This paper presents a sinusoidal pulsewidth modulation (SPWM) based direct digital control with average-voltage model (AVM) and division-summation process for paralleled three-phase three-wire (3φ3W) grid-connected converters to reduce circulating currents. With the direct digital control, plant of each single-phase converter can be derived directly, and a controller is then designed to cover the variation effects of filter inductance and grid voltage. Based on SPWM and AVM over a switching cycle, each 3φ3W converter can be decomposed into three single-phase converters and each converter is controlled individually to track its sinusoidal reference current tightly, reducing circulating currents significantly. Equal current sharing is therefore also achieved. The control laws for achieving grid connection are derived in detail. In the design and implementation, the inductances corresponding to various inductor currents are measured offline and stored in the controller for scheduling loop gain cycle by cycle. Experimental and simulated results from a three-converter system confirm the analysis and discussion of the proposed control approaches.

中文翻译：

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基于 SPWM 的直接数字控制，采用平均电压模型和 D__ 过程，用于并联 33W 并网转换器，以减少环流


本文提出了一种基于正弦脉宽调制（SPWM）的直接数字控制，采用平均电压模型（AVM）和除法求和过程，用于并联三相三线（3φ3W）并网转换器，以减少环流。通过直接数字控制，可以直接导出每个单相变换器的工厂，然后设计控制器来覆盖滤波器电感和电网电压的变化影响。基于一个开关周期内的SPWM和AVM，每个3φ3W转换器可以分解为三个单相转换器，并且每个转换器单独控制以紧密跟踪其正弦参考电流，从而显着减少环流。因此也实现了均流。详细推导了实现并网的控制规律。在设计和实现中，离线测量各种电感电流对应的电感并将其存储在控制器中，用于逐周期调度环路增益。三转换器系统的实验和模拟结果证实了对所提出的控制方法的分析和讨论。