Parallel-form power quality conditioner for direct current power system

Abstract

The invention provides a parallel-form power quality conditioner for a direct current power system. The parallel-form power quality conditioner comprises a direct current / direct current (DC / DC) bidirectional converter, a direct current energy storage unit, a filtering unit, a voltage and current signal acquisition unit and a controller, wherein the voltage and current signal acquisition unit is connected with the controller; the controller is connected with the DC / DC bidirectional converter and the energy storage unit respectively; the DC / DC bidirectional converter is connected with the filtering unit and the energy storage unit respectively; and the filtering unit is connected in parallel with a direct current bus. The turning-on and turning-off of the DC / DC bidirectional converter are controlled by the controller to regulate direct current electric power output by the direct current energy storage unit into proper compensation current and output the compensation current to the direct current power system or transmit the residual direct current electric power of the direct current power system to the energy storage unit, so that fluctuations caused by the use and removal of an impact load are suppressed; the current harmonics of the direct current power system are filtered; current is quickly injected when an open circuit failure occurs to temporarily support the load; and the load is stably transferred in mutual loop switching processes, and the fluctuations of the mutual loop switching processes are stabilized to condition the power quality of the direct current power system.

Description

technical field [0001] The invention belongs to the field of direct current power systems, and in particular relates to a parallel type direct current power system power quality regulator, which is used to realize the power quality adjustment of the direct current power system. Background technique [0002] With the development of the power system, the shortcomings and limitations of the AC power system have become increasingly prominent. In the AC transmission line, in addition to the resistance loss of the wire, there is also the loss of the AC inductance, the line loss is large, and the long-distance transmission efficiency is low. In the AC transmission line, if any phase has a permanent fault, the whole line must be cut off, and the loss of the fault will be large. AC power transmission must run synchronously, and phase consistency must also be considered for grid-connected AC systems, which complicates control. In the AC distribution network, the AC transmission capa...

AI Technical Summary

Problems solved by technology

However, the current power quality control devices are all designed for AC power systems, and there are few researches and inventions on power quality conditioners for DC power systems.

Once the DC power system is put into use, similar power quality problems will inevitably be encountered, and the existing power quality regulation technologies and devices will basically not be able to meet the requirements of the DC power system

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