Study On Special Harmonic Elimination Technique Based On Immune Algorithm

In recent decades,with the continuous improvement of material technology and technology,power electronic devices have been rapidly developed and advanced.The development of power electronic devices pushes the power electronic technology forward and makes it widely used in various fields.All kinds of power electronic devices improve the production efficiency and quality of life,but also bring harmonic problems.In this paper,theoretical analysis,simulation and experimental study are carried out on the special harmonic elimination technology for single-phase half-bridge,single-phase full-bridge and three-phase bridge voltage inverter.At present,there are many methods to remove harmonics,among which the special harmonic elimination technique is an efficient method.What method can be used to solve the nonlinear transcendental equations of specific harmonic elimination efficiently and quickly becomes a key problem in the study of specific harmonic elimination technology.In this paper,the intelligent algorithm-immune algorithm is applied to specific harmonic elimination technology.Firstly,the special harmonic elimination mathematical models of unipolar and bipolar output voltage waveforms for the topology of single-phase half-bridge,single-phase full-bridge and three-phase bridge PWM voltage inverter are presented.Based on an example,how to apply Newton iterative algorithm and particle swarm optimization algorithm to solve the switching Angle of specific de-harmonic technique is given.Secondly,how to apply the immune algorithm to the special harmonic elimination technique to solve the switching Angle is analyzed.In this paper,the coding mode of immune operators in immune operation is designed and its value is assigned,and the affinity function of immune algorithm is designed for specific harmonic elimination technology.Thirdly,different PWM control technologies and special de-harmonic technology based on different algorithms are used to carry out simulation tests with the bipolar three-phase bridge voltage inverter as the simulation object for different loads.Under the same conditions,the spectrum analysis of the output waveform obtained from simulation is carried out to observe the characteristics of the output waveform of the inverter,and analyze the total harmonics of the output waveform of the inverter and the elimination of the proposed harmonics.Through the simulation experiment,the similarities and differences of the dc voltage utilization of the output voltage waveform of the bipolar three-phase bridge voltage inverter with different PWM control technologies are obtained,providing a new method for improving the dc voltage utilization.Finally,a special de-harmonic inverter is designed,which can change frequency conversion and voltage change simultaneously.The control circuit is composed of analog-to-digital converter,voltage-frequency converter,cyclic addition counter and data storage.The main circuit is composed of rectifier,inverter and protection circuit.The inverter is a three-phase bridge voltage inverter with intelligent power module IPM as the core.Through the above hardware circuit design and debugging,the construction of specific harmonic elimination inverter is completed,and the correctness and practicability of specific harmonic elimination technology based on immune algorithm is verified.