A low-voltage distribution network line reactive power compensation device and compensation method

Abstract

The invention discloses a low-voltage distribution network line reactive compensation device, comprising a compensation unit connected in parallel in a low-voltage line in a low-voltage distribution network and a control unit controlling the switching of the compensation unit. The compensation unit comprises phase selection switches and capacitors which are sequentially connected in the low-voltage line. The control unit comprises a wireless communication circuit used for receiving low-voltage distribution network reactive power daily load curve data transmitted from an upper computer; an FPGA central processing circuit used for processing the curve data and transmitting a time switching signal; a storage used for storing the curve data; and a drive circuit used for controlling the switching of the phase selection switches based on the switching signal. A reactive compensation method of the invention comprises the following steps of 1) transmitting the time switching signal and calculating time reactive power needing compensation; 2) transmitting a comparison switching signal and calculating comparison reactive power needing compensation; 3) transmitting a request switching signal and request reactive power; 4) selecting and executing one switching signal; and 5) selecting the number of devoted capacitors.

Description

technical field [0001] The invention relates to an electrical control device in the field of power supply and distribution, in particular to a reactive power compensation device and a compensation method for a low-voltage distribution network line. Background technique [0002] Due to the complex structure of the low-voltage distribution network, there are few types of low-voltage reactive power compensation products in the prior art, and automatic switching is performed by considering parameters such as reactive power requirements, voltage and current values, and the capacitor compensation capacity is large and the grouping is small. Switching can only be performed when the reactive power demand is greater than 10kvar. On the one hand, the load in rural areas fluctuates frequently, resulting in unstable switching of the low-voltage reactive power compensation device, which is prone to overcompensation. At the same time, the price of the product is high, and the compensation ...

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Problems solved by technology

[0002] Due to the complex structure of the low-voltage distribution network, there are few types of low-voltage reactive power compensation products in the prior art, and automatic switching is performed by considering parameters such as reactive power requirements, voltage and current values, and the capacitor compensation capacity is large and the grouping is small. Switching can only be performed when the reactive power demand is greater than 10kvar. On the one hand, the load in rural areas fluctuates frequently, resulting in unstable switching of the low-voltage reactive power compensation device, which is prone to overcompensation. At the same time, the price of the product is high, and the compensation effect is not ideal.

[0003] On the other hand, in the reactive power compensation of the low-voltage distribution network lines in mountainous areas, the lines are too long, the terminal voltage is low, and the reactive power gap is large. The response during compensation is delayed, and it cannot meet the needs of the low-voltage distribution network in advance. Demand, the high-power equipment of large users at the end of the line is often difficult to start and run normally

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