The Design Of Dynamic Reactive Power Compensation For Power Supply Of Outsert Coil Of 40T Hybrid Magnet

High Steady magnetic field is a kind of extreme condition which is required by modern basic scientific research. At present, the 40T hybrid magnet has been finished by the high magnetic field laboratory of the Chinese Academy of Sciences.Its Magnetic field intensity ranks No.2 in the world. The hybrid magnet is consist of outsert coil and water-cooled inserts which is powered by separate power systems.The superconducting magnet power supply for outsert coil adopts double reverse-stars type of silicon controlled rectifier, which is a typical nonlinear load.While it is running, there will be a great deal of reactive power impact and harmonic pollution. The research is mainly about harmonic elimination and reactive power compensation.To begin with, the system structure of outsert power supply is introduced.According to actual field test, the parameters of each sub-system is calculated. In view of the rectifier may operate under various non-ideal situations, the common harmonics and non-characteristic harmonics are analyzed. Based on the operating data, the dynamic characteristics of the reactive power is studied. From the point of feedback control, the dynamic variation of reactive power which is caused by outsert power supply during the procedure of 50Hz harmonic suppression. The performance index of the compensators is confirmed.In this paper, three different compensatory method are compared, which gives the reason why the SVG method was selected. The shortcoming of conventional power theory is researched and the principle of the active compensator is explained,which provides the theoretical basis of the construction of the Flexible compensating device.From the point of realization of the compensator, the key technologies of the multi-level inverters SVG(Static Var Generator) is studied, which contain the main circle topology, the structure of AC filter, Voltage synchronization, current calculation, the design of digital filter and current feedback controller. The experimental prototype is developed whose test results showed that the SVG has good performance. In the end of this paper, the practical compensator is developed and equipped. The good performance of this device provide theory gist for the upgrading of the compensator of the 28MW power supply.