The Harmonically Partitioned Power Converter Architecture: Single-Stage Single-Phase ac/dc Power Conversion Using Bidirectional Switches

This paper proposes a novel single-stage single-phase ac/dc power conversion architecture called a harmonically partitioned power converter (HPPC). The HPPC leverages bidirectional switches (BDSs) to directly modulate the ac line voltage and enforces a harmonically partitioned loading network, resulting in automatic unity power factor, complete power pulsation decoupling, continuous gain variation, and galvanic isolation within a single conversion stage. This architecture provides a substantial opportunity for miniaturization and performance advances to all single-phase ac/dc power converters with power factor requirements on the ac port. The HPPC enables miniaturization by relegating all magnetic components to a high frequency ac tank and by operating the buffer capacitor at a port with no dc voltage regulation requirements. Further, the conversion is achieved in a single stage, eliminating the efficiency penalty traditionally suffered by single-phase ac/dc converters which achieve these functionalities via individual conversion stages processing the entire power throughput sequentially. The paper introduces the principle of operation of the HPPC, derives the high level governing equations of the architecture, and presents design equations for a simple “single-branch” implementation of the general architecture. An experimental prototype utilizing anti-series connected GaN HEMTs to emulate monolithic BDS devices is presented and validates the operating principles and modeling for a single-branch implementation with the following specifications: <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V_\rm {in}=120\rm {V_{rms}}$</tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm {f}_{g}=60Hz$</tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm {V_{o}}=250\rm {V_{dc}}$</tex-math></inline-formula>, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm {P_{o}}=250\rm {W}$</tex-math></inline-formula>, and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm {f}_\rm {HF}=210\rm {kHz}$</tex-math></inline-formula>.