Research On Control Stratgy Of Switching Contactor Based On Analyzing Stability By Semi-tensor Product

Contactor switched reactive power compensator(HVC——High-voltage VarCompensator) has a wide field of application in the power quality practicalapplication with many advantages including high voltage, large capacity and lowcost. However surge current and over voltage at the switched moment as well as theadverse effect on the voltage stability after the equipment switching into the gridgreatly threaten the reliable operation of the power system, thus reducing the HVCswitching instant negative effects become an urgent problem to be solved.This paper analyses the basic principle of HVC switching capacitor and itsswitching transient process at zero and non-zero point from theoretic analysis, thenputs forward the control strategy of HVC. In order to control the contactor precisezero-on and zero-off, a determination of contactor response time under differentenvironment is made to establish a response time database and put forward thecorresponding prediction algorithm. At the same time the HVC reactance rate iscalculated to prevent harmonic amplification and resonance.The calculation method of the electric power system transient voltage stabilitycriterion based on the semi-tensor product is put forward by establishing the HVCsystem model and the system differential algebraic equations.Meanwhile Analys is ofthe relation of system parameters and stability in the HVC control system atdifferent fault or disturbance, so as to effectively predict system stability.The hardware circuit of HVC control system inc luding a power supply circuit,a signal conditioning circuit, display circuit, the control circuit based on the STM32is built and debugged. On the basis of the hardware circuit, the software algorithmand the control strategy consist of a system stability judgment module based onsemi-tensor product, a contactor response time prediction module based ontwo-dimensional interpolation, a reactive power detection module based on theinstantaneous reactive power theory and a zero-crossing switched control moduleare designed.The simulation of the HVC system is made to verify the validity of the controlstrategy of HVC system. Build the system hardware platform using existinglaboratory conditions to ensure the correction of the software and hardware system.Simulation and experimental results show that the control strategy can effectivelyavoid the HVC switching negative effect, thus validating the reliability andfeasibility of the scheme.