Reactive compensation technology of parallel connection energy unidirectional flow controlled rectifier

Abstract

The present invention provides a reactive compensation technology of parallel connection energy unidirectional flow controlled rectifier which can achieve the static reactive compensation technology when a power grid has a non-linear load. The technology comprises the following steps of: 1, performing parallel connection of a plurality of energy unidirectional flow controlled rectifiers to accessa power grid; 2, when the power grid has a non-linear load, performing current phase shift of part of the energy unidirectional flow controlled rectifiers in the parallel connection structure to generate a reactive power required by the power grid; 3, detecting and extracting harmonic components of an input current at a common coupling point; and 4, injecting the harmonic components after uniformdivision to the rest of energy unidirectional flow controlled rectifiers to achieve the purpose of inhibition of input current distortion of the common coupling point. The reactive compensation technology can supply required reactive power for the power grid, reduce or eliminate the harmonic waves in the input current, can complete compensation of the harmonic current with no need for a sensor anda phase-locked loop, and is good in robustness and high in wide adaptability.

Description

technical field [0001] The invention relates to the fields of power electronics and power systems, in particular to a reactive power compensation technology for parallel energy unidirectional flow controllable rectifiers. Background technique [0002] With the increasingly widespread application of power electronic devices in the power system, more and more non-linear loads are connected to the power system, and the power quality problem of power supply is becoming more and more prominent. The power quality control technology with power electronic converter as the core has attracted people's attention. More and more attention. At the same time, power quality control devices based on power electronics technology, such as: Static Var Compensator (SVC), Static Var Generator (SVG), Active Power Filter (APF), Universal Power Quality Controller (UPQC) ) has been more and more widely used, and these power quality control devices can well realize the compensation of reactive power ...

AI Technical Summary

Problems solved by technology

[0004] However, the traditional single-cycle control can only work at unity power factor, and its current phase is not controllable, so it cannot achieve quantitative output of reactive power

And in the energy unidirectional flow controllable rectifier, due to the existence of the diode and the filter inductor on the AC side, the actual input current will not be able to track its given value when the voltage and current are in reverse phase, and the input current will be distorted, which will lead to such Energy unidirectional flow controllable rectifiers have very limited ability to provide reactive power compensation to the grid. Therefore, the degree of current distortion limits the ability of such converters to provide power quality control

Images