Excitation on the use of semiconductor devices (electronic excitation ) of self-encouragement constant voltage generator , but to use quasi- year grid circuit . Capacity equal to two self-encouragement and constant voltage generator network should be outside the first two generating units characteristics ( terminal voltage and load curve ) and the prime mover ( internal combustion engine or turbine ) of the rate characteristics ( speed and load curve ) adjusted to as close as possible , needs to be two units of the excitation winding up with a balanced cable . Here are a network of semiconductor excitation generator and control circuit . Circuit works The semiconductor excitation generators and network control circuit shown in Figure 5-166 . Circuit , Gl is already running generator , G2 is a grid generator to be ; WEl and WE2 are Gl and G2 of the field windings . Button to stop and net s1 , s2 , and net control for the button , S3 for the control switch , RP for the excitation rheostat , KM for the contactor . PA to zero value for the excitation voltage meter ammeter LPV . HLl-HL3 for the same indicator . Grid before the first turn switch S3, the WEI and WE2 balanced link . When starting grid generators G2, to adjust its phase sequence , frequency and voltage , then the agreement with the Gl to HLl-HL3 are off , PV instructed to 0 , press the S2, so that KM pull power , its normally open contact Point KMl and KM2 connected , you can achieve two generating units and network . Components Selection KM choose coil voltage 380V AC contactor . s1 and s2 are chosen LAl8-22 -type spread compression button . s3 choose H210-10 / 2 type control switch . PV use 0-1OOV AC voltmeter . PA should be selected according to the power generator , lOkW generators can use 0-30A DC ammeter , 2OkW generators can use 0-50A DC ammeter , 4OkW generators can use 0-100A DC ammeter . Rp using the random variable resistor matching the magnetic field . HLl-HL3 220V lights are used .