scholarly journals Hybrid Resonant Converter with Three Half-Bridge Legs for Wide Voltage Operation

2019 ◽  
Vol 10 (1) ◽  
pp. 310 ◽  
Author(s):  
Bor-Ren Lin ◽  
Yong-Sheng Zhuang

This paper studied a hybrid resonant converter with three half bridge legs for wide input voltage operation. Compared to the conventional resonant converters with narrow voltage operation, the presented converter can achieve wider voltage operation. On the basis of the proper switching status of power switches, the developed converter can operate at half-bridge resonant circuit under high input voltage range and the other two full-bridge resonant circuits under medium and low input voltage ranges. Each resonant circuit has a 2:1 (Vin,max = 2Vin,min) input voltage operation range. Therefore, the developed converter can achieve an 8:1 (Vin,max = 8Vin,min) wide voltage operation. The main advantage of the studied converter is the single-stage direct current (DC)/DC power conversion instead of the two-stage power conversion to achieve wide voltage operation. Because the equivalent resonant tank of the adopted converter is controlled by frequency modulation, the soft switching operation on power switches or rectifier diodes can be realized to improve circuit efficiency. The performance of the proposed circuit was confirmed and verified by experiments with a laboratory circuit.

Energies ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 4095 ◽  
Author(s):  
Bor-Ren Lin

A new resonant converter is presented to have the advantages of soft switching operation on power devices, without reverse recovery current loss on power diodes and wide input voltage range operation. Resonant converter with frequency modulation is adopted in the proposed circuit to accomplish the low switching loss on power switches and possible zero current switching operation on fast recovery diodes. To improve the problem of limit voltage range operation in the conventional resonant converter, a new parallel-series structure resonant converter is studied to achieve wide input voltage operation capability, such as from Vin,min to 4Vin,min. A 1.8 kW laboratory circuit is implemented, and the measured results are provided to confirm the theoretical analysis and circuit performance.


Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1110
Author(s):  
Bor-Ren Lin ◽  
Alexis Phaik Imm Goh ◽  
Kai-Wei Wang

A DC-DC converter with a 16:1 (Vin,max = 16Vin,min) wide input voltage operation is presented for auxiliary power supplies on solar power conversion circuits or railway vehicles. The solar cell output voltage is associated with the solar intensity (day or night) and geographical location. Thus, the wide input voltage capability of DC converters is required for photovoltaic power conversion. For low power supplies on railway vehicles, the nominal input voltages are 24 V~110 V for the electric door system, motor drive, solid state lighting systems and braking systems. The presented converter uses buck/boost and resonant circuits to achieve the wide input voltage range operation from 18 V to 288 V. If Vin stays on a low input voltage range (18 V~72 V), the buck/boost circuit is operated at a voltage boost characteristic. On the other hand, the buck/boost circuit is operated at a voltage buck characteristic when the input voltage climbs to a high voltage range (72 V~288 V). Thus, the buck/boost circuit can output a constant voltage. Then, the resonant circuit in the second stage is worked at a constant input voltage case so that the frequency variation range is reduced. Finally, to investigate the performance and effectiveness of the studied circuit, experiments with a 500 W prototype were conducted to investigate the performance of the studied circuit.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2536
Author(s):  
Bor-Ren Lin ◽  
Yi-Kuan Lin

A full-bridge converter with an additional resonant circuit and variable secondary turns is presented and achieved to have soft-switching operation on active devices, wide voltage input operation and low freewheeling current loss. The resonant tank is linked to the lagging-leg of the full bridge pulse-width modulation converter to realize zero-voltage switching (ZVS) characteristic on the power switches. Therefore, the wide ZVS operation can be accomplished in the presented circuit over the whole input voltage range and output load. To overcome the wide voltage variation on renewable energy applications such as DC wind power and solar power conversion, two winding sets are used on the output-side of the proposed converter to obtain the different voltage gains. Therefore, the wide voltage input from 90 to 450 V (Vin,max = 5Vin,min) is implemented in the presented circuit. To further improve the freewheeling current loss issue in the conventional phase-shift pulse-width modulation converter, an auxiliary DC voltage generated from the resonant circuit is adopted to reduce this freewheeling current loss. Compared to the multi-stage DC converters with wide input voltage range operation, the proposed circuit has a low freewheeling current loss, low switching loss and a simple control algorithm. The studied circuit is tested and the experimental results are demonstrated to testify the performance of the resented circuit.


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 473 ◽  
Author(s):  
Bor-Ren Lin ◽  
Yen-Chun Liu

A hybrid PWM converter is proposed and investigated to realize the benefits of wide zero-voltage switching (ZVS) operation, wide voltage input operation, and low circulating current for direct current (DC) wind power conversion and solar PV power conversion applications. Compared to the drawbacks of high freewheeling current and hard switching operation of active devices at the lagging-leg of conventional full bridge PWM converter, a three-leg PWM converter is studied to have wide input-voltage operation (120–600 V). For low input-voltage condition (120–270 V), two-leg full bridge converter with lower transformer turns ratio is activated to control load voltage. For high input-voltage case (270–600 V), PWM converter with higher transformer turns ratio is operated to regulate load voltage. The LLC resonant converter is connecting to the lagging-leg switches in order to achieve wide load range of soft switching turn-on operation. The high conduction losses at the freewheeling state on conventional full bridge converter are overcome by connecting the output voltage of resonant converter to the output rectified terminal of full bridge converter. Hence, a 5:1 (600–120 V) hybrid converter is realized to have less circulating current loss, wide input-voltage operation and wide soft switching characteristics. An 800 W prototype is set up and tested to validate the converter effectiveness.


Most of the devices in power system become faulty due to the large content of harmonics present in voltage and current. It is mainly caused by the conduction losses in the system. At first, it is necessary to determine the extent of harmonic present by calculating the total harmonic distortions i.e., root over sum of the integral harmonics divide by fundamental harmonic. Later, identification of type of method for reducing harmonics is essential. In this project we are mainly focusing on two types of PFC bridge boost rectifier to improve the efficiency for low and high input voltage range. It using back to back bridgeless PFC boost rectifier for high input voltage and for low input voltage range, three level bridgeless boost rectifiers respectively. Fast recovery diode instead of normal diodes for better reliability and efficiency is utilized. The end model is obtained by combining two circuits BTBBL (Back to back bridgeless boost PFC) and TLBL (Three level bridgeless boost PFC) to get the FMBL (Flexible mode bridgeless boost PFC). Due to presence of less no of components, conduction losses are less hence less distortion is observed with improved efficiency. A simulation is carried out for all three models using MATLAB Simulink platform. In hardware, TLP250 driver for MOSFET is used and which is interfaced with PIC microcontroller. The hardware results are obtained that validates the simulation results.


Interleaved Boost Full Bridge integrated LLC resonant (IBFB- LLC) is an isolated DC/DC converter with directional power flow, which can cope with a wide input voltage range of PV applications. The main losses of the converter are switching losses of the power switches and transformers losses. This paper proposes a method to improve the efficiency of the IBFB converter due to zero voltage switching technique, in combination with employing new SiC MOSFET technology instead of the conventional Si MOSFET. In addition, Litz wire is also adopted to reduce the losses on the high frequency isolation transformer. Both numerical simulations and experiments with a prototype 2.5kW converter are implemented to verify the feasibility and effectiveness of the proposed solution.


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