Measurement and Testing of the NSRRC Power Supply for Conduction EMI

Abstract

The correction power supplies are working in the Taiwan Photon Source (TPS) of NSRRC. They are required to output current at high quality and with high performance and that has long-term stability, with output current ripple required to be less than 10ppm. The TPS comprises more than 1200 units of independent power-supplymodules working together when the beam current is at3-GeV status. The power supplies are all working in current mode. We willplan to build a new measurement laboratory for conduction Electromagnetic Interference (EMI) to measure and to test the switching DC power bus thatfeeds the correction power supplies. We can get conduction electromagnetic interferencenoise from the measurement equipmentto measure the switching DC power bus is an AC-to-DC voltage bus source.With the LISN obtainingthe conduction noise, it is a high-frequency voltage noise generated by the switching mode of the power-supply conduction noise. The current signal passes an AC source-impedance stabilized network LISN, and a spectrum analyzer obtains the conduction noise. We use a noise separator to separate the common EMI noise and the difference-mode EMI noise for EMI filtering design. The measurement results are illustrated in this paper.