Grid-side anti-islanding system for distributed photovoltaic grid-connected power generation and its control method

Abstract

The invention provides a grid-side anti-islanding system used for distributed photovoltaic grid connected power generation. The anti-islanding system includes a grid connected switch cabinet. A secondary circuit of the grid connected witch cabinet includes a closing coil HJ, an opening coil FJ, a remote control closing contact K1, a remote opening contact K2, a manual closing button AH, a manual opening button AF, a closing interlocking contact BS, a first normally-open contact HJ1, a second normally-open contact HJ2, a third normally-open contact FJ1, a first normally-closed contact FJ2 and a second normally-closed contact HJ3. According to the invention, a photovoltaic grid connected switch needs to be turned off in principle when power failure of the power grid occurs. A grid-side worker can interlock a closing control circuit remotely through a client terminal, so that the grid connected switch is prevented from closing again and the connection between a distributed photovoltaic power station and a power distribution network can be cut off. Current flowing back to a dead line is eliminated. Life security of a maintenance worker is guaranteed. Besides, damage to power failure equipment is also avoided.

Description

technical field [0001] The invention relates to the technical field of distributed power supply access, in particular to a grid-side anti-islanding system for distributed photovoltaic grid-connected power generation and a control method thereof. Background technique [0002] Distributed photovoltaic power generation specifically refers to a distributed power generation system that uses photovoltaic modules to directly convert solar energy into electrical energy. It is a new type of power generation and comprehensive utilization of energy with broad development prospects. It advocates the principles of nearby power generation, nearby grid connection, nearby conversion, and nearby use. It can not only effectively increase the power generation of photovoltaic power plants of the same scale, but also It effectively solves the problem of power loss in boosting and long-distance transportation. [0003] Distributed photovoltaic power generation needs to convert direct current int...

AI Technical Summary

Problems solved by technology

The so-called isolated island means that when the power grid is repaired due to an accident or power outage, the user-side distributed power generation system does not cut itself off from the grid-connected power grid, and forms a self-sufficient power supply system composed of distributed power generation and surrounding loads. After the grid power failure, stop supplying power to the load, otherwise the grid cannot control the voltage and frequency of the system when the distributed photovoltaic power generation system is in an island operation state, which may not only cause damage to the user's equipment, but also may cause damage to the line maintenance staff. Dangerous contacts, reducing the security of the power grid, it can be seen that effective measures must be taken to prevent the occurrence of the island effect

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