Abstract In this paper, a combined water treatment system that uses both reverse osmosis process (R.O.) and evaporation-distillation process (E.D.) sequentially is studied. The electrical supply of the process is a 1.1 kW battery-less photovoltaic system. One major problem here is the system's inability due to start-up electric motors, which the largest one is an AC compressor. As a result, voltage of different parts of the system falls at compressor starting moment, leading to under-voltage lockout function to operate in power converters. This will make the power converter output shut down for a second. Eventually, the compressor will not start to run and the system may get totally unstable. This paper proposes a starting step-down power transformer to run the AC compressor, and pass the starting moment. The transformer turn ratio is determined so that the compressor start with the least possible voltage. This will prevent system instability and PV operating point hanging situation. After the start-up moment, a mechanical switch will trigger the compressor to the nominal voltage to reach the nominal torque and speed at steady state. The experimental results shows that using a starter transformer can effectively strict the compressor's inrush current and prevent the PV-based system instability.

中文翻译：

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在基于光伏的无电池蒸发蒸馏水处理系统中使用多绕组电源变压器限制交流压缩机启动电流

摘要 本文研究了一种依次采用反渗透工艺（RO）和蒸发蒸馏工艺（ED）的组合式水处理系统。该过程的电源是一个 1.1 千瓦的无电池光伏系统。这里的一个主要问题是系统由于启动电动机而无法启动，其中最大的一个是交流压缩机。结果，系统各部分的电压在压缩机启动瞬间下降，导致电源转换器中的欠压锁定功能运行。这将使电源转换器输出关闭一秒钟。最终，压缩机将无法启动，系统可能会变得完全不稳定。本文提出了一种启动降压电源变压器来运行交流压缩机，并通过启动时刻。确定变压器匝数比，以便压缩机以尽可能低的电压启动。这将防止系统不稳定和光伏工作点挂起的情况。启动瞬间后，机械开关将触发压缩机至额定电压，以达到稳态时的额定扭矩和速度。实验结果表明，使用起动变压器可以有效地限制压缩机的涌流，防止光伏系统不稳定。