ON Effect of Right-Half-Plane Zero Present in Buck Converters With Input Current Source in Wireless Power Receiver Systems

Abstract

In wireless power receiver systems, the buck converter is widely used to step down the higher rectified voltage derived from the wireless receiver coil, to a lower output voltage for the immediate battery charging process. In this work, the presence and effect of the right-half-plane (RHP) zeros found in the smallsignal inductor-current-to-duty-ratio and output-voltage-to-dutyratio transfer functions of the buck converter in the wireless power receiver system on the control performance, are investigated. It is found and mathematically proved that the RHP zeros are introduced by the current source nature of the system attributed to the series-series compensation and finite DC-link capacitance. The RHP zero not only results in non-monotonic open-loop dynamic response but also complicates the design of feedback control and causes potential closed-loop instability. Theoretical and experimental results are provided to validate the presence of the RHP zeros and their effect on open-loop and closed-loop dynamic responses.

A three‐level isolated dc‐dc SEPIC converter with parallel‐connected output

“…The output voltage‐oriented control model is a first‐order transfer function without right‐half‐plane (RHP) zero. RHP zero appears in the model of many converters operating in continuous conduction mode (CCM) and may show instability 34 . Regarding the inductance values, they are lower in DCM, particularly the value of the magnetizing inductance from the coupled inductors, when compared with operation in CCM.…”

“…RHP zero appears in the model of many converters operating in continuous conduction mode (CCM) and may show instability. 34 Regarding the inductance values, they are lower in DCM, particularly the value of the magnetizing inductance from the coupled inductors, when compared with operation in CCM. With lower inductances, the weight and volume of the converter are reduced.…”