An Improved Linear Model for High-Frequency Class-DE Resonant Converter Using the Generalized Averaging Modeling Technique

Abstract

As the operating frequency of power converters increases, the passive component values likewise decrease. This results in the effect of the parasitic components becoming more prominent, leading to significant modeling errors if not considered. For resonant converters this especially becomes a problem at high frequencies. This paper presents a reduced model for a class-DE series resonant converter based on generalized averaging that incorporates the relevant parasitics and uses multiple harmonics to obtain an accurate linear model. Comparison between the proposed model, prior art, and a prototype converter running at 1 MHz is conducted, and a PI-controller is designed based on each model and tested. The results show that the parasitics have a significant impact on the DC-gain and dynamics of the converter, and that the proposed model improves on the prior art by reducing the DC-gain error by more than 7 dB, and the error in the low frequency pole from 168 % to 16.9 %. Furthermore, the PI-controller designed on the prior art was found to have more than 40 times larger overshoot in the control signal when measured compared to the model prediction, while the controller based on the proposed model showed correct performance when simulated and measured.

Identification of ZVS Points and Bounded Low-Loss Operating Regions in a Class-D Resonant Converter

“…where θ = F 1 V sw . The switching node V sw is described by a piecewise function such that the charge and discharge of the output capacitance is included [28]. A result of this is that the phase of the Fourier approximation becomes non-zero.…”

“…These converters benefit from low device stress compared to other typologies like the class-E [4,18,19] and have a broad range of applicable controllers available. Some of the most common control techniques are: Tunable resonant tank capacitor control [20][21][22][23], bang-bang control [24][25][26][27], frequency modulation (FM) control [28][29][30][31], and lastly, phase-shift control [32,33]. Unlike any of the other control methods, the phase-shift control uses double the number of switches in the inverter to achieve phase-control, thereby making it less compelling if cost or power density is of concern.…”

A 1-MHz Resonant LED Driver With Charge-Pump-Based Power Factor Correction

“…That is shown by ( 9), ( 13), ( 28) and ( 29) for the resonant tanks components, as well as the input filter size when designed for a higher cross-over frequency. On the other hand, the size of C DC is dictated by the 50/60 Hz standard line frequency, as shown by (22). Therefore, the higher the switching frequency is, the higher the overall converter's power density.…”

“…That makes them a primary candidate for achieving high efficiencies at high frequencies, resulting in reduced sizes for the passive components and, therefore, higher power densities. In addition, high-frequency operation offers This has led to the investigation of their adoption into the converter stages in different applications [17], including the acdc [18]- [21] and the dc-dc [22]- [24] stages. One of such applications is the LED driver, where there is a high demand for small-size and compact solution for several applications, such as in-track LED drivers [25].…”

Modelagem Dinâmica de um Conversor CC-CC Duplo-Série Ressonante com Grampeamento Ativo

“…Em Tahavorgar and Quaicoe (2019) e Buccella et al (2015), a abordagem com a Série de Fourier trigonométrica é adotada. Em Dahl et al (2020), é utilizada a Série de Fourier complexa e o efeito da quantidade de coeficientes utilizados na aproximação das variáveis é investigado.…”