An anpc three-level inverter and its model predictive control method

Abstract

The invention discloses an ANPC three-level inverter, which includes a three-phase bridge arm, and the phase bridge arm includes six IGBTs, wherein four series-connected IGBTs are connected to the positive and negative poles of a DC bus, and two series-connected IGBTs realize Midpoint clamping function, the input end of each bridge arm is connected to the DC voltage source, and the midpoint is connected to the midpoint O of the DC side voltage dividing capacitor. The switching action of each IGBT is controlled by the driving circuit. The ANPC three-level inverter and Its model predictive control method, compared with the traditional control method, the new model predictive control considers the influence of the unbalanced situation of the power grid, does not need complicated positive and negative sequence separation and adjustment of PI parameters, the control is simple, the quality of the grid-connected current waveform is better, and it can Fixed switching frequency, easy filter design, can realize the ability to actively control the balance of the neutral point potential, the fluctuation of the neutral point potential is greatly reduced, and can effectively suppress the shift of the neutral point potential caused by abnormal conditions, and can be applied to photovoltaic power generation systems and other renewable energy power generation fields.

Description

technical field [0001] The invention relates to the technical field of three-level inverters, in particular to an ANPC three-level inverter and a model predictive control method thereof. Background technique [0002] Compared with the traditional two-level inverter, the three-level inverter has the advantages of small switching loss and good output waveform quality, and is widely used in distributed voltage occasions such as photovoltaic power generation and wind power generation. Among them, the diode-clamped (NPC) three-level inverter is the most widely used three-level topology due to its simple control. However, the NPC three-level inverter has the disadvantage of uneven loss of power devices, which will cause serious heat generation and damage to some switching devices, which greatly shortens the life of the NPC inverter. [0003] The appearance of the active neutral point clamp (ANPC) three-level inverter solves the above problems, and is known as a new choice for pho...

AI Technical Summary

Problems solved by technology

[0007] Aiming at the deficiencies of the prior art, the present invention provides an ANPC three-level inverter and its model predictive control method, which solves the problem of unbalanced midpoint potential in the active neutral point clamp (ANPC) three-level inverter Problem, the traditional method uses PI controller to suppress the midpoint potential imbalance, but the system needs to adjust a large number of PI parameters

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