Electric Locomotive Reactive Power Compensation And Harmonic Suppression System Design

As we all know, railway locomotive since its birth to the human economic development and social progress made tremendous contributions. Its main feature is greater traction, strong overload capacity, comply with environmental requirements, both to meet the heavy load freight, high-speed passenger and passenger-cargo transport requirements. At present, China's main line railway locomotive running most of the AC - DC Thyristor phase control electric locomotive, the locomotive with a large number of phase-controlled rectifier device is a major problem caused by the low power factor and harmonic interference . If we do not install power factor compensation device, allowing lower power factor and harmonic interference increases, it may direct result of the 25kV catenary serious distortion of voltage waveform.With the rapid development of power electronic devices, thyristors and power capacitor size is reduced, the performance continues to strengthen, we can consider using thyristor switched capacitor (TSC) technology and achieve the purpose of reactive power compensation on the spot. Using this scheme can achieve the filter and improve the power factor requirements, and can solve the fixed capacitor compensation equipment installed substation caused over compensation issues. Specific ideas in the locomotive by a certain mode of optimization, design multiple times or several times a filter, according to traction load changes, changes in compensation and efforts, so that power factor and harmonic content of the system can meet operational requirements.In this paper, for the 8-axis 6400kW electric locomotives designed a heavy electric locomotive dynamic reactive power compensation and harmonic suppression devices. The device is designed based on the hardware controller C8051F020 microcontroller, controller peripheral circuit and main circuit (filter) of three modules. Able to 1kV side traction for quick change, no impact, low loss of reactive power compensation.This paper also analyzes the principle of compensation device and the switching process, switching control, protection measures, the limits of compensation device working status, the compensation circuit fault causes and measures to be taken. Software design using half-wave Fourier algorithm, the average filtering, powerful protection and fault diagnosis module to improve the efficiency and safety of the device reliability. Finally, this device simulation, simulation results show that the device's power factor of electrified railway has greatly improved, and the 3rd and 5th harmonic has a good inhibitory effect.