Application Of Frequency Conversion Energy Saving Technology In Electric Locomotive Industry

In recent years, the application range of up-conversion energy-saving technology for electric locomotives has become wider and wider. Various mining equipment control systems such as ground and underground lifting, ventilation, coal mining, transportation, and coal preparation in mining areas have been widely used, and have good reference value for domestic counterparts.

Special functions of frequency conversion speed control of hoist for electric locomotive are as follows:

1. The role of DC braking.
When the heavy truck needs to stop in the middle of the wellbore, the inverter is smoothly reduced from high speed to low speed, and then a DC braking signal is applied to stop the hoist. The DC braking signal can be removed after the mechanical braking is activated, so that the heavy truck can lean The role of the mechanical brake is stopped in the middle. When starting, a DC braking signal is applied to the motor. When the opening of the mechanical brake is detected, the DC braking signal can be removed. The starting voltage is added and the hoist rotates. The holding state of the mechanical holding brake is always detected by the inverter. Once the mechanical holding brake is opened, a DC braking signal is applied to the motor to ensure that the heavy vehicle "slipping" phenomenon is avoided.

2. S-shaped speed curve.
In order to reduce the mechanical impact of the operation, it is best to make the acceleration continuous during the start and stop of the inverter, that is, the S-shaped acceleration and deceleration curve. When the inclination of the underground and wellhead parking is very small, it is required that the operating speed of the hoist is very low, otherwise the "loosening" phenomenon will occur. In addition, the wellbore channel requires that the frequency converter can work at different frequencies. According to the situation on the site, the inverter can set 5 frequency bands. Different positions of the master controller correspond to different DC control voltages, that is, different operating frequencies.

3. Automatic speed limit protection.
When the operation is nearing the end point, a deceleration signal is given. After receiving this deceleration signal, if the master controller has operated the deceleration, the inverter will change the running speed according to the operation of the master controller; The inverter does not operate normally, it will automatically start the automatic deceleration program in the machine, and gradually change the operating frequency of the inverter to low speed operation according to predetermined requirements. This is necessary to prevent "over-rolling". In addition, when the hoist is equipped with a speed measuring generator to give an overspeed signal, the frequency converter can also automatically decelerate.

4. Chain start function.
The battery locomotive hoist must be started according to the given command. When the "up" or "down" command is given, if the personnel operation does not match the command, the interlock function will not respond to this operation and the inverter will not start. Chain function is an important measure to ensure safe operation.

5. Treatment of regenerative energy.
The main circuit of the battery locomotive inverter uses a two-way inverter scheme.