Inverter improved multistep model prediction control method and equipment and storage equipment

Abstract

The invention provides an inverter improved multistep model prediction control method and equipment and storage equipment. Output current under the actions of all switch combination states is calculated within one control period by a traversing method, and inversion of the current is realized with an inverter under a switch combination state corresponding to a minimum cost function. According to the method, an optimal prediction switch combination state in two periods is constructed, only three optimal vectors are selected for prediction in a second period, and a switching frequency parameteritem is added in setting of the cost function, so that the limitation of the conventional single-step model prediction is avoided, the calculated amount is lowered; and optimal information included inother switch function combinations is kept. The inverter improved multistep model prediction control method and equipment have the beneficial effects that the tracking accuracy of the current is improved effectively; the quality of output electric energy is improved; the switching times of switching device combinations are reduced; and the average service life of switching devices is prolonged.

Description

technical field [0001] The invention relates to the field of inverter control, in particular to an inverter improved multi-step model predictive control method, equipment and storage equipment. Background technique [0002] The inverter is an important interface of the photovoltaic power generation system. It converts solar energy into alternating current with the same frequency and phase as the grid voltage. The quality of grid-connected power depends on the current control strategy of the inverter. The quality of the output inverter current is an important indicator. The current control commonly used in grid-connected inverters includes hysteresis control, proportional-integral control, and traditional predictive control. Among them, the hysteresis control has a fast dynamic response, but the switching frequency is not fixed, resulting in large current harmonics; the proportional integral control is simple, but the dynamic response is slow, and it is easy to overshoot; the...

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Problems solved by technology

The traditional FS-MPC has the advantages of fast dynamic response, flexible processing system constraints and no need for PWM modulator and related parameter design by considering all voltage vectors on the space vector diagram, but the online calculation is too large and time-consuming. It can only ensure the optimality of the selected switching function combination in one control cycle, without considering its optimality in the next two or more control cycles; only the optimal switching function combination of the converter at each control time is considered , without taking into account suboptimal or optimal information that other combinations of switching functions may contain

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