Research On TSF For Harmonic Control Based On Dynamics Modeling

Based on the application of frequency converters and rectifying devices, harmonics and reactive power compensation is a serious problem. In order to respond to the call of building green power system, TSF (Thyristor Switched Filter) is researched in the paper. The research is based under the background of suppressing especial harmonic current and compensate reactive power of 6.3kV bus of a coal mine of Heilongjiang province in China.A modeling method of designing parameter of TSF (Thyristor Switched Filters) is presented. The work conditions of TSF were modeled and analyzed according to Thevenin theorem and Norton theorem, respectively. Under the perturbation of source impedance and frequency of the power system, changes in fundamental current of inject into every filter of passive power device was analyzed based on numerical method. Expressions of harmonic current of inject into every filter of passive power device were given through character calculation.The key of the TSF design is the signal detection and switching choice. The paper uses i p ? iq harmonic current signal detection method. The method is based on the instantaneous reactive power theory. The method has good real-time. It is not influenced on the power system voltage distortion. The research uses nine-realm method to analyze the relationship between harmonics and reactive power compensation. Then the switching sequence of thyristors is detemined.In order to realize the control method above, the digital control system is designed. DSP is used to detect the harmonic current and CPLD is used to control zero crossing point. The hardware includes power circuit and drive circuit.To simulate TSF result, PPF (Passive Power Filter) and TSC (Thyristror Switched Compensator) is designed to doing Matlab simulation. The device of PPF and TSC is a high voltage harmonics suppression and dynamic reactive power compensation. It is analyzed the work effect under the different reactance. It can be used to choose the filtering device. The simulation result shows that TSF system can suppress harmonics and compensate reactive power effectively.