Researchon The Dynamic Reactive PowerCompensation Device

Reactive power is an essential factor for the design and operation of AC power system.It is closely relevant to the power system economic operation, security and stability.Reactive power is a key influencing factor for power system line loss, power quality andstatic-state stability limit. As the power system load gradually grows, the requirements forreactive power in power system becomes more and more strict, and the importance ofdynamic reactive power compensation to the modern power system becomes more andmore obvious. Therefore, it is imperative and profound to develop dynamic reactive powercompensation technology in the power system.Thyristor controlled reactor (TCR) and fixed capacitor (FC) are the commonly-useddevices in reactive power compensation. The mechanicallyswitched capacitor (MSC) andTCR hybrid structure is proposed in the paper. FC is adopted to meet the requirement ofstatic-state reactive power in the system, while the TCR is adopted to respond to thedynamic part of the reactive power requirements. In this way, the defect of discontinuity ofFC for compensating the reactive power is made up, and the response speed of the systemis enhanced at the same time.Beginning with the basic theories of dynamic reactive power compensation technologyin the distribution system in the fields of reducing the line loss, increasing the transmissioncapacity of the transmission line as well as improving the power quality, this paper putsforward the mathematical model of TCR and FC hybrid structure. The quantitative relationof thyristor firing angle and TCR equivalent susceptance is deduced. The model of TCRcircuit is established based on the platform of MATLAB/Simulink for the simulation ofTCR inductive current. The fundamental wave of current is analyzed by FFT, and thecorrespondence of fundamental waveof current and thyristor firing angle is tabulated whichprovides the data basis for digital circuit.The hardware platform of the device is a key factor of the performance of the wholesystem. In light of the fact that the system needs to take control while processing massivedata, the floating point DSP controller of TMS320C28X series made by TI is adopted in this paper for data acquisition and process, ARM is used for control and panel display, andtwo kinds of microprocessor is used to guarantee the fast response and precision. In thepaper, the design thought and flow chart of the software is proposed. The program is writtenin C language. With modularization design, the program is distinct with high readabilityand portability.At last, a compensating device is designed for the use of10kV distribution network.The device is able to put16groups of capacitor banks into power system at most. Thecapacity of a single capacitor bank is set by the user. The switching oscillation andprotection of the capacitor is considered. And the device is tested by related organizationwhich proves that the device can be put into use in the power nerwork.