Transformer substation direct current system based on lithium iron phosphate storage battery

Abstract

A transformer substation direct current system based on a lithium iron phosphate storage battery comprises power supply direct current buses KM + and KM-, the power supply direct current buses KM + and KM-are connected with a direct current charging screen CHC, a lithium iron phosphate storage battery screen BAT and a direct current feed screen DISC, the direct current charging screen CHC and the direct current feed screen DISC are placed in a direct current load chamber, the lithium iron phosphate storage battery screen BAT is placed in a storage battery chamber, and the lithium iron phosphate storage battery screen BAT is placed in the storage battery chamber. A partition wall is arranged between the direct current load chamber and the storage battery chamber. The system can realize electrical isolation and spatial geographical isolation between the lithium iron phosphate storage battery pack and the DC system load, ensures safe operation of the load, can intelligently control charging and discharging of the storage battery by using the charging and discharging control management switches BMS1 and BMS2 and the controller thereof, and has three-level power supply guarantee for the DC bus of the system, so that the safety of the system is improved. Multiple guarantees are provided in each stage of power supply mode, the stability of the direct current system can be improved, and the system completely comprises a direct current power supply part and a storage battery power supply part under the condition that the storage battery pack is maintained.

Description

technical field [0001] The invention relates to the technical field of direct current systems of substations, in particular to a direct current system of substations based on lithium iron phosphate batteries. Background technique [0002] The P-O bond in the lithium iron phosphate crystal is stable and difficult to decompose. Even at high temperature or overcharge, it will not collapse and generate heat like lithium cobalt oxide or form strong oxidizing substances, so it has good safety. The cycle life of long-life lead-acid batteries is about 300 times, and the maximum is 500 times of lithium iron phosphate batteries, while the cycle life of lithium iron phosphate power batteries can reach more than 2,000 times, and the standard charging (5-hour rate) can reach 2,000 times. . The lead-acid battery of the same quality is "new half year, old half year, and maintenance and maintenance for half a year", which is 1-1.5 years at most, while lithium iron phosphate battery is used...

AI Technical Summary

Problems solved by technology

The self-discharge rate of lithium iron phosphate batteries is low, and there is basically no need to supplement the self-discharge capacity. Long-term floating charging will cause overcharging of lithium batteries and increase its risk. Therefore, it cannot be directly replaced by lithium iron phosphate batteries in the DC system. And the safety of matching the lithium iron phosphate battery with the DC system of the substation also requires long-term experimental research

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