Periodically Swapping Modulation (PSM) Strategy for Three-Level (TL) DC/DC Converters With Balanced Switch Currents

Abstract

The asymmetrical modulation strategy is widely used in various types of three-level (TL) DC/DC converters, while the current imbalance among the power switches is one of the important issues. In this paper, a novel periodically swapping modulation (PSM) strategy is various types of TL DC/DC converters. In the proposed PSM strategy, the driving signals of the switch pairs are swapped periodically, which guarantees that the currents through the power switches are kept balanced in every two switching periods. Therefore, the proposed PSM strategy can effectively improve the reliability of the converter by balancing the power losses and thermal stresses among the power switches. The operation principle and performances of the proposed PSM strategy are analyzed in detail. Finally, the simulation and experimental results are presented to verify the proposed modulation strategy.

Triple-Phase-Shift Control Strategy for Full-Bridge Three-Level (FBTL) DC/DC Converter

“…If Vo ≥ Vin/2n, the ripple current on the output filter inductor namely Δ iLo can be calculated by (7). If Vo < Vin/2n, the ripple current on the output filter inductor can be calculated by (8).…”

“…The DC-DC converters aims to change the voltage levels for the DC applications [2][3][4][5]. Among various types of DC/DC converters, three-level (TL) based DC/DC converters are one of most attractive choices for high voltage applications because the voltage stress on the power switches in TL based DC/DC converters is only half of the input voltage (Vin/2) [6][7][8]. Normally, the full-bridge DC/DC converter is more suitable for higher power applications [9], [10] in comparison with the half-bridge DC/DC converter because of the current stress on the power switches in the full-bridge DC/DC converter is half of that in the half-bridge DC/DC converter.…”

“…According to (7), (8), and (9), the output filter inductance under the proposed TPS control strategy can be obtained by (10).…”

High Performance Flexible Structure Three-Level DC-DC Converter: A Candidate DC Interface for Microgrids With Distributed Energy Resources

“…With interleaving control strategy, a new inputparallel output parallel TL dc-dc converter achieves minimizing and balancing capacitor ripple currents, which may improve the expected lifetime of the DC link capacitors [14]. Other new interleaved PWM methods in [15]- [16] balance the voltage or current distributions in TL dc-dc converters. Reference [17] reported a high-efficiency TL dcdc converter with reduced circulating current and rectifier voltage stress.…”

A zero-voltage switching control strategy for dual half-bridge cascaded three-level DC/DC converter with balanced capacitor voltages

“…The TL circuit structure was first proposed for the DC/DC converter in [11]. Then many studies have been carried on the TL DC/DC converter [12][13][14][15]. Improving the power density and efficiency is one of the hot topics about the TL DC/DC converters.…”