Research On Stability Multi-pulse High Magnetic Field System Based On Freewheel Energy Storage

Repeated pulsed high flat-top magnetic field having a high magnetic field strength, flattened ripple coefficient is small, flattened continuously repeated and long-running, etc, which can be applied in the field of scientific research such as neutron diffraction and terahertz radiation, it is also have broad prospects applied in magnetic refrigeration and sewage treatment. better able to meet a number of scientific experiments for the increasing demands of the magnetic field, thus repeating flattened pulsed magnetic field will be one of a new direction for future research and development field. Based on the characteristics of a strong magnetic field pulse repetition flat top, and with the state pulsed magnetic field science center Huazhong University of Science and magnet current supply conditions, the selection pulse generator as a power source, focused on the actual circuit design repeat topping pulsed magnetic field generated specific implementation flattened field ripple control strategy and analysis and remote monitoring systems.Repeated topping pulsed magnetic field power supply system design, select high energy storage, good controllability 100 MVA / 185 MJ Pulse generator power supply, the series 12 pulse rectifier power supply system for long pulse magnet generating a magnetic field. And design of the inverter stage can be fed in to make up for the low efficiency of energy storage flywheel pulse generator disadvantage while improving the efficiency of energy use.Flat top magnetic field ripple analysis and control strategy research, according to magnet generator power characteristics and resistance fever model, the introduction of the first segment on the basis of the traditional PID control on the feed plus closed-loop control system to keep the feedback system overcomes of uncertain disturbance and controlled variable feedback test, reducing the overshoot while improving the tracking performance of the control system to increase the response speed and accuracy. Repeat pulsed magnetic field were calculated into the plateau phase of the initial firing angle and maintaining compensation flat top magnetic field firing angle. Repeat flat top so that a pulse magnetic field can be accurately reaches the set value of the magnetic field and the magnetic field quickly stabilized at a flat top.Repeated flat top pulse magnetic field remote monitoring system design, equipment and on-site analysis of the actual environment, using a remote control system based on OPC and Profibus_DP fieldbus. In MCGS for the PC monitoring software, PLC300 and PLC200 main slave controller in S7-300 and MCGS communication, using the OPC server as an intermediary platform to address the Siemens communication protocol does not open problem, and S7-300 between S7-200 Profibus_DP using fieldbus technology to achieve data sharing, build a control experiment platform. The realization of pulsed magnetic field device charge, excitation, discharge, release real-time monitoring and remote control of the operating state of energy and other work.After the final, in Matlab discharge circuit and associated control strategy simulation, debugging obtained through experiments 5T / 10 T / 15 T / 20T(80ms) stepped waveform flat top, repeat four flattened 20 T / 50 ms pulse magnetic field, flat field single thousandth ripple factor, the overall ripple coefficient thousandths prove the feasibility of the design, with practical engineering reference value.