Research On SHEPWM Technology Based On CBSO Algorithm

As a form of inverter with simple control and simple structure,the two-level inverter is widely used in various medium and low voltage applications.However,with the increase of low-order harmonic content requirements in systems such as motor control applications,research on how to eliminate low-order harmonics by two-level inverters is increasing.In order to suppress harmonics,at present,the commonly used methods include installing the LC filter,the active power filter,and using the method of controlling the inverter with the SHEPWM modulation method.But the first two harmonic elimination methods require additional equipment,and the difficulty of system control is increased,mainly used in occasions with high requirements on power quality,and because SHEPWM modulation method can eliminate the low-order harmonics of the system without adding additional equipment so it has received extensive attention.In this paper,the three-phase two-level inverter is taken as the research object.The application of SHEPWM method in its control is discussed in detail,and it is analyzed in detail with simulation and experiment.The main difficulty of the SHEPWM modulation method lies in the solution of its nonlinear transcendental equations.For the solution of this problem,numerical methods such as Newton-Raphson method,homotopy algorithm and Walsh function method are first introduced,but The traditional numerical solution method is very dependent on the initial value.Therefore,some people have proposed the method of solving the SHEPWM nonlinear equations by using the intelligent optimization algorithm.At present,there are many researches on SHEPWM SHEPWM modulation method with particle swarm algorithms and genetic algorithms.Although the intelligent optimization algorithm does not have the problem of dependence on the initial value,there is a general problem that the convergence speed of the iteration is slow and the accuracy of the solution is not high.Therefore,the method of using the logistic model in chaos theory to improve the system of the CBSO algorithm is applied to the SHEPWM nonlinearity.The method of solving the equations combines the advantages of individual search in the search algorithm of BAS,the advantage of group search in particle swarm optimization and the disturbance of chaos algorithm,which improves the search range and accuracy of the algorithm.The effectiveness of the proposed algorithm,the first use of single-peak multi-dimensional functions Multidimensional and multimodal function tested it,it was then used to solve the equations of SHEPWM.In the paper,Firstly,the single-peak multi-dimensional function and the multi-peak multi-dimensional function are used to test it,and then the SHEPWM equations are solved by using it.In order to verify the effectiveness of the proposed algorithm for solving the SHEPWM nonlinear equations,a seven-level cascade inverter and a three-phase two-level inverter simulation model are built,and the physical model of the experimental prototype of the three-phase two-level inverter is given at the end of the paper.In order to verify the effectiveness of the proposed algorithm for solving the SHEPWM nonlinear equations,a seven-level cascade inverter and a three-phase two-level inverter simulation model are built respectively.At the end of the paper,three phases are given.The experimental prototype physical model of the two-level inverter verifies the effectiveness of the CBSO algorithm for solving the SHEPWM nonlinear equations through simulation and experimental results.At last,the effectiveness of the CBSO algorithm for solving the SHEPWM nonlinear equations is verified by simulation and experimental results.