Vector sector positioning method and local optimization model prediction control method and device

Abstract

The invention discloses a vector sector positioning method and a local optimization model prediction control method and device. By means of establishing a detailed prediction model, the output currentis controlled, and the neutral point potential of the direct current side and the suspension capacitor voltage of each phase can be controlled. Meanwhile, in allusion to the problems of large calculation amount and difficult hardware implementation when global optimization is carried out for traditional model prediction control, the triangular region where the reference voltage is located in an output voltage vector diagram is judged in advance by utilizing the vector sector positioning method provided by the invention, cost function judgment is carried out in a target triangular region, anda global optimization problem is converted into a local optimization problem in the reference region. According to the method, on the premise that the control over multiple output variables is achieved, the calculation load of the system is greatly reduced, calculation resources are saved, delay of algorithm control is reduced, and a five-level inverter controlled through the method has a good output effect.

Description

technical field [0001] The invention belongs to the technical field of multi-level inverter control, and in particular relates to a vector sector positioning method for a five-level grid-connected inverter, a local optimization model predictive control method and a device. Background technique [0002] As an interface for energy conversion, the inverter is a key component in the fields of power grid connection and motor frequency conversion speed regulation. However, with the development of power systems, traditional two-level inverters are gradually unable to meet the needs of large-capacity and high-quality grid connection. The five-level inverter not only has a smaller output voltage and current distortion rate, but also limits dv / dt. At the same time, the five-level inverter requires smaller filter inductors, which greatly reduces the weight and volume of the system. In new energy Grid-connected, rail transit, high-voltage power transmission and distribution and other f...

AI Technical Summary

Problems solved by technology

However, when the traditional model predictive control is applied to the control of the five-level active neutral point clamped inverter, each sampling cycle needs to be calculated 8^3=512 times, which consumes a lot of computing resources and increases the system cost. Delay

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