The rapid development of rail transport industryWith continuous development of economic in China, the level of industrialization, urbanization, ecological environment and living standard in China, will be to enhance entirely. The inter-regional economic exchanges and cooperation will be strengthened further. To meet the growing demand of passenger and freight, the scale of transport infrastructure and equipment needs a rapid development. Therefore, it is the critical period for the rapid development of the rail transportation. The development of socio-economic, has brought unlimited opportunities for construction of rail transportation. However, there are enormous challenges that the entire industry is facing, such as how to build a safe, comfortable, convenient, smooth, efficient, environmentally friendly, sustainable, diversified integrated transport system, and how to promote regional economic exchanges and development to meet the requirements of the development of a comprehensive well-off society.Reactive power compensation and harmonic suppression projects of a subway project There are 28underground stations,5 ground stations, 28 traction substations, 33 step-down substation, two car parks, a control center.The requirements of reactive power compensation of this project is achieving the set of power factor and suppress the occurrence of resonance phenomena with the auto-switching power capacitor bank for reactive power compensation system. To ensure the safe and effective operation of the power supply system in subway, reactive power compensation device of low voltage must meet the conditions of the subway environment. Technology should be advanced, and production technology is mature and reliable. And they should be compact, easy to install and maintain.The requirement of the project is that low-voltage active filter should be enclosed indoor equipment, with its function for dynamic harmonic suppression and reactive power compensation. And it can the compensation for the harmonics of changing the size and frequency and the changing reactive power. To ensure the safe and effective operation of the power supply system in subway, active filter device of low voltage must meet the conditions of the subway environment. Technology should be advanced, and production technology is mature and reliable. And they should be compact, easy to install and maintain.Scheme of reactive power compensation A total of 124 units of reactive power compensation panel are supplied by AKSON for this project. According to system load and harmonic characteristics, the following schemes for reactive compensation are provided by AKSON.The program consists of power module (capacitors and reactors), the control module (power factor controller and contactors for switching capacitor), as well as the protection device (fuse)

etc.

■ Reactive power compensation device, which can be automatic or manual control, has the protection function of short-circuit, over voltage, under voltage, overheating and harmonic distortion.

■ Remote communication interfaces, which can meet the requirements of the rail transit power supply system power monitoring function.

■ 7% electric reactor is in series with the device, which can effectively avoid harmonic generation 5 times or more.

■ Capacitors with the 480V voltage levels, which is enough to withstand the grid fundamental and harmonic overvoltage.