Design of a Bidirectional CL3C Full-Bridge Resonant Converter for Battery Energy Storage Systems

Abstract

In this study, a bidirectional CL3C full-bridge resonant converter was developed using a bidirectional active bridge converter as the main framework to improve conventional LLC resonant converters. A resonant inductor and resonant capacitor were installed at the secondary side of the developed resonant converter. The bidirectional operation of this converter enables zero-voltage switching at the supply-side power switch and zero-current switching at the load side. The aforementioned phenomena enhance the overall circuit efficiency and enable the resonant tank voltage to be increased in the reverse mode, which cannot be achieved with conventional bidirectional LLC resonant converters. The electrical equipment isolation function provided by a transformer made electricity usage safer, and digital control technology was adopted to control electrical energy conversion and simulate bidirectional energy conversion. Specifically, the experiment and simulation emulated how the developed converter enables energy transmission from a DC grid to a battery energy storage system through constant current–constant voltage charging and energy transmission from a battery energy storage system to a DC grid through constant power discharging.

A critical review on contemporary power electronics interface topologies to vehicle‐to‐grid technology: Prospects, challenges, and directions

“…These converters offer more advantages over non-isolated topologies, including HF operation, fewer component counts, soft switching, simple control, high efficiency, and elimination of the snubber circuitry [74]. The CLLC resonant converter [75] illustrated in Figure 17a is a favourable topology for BPT due to its high power density and high efficiency. This converter has two symmetrical FB structures, which are the primary inverter phase and the secondary rectifier phase, coupled by a symmetrical HFT.…”

A Control Design Technology of Isolated Bidirectional LLC Resonant Converter for Energy Storage System in DC Microgrid Applications

“…The backward boost discharge behavior belongs to the PWM duty cycle control for the pushpull converter designed to use one set of PWM3 channels containing two signals, PWM3H and PWM3L, which drives the primary-side switches S 5 and S 6 , respectively. According to the literature [30], since the voltage source is embedded in the DC grid, the converter will be unstable when the converter is controlled under the constant voltage output. Therefore, the discharge mode proposed in this paper sets the battery to be discharged in a constant current mode according to the battery voltage to avoid the battery discharging under a high current at a low state of charge (SOC), resulting in reducing the battery temperature and increasing the battery life.…”

A Comprehensive Review of Power Converters for E-Mobility

“…In this case, the LLC resonance circuit operates similarly to an LC series resonance circuit with a maximum voltage gain of one. As a result, ZCS is impeded at the rectifier side, lowering converter efficiency dramatically [77,78]. To address this issue, the full-bridge CLLC symmetric resonant circuit shown in Figure 7g is frequently used in bidirectional power flow applications.…”