Research On A Low Voltage Synthetic Harmonic And Reactive Power Compensation Device

Active power filter (APF), as a real-time harmonic and reactive power compensationdevice, can solve the harmonic and reactive power problems of power grid with excellentperformance. But when there is a lot of changing reactive power in the power grid, the APFrequired great capacity to compensate reactive power and suppress harmonic at one time. So itincreases the costs and restricts the universal application. Thyristor switched capacitor(TSC) asa low-priced, dynamic reactive power compensation device with matured technology, has beenwidely used, but it is unable to deal with harmonics. Then, a synthetic harmonic and reactivepower compensation scheme with using TSC to reduce the capacity of APF has been proposed.However two devices simply parallel operated in the low voltage power grid with no mutualcommunication, it leaded to system instability, frequent switching of TSC. Therefore, in thispaper, APF and TSC are integrated into a set of synthetic compensation device, unified controland management by only one controller.The introduction of the APF can greatly reduce the reactance rate of series reactor in TSC,If still designed the reactance rate of TSC as the original way will be a big waste. Consideringthe device volume, cost saving, and the convenience for the engineering application of modularproduction and other various aspects factor, proposed that APF and TSC shared their reactors.This paper firstly analyzed the main circuit topology and the working principle of APF andTSC. According to their respective characteristics and problems of their simply paralleledoperation, designed the main circuit and its related parameters of the Synthetic CompensationDevice. Secondly focus on research the reactive power and harmonic detection algorithm, thevoltage current control algorithm of the active part, the capacitor switching control algorithm ofthe passive part of integrated device, completed the software and hardware design of controllerwhich based on DSP (TMS320F28335). At last, the integrated device simulation model hasbeen built in using the power system toolbox of SimPowerSystems provided byMATLAB/Simulink, through the analysis of the simulation results, verified the feasibility andvalidity.