Photovoltaic inverter control method capable of improving power quality of distribution network

Abstract

The invention relates to a photovoltaic inverter control method capable of improving the power quality of a distribution network. The method comprises the steps that 1 the first control state of independent filter control: when a non-linear load is enabled on a user side, a load side sensor detects voltage and current, and calculates THDu and harmonic current in real time through an instantaneousreactive power method; when the load side THDu is higher than the limit and lasts for N power frequency cycles, compensation current is calculated based on the remaining capacity of photovoltaic grid-connected inverters, and harmonics are filtered out; and 2 the second control state of multi-inverter linkage filter control: when the load side sensor detects that THDu is below the limit and lasts for N power frequency cycles, the inverters stop the first control state; after an energy storage module is charged, the inverters can enter the second control state, and multiple inverters can coordinate to compensate power grid harmonics. According to the invention, the cost of improving the power quality can be reduced, and at the same time the user's profit is ensured.

Description

technical field [0001] The invention belongs to the technical field, and relates to an intelligent soft-switching voltage control method of an active distribution network, in particular to a photovoltaic inverter control method capable of improving the power quality of a distribution network. Background technique [0002] With the continuous development of photovoltaic power generation technology, the cost of photovoltaic power generation is gradually reduced. The continuous improvement of new energy grid-connected subsidy policies has further promoted the development of the entire industry. At present, distributed photovoltaic power generation has entered thousands of households. Users can install a solar power generation system on their roofs and earn income by selling electricity. However, with the use of a large number of power electronic equipment, a large number of harmonics will be injected, which not only reduces the power factor, but may also face fines when the ha...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, propose a photovoltaic inverter control method that can improve the power quality of the distribution network, and solve the technical problem of insufficient harmonic compensation capability of a single inverter. Linkage control can make full use of the remaining capacity of each photovoltaic grid-connected inverter, reduce the cost of improving power quality, and at the same time ensure user benefits

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