A Versatile UPQC Applied To Power Quality Of Rural Grids

In recent years,with the national economic development and industrial restructuring and upgrading,various power quality problems in the power system have drawn more and more attention from all walks of life and become the focus of the study of electrical engineering.Aiming at the problems of power quality problems such as harmonic pollution,low power factor,voltage sag and three-phase unbalance in rural areas,remote areas and complex power supply environments,this paper introduces a multi-functional unified power quality controller,Analysis and application for the management of power quality problems of three-phase three-wire and three-phase four-wire power distribution system.In this paper,the working principle of series-type converter module,parallel converter module and series-parallel converter module are analyzed in detail.The main circuit of the device is composed of series-connected circulation module and parallel-connected circulation module.Among them,the series type circulation module can be regarded as the current source,and the parallel type circulation module can be regarded as the voltage source.Unlike most UPQCs that have already been put into operation,the control strategy of using non-sinusoidal control volume is different.This design uses double compensation control strategy to control the amount of sinusoidal variable and reduce the time complexity of the compensation algorithm.Furthermore,the design voltage control algorithm and the current control algorithm are synchronized in the reference coordinate system,and the control variables are also continuous.In the traditional PI regulator,the synchronization error is reduced.The design of the main circuit using the bridge structure,the switching device selection insulated gate bipolar transistor module FF600R12ME4,the drive circuit using M57962 integrated drive circuit,the sampling circuit sensor selection Hall current sensor and Hall voltage sensor for collecting grid voltage,load Current,DC bus voltage and other parameters,the sampling circuit and A / D conversion circuit into the control module.Control module uses dual-core control,the use of DSP chip for data processing and computing,and the use of programmable logic devices for system logic control.In this paper,the static performance and dynamic performance of the multi-functional unified power controller are evaluated through experimental results.By comparing the power quality parameters of the power grid before and after the operation of the device,the present device can solve a variety of power quality problems.