Modified High-Efficiency LLC Converters With Two Split Resonant Branches for Wide Input-Voltage Range Applications

Sun, Wen; Xing, Yan; Wu, Hongfei; Ding, Jie

doi:10.1109/tpel.2017.2773484

Cited by 116 publications

(51 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The primary side voltage v Lr and current i Lr are derived the same as in (3) and (4). If the f sw is close to f r , the current variation ∆i Lm on the magnetizing inductor L m in steps 1 and 2 (about half of the switching period T sw /2) is approximately expressed by (13).…”

Section: Step 2 [T 1~t2 ]mentioning

confidence: 99%

“…On the primary side, the components L r , C r and L m are resonant with frequency f r2 = 1/2π (L m + L r )C r . If the f sw is close to f r , the current variation ∆i Lm on L m in Steps 4 and 5 is the same as in (13).…”

Section: Step 2 [T 1~t2 ]mentioning

confidence: 99%

“…The third solution is using single stage hybrid resonant circuit topology [12][13][14] as shown in Figure 1c. The wide voltage range resonant converter with full-bridge circuit (S 1~S4 are operation) or half-bridge (S 1 , S 2 and S 3 are operation) circuit topology used on the primary side [13,14] has been proposed to extend the input voltage range. The main advantage of the full-bridge and half-bridge resonant converter on the primary side is the wide input voltage range (v in,max = 4 v in,min ).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Resonant Converter with Voltage-Doubler Rectifier or Full-Bridge Rectifier for Wide-Output Voltage and High-Power Applications

Lin

Jian³

2018

Electronics

View full text Add to dashboard Cite

This paper presents a resonant converter with the benefits of wide output voltage, wide soft switching characteristics for power devices and high circuit efficiency. Since the series resonant circuit is adopted on the primary side, the power switches are turned on under zero voltage switching and power diodes on the secondary side can be turned off under zero current switching. To overcome the drawback of narrow voltage operation range in the conventional resonant converter, full-bridge rectifier and voltage-doubler rectifier topologies are employed on the secondary side for low-voltage output and high-voltage output applications. Therefore, the voltage rating of power devices on the secondary side is clamped at output voltage, rather than two times output voltage, in the center-tapped rectifier circuit. Synchronous power switches are used on the secondary side to further reduce the conduction losses so that the circuit efficiency can be further improved. To verify the theoretical analysis and circuit performance, a laboratory prototype with 1 kW rated power was built and tested.2 of 16 needed for EV and HEV applications or outdoor LED lighting systems with variable series or parallel combinations of LED strings. There are several solutions to overcome the challenges of wide input or output voltage range operation. First, the conventional full-bridge converter, as shown in Figure 1a, with wide duty cycle control can be adopted to achieve wide voltage operation. If the maximum duty cycle is four times the minimum duty cycle (d max = 4 d min ), then the output voltage of full-bridge converter is controlled at the constant value for 4:1 input voltage range (v max = 4 v min ). However, wide duty cycle operation will result in low circuit efficiency in cases of high input voltage and low duty cycle. The second solution to achieve wide voltage operation is using two-stage dc-dc converters, as shown in Figure 1b, such as buck or boost circuit and full-bridge circuit. Since two-stage circuits are used, the circuit efficiency is decreased and the circuit reliability is also reduced. The third solution is using single stage hybrid resonant circuit topology [12][13][14] as shown in Figure 1c. The wide voltage range resonant converter with full-bridge circuit (S 1~S4 are operation) or half-bridge (S 1 , S 2 and S 3 are operation) circuit topology used on the primary side [13,14] has been proposed to extend the input voltage range. The main advantage of the full-bridge and half-bridge resonant converter on the primary side is the wide input voltage range (v in,max = 4 v in,min ). However, there is a transient duration between the half-bridge resonant converter and the full-bridge resonant converter operation, and one power switch S 3 is always in the on-state under half-bridge resonant circuit, which will result in one more conduction loss on a powered device. The secondary side of the circuit topologies in Figure 1 is the center-tapped rectified circuit with two diodes to obtain low voltage output. If a wide output voltage i...

show abstract

Section: Step 2 [T 1~t2 ]mentioning

confidence: 99%

Section: Step 2 [T 1~t2 ]mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Resonant Converter with Voltage-Doubler Rectifier or Full-Bridge Rectifier for Wide-Output Voltage and High-Power Applications

Lin

Jian³

2018

Electronics

View full text Add to dashboard Cite

show abstract

“…On the other hand, the LLC resonant converter is also one choice for the isolated DC/DC converter, because it has good performance to reduce the switching losses utilizing Zero Voltage Switching (ZVS) and Zero Current Switching (ZCS) by series resonance [4][5][6][7][8][9]. In particular, the parasitic capacitor is discharged before being turned on by the negative current.…”

Section: Introductionmentioning

confidence: 99%

PV Micro-Inverter Topology Using LLC Resonant Converter

Watanabe

Itoh

Koike³

et al. 2019

Energies

View full text Add to dashboard Cite

In this paper, a DC–single-phase AC power converter with an LLC resonant converter is presented for a photovoltaic (PV) micro-inverter application. This application requires the leakage current suppression capability. Therefore, an isolated power converter is usually combined for DC/AC systems. The LLC resonant converter is the one of the isolated power converter topologies, and it has good performance for conversion efficiency with easy control. On the other hand, a double-line frequency power ripple has to be compensated for in order to improve the performance of the maximum power point tracking (MPPT). Therefore, a bulky electrolytic capacitor is usually necessary for the power converter. However, the electrolytic capacitor may limit the lifetime of the micro-inverter. This paper introduces the PV micro-inverter with a LLC resonant converter. In addition, the active power decoupling circuit is applied in order to compensate the double-line frequency power ripple by the small capacitor in order to eliminate the electrolytic capacitor. Finally, the transformer design is considered in order to reduce the transformer losses. As a result, the conversion efficiency of the LLC converter is improved by 1% when the litz wire has many strands.

show abstract

“…As a result, the voltage gain is enhanced, and Energies 2019, 12, 2905 3 of 25 the output voltage is kept steady. The literature [21] presents a DSBS LLC converter with two split resonant branches for wide input-range applications. Here, DSBS LLC converter represents the LLC converter with dual-bridge and two split resonant branches.…”

Section: Introductionmentioning

confidence: 99%

A Structure-Reconfigurable Soft-Switching DC-DC Converter for Wide-Range Applications

Huo

Liu

et al. 2019

Energies

View full text Add to dashboard Cite

In this paper, a structure-reconfigurable resonant DC-DC (direct current -direct current) converter is presented. By controlling the state of the auxiliary switch, the converter could change the resonant structure to acquire a high efficiency and wide voltage gain range simultaneously. The characteristics of the LLC (inductor-inductor-capacitor) resonant converter are firstly analyzed. Based on this, through introducing additional resonant elements and adopting the topology morphing method, the proposed converter can be formed. Moreover, a novel parameter selection method is discussed to satisfy both working states. Then, a detailed loss analysis calculation is conducted to determine the optimal switching point. In addition, an extra resonant zero point is generated by the topology itself, and the inherent over-current protection is guaranteed. Finally, a 500 W prototype is built to demonstrate the theoretical rationality. The output voltage is constant at 400 V even if the input voltage varies from 160 to 400 V. A peak efficiency of 97.2% is achieved.Energies 2019, 12, 2905 2 of 25 efficiency is another requirement to be met. To sum up, DC-DC converters with a high efficiency and wide voltage gain range have considerable research significance.Energies 2019, 12, x FOR PEER REVIEW 2 of 25 high conversion efficiency is another requirement to be met. To sum up, DC-DC converters with a high efficiency and wide voltage gain range have considerable research significance.

show abstract

Modified High-Efficiency LLC Converters With Two Split Resonant Branches for Wide Input-Voltage Range Applications

Cited by 116 publications

References 28 publications

Resonant Converter with Voltage-Doubler Rectifier or Full-Bridge Rectifier for Wide-Output Voltage and High-Power Applications

Resonant Converter with Voltage-Doubler Rectifier or Full-Bridge Rectifier for Wide-Output Voltage and High-Power Applications

PV Micro-Inverter Topology Using LLC Resonant Converter

A Structure-Reconfigurable Soft-Switching DC-DC Converter for Wide-Range Applications

Contact Info

Product

Resources

About