| 摘要 |
<p>PURPOSE:To continuously control an electric rolling stock by the field current of a main motor and the control of the angle of the flow of a shunt thyristor, which has not a commutation device, by forming the shunt thyristor and a diode in a circuit arrangement combined with chopper controllers. CONSTITUTION:When a gate of a shunt thyrsistor DTh is provided with an ignition signal and conducted after time T1 from a point of the time of the starting of the conduction of chopper controllers CH1, CH2, and the gate is conducted during time T2, one portion (Mean value Iw) of the armature current Ia of a main motor flows through the shunt thyrsitor DTh as shunt current, field current If is If=Ia- Iw and the main motor is brought to a field-weakening condition. In this case, the conduction period T2 can also be controlled arbitrarily because time T1 can freely be controlled by the control of a point of the time of the whole arc of the shunt thyristor DTh, the mean value Iw of shunt current is proportional to T2/T and field-weakening (If=Ia-Iw) can continuously be controlled.</p> |
