A three-phase single-stage solar energy conversion system (SECS) integrated into a weak distribution network is presented. The grid integration and maximum power point operation of the photovoltaic (PV) array are achieved by a voltage source converter. The SECS is capable of feeding distortion-free and balanced grid currents with power factor correction, even at adverse grid side, PV array side, and load side operating conditions. The integration of SECS into the weak grid having distorted, unbalanced, and varying grid voltages is achieved while maintaining the power quality. The dc offset introduced in the sensed grid voltages is also effectively eliminated. For swift system response to changes in load currents, their fundamental weights are swiftly extracted. In the absence of solar irradiance, the power is imported from the utility to supply the local loads, and the system continues to execute its power quality improvement functions. In case of loss of PV power or large voltage deviations, the dc-link voltage is adaptively varied according to the grid voltage changes, increasing system reliability, and reducing operating losses. The efficacy of the SECS is validated through test results at different operating scenarios.

中文翻译：

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在各种工作条件下具有改善电能质量功能的单级太阳能转换系统的弱电网集成

提出了一种集成到弱配电网络中的三相单级太阳能转换系统（SECS）。光伏（PV）阵列的电网集成和最大功率点操作是通过电压源转换器实现的。即使在不利的电网侧，光伏阵列侧和负载侧的工作条件下，SECS仍能够通过功率因数校正提供无失真且平衡的电网电流。将SECS集成到具有畸变，不平衡和变化的电网电压的弱电网中，同时保持了电能质量。还可以有效消除感应到的电网电压中引入的直流偏移。为了使系统快速响应负载电流的变化，可以快速提取其基本权重。在没有太阳辐射的情况下，电力从公用事业部门进口以供应本地负载，并且系统继续执行其电能质量改善功能。如果发生PV功率损失或较大的电压偏差，则可根据电网电压变化自适应地改变直流母线电压，从而提高系统可靠性并减少运行损耗。通过在不同操作场景下的测试结果可以验证SECS的有效性。