With the increasing switching frequencies and power densities in modern power converters, magnetic core losses are becoming more essential for efficiency and thermal optimization. Traditionally, the two-winding method suffers from sensitivity to phase error in practical measurements; this is mainly created by the unknown phase shift of a current-sensing resistor. Several methods have been developed to characterize the phase shift of a current shunt resistor; however, the load effects of oscilloscopes are ignored. As a result, the corresponding phase shift can be significantly underestimated. This paper proposes an improved method for phase shift extraction of a current shunt to solve the problem. The effectiveness of the shunt characterization method is experimentally verified up to 50 MHz. Benefits from the proposed method, the time-consuming component tuning process is not required for core loss measurement. A measurement verification at 10 MHz shows its validity. Finally, a current shunt implemented with a coaxial resistor array is designed with a phase shift of 0.05⁰ at 10 MHz and a parasitic inductance as low as 42 pH.
- Coaxial Resistor,
- Core Loss,
- Core Loss,
- Current Measurement,
- Current-To-Voltage Impedance,
- Impedance,
- Loss Measurement,
- Resistors,
- Transmission Line Measurements,
- Two-Port Resistor,
- Voltage Measurement
Available at: http://works.bepress.com/jun-fan/393/