Uniform prediction control method for quasi-Z source inverter-permanent magnet synchronous motor systems

Abstract

The invention discloses a uniform prediction control method for quasi-Z source inverter-permanent magnet synchronous motor systems. According to the method, stator current d and q axis components areobtained through coordinate transformation, each control variable is obtained through a delay compensation link, a torque given value is obtained through a rotation speed closed loop, and d and q axiscurrent given values are obtained to calculate a stator flux linkage given value; an inductive current given value is calculated through a power compensation manner so as to obtain an inductive current critical value; and an optimum vector is judged according to a relationship between inductive current and the inductive current given value so as to obtain each control variable at the next moment,the control variables at the next moment are substituted in an evaluation function to obtain an optimum vector, and a switch state corresponding to the optimum vector is output to an inverter. The uniform prediction control method is capable of decreasing the operand of controllers, avoiding the influences, on prediction control of quasi-Z source inverter-permanent magnet synchronous motor systems, of quasi-Z source inverter negative modulation, realizing the uniform prediction control of quasi-Z source inverter-permanent magnet synchronous motor systems, and solving the control conflict problems in two-stage control.

Description

technical field [0001] The invention relates to a permanent magnet motor system control method in the field of power electronics and motor control, in particular to a quasi-Z source inverter-permanent magnet synchronous motor system unified predictive control method. Background technique [0002] The traditional voltage source inverter (VSI) is a commonly used converter in the permanent magnet synchronous motor (PMSM) drive system. Since it can only realize step-down conversion, it is not suitable for applications where the input voltage varies widely. For example, in the field of electric vehicles, the power supply battery is affected by the battery power and the operating conditions of the vehicle, and its output voltage, that is, the input voltage of the inverter may fluctuate greatly, which in turn affects the output performance of the motor connected to the output side of the VSI. Lead to the deterioration of the power performance of electric vehicles. At present, a DC...

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Problems solved by technology

On the one hand, this two-stage control method brings convenience to the design of the controller, but on the other hand, in order to ensure that there is no conflict between the two controllers, a higher input voltage is usually required, which will reduce the size of the power supply. And the stress of the switch tube increases, which brings challenges to the system design

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