Mid-point potential balance control system for T-type three-level inverter based on neuron PI adaptive control

Abstract

The invention discloses a mid-point potential balance control system for a T-type three-level inverter based on neuron PI adaptive control. A voltage outer loop employs a neuron PI adaptive controller, and a current inner loop employs a traditional PI controller. The input of the voltage outer loop at the direct current side is a deviation value of two capacitor voltages to take as input of the PIadaptive controller, output of the voltage outer loop through the neuron PI adaptive controller is taken as input of the current inner loop, the difference of the input of the current inner loop andthe output of the voltage outer loop is subjected to the neuron PI adaptive controller to compare with a triangular wave to obtain mid-point potential balance control system for the T-type three-levelinverter with a balance circuit of complementary two-path PWM signal control. The voltage outer loop employs adaptive controller based on the neuron PI parameters to perform regulation of the parameters of the controller on line in real time. Compared to a traditional PI controller, the adaptive ability is high, the response speed is fast, and the output result of the voltage outer loop controller is better.

Description

technical field [0001] The invention relates to a T-type three-level inverter midpoint potential balance control system based on neuron PI self-adaptive control, which belongs to the technical field of power electronics and micro-grid. Background technique [0002] In 2007, TNPC single-phase topology was proposed by KNAUP and Peter. The T-type neutral point clamped ("T" Type NeutralPoint Clamped, TNpc) three-level circuit is a new one obtained by further modifying and optimizing the NPC three-level circuit. However, the T-type three-level inverter still has the problem of unbalanced midpoint potential, which seriously affects the output voltage and current waveform of the AC side. If the midpoint potential is seriously shifted, the three-level inverter may become a two-level structure, resulting in damage to the two DC capacitors on the DC side. In severe cases, it will affect the normal operation of the inverter, and it is very likely to cause a system crash. Contents of...

AI Technical Summary

Problems solved by technology

[0002] In 2007, TNPC single-phase topology was proposed by KNAUP and Peter. The T-type neutral point clamped ("T" Type NeutralPoint Clamped, TNpc) three-level circuit is a new one obtained by further modifying and optimizing the NPC three-level circuit. However, the T-type three-level inverter still has the problem of unbalanced midpoint potential, which seriously affects the output voltage and current waveform of the AC side.

If the midpoint potential is seriously shifted, the three-level inverter is likely to become a two-level structure, resulting in damage to the two DC capacitors on the DC side

In severe cases, it will affect the normal operation of the inverter, and it is very likely to cause a system crash

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