High-Frequency Conditioning Circuits for Power-Related Information Extraction in Non-Sinusoidal Power Electronic Systems

Power electronic converters often have non-sinusoidal voltages and/or currents but must perform calculations on individual harmonics of those waveforms, particularly the fundamental. If these calculations must be done online, then rapidly sampling the waveform and performing a Fast Fourier Transform is often unfeasible in terms of cost and power consumption.One example scenario is the control of multi-port DC-DC converters to achieve low rms current, soft switching, and regulation, which is an analytically and computationally difficult task. Prior work has emphasized offline optimization because computational burden of online computations can be high. To address this challenge, control based on real-time measurements of port power at the fundamental frequency has been developed, which uses closed-loop control to minimize rms current with a very low computational burden. The key to this approach, and other design scenarios, is a circuit to compute the power at the fundamental frequency alone.This paper presents high-frequency conditioning circuits to measure port real and reactive power at the fundamental switching frequency, despite highly non-sinusoidal waveforms, to enable the online control technique mentioned and other scenarios with similar requirements. Test results show that the proposed circuit functions fast and produces accurate measurements. Generally, the conditioning circuits can be implemented in any non-sinusoidal power electronic systems where magnitude or phase information is required at frequencies up to several MHz.