Reduced-order model of a half-bridge series resonant inverter for power control in domestic induction heating applications

Abstract

Abstract--From the controller design framework, a simple analytical model that captures the dominant behavior in the range of interest is the optimal. When modeling resonant circuits, complex mathematical models are obtained. These high-order models are not the most suitable for controller design. Although some assumptions can be made for simplifying these models, variable frequency operation or load uncertainty can make these premises no longer valid. In this work, a systematic modeling order reduction technique, Slowly Varying Amplitude and Phase (SVAP), is considered for obtaining simpler analytical models of resonant inverters. SVAP gives identical results as the classical model-order residualization technique from automatic control theory. A slight modification of SVAP, Slowly Varying Amplitude Derivative and Phase (SVADP) is applied in this paper to obtain a better validity range. SVADP is validated for a half-bridge series resonant inverter (HBSRI) and for a highorder plant, a dual-half bridge series resonant inverter (DHBSRI) giving analytical second-order transfer functions for both topologies. Simulation and experimental results are provided to show the validity range of the reduced-order models.

Adaptive multi‐resolution framework for fast simulation of power electronic circuits

“…PCA has also been used in [16] to approximate the frequency response of a fourth‐order DC–DC converter by a second‐order system. Balanced truncation (BT) has been used in [17] to derive ROM for a half‐bridge series resonant inverter. Order reduction techniques have been applied to high‐fidelity magnetic equivalent circuits incorporating saturation, relative motion and multiple winding systems yielding efficient simulations [18].…”

Singular perturbation‐based model reduction of power electronic circuits

“…The frequency response of the fourth-order converter is approximated by a second-order system. The work in [18] focusses on deriving a reduced-order model of half-bridge series resonant inverters (HBSRI) for use in induction heating applications using balanced truncation. In [19], order reduction techniques are applied on high-fidelity magnetic equivalent circuits.…”

Reduced-Order Models of Series Resonant Inverters in Induction Heating Applications

“…The SVAP approach or similar techniques have been applied to mixed systems or converters operating in DCM where one variable can be considered static. Although after applying SVAP/residualization a valid low frequency HBSRI model is obtained [27], it is not formally valid to separate the dynamics of v c and i L because a HBSRI is not a mixed system. In order to improve the dynamic results, a SVADP technique is proposed in this paper.…”

“…In this paper, it's shown that residualization of series resonant capacitor voltage is identical to Slowly Varying Amplitude and Phase (SVAP) approach [22]. In order to provide better dynamic results than residualization in [27], a Slowly Varying Amplitude Derivative and Phase (SVADP) technique is proposed. The obtained results match with the ones recently published in [11] for a SRC.…”

“…This work is an extension of [27] where a reduced-order model of a HBSRI is obtained by residualization. This technique is a classical reduced-order modeling technique in automatic control systems [25].…”