This paper presents a weak grid coupled single stage photovoltaic (PV) system. The system incorporates a battery energy storage (BES) via a bi-directional DC-DC converter (BDDC). The system does not allow the grid power quality to be deteriorated at nonlinear loading conditions, as well as when the grid voltages are unbalanced or distorted. Moreover, the control scheme is resilient to DC offset in the acquired grid voltage signals due to sensor circuit anomalies. The flexibility afforded by the BES is utilized for several benefits. The intermittent power injection associated with the PV system, is resolved by sustaining the defined grid power at fluctuating PV generation or local loads. The developed control makes use of the BES to adjust the grid power with the feed-in tariffs, adding the capability to act as a power sink at low tariff periods, thus increasing the economic returns. The control avoids overcurrent tripping at large voltage dips and enables fault ride through, whereas the conventional single stage system frequently trips and ceases operation. The system helps the utility at large voltage rise by stopping power flow to the grid while allowing power import from the grid. The BES is prevented from being excessively charged or discharged by the monitored transfer to a recovery mode. Moreover, the dual mode control of the DC link voltage allows peak power extraction from the PV array, while conserving grid power quality. The claimed benefits are evaluated at different operating scenarios using simulated and test results.

中文翻译：

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具有调节功率注入和电网支持功能的光伏电池系统能够适应弱电网条件


本文提出了一种弱并网耦合的单级光伏（PV）系统。该系统通过双向 DC-DC 转换器 (BDDC) 集成了电池储能 (BES)。该系统不允许在非线性负载条件下以及电网电压不平衡或畸变时电网电能质量恶化。此外，该控制方案对于由于传感器电路异常而获取的电网电压信号中的直流偏移具有弹性。 BES 提供的灵活性可带来多种好处。通过在波动的光伏发电或本地负载下维持规定的电网功率来解决与光伏系统相关的间歇性电力注入。所开发的控制利用BES通过上网电价调整电网功率，增加了在低电价时段充当电力接收器的能力，从而增加了经济回报。该控制避免了大电压跌落时的过流跳闸，并实现故障穿越，而传统的单级系统经常跳闸并停止运行。该系统通过停止流向电网的电力同时允许从电网输入电力来帮助公用事业公司应对大幅电压上升。通过受监控的转换到恢复模式来防止BES过度充电或放电。此外，直流母线电压的双模式控制允许从光伏阵列提取峰值功率，同时保持电网电能质量。所声称的好处是使用模拟和测试结果在不同的操作场景下进行评估的。