Model predictive power control (MPPC) is considered as a promising algorithm utilised in grid-connected inverter due to its fast dynamic response, simple control structure and multi-objective optimisation. However, under unbalanced network, the grid current with excessive distortion troubles the application of MPPC. Based on the conventional MPPC, this study proposes a model predictive flexible power control (MPFPC) to reduce the current total harmonic distortion and achieve three flexible targets, including the cancellation of the active- and reactive-power oscillation and the negative-sequence grid current. In this algorithm, the power references are divided into two parts, which are used as reference values for the instantaneous active power control (IAPC) and the instantaneous reactive power control (IRPC), respectively. The three flexible targets are achieved by regulating the ratio of the two parts of power reference. Meanwhile, the grid current of MPFPC is the sum of IAPC and IRPC; therefore, the grid current distortion can be suppressed effectively. Simulation and experimental platform constructed by a three-level inverter are established to validate the effectiveness of MPFPC, and the results exhibit that the MPFPC meets the above expectations.

中文翻译：

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不平衡网络下并网逆变器的模型预测柔性功率控制

模型预测功率控制（MPPC）由于其快速的动态响应，简单的控制结构和多目标优化而被认为是并网逆变器中一种有前途的算法。然而，在不平衡网络下，电网电流畸变过大会给MPPC的应用带来麻烦。基于常规MPPC，本研究提出了一种模型预测柔性功率控制（MPFPC），以减少电流总谐波失真并实现三个柔性目标，包括消除有功和无功振荡以及负序电网电流。在该算法中，功率参考分为两部分，分别用作瞬时有功功率控制（IAPC）和瞬时无功功率控制（IRPC）的参考值。这三个灵活的目标是通过调节功率基准的两个部分的比率来实现的。同时，MPFPC的电网电流为IAPC和IRPC之和。因此，可以有效地抑制栅极电流畸变。建立了由三电平逆变器构建的仿真和实验平台，以验证MPFPC的有效性，结果表明MPFPC符合上述期望。