| Controllable reactors have wide applications and good performance, and they are applied in high-voltage distribution network and reactive power compensation system to improve the power reliability. Among them, Magnetic Valve Controllable Reactor (MVCR) has many advantages such as low cost, highly dependability and small harmonic. It can be used in distribution network of neutral earthing via arc suppression coil, and this mode can improve the power supply reliability and security. So MVCR has a good significance of theoretical research and practical application value.Firstly, this paper introduces the configuration and operating principle of the MVCR. The electromagnetic equations are derived, and the conversion of different states is analyzed in depth. The engineering design and electromagnetic calculation of the MVCR are researched. Special emphasis is placed on the selection and calculation of the iron core, windings and magnetic valve. On this basis, the electromagnetic parameters of a single phase 20kVar,0.4kV reactor is designed, and the prototype machine is produced. According to the equivalent electric circuit of the MVCR, a model of the MVCR is set up and simulated in MATLAB. The operating characteristics of the MVCR prototype are analyzed based on simulation and experiment results.Secondly, this paper analysis the characteristics of the neutral earthing system via arc suppression coi, as well as compensation principle of arc suppression coil when the single-phase earth fault occurs. Several common arc suppression coils are enumerated, and their characteristics are analyzed. Based on above fundamental research, this paper presents an improved method according to the defaults of arc suppression coil with variable tuning capacitors. Namely the MVCR is in parallel with the arc suppression coil with variable tuning capacitors. Then a novel arc suppression coil is formed. It can resolve the problems of impulse current and waveform distortion as capacitors switching, and its equivalent reactance value can also be continuously and smoothly adjusted.At last, according to the 10kV,290kVar novel arc suppression coil with variable tuning capacitors, a compensation system is designed and simulated in MATLAB software. The simulation results verify the advantages of the novel arc suppression coil with variable tuning capacitors. |
