Practical LC Filter Design Method Based On Network Structure Studies

Filter design can be used to achieve precise technical specifications for the transfer function approximation methods. The implementation of the transfer function have a lot of methods, such as simultaneous circuit node voltage and current equations transfer function of the voltage ratio method to achieve instigated point function methods. Although these methods are practical and effective, but because of the complexity of the calculation process or esoteric mathematical knowledge, design and production time consuming, Therefore, network analysis and comprehensive theory, based on a detailed study of the network structure, and from that direction, preliminary exploration of the LC filter design method based on network structure.Doubly terminated LC ladder network structure contained in line with actual circuit universal connectivity. Dual relationship exists T network and ∏ network in ladder network. From the simplest T network structure, analyze and derive the recursive formula of the transfer function of the network, and confirmed the correctness of recursive formula. Thus, to facilitate the transfer functions of the LC filter trapezoid network structure possible to achieve. By solving the recurrence formula transfer function, effectively solve the traditional method for solving simultaneous equations are time-consuming and cumbersome problem, no study the distribution of zeros and poles, etc., successfully design a good performance LC filter, and the method is suitable for double-terminated network load conditions contained in any match.The actual filter production, due to the large number of numerical approximation, the deviation of the elements themselves and influence each other, performance of the filter is designed to go through in order to achieve the best debugging. This paper mainly discusses the analysis in the frequency domain filter debugging method to analyze the relationship between change and filter performance inside each element, can effectively guide the analysis and debugging LC filter can also be quickly and accurately find driving waveform changes the reason.Engineering fields, passive filter by multiple sets of LC filter consisting of grid systems are widely used to solve harmonic problems caused by internal power electronic devices. Harmonic source harmonics injected into the system to make the system voltage and system current waveform distortion serious threat to the safe operation of the power grid and electrical equipment. Passive filter in meeting Harmonic and reactive power compensation and other technical requirements of the premise, try to choose the economy, reasonable and practical solution. In order to optimize the parameters of passive filter, it should be possible to improve the filtering and the combined effect of reactive power compensation, the economic cost savings. Passive filter design methods for the current excessive dependence on engineering experience, insufficient degree of optimization, optimization space is small and practical considerations are not comprehensive and other issues, the optimization method of passive filter design parameters conducted in-depth research proposed use of the realization of passive filter parameters based on chaotic cat map genetic algorithm multi-objective optimization design, analysis and gives a mathematical description of the passive filter design optimization problems, the objective function and constraints. Through the establishment of passive filter simulation models to verify the effectiveness of the method has better harmonic suppression.