380V digital isolated quasi-resonant multiphase converter for high power LED application

Saggini, S.; Rizzolatti, Roberto; Ursino, Mario; Zambetti, Osvaldo

doi:10.1109/apec.2018.8341601

Cited by 2 publications

(2 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this control scheme introduces a permanent error in the current sharing due to the response time of other converters [27]- [31]. On the other hand, the master-slave strategy has been proposed to interleave the LLC converters and tracking the master-unit frequency, improving the steady-state error of current sharing, but the control reliability is reduced due to complete dependence on the master control and the communication bus [15], [32]- [34]. Both control schemes use master or centralized controllers, which reduce the modularity and increase the complexity due to their coupled behavior, resulting in complicated tuning processes every time a parallel converter is added [8].…”

Section: Introductionmentioning

confidence: 99%

“…This paper presents a current sharing method using independent current loops for each LLC converter, which shows a suitable dynamic transition under variation of the reference current and the ability to compensate load disturbances. The proposed solution stands out for its simplicity, and as far as the authors know, it has not been addressed in other works, since there are other papers that use frequency control in LLC converters, but none of them perform it independently or analyze the circulating currents under independent modulations [15], [29]- [34].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Decoupled PI Controllers Based on Pulse-Frequency Modulation for Current Sharing in Multi-Phase LLC Resonant Converters

et al. 2021

View full text Add to dashboard Cite

The LLC series resonant converter has emerged as a solution to applications requiring power conversion with isolation, reduced volume and high efficiency, such as PV systems and EV chargers. However, the LLC resonant converter is limited in power, so it requires a multi-phase configuration in order to provide higher currents. This configuration connects the outputs of two or more LLC converters in parallel, increasing the output current but introducing imbalance and circulating currents due to the mismatch and tolerance values of components in each resonant tank. This paper proposes a simple PI control scheme to compensate the current imbalance and eliminate circulating currents generated when several LLC resonant converters are connected in parallel. Unlike reported current sharing methods, the proposed control scheme is based on multiple current control loops operating independently, using the switching frequency of each parallel-connected unit as a degree of freedom of the overall converter. The proposed control scheme has been successfully validated under simulations and experimental assessment, implementing two resonant tanks with ±5% tolerance of parameters, providing excellent steady-state and transient performance.

show abstract