High Power Rectifier and Thyristor in Electric Train
- Rectifier electric train: as single phase-DC electric train, it’s the most widely used AC electric train. On the rectifier electric train, the single-phase high-voltage AC on the contact network is stepped down by the traction transformer at first, and then the single-phase AC is converted into DC by a rectifying device composed of silicon rectifier element or thyristor, and supplied to the traction motor. Perform phase control on the rectifier to change the rectified voltage in order to adjust the train speed.
- Single-phase commutator motor electric train: also known as direct AC electric train, single-phase commutator traction motor is applied. The high-voltage AC power on the contact network will be reduce the voltage by the transformer, then supplied to the traction motor directly.
- AC-DC-AC electric train: also known as single-phase-three-phase electric train. The high-voltage AC power on the contact network is first stepped down and rectified by the traction transformer, such to maintain the DC voltage or DC current of intermediate DC link is stable. Then, the inverter circuit converts the intermediate DC power into three-phase AC power and supplies it to the three-phase asynchronous traction motor or the three-phase synchronous traction motor. The output power and speed of the train can be adjusted by regulating the frequency and voltage of the three-phase alternating current by the inverter device.
- Rectifier device in traction substation: convert the electrical energy transported from the power transmission line into the power frequency, low frequency single-phase and power frequency three-phase AC power, and distributed to the corresponding contact network.