A bidirectional DC/DC converter charge/discharge controller for solar energy illumination system integrating synchronous rectification SEPIC converter and active clamp flyback converter

Abstract

This paper presents a novel bidirectional DC-to-DC converter charge/discharge controller for solar energy illumination system. The bidirectional converter architecture integrates the synchronous rectification Single Ended Primary Inductor Converter (SEPIC) converter and an active clamp flyback converter. In addition to fully use the properties of the shared components and compensate for the shortcomings of conventional two-stage illumination systems, the proposed system has the advantages of soft-switching, simple structure, and high efficiency. During daytime, a SEPIC converter with synchronous rectification function was used to charge the lead acid battery through three-stage charging and maximum power point tracking. At night, the battery discharges, driving and dimming high-brightness LEDs using the active clamp flyback converter. Finally, a solar energy illumination system with both a 160 W charge/discharge controller and an 80 W LED driver was implemented to verify the feasibility and practicality of the proposed system. Figure 5. Operation principles of the synchronous rectification SEPIC converter: (a) operation mode 1, (b) operation mode 2, and (c) operation mode 3. DPDT, double-pole double-throw.Equation 13 describes the step-up mode when D > 0.5 and the step-down mode when D < 0.5. The range of V pv in the currently proposed system is 20-36 V, and the battery output is 24 V. 310 a. Conduction loss:Overall efficiency curve of the synchronous rectification SEPIC converter. Figure 15. V gs1 /V ds1 and V ds2 /V gs2 waveforms of S 1 and S 2 of the active clamp flyback converter. 26. Chen M, Rincon-Mora GA. Accurate electrical battery model capable of predicting runtime and I-V performance. IEEE Transactions on Energy Conversion 2006; 21 (2):504-511. 27. Oh IH. An analysis of current accuracies in peak and hysteretic current controlled power LED drivers.

A three‐level isolated dc‐dc SEPIC converter with parallel‐connected output

“…Converters derived from the single‐ended primary‐inductance converter (SEPIC) structure are widely used in renewable energies applications 3–7 . Other examples where the SEPIC is also used include power factor correction (PFC), 8–11 LED lighting drivers, 12–16 battery chargers 17–19 and DC microgrids 20 …”

“…Converters derived from the single-ended primary-inductance converter (SEPIC) structure are widely used in renewable energies applications. [3][4][5][6][7] Other examples where the SEPIC is also used include power factor correction (PFC), [8][9][10][11] LED lighting drivers, [12][13][14][15][16] battery chargers [17][18][19] and DC microgrids. 20 The SEPIC-type topologies present attractive characteristics when compared with other structures, including (i) continuous input current with low ripple; (ii) operation as a step-down/step-up voltage regulator without reversing the polarity of the output voltage, unlike the buck-boost, and Cùk converters; (iii) operating with a wide input voltage range due to step-up/step-down static gain; (iv) output voltage source characteristic, attractive for some applications;…”

A novel low‐loss control strategy for bidirectional DC–DC converter

“…To achieve ZVS in wide power range is a challenge because the optimization of RMS inductor current is difficult with ZVS condition [7,15]. Conduction losses are quite high even at light-load condition [18][19][20][21][22][23][24][25][26]. In this study, a state-of-the-art control scheme is proposed to meet all abovementioned requirements.…”

Analysis and implementation of a new zero current switching flyback inverter

“…[20][21][22][23] In these topologies, active clamp circuit absorbs the leakage inductance energy of the transformer and the primary switch turns on at zero voltage switching (ZVS) condition. An active clamp circuit is usually used in the flyback inverters.…”

“…An active clamp circuit is usually used in the flyback inverters. [20][21][22][23] In these topologies, active clamp circuit absorbs the leakage inductance energy of the transformer and the primary switch turns on at zero voltage switching (ZVS) condition. Although the switching losses and the voltage stress in the primary switch are mitigated with the active clamp approach, the additional switch used in the clamp circuit is usually switched at hard switching, and the main switch is turned off at hard switching too, which reduces efficiency especially at high switching frequencies.…”