The control coupling and stability of three-phase photovoltaic systems with constant power loads (CPLs) are two key technical issues that urgently need to be addressed. However, current methods are difficult to solve both technical challenges simultaneously. To address these issues, this article proposes a novel decoupled continuous control set model predictive control (CCS-MPC) strategy for LC -filter T-type three-phase four-leg three-level voltage source inverters (3P4L-3L-VSIs) driving CPLs. The control strategy is developed in αβγ frame. The model of 3P4L-3L-VSIs is first transformed from abc frame to the αβγ frame to remove the coupling effects in the abc frame. Then based on the decoupled model in the αβγ frame, a novel CCS-MPC strategy is proposed to provide balanced sinusoidal voltages. The α and β components are regulated by the A, B, and C legs, while the zero-sequence component is regulated by the N leg. To confirm the effectiveness of the proposed strategy, both simulation and experimental results are presented to verify the proposed decoupled CCS-MPC strategy. The results show that the proposed control achieves low computational burden and total harmonic distortion and can increase the stability margin especially for CPLs compared with the commonly used PI-based control, PR-based control, and deadbeat control.

中文翻译：

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驱动恒功率负载的T型三相四桥臂三电平逆变器的解耦连续控制集模型预测控制

恒功率负载三相光伏系统（CPL）的控制耦合和稳定性是急需解决的两个关键技术问题。然而，目前的方法很难同时解决这两个技术挑战。为了解决这些问题，本文提出了一种新颖的解耦连续控制集模型预测控制（CCS-MPC）策略驱动 CPL 的 LC 滤波器 T 型三相四桥臂三电平电压源逆变器 (3P4L-3L-VSI)。控制策略是在αβγ 框架。 3P4L-3L-VSI的模型首先由abc 帧到αβγ框架消除了耦合效应abc 框架。然后基于解耦模型αβγ框架，提出了一种新颖的CCS-MPC策略来提供平衡的正弦电压。这α 和β分量由A、B和C桥臂调节，而零序分量由N桥臂调节。为了证实所提出策略的有效性，提出了仿真和实验结果来验证所提出的解耦 CCS-MPC 策略。结果表明，与常用的基于 PI 的控制、基于 PR 的控制和无差拍控制相比，所提出的控制实现了较低的计算负担和总谐波失真，并且可以增加稳定性裕度，特别是对于 CPL。