by voltage detection component is converted into digital signal;
and the digital voltage signal can be processed by SCM chip.
SCM chip controls the close or open of contactor drive circuit.
Besides, it controls the turn-on and turn-off of thyristors.
3) Wye soft switching component, which is composed of a
silicon controlled rectifier (SCR1) and contactor (KM1) in
series, is connected with stator three-phase windings in wye
form.
4) Wye-delta soft transform component, which consists of
a silicon controlled rectifier (SCR2) and contactor (KM2) in
series, is connected with stator three-phase windings in delta
form.
5) Other components and wiring of main circuit include air
switch QF connecting the power supply and the controlled
motor, all the wirings between wye soft switching component
and wye-delta soft transform component, and wirings of
secondary control loop.