• K.-B. Liu, K.T. Hsu, Y.D. Li, B.S. Wang
  NSRRC, Hsinchu
• J.C. Hsu
  CMS/ITRI, Hsinchu

Based on the requirement of beam stability for the third-generation synchrotron radiation light source is more stringent, lower ripple and higher bandwidth of output current of corrector magnet power converters should be developed to implement the closed orbit correction of Taiwan Photo Source (TPS). The ±10A/±50V corrector magnet power converter uses a full bridge configuration, the switching frequency of power MOSFET is 40 kHz, in that each bridge leg has its own independent PWM controller and the output current bandwidth is 1 kHz when connected with the corrector magnet load. Using a DCCT as the current feedback component the output current ripple of this converter could be lower than 5 ppm. In this paper, we will describe the hardware structure and control method of the corrector magnet power converter and the test results will be demonstrated.

• C.-Y. Liu, Y.D. Li
  NSRRC, Hsinchu

We design and implement a power convert to supply dc power bus for the MCOR30 correction supply. The dc power supply's characteristics were variable frequency at heavy and medium/light load. These characteristics matched with the correction supply working requirement. The dc power bus has a relaxation oscillator generating a symmetrical triangular waveform, which MOSFET's switching is locked to. The frequency of this waveform is related to a current that will be modulated by feedback circuitry. As a result, the tank circuit driven by half-bridge will be stimulated at a frequency dictated by the feedback loop to keep the output voltage regulated, thus exploiting its frequency-dependent transfer characteristics. The high performance characteristics of the resonant dc power bus are illustrated in this paper.

• K.-B. Liu, K.T. Hsu, Y.D. Li, B.S. Wang
  NSRRC, Hsinchu

The Taiwan Photon Source (TPS), a third-generation synchrotron radiation light source, should be installed with 1032 sets of magnet power supplies for the storage ring and 152 sets for the injector. All of the power supplies are preferred in PWM switched mode with IGBT or MOSFET. A high precision DC power supply for 48 dipoles of the storage ring; there are 240 quadrupole magnets and 168 sextupole magnets in storage ring, the main winding of quadrupole and 168 sextupole magnets are powered by individual power supplies. In the booster ring, one set of dynamic power supply for the dipole magnets and four sets for quadrupole magnets run at the biased 3Hz quasi sinusoidal wave. There are several hundred corrector (fast and slow) magnets and skew quadrupole magnets in storage ring and injector are powered by the same bipolar power converters.

• B.S. Wang, K.T. Hsu, Y.D. Li, K.-B. Lin, K.-B. Liu
  NSRRC, Hsinchu

This paper presents an implementation of a precision corrector magnet power converter using the digitally controlled pulse width modulation method. The output current precision of this ±10A/±50V corrector magnet power converter is within ±10ppm. The digital control circuit of the power converter is implemented with using a high speed ADS8382 18-bits analog-to-digital converter and a TMS320F28335 digital signal processor. The converter uses a full bridge configuration, the switching frequency of power MOSFET is 40 kHz and the control resolution is 17-bits. Using a DCCT as the current feedback component the output current ripple of this converter could be lower than 5 ppm that is beyond the requirement of TLS corrector power converter and suitable to be used in TPS.