样例视频记录
以下是本模块提供的视频样本的文字记录:
广泛使用的备用电力系统主要有两大类;发电机和UPS。这门课我只讲生成器。发电机是什么?这门课讲的发电机是一种旋转机器，它的设计原理是，通过某种电机或发动机以一定的速度旋转时发电。这个系统的发电机部分通常是一个非常健壮、可靠的设备，当运行时，它以与它馈电的系统电压一致的电压输出指定数量的电流。今天，大多数发电机内置的电子调节装置，使它能以一种与正常的公用事业供应的电力没有区别的形式发出电力。在电力中断期间，当给敏感电子设备和大多数小型电机供电时，在发电机中包含这种电源调节是特别重要的。大多数发电机是由内燃机旋转的。这些发动机可以设计成使用一个(有时两个; also known as “dual fuel”) of several different types of fuels, such as: gasoline, diesel fuel, natural gas, or propane. However, the most common generator fuel is diesel fuel. This is due to the fact that diesel fuel is readily available, easily stored and not easily ignited. The internal combustion engines used in generators are very similar to the engines used in your car or truck, with just a couple of modifications. Those modifications allow the generator engine to start-up very quickly and to run at a fixed speed for many hours, or days, without undue wear and tear on the engine. Like most internal combustion engines, generator engines are normally started by using a lead-acid storage battery. Almost all generator engines are designed to use what is known as “block heaters”, which must be connected, and kept operational all the time, especially when the generator is in a stand-by mode (not running). Block heaters are powered by normal line power. If the block heater doesn’t run all the time, there is a good possibility, particularly in colder climates, that the engine lifespan would be shortened considerably, as it must come up to full RPM’s as soon as it is started. Your typical automobile engine wouldn’t last long if, when started cold, it was revved up to a high RPM right away, and this procedure was repeated every few days. To prolong the engine life in a generator, the block heater is used to keep the engine coolant warm, but, even more important, this keeps the engine lubricating oil at a free-flowing temperature, allowing it to circulate properly as soon as the engine is started, thereby facilitating quicker starting of the engine and maximizing engine life.
