Separately excited DC motor controller for electrical vehicle - uses thyristor chopper circuit with motoring and braking control thyristors with single commutation circuit

摘要

The separately excited DC motor controller allows drive, regenerative braking, or rheostatic braking and also reverse direction operation under complete solid state control. The controller comprises a chopper circuit, able to operate in either step up or step down mode, and having an anti parallel thyristor pair (T9,T10) supplied through a capacitive divider (C1,C2) from the DC line and coupled to the junction between the cathode of the first principal (motoring) thyristor (T1), and the anode of the second principal (braking) thyristor (T2). The anti parallel pair (T9,T10) act as commutation thyristors for whichever of the two principal thyristors is operating. An electronic control circuit (E) drives the thyristor gates to ensure the required operation.