A PWM rectifier predictive control method and device for suppressing power fluctuations

Abstract

The invention discloses a PWM rectifier predictive control method for inhibiting power fluctuation and a device thereof. The method comprises the following steps of: selecting two adjacent voltage vectors corresponding to the minimum cost function through a cost function corresponding to each voltage vector, calculating execution time corresponding to the selected cost function and execution timeof a zero voltage vector, and updating and adjusting the selected voltage vector and the execution time thereof according to the execution time corresponding to the comparison of the execution time corresponding to the selected voltage vector and 0 according to an adjusting rule so that the adjusted voltage vector and the execution time thereof do not have the condition of being less than 0. The PWM rectifier predictive control method for inhibiting power fluctuation and the device thereof can quickly select a new voltage vector and can calculate the execution time of the vector to obtain theexcellent power control effect, improve power pulsation in control and further improve the control performance of the system.

Description

technical field [0001] The invention belongs to the technical field of rectifier control, and in particular relates to a PWM rectifier predictive control method and device thereof for suppressing power fluctuations. Background technique [0002] PWM rectifiers have the advantages of adjustable power factor, adjustable DC bus voltage, bidirectional flow of energy, and good current sine, and are widely used in new energy power generation and high-precision DC power applications. At present, the commonly used control methods of PWM rectifiers are: grid voltage vector control and direct power control. Among them, the grid voltage vector control uses voltage and current double closed-loop control to realize the adjustment of active power and reactive power. However, for the occasions with high performance requirements and fast response speed, the traditional PI linear adjustment method is difficult to meet its dynamic performance requirements; direct power control method, direct...

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Problems solved by technology

However, the power change rate caused by different voltage vector effects in different sectors is different, so in the very short time of sector switching, there will be frequent cases where the execution time of the calculated voltage vector is less than 0, This is not the optimal vector selection result. If it is not adjusted, it will cause power fluctuations, increase current distortion, and seriously affect system performance.

Then by returning to the method of reselecting the voltage vector, it is necessary to recalculate the power change rate and vector execution time under the voltage vector, which will increase the calculation amount of the system program

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