STATCOM will be utilized in the night for power factor correction and voltage control at the terminals of an induction motor operating at poor power factor. PV solar farms produce power during the day and are completely idle in the nights. The proposed new control on PV solar system will help in increase the utilization of the PV solar system. A key component of the PV solar plant is a voltage source converter which is also a core element of STATCOM. Using this fact we present a simple open-loop control method of using PV solar plant as STATCOM, in dark periods without sunlight, for load reactive power compensation and voltage control. PV system inverter control is not suitable for night time. Improvement of

power factor leading to decrease the continuous load KVA load demand and reduction in the line losses

The project of 20MW photovoltaic is located in the city of Geermu in Qinghai Haixi, and the power station has passed all acceptances and achieved parallel running successfully.

The site configuration is 5Mvar Statcom(FGSVG-C5.0/35T) with Transformer type, running well.

Figure1 Single Line Diagram in plant

After commisioning, the datas of the waveforms and response time test are as follows,

Figure2 Geermu field Figure                 3 Parallel running waveform Figure4 Response time test

A normal solar plant remains idle when sunlight is not good. Voltage source inverter is a key component of both solar plant and STATCOM. Hence solar plant is used as STATCOM during dark periods to improve voltage regulation and power factor. Due to improvement in power factor load current reduces. Also the system remains balanced with better efficiency and less transmission losses. Simulated distribution system’s results validate these points. Hence the power quality and electrical performance of the distribution system is improved.