Reasons for battery overload trip

　　 After the battery trips, check the insulation of the 640 switch control circuit, and the operating voltage of the trip coil and the intermediate relay is normal. According to the above situation, combined with the actual analysis of the field equipment: due to the low operating power of the trip relay TJ in the 640 switch trip circuit (measured 2W); the length of the control cable in the circuit exceeds 400m, and the long cable has a battery effect on the ground. When the DC system has a low voltage to the ground due to liquid leakage in the group (measured 52V), when a large disturbance occurs in the DC system (such as the start of a high-power load, or a momentary grounding), the DC system voltage will be instantaneously higher. Large fluctuations or shocks, and generate shock currents in the capacitive circuit in the control long cable, which in turn causes the trip relay TJ to act.

　　 To avoid the load is too large or too small, too large load will cause the equipment to work in the overload state for a long time and shorten the service life of the equipment; if the load is too small, the working circuit of the equipment Long-term working in an abnormal state is also harmful to the Haizhi battery in the equipment. A reasonable load should be controlled between 50% and 80%. Practice has proved that the output device load control is the best at about 60%, and the reliability is the best. The load is 300MW, the 640 switch of the factory-used power supply of the unit has tripped. When the fault record shows that the 640 switch has tripped, the unit operation signal is normal, and the 640 switch trip is the first output; no fault signal is issued for the protection of the transformer group, and no protection action record; the grid system voltage is normal, the bus Poor, failure protection, high-cycle cutting machine combined cutting without any signal, no protection action record.

　　 The battery of the power supply system, the bus bar of the battery pack to prevent tripping, the minimum cross section of the cable between the bus bar on the DC screen and the DC screen are all selected according to the maximum load current. A separate cable should be used for the positive or negative pole between the battery and the DC screen, and the end can be a single-core cable, generally an aluminum cable with an area of u200bu200bnot less than 2.5mm2. Contact: 18038382979