Research On The New Arc-suppression Coil With The Function Of Auto-tracking And Auto-compensating

The Arc-suppression coil grounding manner of the distribution network is vital to the quality and reliability of the power supply, and it increases the security of the circulating network.The recent researches on arc-suppression coil at home and aboard are based on the compensation for the reactive currents, can not compensate for the active current in the single grounding fault current.In practical application, the grounding leakage conductance current of the cable network at the normal insulation has as 2 to 4 percents as that of the grounding capacitive current when it passes the single grounding fault point ignoring the influence of the zero-sequence active current. When the insulation system goes to ageing, the grounding leakage conduction current can amount to as 10 percents as that of the grounding capacitive current. The grounding capacitive current being too huge, the consideration of the absolute value of this part is necessitated.Utilizing the former research on the arc-suppression coil, this paper puts forward a new formula of the arc-suppression coil based on the principle of the controllable reactor, and verifies the validity of this new arc-suppression coil theoretically and in Matlab/Simulink simulation.Firstly, the port models of double-winding and multi-winding transformer is built and the practical principles of the double-winding reactor and multi-winding large-capacity reactor are discussed respectively. Then, the practical principle of the new arc- suppression coil with the function of auto-tracking and auto-compensating is derived and analyzed in detail. Simultaneously for the structure of arc-suppression coil in this paper, the principle of the grounding leaking conduction current based on poured into the signal method is derived exactly.Secondly, the controlling methods of the new arc-suppression coil with the function of auto-tracking and auto-compensating is studied. Combined with the whole-bridge converter of the structure of the new arc suppression, the hysteresis current control, the triangular-wave comparative current control and the current control technology in weekly sampling are analyzed. Simulated the above-mentioned technologies in the way of Matlab/Simulink respectively, the following and controlling rules of currents are figured out and the designing schemes of the hysteresis phase shift control current is put forward.Finally, the new arc-suppression coil system is modeled and simulated in Matlab/Simulink, and the validity of the principles of the new arc- suppression coil with the function of auto-tracking and auto-compensating is verified, that is, it can also compensate the resistive component of the current flowing towards single-phase earth fault point except the capacitive component. And at the same time, the effectiveness of following the primary side winding currents with the technology of current controlling in weekly sampling is verified.