电气工程及其自动化专业英语第6章6-2翻译

Section 2 Components of Power Systems 第2节电力系统的组成部分

Modern power systems are usually large-scale, geographically distributed, and with hundreds to thousands of generators operating in parallel and synchronously. 现代电力系统通常规模大，地域分布，并与数百名，并同步在数以千计的发电机并联运行。They may vary in size and structure from one to another, but they all have the same basic characteristics: 他们可能会有所不同的规模和结构从一个到另一个，但它们都具有相同的基本特征：

（1）Are comprised of three-phase AC systems operating essentially at constant voltage. （1）是由三个三相交流电压恒定系统经营本质上。Generation and transmission facilities use three-phase equipment . 发电和输电设施使用三个阶段的设备。

Industrial loads are invariablythree-phase; single-phase residential and commercial loads are distributed equally among the phases so as to effectively form a balanced three-phase system. 工业负荷总是三相，单相负载的住宅和商业之间平等分配的阶段，从而有效地形成一个平衡的三相系统。

（2）Use synchronous machines for generation of electricity. （2）使用电力同步一代机器。Prime movers convert the primary energy (fossil, nuclear, and hydraulic) to mechanical energy that is, in turn, converted to electrical energy by synchronous generators. 牵引车转换的一次能源（化石，核能和水力）为机械能就是反过来，中，转换为电能的同步发电机。

（3）Transmit power over significant distances to consumers spread over a wide area. This requires a transmission system comprising subsystems operating at different voltage levels. （3）重大的距离发射功率超过的面积分布在一个广大消费者。这就要求传输系统的子系统组成的经营水平在不同的电压。

The basic elements of a modern power system in USA are shown in Fig.6-1. Electric power is produced at generating stations (GS) and transmitted to consumers through a complex network of individual components, including transmission lines, transformers, and switching devices. 系统在美国一个现代化强国的基本要素是：1显示在图6 -。电功率）产生于发电厂（GS和传播给消费者通过一个复杂网络的各个组成部分，包括输电线路，变压器和开关设备。

It is common practice to classify the transmission network into the following subsystems: Transmission system; Subtransmission system; Distribution system. 它通常的做法是分类传输网络分为以下子系统：传输系统; Subtransmission制度;分配制度。

Fig.6-1 图6 - 1

Basic elements of a power system 电力系统的基本要素1

The transmission system interconnects all major generating stations and main load centers in the system. 该传输系统互连所有主要发电厂在系统中心和主要负载。It forms the backbone of the integrated power system and operates at the highest voltage levels (typically, 230 kV and above in USA). 它形成了系统的骨干力量的整合和经营水平在最高电压（通常为230千伏及以上美国）。The generator voltages are usually in the range of 11 to 35 kV. 发电机的电压范围通常在11至35千伏。These are stepped up to the transmission voltage level, and power is transmitted to transmission substations where the voltages are stepped down to the subtransmission level (typically, 69 to 138 kV). 这是加强宣传，电压等级输电和电力传输到传输）变电站的电压在那里下台的subtransmission水平（通常是69至138千伏。The generation and transmission subsystems are often referred to as the bulk power system.发电和传输子系统通常称为大容量电源系统。