CRH2 traction circuit of the main circuit 25

The main circuit system of CRH2 EMU is based on two cars and one unit of M1 car and M2 car. The power supply is connected by the pantograph with a line voltage of single-phase AC 25KV50Hz and the primary side winding of the traction transformer through VCB. The main circuit is opened and closed by a VCB.

A voltage of 1500V (25 kV on the primary side) is induced by the excitation of the two traction windings on the secondary side of the traction transformer and input into the rectifier part of the main converter under the excitation action of the primary winding. The M1 and M2 vehicles are each equipped with a main converter that provides power to the traction motor during traction operation and regenerative braking control during braking, as well as protection functions. In addition, based on the information from the vehicle information control device, the phase difference operation of the rectifier between carriers is carried out to reduce the higher harmonics of the catenary current.

The traction motor uses a 3-phase squirrel cage induction motor, and a speed sensor is provided at the shaft end for sending a speed sub-frequency signal to the main conversion device and brake control device. Auxiliary power supply system: The EMU has set up an auxiliary power supply device in the No. 1 and No. 8 cars.

Provide corresponding power supply for air compressors, lighting, control, broadcasting, train wireless and other equipment. Car No. 246 has a battery box for each of them.

I understand but I can't express it to you.

First of all, the equipment of the main circuit is composed of pantograph, lightning arrester, traction transformer, main conversion device (traction converter), traction motor, etc. The 4 and 6 cars of CRH2 EMUs are equipped with pantographs on the roof, and one of them is raised according to the different driving directions (double bows are generally prohibited in the state of a single train). The pantograph receives high-voltage electricity from the catenary, and the current is transmitted through the high-voltage cable to the traction transformer of the 2 cars (it should be 2 cars, I don't remember very clearly), and then through the converter, and finally input to the traction motor.

To put it simply, it is to control the speed and torque control of the traction motor through variable voltage and frequency conversion (VVVF technology). Of course, some circuits are used to supply electricity for lighting, air conditioning, and other systems. Let's start with that.

The main circuitry and control methods of Type 1 and Type 2 cars are completely different.

CRH1 outputs 700V from the main transformer and then outputs 1650V intermediate bus through a 2-level rectifier, from which the traction inverter and auxiliary inverter are de-energized. The auxiliary inverter outputs 3ac 380V to supply power to the charger module, and the charger module supplies power to the vehicle lighting and each control unit.

CRH2 outputs 3 channels of 1500V by the secondary transformer of the main transformer, and 2 channels through the three-level rectifier, and outputs the intermediate voltage of DC2600-3000V to supply power to the traction inverter, and one channel to supply power to the auxiliary inverter.