Design of Controller for New EAST Fast Control Power Supply

The effectiveness of the magnetic confinement of plasma can be improved by elongat- ing the plasma cross-section in tokamak devices. But elongated plasma has vertical displacement instability, so a feedback control system is needed to restrain the plasma＇s vertical displacement. A fast control power supply is needed to excite the active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, the fast control power supply needs to keep on enhancing the fast response and output current. The structure of a new power supply is introduced in this paper. The method of multiple inverters paralleled with the current sharing reactor is presented to meet the need for large current and fast control. According to the design demands of the EAST fast control power supply, the adjuster of the current close loop is applied to the inverter, which can advance its ability to restrain the loop current in low frequency and DC output. The result of the experiment confirms the validity of the proposed scheme and control strategy.

Application of a Current and Voltage Mixed Control Mode for the New Fast Control Power Supply at EAST

A feedback control system is needed to restrain plasma vertical displacement in EAST （Experimental Advanced Superconducting Toknmak）. A fast control power supply excites active feedback coils, which produces a magnetic field to control the plasma＇s displacement. With the development of EAST, new demands on the new fast control power supply have led to an enhanced ability of fast response and output current, as well as a new control mode. The structure of cascaded and paralleled H-bridges can meet the demand of extended capacity, and digital control can reMize current and voltage mixed control mode. The validity of the proposed scheme is confirmed by experiments.

Study of the EAST Fast Control Power Supply Based on Carrier Phase-Shift PWM

EAST （experimental advanced superconducting tokamak） fast control power supply is a high-capacity single-phase AC/DC/AC inverter power supply, which traces the displacement signal of plasma, and excites coils in a vacuum vessel to produce a magnetic field that realizes plasma stabilization. To meet the requirements of a large current and fast response, the multi- ple structure of the carrier phase-shift three-level inverter is presented, which realizes parallelled multi-inverters, raises the equivalent switching frequency of the inverters and improves the per- formance of output waves. In this work the design scheme is analyzed, and the output harmonic characteristic of parallel inverters is studied. The simulation and experimental results confirm that the scheme and control strategy is valid. The power supply system can supply a large current, and has a perfect performance on harmonic features as well as the ability of a fast response.

A Universal Portable Appliance for Stellarator W7-X Power Supply Controlling

In the project Wendelstein 7-X (W7-X), the popular fieldbus Profibus has been determined as a uniform connection between the central control system and all the subordinate systems. A universal embedded control system has been developed for W7-X power supply controlling. Siemens 80C167CR microcontroller is used as the central control unit of the system. With a user-defined printed circuit board (PCB) several control buses, i.e., Profibus, CAN, IEEE 488, RS485 and RS 232 have been connected to the microcontroller. The corresponding hardware interfaces for the control buses have been designed. A graphic liquid crystal display(LCD) and a user-defined keyboard are used as user interface. The control software will be developed with a C-like language, i.e., C166 for the controller.

Design and Simulation of a Electrorheological(ER) Control High Voltage Power Supply

Few applications with electrorheological （ER） fluids have been found in industry. One reason is high voltage power supplies cannot meet the requirement for ER effect. In this paper, an ER control high voltage power supply for engineering application was designed which reduced power wastage by adopting soft switch technology; lessened its volume to satisfy micromation when adopting the planar transformer and improved its response character- istic by choosing an assistant discharging circuit. Simultaneously, a simulation analysis has been carried out. As results, the output voltage of this high voltage power supply is 5 kV, and the voltage can be continuously regulated and the voltage ripple is only 0. 7 %, so the requirement of stability is also achieved.

Research on the application of digital power supply based on domestic FPGA

Purpose The digital controller for the accelerator magnet power supply typically employs a field-programmable gate array(FPGA)as the signal processing chip for executing digital processing of closed-loop control.Currently,FPGA chips are predominantly utilized in Intel or Xilinx products.To address the“key areas and stranglehold”issue pertaining to FPGA chips in accelerator power supply,we have devised a digital power supply prototype using a domestic FPGA chip and validated its feasibility in the upgrade project’s magnet power supply digital transformation plan for the Beijing Electron Positron Collider(BEPCII).Method A domestic FPGA chip from the Seal5000 SA5Z-30-D1 series by Xi’an ZhiDuoJing Microelectronics Co.serves as the core component for the design of a digital corrector magnet power supply to replace the existing analog controlled corrector power supply at BEPCII.The power supply’s digital control of the closed loop is achieved through the use of a hardware description language,and the digital controller hardware is constructed based on the original power supply power topology.Results and conclusions After conducting experiments and tests on the power supply prototype,we have successfully met the current operational requirements of the BEPCII corrector power supply,thus confirming the feasibility of utilizing domestic FPGA for digital application on accelerator power supply.

Control application of a superconducting magnet power supply based on EPICS

The superconducting quadrupole magnets （SCQs） are powered by 16 power supplies in the inter- action region of the BEPC Ⅱ. The control application of these power supplies must be interlocked with the quench protection system to protect the superconducting magnet and relevant devices. This paper describes the development procedures of this control application using EPICS and the operating result with the quench protection system on-site.