Series active voltage quality treatment system and control method

Abstract

The invention discloses a series active voltage quality treatment system and a control method. The system comprises a controller, an alternating current power grid, a main circuit unit, a bypass unit and a load; the bypass unit is arranged between the alternating current power grid and the load, and the main circuit unit comprises a parallel connection part and a series connection part. The parallel connection part comprises an LCL passive filter, a single-phase three-level half-bridge rectifier and an energy storage capacitor; the parallel connection part comprises a single-phase three-level half-bridge inverter and an LC filter, the series connection part comprises a single-phase three-level half-bridge inverter and an LC filter, the controller comprises a DSP, a data interaction buffer unit, an FPGA and a sampling unit, the control method adopts DSP and FPGA dual-CPU control, the parallel connection part and the series connection part can be independently controlled, delay is small, performance is excellent, timely and reliable compensation processing can be conducted on the power grid voltage, and the quality of the power grid voltage is improved; meanwhile, the technical problem that the direct-current bus voltage is unstable due to the fact that current of a parallel part is affected by power grid voltage distortion is solved, static errors of alternating-current signals of a series part are eliminated, and error-free tracking of the alternating-current signals is achieved.

Description

technical field [0001] The invention relates to the field of power quality control, in particular to a series active voltage quality control system and control method. Background technique [0002] At present, the power quality problem has received more and more attention. With the wide application of nonlinear power electronic devices and impact and fluctuating loads in modern industry, there are overvoltage, undervoltage, voltage sag and Voltage quality problems such as harmonics, these problems will lead to performance degradation and shortened life of some important loads or equipment sensitive to power quality. [0003] To solve this problem, a direct and effective measure is to install an active voltage quality regulator (AVQR) in series between the grid and sensitive loads to ensure the voltage quality at the user end by injecting compensation voltage into the grid. Since the series devices only need to compensate the distortion of the system voltage and the deviatio...

AI Technical Summary

Problems solved by technology

The problems of this structure are: there is coupling between the bridge arms of the two-level structure, the system efficiency is low, the single CPU control cannot make timely and reliable compensation for the grid voltage, and the grid voltage quality is poor

Images