A dual pulse modulated five-element multi-resonant DC-DC converter and its performance evaluations

Abstract

A five-element multi-resonant (LLC − LC) dc-dc converter can attain the wide range output power and voltage regulations by a practical-range pulse frequency modulation (PFM). It is a drawback, however, the power conversion efficiency deteriorates under the light load condition due to the conduction power loss in the LC anti-resonant circuit. As a solution to this technical problem, the pulse density modulation (PDM) is applied to the LLC −LC dc-dc converter as the submode power regulation scheme. In this paper, the essential performances of the new prototype of the PFM/PDM dual mode controlled LLC − LC dcdc converter are presented with the experimental verification. The comparison between the LLC − LC dc-dc converter and the conventional LLC dc-dc converter is described in terms of efficiency as well as output voltage and power regulations characteristics, and the effectiveness of the LLC − LC dc-dc converter is evaluated from a practical point of view. I. INTRODUCTIONAn LLC dc-dc converter utilizing parasitic parameters in the high-frequency (HF) transformer has excellent characteristics of a low EMI noise, soft-switching operations over the widerange output power variations, and high efficiency [1]-[5].One of the practical applications of the LLC dc-dc converters could be the front-end dc-dc converter in a plasma radio frequency (RF) power generator for semiconductor manufacturing machinery. Fig.1(a) and (b) illustrate the typical electric power conversion process of the plasma power generator. The plasma chamber has a wide range of load power variations, thereby the wide-range output power and voltage regulations are demanded for its power converters, especially in the frontend dc-dc converter.The conventional concept of the power conversion scheme for the wide-range voltage and power regulations consists of the two-stage power conversion [6]. The first stage of this power processing is the buck-boost dc-dc converter which regulates the dc voltage and power by pulse-amplitudemodulation (PAM). This power converter is followed by a HF-link dc-dc converter operating as the electric transformer. Although the power factor correction can be ensured together with PAM, the power conversion efficiency might be degraded in the light load condition due to the number of circuit components, which is also another disadvantage with respect to cost effectiveness.

A Five‐Element Multiplex Resonant Full‐Bridge DC‐DC Converter with a Variable Inductive Reactance

“…Based on the results of the power loss analysis, we confirmed that the turn‐off loss from a heavy load to a light load is recued due to the effects of ZVS in the active switch on the primary side, and moreover, the turn‐off loss due to the reverse recovery current could be suppressed because ZCS was enabled during normal operation in the diode on the secondary side. Furthermore, because the output conditions are all in the ZVS area1 region, the proportion of the antiresonant tank conductive loss is relatively small compared to the total loss in the circuit .…”

“…Figure shows the circuit configuration of the LLCLC DC‐DC converter using a LC antiresonant tank in the full‐bridge inverter on the primary side of the HF transformer as a method to improve sensitivity with respect PFM in the LLC DC‐DC converter . Here, the series resonant tank impedance Z s and the antiresonant tank impedance Z p (the admittance Y p ) are given by …”

“…As a result, the input voltage V m is directly applied to the L s -C s series resonant tank, a low impedance state during startup or a load short, and excessive voltage stress is induced in L s and C s as the operating current rises. Figure 4 shows the circuit configuration of the LL-CLC DC-DC converter using a LC antiresonant tank in the full-bridge inverter on the primary side of the HF transformer as a method to improve sensitivity with respect PFM in the LLC DC-DC converter [15][16][17][18][19]. Here, the series resonant tank impedance Z s and the antiresonant tank impedance Z p (the admittance Y p ) are given by In the multiplex resonant DC-DC converter, by taking advantage of the principle that the antiresonant impedance Z p is in theory infinitely large (Y p is zero) when the operating frequency f s reaches the antiresonant frequency f rp , the voltage stress on the series resonant tank and the occurrence of overvoltage with respect to load short phenomena can be suppressed.…”

Resonant Power Converters: An Overview with Multiple Elements in the Resonant Tank Network

“…Multielement RPCs combine all the properties of the RPC topologies of lower order, absorbing all the parasitic elements and enabling operation with low switching losses at high switching frequencies. Analyses of multielement resonant converters are documented in [87]- [89]. A review of multielement resonant converters is in [90], and a comparison of different topologies of multielement RPCs is presented in [91].…”

A Sensitivity-Improved PFM <italic>LLC</italic> Resonant Full-Bridge DC–DC Converter With <italic> LC</italic> Antiresonant Circuitry

“…As a more advantageous solution for the OCP, the antiresonant circuitry-applied dc-dc converter has been proposed in [20]- [25]. Among those literatures, an LLC asymmetrical half-bridge dc-dc converter with a notch filter has been reported in [20].…”