlinear system can realize using this method.Combining the neural network inverse into PLC can easily make up the insufficiency of solving the problems of nonlinear and coupling in PLC control system. This combination can promote the application of neural network into p r a c t i c e t o a c h i e v e i t f u l l e c o n o m i c a n d s o c i a l b e n e f i t s In this paper, firstly the neural network inverse system method is introduced, and mathematic model of the variable frequency speed-regulating system in vector control mode is presented. Then a reversible analysis of the system is performed, and the methods and steps are given in constructing NN-inverse system with PLC control system. Finally, the method is verified in experiments, and compared with traditional PI control and NN-inverse control.2.Neural Network Inverse System Control MethodThe basic idea of inverse control method [6] is that: for a given system, anα-th integral inverse system of the original system is created by feedback method, and combining the inverse system with original system, a kind of decoupling standardized system with linear relationship is obtained, which is named as a pseudo linear system as shown in Fig.1. Subsequently, a linear close-loop regulator will be designed toachieve high control mathematic model of the variable performance.Inverse system control method with the features of direct, simple and easy to understand does not like differential geometry method [7], which is discusses the problems in "geometry domain". The main problem is the acquisition of the inverse model in the applications. Since non-linear system is a complex system, and desired s t r i c t a n a l y t i c a l i n v e r s e i s v e r y obtain, even impossible. The engineering application of inverse system control doesn’t meet the expectations. As neural network has non-linear approximate ability, especially for nonlinear complexity system, it becomes with the powerful e x p e c t a t i o n s t o o l t o s o l v e t h e p r o b l e m.a − th NN inverse system integrated inverse system with non-linear ability of the neural network can avoid the troubles of inverse system method. Then it is possible to apply inverse control method to a complicated non-linear system. a − th NN inverse system method needs less system information such as the relative order of system, and it is easy to obtain the inverse model by neural network training. Cascading the NN inverse system with the original system, a pseudo-linear system is completed. Subsequently, a linear close-loop regulator will be designed.3. Mathematic Model of Induction Motor Variable FrequencySpeed-Regulating System and Its ReversibilityInduction motor variable frequency speed-regulating system supplied by the inverter of tracking current SPWM can be expressed by 5-th order nonlinear model in d-q two-phase rotating coordinate. The model was simplified as a 3-order nonlinear model. If the delay of inverter is neglected system original system, the model is e x p r e s s e d a s f o l l o w s:(1)where denotes synchronous angle frequency, and is rotate speed.a r e s t a t o r’s c u r r e n t,a n d a r e r o t o r’s f l u x l i n k a g e i n(d,q)axis.is number of poles. is mutual inductance, and is rotor’sinductance. J is moment of inertia.is rotor’s time constant, and is l o a d y n c h r o n o u s a n g l e f r e q u e n c y t o r q u e.I n v e c t o r m o d e,t h e nSubstituted it into formula (1), then(2) Taking reversibility analyses of forum (2), thenThe state variables are chosen as followsInput variables areTaking the derivative on output in formula(4), then(5)(6) Then the Jacobi matrix is Realization of Neural Network Inverse System with PLC(7)(8)As so and system is reversible.Relative-order of system isWhen the inverter is running in vector mode, the variability of flux linkage can be neglected (considering the flux linkage to be invariableness and equal to the rating). The original system was simplified as an input and an output system concluded by forum (2).According to implicit function ontology theorem, inverse system of formula (3) can be expressed as(9)When the inverse system is connected to the original system in series, the pseudolinear compound system can be built as the type of4. Realization Steps of Neural Network Inverse System4.1 Acquisition of the Input and Output Training SamplesTraining samples are extremely important in the reconstruction of neural network inverse system. It is not only need to obtain the dynamic data of the original system, but also need to obtain the static date. Reference signal should include all the work region of original system, which can be ensure the approximate ability. Firstly the step of actuating signal is given corresponding every 10 HZ form 0HZ to 50HZ, and the responses of open loop are obtain. Secondly a random tangle signal is input, which is a random signal cascading on the step of actuating signal every 10 seconds, and theclose loop responses is obtained. Based on these inputs, 1600 groups should includea l l t r a i n i n g s a m p l e s a r e g o t t e n.4.2 The Construction of Neural NetworkA static neural network and a dynamic neural network composed of integral is used to construct the inverse system. The structure of static neural network is 2 neurons in input layer, 3 neurons in output layer, and 12 neurons in hidden layer. The excitation function of hidden neuron is monotonic smooth hyperbolic tangent function. The output layer is composed of neuron with linear threshold excitation function. The training datum are the corresponding speed of open-loop, close-loop, first order derivative of these speed, and setting reference speed. After 50 times training, the training error of neural network achieves to 0.001. The weight and threshold of the neural network are saved. The inverse model and a dynamic neural network c o m p o s e d o f o r i g i n a l s y s t e m i s o b t a i n e d.5 .Experiments and Results5.1 Hardware of the SystemThe hardware of the experiment system is shown in Fig 5. The hardware system includes upper computer installed with Supervisory & Control configuration software WinCC6.0 [8], and S7-300 PLC of SIEMENS, inverter, induction installed with m o t o r a n d C o n t r o l p h o t o e l e c t r i c c o d e r.PLC controller chooses S7-315-2DP, which has a PROFIBUS-DP interface and a MPI interface. Speed acquisition module is FM350-1. WinCC is connected with the e x p e r i m e n t s y s t e m S7-300b y C P5611u s i n g M P I p r o t o c o l.The type of inverter is MMV of SIEMENS. It can communicate with SIEMENS PLC by USS protocol. ACB15 module is added on the inverter in this system.5.2 Software Program5.2.1 Communication IntroductionMPI (MultiPoint Interface) is a simple and inexpensive communication strategy using in slowly and non-large data transforming field. The data transforming between W i n C C a n d P L C i s n o t l a r g e,s o t h e M P I c h o s e n.The MMV inverter is connected to the PROFIBUS network as a slave station, which is mounted with CB15 PROFIBUS module. PPO1 or PPO3 data type can be chosen. It permits to send the control data directly to the inverter addresses, or to use t h e s y s t e m f u n c t i o n b l o c k s o f S T E P7V5.2 SFC14/15.OPC can efficiently provide data integral and intercommunication. Different type servers and clients can access data sources of each other. Comparing with the traditional mode of software and hardware development, equipment manufacturers only need to develop one driver. This can short the development cycle, save manpower resources, and simplify the structure the experiment system of the entire c o n t r o l s y s t e m.Variety data of the system is needed in the neural network training of Matlab, which can not obtain by reading from PLC or WinCC directly. So OPC technology can be used l to obtain the needed data between WinCC and Exce. Setting WinCC as OPC DA server, an OPC client is constructed in Excel by VBA. System real time data is readed and writen to Excel by WinCC, and then the data in Excel is transform to M a t l a b f o r o f f l i n e training to get the inverse system of original system.5.2.2 Control ProgramUsed STL to program the communication and data acquisition and control algorithm subroutine in STEP7 V5.2, velocity sample subroutine and storage subroutine are programmed in regularly interrupt A, and the interrupt cycle chooses 100ms. In order to minimum the cycle time of A to prevent the run time of A exceeding 100ms and system error, the control procedure and neural network a l g o r i t h m a r e p r o g r a m m e d i n m a i n procedure B.In neural network algorithm normalized the training samples is need to speed up the rate of convergence by multipl ying a magnification factor in input and output data before the final training.5.3 Experiment ResultsWhen speed reference is square wave signal with 100 seconds cycle, where thei n v e r t e r i s r u n n i n g i n v e c t o r m o d e.T h e r e s u l t s s h o w t h a t t h e tracking performance of neural network control is better than traditional PI control.When speed reference keeps in constant, and the load is reduced to no load at 80 seconds, and increased to full load at 120 seconds, the response curves of speed with traditional PI control and neural network inverse control are shown in Fig. 11 and 12 respectively. It is clearly that the performance of resisting the load disturbing with neural network inverse control is better than the traditional PI control.(Speed response in PI control)(Speed response in neural network inverse control)6. ConclusionIn order to improve the control performance of PLC Variable Frequency Speed-regulating System, neural network inverse system is used. A mathematic model of variable frequency speed-regulating system was given, and its reversibility was testified. The inverse system and original system is compound to construct the pseudo linear system and linear control method is design to control. With experiment, neural network inverse system with PLC has its effectiveness and its feasibility in industryPLC变频调速的网络反馈系统的实现变频调速系统,包括一个异步电动机和通用逆变器、且PLC控制被广泛地应用于工业领域。
变频技术中英文翻译资料
变频技术1.1变频技术的普及前景电机交流变频调速技术是当今节电、改善工艺流程以提高产品质量和改善环境、推动技术进步的一种主要手段。
变频调速以其优异的调速和起制动性能，高效率、高功率因数和节电效果，广泛的适用范圉及其它许多优点而被国内外公认为最有发展前途的调速方式。
电气传动控制系统通常山电动机、控制装置和信息装置3 部分组成，电气传动关系到合理地使用电动机以节约电能和控制机械的运转状态, 实现电能■机械能的转换，达到优质、高产、低耗口的。
电气传动分成不调速和调速两大类，调速乂分交流调速和直流调速两种方式。
不调速电动机直接山电网供电，但随着电力电子技术的发展这类原本不调速的机械越来越多地改用调速传动以节约电能(节约15%^20%或更多)，改善产品质量，提高产量。
在我国60% 的发电量是通过电动机消耗的，因此调速传动是一个重要行业，已经得到国家重视，目前已有一定规模。
近年来交流调速中最活跃、发展最快的就是变频调速技术，变频调速是交流调速的基础和主干内容。
上个世纪变压器的出现使改变电压变得很容易，从而造就了一个庞大的电力行业。
长期以来，交流电的频率一直是固定的，变频调速技术的出现使频率变为可以充分利用的资源。
这10年来，变频技术的应用在我国有很大的发展，并取得了良好的效果可以说，变频技术已为大多数用户所接受，但是不能不指出，我国在变频技术的应用方面，与发达国家的水平尚有很大差距，LI前，我国在用的交流电动机使用变频调速运行的仅6%左右，而下业发达国家已达(60%^70%),日本在风机、水泵上变频调速的采用率已达10%,而我国还不足0.01%.在日本，空调器的70%采用了变频调速，而我国才刚刚起步。
从这个现实出发，变频技术尚有很大的发展空间，应该锲而不舍地做好推广应用工作。
且随着控制技术和控制手段的不断提高，变频调速乂山变压变频控制的变频调速发而展到了矢量控制变频调速，通过控制交流电动机里相当于并励直流电动机励磁绕组的磁通变化，提高变频器的恒转矩输出范围和动静态特性，使得交流电动机变频调速系统的性能超过了直流电动机调压调速系统的性能。
变频调速的原理及应用教案
变频调速的原理及应用教案变频调速（Variable Frequency Drive，缩写为VFD）是一种用于调节电机转速的技术，它通过调整电机供电的频率和电压来控制电机的转动速度。
变频调速技术广泛应用于工业领域，如制造业、水泵、风机、压缩机、输送带等。
1.基本构成：变频调速系统由三个部分组成，即电源、变频器和电动机。
电源将交流电转换为直流电，然后经过变频器将直流电转换为可调的交流电，最后通过电动机将电能转换为机械能。
2.频率调节：变频器可以通过改变输出电压的频率来改变电机的转速。
当输出频率增大时，电机的转速也会相应增加；当输出频率减小时，电机的转速也会相应减小。
3.电压调节：变频器还可以通过改变输出电压的幅值来调节电机的转矩。
当输出电压增加时，电机的转矩也会相应增加；当输出电压减小时，电机的转矩也会相应减小。
1.节能：变频调速可以根据实际工作负荷来调节电机的转速，避免了电机运行时的过度能耗，从而实现节能的目的。
2.系统平稳：传统的启停方式容易产生冲击和振动，而变频调速可以使电机平稳启动和停止，减小震动和冲击，延长机械设备的使用寿命。
3.精度控制：变频调速系统可以精确地控制电机的转速，实现对生产过程的精细控制，提高生产效率和产品质量。
4.降噪：由于变频调速使得电机运行平稳，减少了机械设备的震动和噪音，从而改善了工作环境。
5.起重和运输：变频调速广泛应用于起重机和运输设备中，可以实现对货物的平稳提升和运输，提高生产效率和安全性。
6.水泵和风机控制：变频调速可以根据实际需要调节水泵和风机的运行速度，使其在不同负载下工作，提高工作效率和节能效果。
教案设计如下：一、教学目标1.了解变频调速的基本原理和应用。
2.掌握变频调速系统的组成和工作原理。
3.了解变频调速在工业领域的应用。
二、教学内容1.变频调速的原理和基本构成。
2.变频调速系统的工作原理和调节方法。
3.变频调速在工业领域的应用案例。
三、教学过程1.提出问题：请同学们简单介绍一下变频调速的基本原理和应用。
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淮阴工学院毕业设计(论文)外文资料翻译学院：机械工程学院专业：机械设计制造及其自动化姓名：许斌学号：1071101215外文出处：Design of PWM Controller in a MCS-51 Compatible MCU(用外文写)附件： 1.外文资料翻译译文；2.外文原文。
注：请将该封面与附件装订成册。
附件1：外文资料翻译译文基于C51兼容微处理器单片机的PWM控制器设计导言PWM技术，是一种电压调节方法，通过控制具有固定电压的直流电源的开关频率来调整两端负荷电压。
这种技术能用于各种应用包括电机、温度、和压力的控制，等等。
在电机系统中的应用，如图1所示，通过调整电源开关的占空比，来控制电机的速度，如图2所示，平均电压通过改变占空比来控制电机的速度（在图中D=t1/T）,这样当电机的电源打开时，它的速度加快，相反，当电源关闭时，速度下降。
图1 PWM控制框图图2 电压的电枢和占空比之间的关系所以，通过定期地调整时间的开通和关断来控制电机的转速：这儿有三种方法可以完成占空比的调整（1）通过脉宽来调整频率；（2）通过同时调整频率和脉宽；（3）通过频率来调整脉宽。
一般情况下，有四中方法可以产生PWM信号，正如以下：（1）由独立逻辑元件组成的装置产生，这种是原始的方法，现在已被淘汰；（2）通过软件产生，这种方法需要CPU持续操作代码来控制I/O口，以致于CPU不能做其他任何事。
所以，这种方法也渐渐被淘汰；（3）通过ASIC产生，ASIC减少了CPU的负担，并获得了稳定的工作，一般有几个功能，如电流保护、死区时间调整等等；然而这种方法现在已被广泛用于许多场合；（4）通过单片机的PWM功能模块产生，只有当需要改变占空比的时候CPU失控，这样就不能产生PWM信号，否则通过在单片机里嵌入PWM功能模块，并使这功能初始化，单片机的PWM口也能自动产生PWM 信号。
这种方法将在文章中讲述。
在本文中，我们建议在8051单片机里嵌入一个PWM模块。
该PWM模块，通过初始化控制寄存器和寄存器的占空比，可以支持PWM脉冲信号，用刚才提到的上述三种方法调整占空比和几个操作模式，以增加用户弹性。
以下这部分解释PWM模块和基本功能模块的结构。
第三部分描述两种操作模式。
这部分还讲述了实验和仿真的结果验证了合适的系统操作。
通过操作模式，PWM模块产生一个或更多的脉宽模块信号，它们的比率可以自主调整。
在单片机上执行PWM模块PWM模块的概述PWM模块如图3所示，从图中，可以很清楚得看到整个模块有两部分组成：PWM 信号产生器和带有频道选择逻辑的死区时间产生器。
用户可以通过执行一些代码使PWM模块初始化，从而启动其功能。
在特殊情况下，支持以下电源和运动控制应用：1.直流电机2.持续电源供应PWM模块也有以下特征：1.两个PWM输出信号以互补或独立的方式运行2.带有互补模式的硬件死区电动机3.占空比更新设置应立刻或与PWM同步图3 PWM模块的结构结构的详细组成PWM电动机二输出PWM电动机的结构如图2.1所示，该结构是基于能产生脉宽调制信号上的16位计数器。
该系统由四分频或十二分频的系统时钟信号合成，时钟信号的频率可通过对在特殊寄存器PWMCON中的PWM0电机的T3M或PWM1电机的T4M的值进行设置而调整，如图4所示：对于PWM0电机，当T3M设置为零时，16位计数器时钟将被默认预分为四分频，当T3M设置为1时，始终将被十二分频；PWM同样有这种功能。
在PWMCON中的其它位的定义，详见表1图4 PWMCON的位的位置表1：PWMCON的位的定义通道选择逻辑通道选择逻辑在互补模式中很有用，如图5所示。
从表中可以清楚得看出，信号的CP和CPWM控制PWM1和PWML的来源，这两个控制信号的详细情况将在第三部分讲述，死区时间电机的结构也将在一下部分的连续性互补模式中讲述。
图5 通道选择逻辑表运行模式和仿真结果这种设计有两种运行模式：独立模式和互补模式。
通过在PWMCON寄存器中设置相应的位CPWM，如图四所示，用户可以选择其中一个运行模式。
当CPWM设置为0时，PWM模式将工作在独立模式，COWM设置为1时，将工作在互补模式。
在这部分两种模式将分别被详细讲述，从VCS EDA平台的PWM模块的仿真结果证明这种设计。
独立PWM输出模块独立PWM输出模块对于驱动负荷很有用，如图6所示。
当在PWMCON寄存器中相应的CP位设置为0，特殊的PWM输出模块是在独立的输出模式里。
在这种情况下，PWM的两种通道输出是相互独立的。
在PWM0/PWML口的信号是从PWM0电机产生的。
通道选择逻辑完成单独情况，如图6所示。
PWM I/O口通过默认意见复位设置为独立模式，但死区时间电机不能在独立模式下工作。
仿真结果如图6所示。
Tr4和Tr3分别与PWM0和PWM1相连，实际上，从图看，单片机的P1[5]/P[4]口被用做PWMH/PWML 或是一般的I/O口。
图6 独立模式下的PWM波形互补PWM输出模式互补输出模式可以用于驱动逆变器负载，如图7所示。
这种逆变器拓扑学是典型的直流装置。
在互补输出模式，PWM的两个输出不能同时用。
PWM通道和输出口都是通过通道选择逻辑内部配置的，如图7所示。
死区时间是在两端输出的开关装置没有工作的短时期时可以选择插入的。
图7 PWM互补输出的典型电路PWM I/O口通过在PWMCON中设置适当的CPWM位选择互补模式，在这种情况下，PSWL是有效果的。
当PSEL设置为0时，PWMH和PWML将来自PWM0电机，这时来自PWM1电机的信号是没用的，而当PSEL设置为1时，PWMH和PWML将来自PWM1电机，这时来自PWM0电机的信号是没用的。
在互补模式时产生PWM输出信号的过程中，死区时间将被插入在以下这部分讲述。
死区时间控制当PWM I/O口在互补输出模式运行时，死区时间是自动启用生成的，因为电源输出装置不能瞬间开关，在互补对模式下，一个PWM输出的关闭与其它晶体管打开之间要一定的时间，2输出的PWM模块有一个带有8位寄存器的可编程死区时间。
PWM模块的互补输出对已有一个用于产生死区时间插入的8位计数器。
死区时间单元有一个上升沿和下降沿探测器，而这个探测器与PWM电机产生的PWM信号连接。
当到达PWM边沿时，死区时间被载入计时器，根据是否是上升沿或下降沿，在互补输出端口上的其中一个过度被延迟，直到计数器降为0。
PWM输出对的死区时间表，如图8a所示：图8a 死区时间单元模块图图8b 互补模式的PWM输出波形总结：本文，我们设计了基于8位兼容8051单片机的PWM模块，这种设计能产生2通道带有两种运行模式的可编程周期PWM信号，即可插入死区时间的独立模式和互补模式。
这种在EDA平台的仿真结果已证明了它的和谐性和有用性。
附件2：外文原文（复印件）Design of PWM Controller in a MCS-51 Compatible MCUIntroductionPWM technology is a kind of voltage regulation method by controlling the switch frequency of DC power with fixed voltage to modify the two-end voltage of load. This technology can be used for a variety of applications including motor control, temperature control and pressure control and so on. In the motor control system shown as Fig. 1, through adjusting the duty cycle of power switch, the speed of motor can be controlled. As shown in Fig. 2, under the control of PWM signal, the average of voltage that controls the speed of motor changes with Duty-cycle ( D = t1/T in this Figure ), thus the motor speed can be increased when motor power turn on, decreased when power turn off.Fig.1: The Relationship between Voltage of Armature and Fig.2Architecture of PWM ModuleTherefore, the motor speed can be controlled with regularly adjusting the time of turn-on and turn-off. There are three methods could achieve the adjustment of duty cycle: (1) Adjust frequency with fixed pulse-width. (2) Adjust both frequency and pulse-width. (3) Adjust pulse-width with fixed frequency.Generally, there are four methods to generate the PWM signals as thefollowing: (1) Generated by the device composed of separate logic components. This method is the original method which now has been discarded. (2) Generated by software. This method need CPU to continuously operate instructions to control I/O pins for generating PWM output signals, so that CPU can not do anything other. Therefore, the method also has been discarded gradually. (3) Generated by ASIC. The ASIC makes a decrease of CPU burden and steady work generally has several functions such as over-current protection, dead-time adjustment and so on. Then the method has been widely used in many kinds of occasion now. (4) Generated by PWM function module of MCU. Through embedding PWM function module in MCU and initializing the function, PWM pins of MCU can also automatically generate PWM out signals without CPU controlling only when need to change duty-cycle. It is the method that will be implemented in this paper.In this paper, we propose a PWM module embedded in a 8051 microcontroller. The PWM module can support PWM pulse signals by initializing the control register and duty-cycle register with three methods just mentioned above to adjust the duty cycle and several operation modes to add flexibility for user.The following section explains the architecture of the PWM module and the architectures of basic functional blocks. Section3 describes two operation modes. Experimental and simulation results verifying proper system operation are also shown in that section. Depending on mode of operation, the PWM module creates one or more pulse-width modulated signals, whose duty ratios can be independently adjusted.Implementation of PWM module in MCUOverview of the PWM moduleA block diagram of PWM module is shown in Fig.3. It is clearly from the diagram that the whole module is composed of two sections: PWM signal generator and dead-time generator with channel select logic. The PWM function can be started by the user through implementing some instructionsfor initializing the PWM module. In particular, the following power and motion control applications are supported:• DC Motor• Uninterruptablel Power Supply (UPS)·The PWM module also has the following features:• Two PWM signal outputs with complementary or independent operation• Hardware dead-time generators for complementary mode• Duty cycle updates are configurable to be immediated or synchronized to the PWMFig.3 Architecture of PWM ModuleDetails of the architecturePMW generatorThe architecture of the 2-output PWM generator shown in Fig.4 is based on a 16-bit resolution counter which creates a pulse-width modulated signal. The system is synthesized by a system clock signal whose frequency can be divided by 4 times or 12 times through setting the value of T3M for PWM0 or T4M for PWM1 in the special register PWMCON as shown in Fig.4. To PWM0 generator, the clock to 16-bit counter will be pre-divided by 4 times by default when T3M is set to zero. And the clock will be divided by 12 times when T3M is set to 1. This is also true for PWM1. The other bits in PWMCON are explained in detail in Table 1.Fig .4 Bit Mapping of PWMCONTable 1: The Bit Definition in PWMCONChannel-select logicThe follow Fig. 5 shows the channel-select logic which is useful in Complementary Mode. From this diagram, it is clear to know that signal CP and CPWM control the source of PWMH and PWML. And the details about the two control signals will be discussed in the section 3, and the architecture of dead-time generator will also be discussed in section 5 for the continuity of Complementary Mode.Fig. 5 Diagram of Channel-select LogicOperation Mode and Simulation ResultsThe design has two operation modes: Independent Mode and Complimentary Mode. By setting the corresponding bit CPWM in register PWMCON shown in Fig.6 user can select one of the two operation modes. When CPWM is set to zero, PWM module will work in Independent Mode, whereas, PWM module will work in Complimentary Mode. In the following of this section, the two operation mode will be explained respectively in detail and the simulation results of the PWM module from the Synoposys VCS EDA platform which verify the design will also be shown.Independent PWM Output ModeAn Independent PWM Output mode is useful for driving loads such as the one shown in Figure 6. A particular PWM output is in the Independent Output mode when the corresponding CP bit in the PWMCON register is set to zero.In this case, two-channel PWM outputs are independent of each other. The signal on pin PWM0/PWMH is from PWM0 generator, and the signal on pin PWM1/PWML is from PWM0 generator. The separate case is achieved by the channel-select logic shown in Fig. 6. The PWM I/O pins are set to independent mode by default upon advice reset. The dead-time generator is disabled in the Independent mode. The simulation result is shown in Figure 6 as the following Fig.6 Tr4 and tr3 are run bits to PWM0 and PWM1, respectively. Actually, from this diagram, Pin P1[5]/ P1[4] of MCU is used for PWMH/ PWML or normal I/O ,alternatively.Fig6 the Waveform of PWM Outputs in Independent ModeComplementary PWM Output ModeThe Complementary Output mode is used to drive inverter loads similarto the one shown in Figure 7. This inverter topology is typical for DC applications. In Complementary Output Mode, the pair of PWM outputs cannot be active simultaneously. The PWM channel and output pin pair are internally configured through channel-select logic as shown in Figure7. A dead-time may be optionally inserted during device switching where both outputs are inactive for a short period.Fig 7 : Typical Load for Complementary PWM Outputs The Complementary mode is selected for PWM I/O pin pair by setting the appropriate CPWM bit in PWMCON. In this case, PSEL is in effect. PWMH and PWML will come from PWM0 generator when PSEL is set to zero, when the signals from PWM1 generator is useless, whereas PWMH and PWML will come from PWM1 generator when PSEL is set to 1, when the signals from PWM0 generator is useless. In the process of producing the PWM outputs in Complementary Mode, the dead-time will be inserted to be discussed in the following section.Dead-time ControlDead-time generation is automatically enabled when PWM I/O pin pair is operating in the Complementary Output mode. Because the power output devices cannot switch instantaneously, some amount of time must be provided betweenthe turn-off event of one PWM output in a complementary pair and the turn-on event of the other transistor. The 2-output PWM module has one programmable dead-time with 8-bit register.The complementary output pair for the PWM module has an 8-bit down counter that is used to produce the dead-time insertion. As shown in Figure 8, the dead time unit has a rising and falling edge detector connected to PWM signal from one of PWM generator. The dead times is loaded into the timer on the detected PWM edge event. Depending on whether the edge is rising or falling, one of the transitions on the complementary outputs is delayed until the timer counts down to zero. A timing diagram indicating the dead time insertion for the pair of PWM outputs is shown in Figure 8a.Fig 8a Dead-time Unit Block DiagramFig. 8b the Waveforms of PWM Outputs in Complementary ModeConclusionsIn this paper, we have designed PWM module based on an 8-bit MCU compatible with 8051 family. The design can generate 2-channel programmable periodic PWM signals with two operation mode, Independent Mode and Complementary Mode in which dead-time will be inserted. The simulation results on the EDA platform have proven its correctness and usefulness.。