Why Choose The Overhead Variable Frequency Speed Control Electric Locomotive?

The trolley variable frequency speed regulating electric locomotive drives the wheels to rotate through the transmission device, thus tracting the train. The current from the motor flows back to the converter through the track. Overhead locomotive is a kind of electric current which is transferred to overhead by traction converter. It enters the electric circuit of the locomotive and the locomotive through the electrical appliances, and then returns to the converter through the track. There are 250V and 550V DC voltage of underground overhead power network in China, and 550V and 750V DC voltage in open air.

The trolley locomotive has the advantages of simple structure, low cost, convenient maintenance, large transportation capacity, high speed, high power efficiency, low transportation cost and wide application.

The positive pole of DC power supply is connected with overhead wire through power supply cable. During the period, the contact becomes the power supply point. The negative pole of DC power supply is connected with track through return cable. The corresponding contact point is called return point. When working, the upper part of the locomotive running along the track relies on the pantograph contacting the overhead line to obtain electric energy, while the lower part uses the wheel contacting with the track to form a loop to make the traction motor work, so that the locomotive can drive the mine car. Thus, the running track of the trolley locomotive is also the conductor of the current loop.

In order to reduce the voltage drop of traction power grid, conductors or copper sheets are usually used to connect the rail joints to reduce the resistance at the joints. During the working process of the overhead variable frequency speed regulating electric locomotive, the positive pole is connected to the overhead line and the negative pole is connected to the rails after the voltage is lowered and rectified by the high voltage AC traction converter. The pantograph on the locomotive contacts with the overhead line, introduces the current into the locomotive, and then enters the traction motor through the air automatic switch, controller and resistance box to drive the motor to run.

There are two main ways to improve the operation efficiency of VVVF electric locomotives for storage batteries.

1. Improve the running efficiency of AC locomotives by adjusting speed with frequency converter.
2. Use efficient motors. Therefore, specific to energy-saving equipment, the market scale of high-voltage converter and high-efficiency motor can not be underestimated.