500kW及以下的农村小水电站,一般采用10kV线路并网,并网线路又长,造成线路电压降较大。在夜间负荷低谷时,电站电压往往高于额定电压,有时单相电压高达260V,电站厂房照明灯泡经常烧坏。我们采用一只双向晶闸管(可控硅)控制厂房照明灯,使照明电压任意调节,既为电站节省了一笔费用开支,又减少了常换灯泡的麻烦,电路接线如图。KS为双向晶闸管。工作过程:接入单相交流电路,电流经RP、R_1向C_1充电, Rural small hydropower stations with a capacity of 500 kW or below generally use 10 kV lines for grid connection, and the length of the grid connection is long, resulting in a large voltage drop. At night when the load is low, the plant voltage is often higher than the rated voltage, sometimes the single-phase voltage is as high as 260V, and the power plant lighting bulb is often burned out. We use a two-way thyristor (SCR) to control the plant lighting, so that the lighting voltage is arbitrarily adjusted, which not only saves a cost for the power plant, but also reduces the trouble of changing the light bulb. The circuit wiring is shown in the figure. KS is a bidirectional thyristor. Work process: access to single-phase AC circuit, the current through the RP, R_1 charge to C_1,