Study On The Intelligent And Low-voltage TSC Dynamic Reactive Power Compensation Device

Reactive power is an important factor to the voltage stability, and it is also related to secure and steady operation of the electric power systems. Reactive power compensation is one of the potent methods of maintaining the effective and reliable operation of the electric power system. A DSP(Digital Signal Processor)controlled Thyristor Switched Capacitor(TSC)system is designed based on TMS320LF2407A for the present electrical power market. This device's working theory is based on the real-time data of the power network and its intention is to complete the most felicitous compensation for the reactive power which exists in the 220V electric network.The paper mainly includes the followed parts: the principle of the TSC, the control method and principle of reactive power compensation device and the hardware and software design of the device. In hardware design, TMS320LF2407A DSP is used in the controller, which carries out the function such as sampling and calculating, regulating the reactive power automatically, giving protection in case of faults, data saving etc. The device has many merits such as high operating speed and high real-time. The thyristor is adopted as switch to connect capacitors to main circuit, which actualizes the capacitor's speediness, no arc, no impact switching, and has superior performance. The C and assemble languages are both used in the software design, and the method of modularization is used which can improve the universal trait of the program and simplify the device's maintenance. Mention of switching law, control method considering reactive power, comparing with familiar control method considering power factor, avoids oscillation on the condition of light loading. In order to realize system's required function, this paper designs and realizes comparatively integrate microcomputer controlled circuit and its peripherals circuit, including triggering circuit, sampling circuit, displaying circuit and communication circuit. The whole controlling program of the system is designed, and the controlling software structure flow chart is given as well. This paper also designs the protection circuit of the capacitor, and the protect measurement in the condition of high harmonic on the power network. Experiment results reveal that both the hardware and the software are of reasonable design, the control method is feasible and the system runs reliably. The device can realize the function anticipated.