National Emission Standard For 6kv Mobile Diesel Generator Set

6kV mobile diesel generator set includes 6kV medium voltage mobile power supply vehicle, 6kV medium voltage mobile power supply interface box (hereinafter referred to as interface box), medium voltage mobile power supply test device, medium voltage switch cabinet, 6kV medium voltage power cable, cable through wall and fireproof sealing materials, etc. Among them, the medium-voltage switchgear is reconstructed by using the 6kV emergency bus backup switchgear, and other equipment are newly added during the reconstruction.

The main equipment of the 6kV medium-voltage mobile power supply vehicle is the non-IE vehicle-mounted diesel generator set. In the event of loss of all AC power supply, any one of the four medium-voltage emergency buses is connected through the interface box to provide temporary power to the emergency bus of the power plant to mitigate the consequences of the accident.

1. Electrical access mode.

Take Unit 1 as an example. Each emergency line 1BEA/1BEB/1BEC/1BED is located in the emergency diesel generator building, and 4 sets of interface boxes are set on the outer wall of the building. The 6kV medium-voltage mobile power supply can be connected to 4 sections of emergency bus respectively through the 1-4 floor junction box. The electrical module from the interface box to the emergency bus is laid along the bridge in the plant in a fixed number way. The cable from the 6kV medium-voltage mobile power supply to the interface box is usually stored on the medium-voltage mobile power supply vehicle, and the operator can quickly pick up the person when in use.

The incoming and outgoing cables are single-core medium-voltage power cables. The incoming cable is quickly connected with the busbar in the interface box through the lug. The outgoing cable is fixed cable. There are long holes on the upper and lower sides of the box for the power supply cable to enter and exit. When leaving the factory, the long holes are sealed with sealing rings. Remove the sealing ring when connecting the cable and connect the incoming cable from the lower part of the box. After the cable is removed, put the sealing ring over the long hole again to prevent rainwater from entering the box. The interface box is equipped with a fixing device for incoming and outgoing cables.

Three-phase busbar is set in the interface box, which is phase A, phase B and phase C from left to right. The busbar shall be fixed with support insulators. The distance between the busbar shall meet the requirements of the safe net distance of the indoor power distribution device. The creepage distance of the support insulator shall meet the requirements of relevant specifications. The non-connection part of the busbar shall be sealed with insulating heat-shrinkable sleeve. High voltage live display device is set on the interface box panel to ensure the safety of operators.

The seismic category of the interface box is seismic Category 1, and it can withstand the seismic stress of five OBE operation reference earthquakes and one SSE safe shutdown earthquake to maintain the structural and functional integrity.

2. Structure and performance requirements of power car.

6.6kV medium-voltage mobile power supply vehicle is composed of tractor, box-type semi-trailer, 6kV diesel generator set (including starting system, fuel system, lubricating oil system, cooling system, air intake system, noise reduction system, etc.), diesel generator set control protection monitoring system, medium-voltage power distribution system, low-voltage power distribution system, control power supply system, cable and receiving and releasing device, and supporting auxiliary facilities. All auxiliary systems are self-contained and operate independently, meeting the requirements of GB/T 2819-1995 General Conditions for Mobile Power Stations.

3. Mobile power capacity calculation.

(1) Load analysis The 6kV medium voltage mobile power supply load is manually loaded step by step. According to different events, the operation conditions of the 6kV medium-voltage mobile power supply of the power plant are divided into three types.

(2) The capacity of diesel generator set shall not be less than 2060kW.

4. Interface box installation and cable through-wall design.

The interface box is installed on the external wall of the emergency diesel generator building. The installation height of the interface box shall meet the height requirements of the power plant for water flooding, while taking into account the convenience of operation.

The outlet cable of the interface box can enter the plant only through the wall. After the cable is laid, the holes in the wall shall be sealed with fireproof sealing materials. The maximum fireproof time limit of this type of fireproof sealing material can reach 4h. It has good smoke tightness, air tightness, water tightness and sound insulation functions, and has good insulation. It is convenient for construction, and can be used for subsequent new cable supplement.

5. Periodic test method.

6kV medium-voltage mobile power supply plays a very important role in nuclear power plants in response to serious accidents. In order to ensure its availability under emergency conditions, it is necessary to conduct regular tests to verify its availability.

The following two methods can be used for the periodic test: first, the grid connection test with auxiliary power. The second is to test with test load.

The latter is independent of the emergency bus, which does not affect the normal operation of the unit during the test, and does not need to set a special synchronizing device. Therefore, it is widely used due to its low risk.

Jiangsu Starlight Electricity Equipments Co.,Ltd. was founded in 1974, as a wholly-owned subsidiary of Jiangsu Starlight Power Group, it is one of the earliest manufacturers of generator sets in China. Starlight Power has 64 sales services, long-term technical advice for users, free debugging, free maintenance, free training services. For more details, please contact us with sales@dieselgeneratortech.com.