Single-phase full-bridge inverter SHEPWM switching angle determination method

Abstract

The invention relates to a single-phase full-bridge inverter SHEPWM switching angle determination method. The method carries out the iterative solution according to a Newton iteration formula, can quickly determine a group of single-phase full-bridge inverter SHEPWM switching angles meeting a preset value, solves a problem that the initial value of the Newton iteration method is difficult to select, expands the equation solving range of the Newton iteration method, andavoids the computational complexity by using the algebraic method. Compared with the existing intelligent algorithm for solving the SHEPWM nonlinear equation set without the waveform symmetry characteristic in the whole period, the method has the advantages that the solving time of the equation set is greatly shortened based on the stepping Newton iteration method, and the real-time solving of the SHEPWM nonlinear equation set without the waveform symmetry characteristic in the whole period becomes possible.

Description

Technical field [0001] The present invention belongs to the technical field of power electronics inverter, and is proposed a single-phase full-bridge inverter SHEPWM switch angle determined based on stepped Newton iterative method. It can quickly determine a set of single-phase full bridges that meet preset values. Inverter ShepWM switch angle. Background technique [0002] With the development of electric electronics technology, the inverter has been widely used in various power electronic devices, and today the inverters can be seen everywhere in daily life. The PWM control method is a key technique in inverter research. The PWM control method is to control the opening, turn-off time and order of the power electronic switches of each inverter, and output the pulse sequence of the output adjustable width. Target waveform. Since the PWM method is to fit the expected waveform by a comparative method, the quality of the output waveform depends on the number of high frequencies. The...

AI Technical Summary

Problems solved by technology

Numerical methods include gradient optimization, sequential quadratic programming, Newton-Raphson, Newton homotopy method, etc., but the biggest problem with numerical methods is that they are heavily dependent on the selection of initial values ​​and cannot find all possible solutions

Although these problems can be solved by algebraic methods, such as synthetic elimination method and Grobner base method, their calculations are too complicated, the solution of SHEPWM nonlinear equations is a function of modulation index, and in the process of inverter operation, The modulation index will change

In the third algorithm, various intelligent algorithms have been applied in SHEPWM nonlinear equations in recent years, such as neural network algorithm, genetic algorithm, bee algorithm, ant colony algorithm, bacterial foraging algorithm, imperialist competition algorithm, Grasshopper optimization Algorithms, etc. These intelligent algorithms need to spend a lot of time in the process of finding the optimal solution, and cannot achieve real-time solutions

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