1. The design of electrical distribution systems varies between commercial nuclear power plants, but they all contain the following:
a. High voltage, offsite distribution
b. high voltage and medium voltage, onsite powerc. Low voltage, control and instrumentation distribution.
1. 每個商業運行和電站的配電系統設計不盡相同，但它們都包含以下部分：
a.高壓廠外配電系統
b.高壓和中壓廠內配電系統
c.低壓控制和儀表配電系統
2. The offsite power system includes two or more power sources capable of operating independently of the onsite power sources and encompasses the grid, transmission lines, transmission line control system, switchyard battery system, etc.
2. 高壓廠外配電系統由2條或以上、相互獨立的電源線組成，包括：電網、輸電線、線路控制系統和開關站等。
3. The onsite electric power system consists of the main generator, the unit station transformers, the common station service transformer, the diesel generators and the electric distribution system.
3. 廠內配電系統由主發電機，主變壓器，廠用變壓器，柴油發電機和相關的配電設備組成。
4. Class 1E is the safety classification of the electric equipment and systems that are essential to emergency reactor shutdown, containment isolation, reactor core cooling and containment and reactor heat removal etc.
4. 1E級電源是定義為與以下系統安全相關電源：緊急停堆、安全殼隔離、反應堆冷卻、以及安全殼和反應堆的熱量導出。
5. The offsite (preferred) power system is, as the name implies, the preferred source of power for class 1E loads.
5. 廠外電源系統作為1E級電源的首選饋電。
6. The onsite electric power system is divided into vital and non-vital distribution.
6. 廠內配電系統分為重要和非重要配電系統。
7. Vital distribution system includes shutdown boards, the diesel generators and interconnecting bus work and the loads supplies by this portion are safety-related and are required to place the plant in a safe shutdown condition.
7. 廠內重要配電系統由安全母線，應急柴油機和聯結的母線組成。這部分的負荷是安全相關的，保證電站處于安全停堆的狀態。
8. The main generator converts the mechanical energy of the turbine into electric energy.
8. 主發電機將汽機的機械能轉化為電能。
9. Under normal operating conditions, the main generators supply electrical power through distribution buses to the main step-up transformers and the unit station service transformer; during startup and shutdown, power is supplied from the offsite power through the common station service transformer.
9. 常運行時，發電機發出電能至配電母線，然后通過主變壓器和廠用變；在啟動和停堆階段，自廠外電經廠用變饋電。
10. The standby onsite power is supplied by diesel generators. Each of which is sized to provide all the electric power required to operate the engineered safety features equipment assigned to the corresponding electrical power train.
10. 柴油發電機（EDG）作為電站備用電源。每一臺都具備向一個系列的專設安全設施設備供電的能力。
11. Diesel generators start automatically on receipt of an engineered safety features actuation signal, loss of voltage to the shutdown board or emergency start initiated by the operator.
11. EDG自啟來自專設安全設施信號和安全母線失電信號，也可由RO應急手動啟動。
12. The vital DC control power system is a class 1E system whose safety function is to provide control power for engineered safety equipment, emergency lighting, vital inventors and other safety related DC power equipment for the entire plant.
12. 重要直流系統是1E級系統，其功能就是向專設，應急照明，重要通風系統和整個電站內其他安全相關的設備提供控制電源。
