Research Of A New Neutral Grounded Method And Its Implementation Technique

The Arc-suppression coil grounding manner of the medium voltage(MV) network is vital to the quality and reliability of the power supply,and it increases the security of the circulating network. Through analyzing the characteristics of the existing grounded neutral style in MV network, this paper puts forward a new neutral grounded style which is multi-tap Arc-suppression coil paralleling electric resistance grounded neutral style. This neutral grounded style not only can limit the linear resonance excessive voltage in network normal running, but also can suppress fault recovery voltage, avoid restrike of arc, and provide active power to select the fault line in single-phase-to earth situation. Based on the performance of this neutral grounded style, this paper presents a new tuning algorithm named gearing and checking phase method. Compare to the traditional two-point algorithm, this algorithm solves the Arc-suppression coil's frequent movement. The massive digital simulation result indicated that this neutral grounded style not only retain the advantage of the multi-tap Arc-suppression coil, but also make selecting the fault line easy, the structure of the complete set simple, and setting facilitative; and the new tuning method can calculate the capacitance current accurately.In this paper, the complete set of automatic tracking and compensating Arc-suppression coil is designed, and the coupled controller is developed. The controller uses the embedded industrial computer, its function units are designed in modular way and it greatly reduces the device's volume. It can resist high temperature, damp, electromagnetism interfere, fly ashes etc. The automatic compensating device's monitoring program is also programmed in modular way, and it is running under the DOS operation system. The controller not only can be operated easily and neatly, but also it has an amity interface and a high practicability. The complete set is about to pilot run.