Power estimation for dual half‐bridge inverter with common resonant capacitor

Abstract

Dual half-bridge inverter with common resonant capacitor is a cost-effective solution that is often used in induction heating appliances. In this topology, a simple and reliable calculation of the power supplied by both inverters would involve measuring the output voltages, both load currents and the resonant-capacitor voltage. This study presents a real-time implementation of two methods to calculate the output powers without measuring the voltage of the resonant capacitor. Simulations are performed to confirm the validity of the methods, which are also experimentally verified through a high-level synthesis implementation in a real prototype with a system-on-chip.

LLC Inverter Design Procedure for Induction Heating with Quantitative Analysis of Power Transfer

“…Where Z LCR (jω) is the equivalent impedance of two parallel branches, where L and R are in series in one branch, and C forms the other branch. From ( 4) and (7), capacitor voltage at series resonance (f 0 ) can be expressed as:…”

“…The resonant inverter is responsible for supplying a large current in the work-head, with a heating load being represented as a resistor R in series or parallel with the coil. A resonant circuit is a popular solution to implement zero voltage switching (ZVS) or zero current switching (ZCS), in order to reduce switching losses 6,7 . Series resonant circuits may be used for all-metal induction heating with adaptive control 8 or tundish induction heating with modular multilevel converter 9 .…”