• Title/Summary/Keyword: Bidirectional DC-DC Converter(BDC)

Search Result 8, Processing Time 0.02 seconds

A 3 kW Bidirectional DC-DC Converter for Electric Vehicles

  • Ansari, Arsalan;Cheng, Puyang;Kim, Hee-Jun
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.4
    • /
    • pp.860-868
    • /
    • 2016
  • A bidirectional DC-DC converter (BDC) is an indispensable electrical unit for the electric vehicles (EVs). High efficiency, high power density, isolation, light weight and reliability are all essential requirements for BDC. In this paper, a 3 kW BDC for the battery charger of EVs is proposed. The proposed converter consists of a half-bridge structure on the primary side and an isolation transformer and a synchronous rectifier structure on the secondary side. With this topology, minimum number of switching devices are required for bidirectional power flow between the two dc buses of EVs. The easy implementation of the synchronous rectification gives advantages in terms of efficiency, cost and flexibility. The proposed BDC achieves high efficiency when operating in both modes (step-up and step-down). A 3 kW prototype is implemented to verify theoretical analysis and the performance of the proposed converter.

Analysis and Control of A Fixed Frequency LCL-type Isolated Bidirectional Converter (고정주파수 LCL타입 절연형 양방향 컨버터 해석 및 제어)

  • Park, Sangeun;Cha, Hanju
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.30 no.3
    • /
    • pp.65-72
    • /
    • 2016
  • This paper discussed the LCL-type & Isolated bidirectional dc-dc converter(BDC) with dual full bridge inverter. In order to verify the analysis of the BDC, Experimental prototype has been designed and implemented to supply constant voltage regardless of loads and proposed a method to select switching frequency that depended on two inductors' inductance ratio and transformer parameters. The proposed converter has been composed of LCL resonant network with unit inductance ratio ($L_r/L_f$=1) and then operated with fixed duty, 50% duty ratio and fixed frequency. There are some characteristics that input voltage and output voltage of the BDC is nearly identical and zero voltage turn-on switching is possible in forward and reverse mode. Finally, it has been showed that BDC is possible to commutate operating mode normally and provide constant output voltage in selected switching frequency.

A Seamless Transfer Method of Bidirectional DC-DC Converter for ESS in DC Micro-grids (DC 마이크로그리드에서 에너지 저장장치를 위한 양방향 DC-DC컨버터의 무순단 절체 제어기법)

  • Kwon, Min-Ho;Park, Jung-Sung;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.19 no.2
    • /
    • pp.194-200
    • /
    • 2014
  • In DC micro-grid system energy storage systems (ESS) are responsible for storing energy and balancing power. Also, control target of the bidirectional DC-DC converter(BDC) for ESS should be changed depending on the operating mode. During the grid connected mode, the BDC controls the battery current or voltage. When a grid fault occurs, the BDC should change the control target to regulate the DC-bus. The BDC with conventional control method may experience large transient state during the mode change. This paper proposes a control method of BDC for ESS. The proposed control method is able to provide autonomous and seamless mode transfer by a variable current limiter. To validate the proposed concept, simulation results using PSIM and experimental results from a 2kW prototype are provided.

Model-based Optimal Control Algorithm for the Clamp Switch of Zero-Voltage Switching DC-DC Converter

  • Ahn, Minho;Park, Jin-Hyuk;Lee, Kyo-Beum
    • Journal of Power Electronics
    • /
    • v.17 no.2
    • /
    • pp.323-333
    • /
    • 2017
  • This paper proposes a model-based optimal control algorithm for the clamp switch of a zero-voltage switching (ZVS) bidirectional DC-DC converter. The bidirectional DC-DC converter (BDC) can accomplish the ZVS operation using the clamp switch. The minimum current for the ZVS operation is maintained, and the inductor current is separated from the input and output voltages by the clamp switch in this topology. The clamp switch can decrease the inductor current ripple, switching loss, and conduction loss of the system. Therefore, the optimal control of the clamp switch is significant to improve the efficiency of the system. This paper proposes a model-based optimal control algorithm using phase shift in a micro-controller unit. The proposed control algorithm is demonstrated by the results of PSIM simulations and an experiment conducted in a 1-kW ZVS BDC system.

Optimal Soft-Switching Scheme for Bidirectional DC-DC Converters with Auxiliary Circuit

  • Lee, Han Rim;Park, Jin-Hyuk;Lee, Kyo-Beum
    • Journal of Power Electronics
    • /
    • v.18 no.3
    • /
    • pp.681-693
    • /
    • 2018
  • This paper proposes a soft-switching bidirectional dc-dc converter (BDC) with an auxiliary circuit. The proposed BDC can achieve the zero-voltage switching (ZVS) using an auxiliary circuit in the buck and boost operations. The auxiliary circuit supplies optimal energy for the ZVS operation of the main switches. The auxiliary circuit consists of a resonant inductor, a back-to-back switch and two capacitors. A small-sized resonant inductor and an auxiliary switch with a low-rated voltage can be used in the auxiliary circuit. Zero-current switching (ZCS) turn-on and turn-off of the auxiliary switches are possible. The proposed soft-switching scheme has a look-up table for optimal switching of the auxiliary switches. The proposed strategy properly adjusts the turn-on time of the auxiliary switch according to the load current. The proposed BDC is verified by the results of PSIM simulations and experiments on a 3-kW ZVS BDC system.

Design and Control Strategy for Autonomous and Seamless Mode Transition of High Efficiency Bidirectional DC-DC Converter for ISG Systems (ISG 시스템용 고효율 양방향 DC-DC 컨버터의 설계 및 자율적이며 끊김없는 모드전환을 위한 제어전략)

  • Park, Jun-Sung;Kwon, Min-Ho;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.21 no.1
    • /
    • pp.19-26
    • /
    • 2016
  • In this study, a bidirectional DC-DC converter for idle stop and go (ISG) is developed to reduce fuel consumption. A three-phase non-isolated half-bridge converter is selected through a design method by considering efficiency and volume. According to the state of charge of the batteries at both the low-voltage and high-voltage sides, buck mode, which charges a low-voltage battery from the generated motor energy, and boost mode, which provides power to the motor from the low- and high-voltage battery sides, are required in the ISG system. Hence, an autonomous and seamless bidirectional control method using a variable current limiter is proposed for mode change. A 1.8 kW engineering sample of the proposed converter has been built and tested to verify the validity of the proposed concept. The maximum efficiencies, including gate driver and control circuit losses, are 96.4% in charging mode and 96.1% in discharging mode.

Development of 12V, 1000A Isolated Bidirectional Resonant DC-DC Converter (12V, 1000A 절연형 양방향 공진형 DC-DC 컨버터 개발)

  • Park, Jun-Sung;Choi, Se-Wan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.19 no.1
    • /
    • pp.57-63
    • /
    • 2014
  • In this paper a bidirectional DC-DC converter is proposed for renewable energy systems, eco-friendly vehicles, energy storage systems, uninterruptible power supply(UPS) systems and battery test equipments. The two-stage bidirectional converter employing a fixed-frequency series loaded resonant converter is designed to be capable of operating under zero-current-switching turn on and turn off regardless of voltage and load variation, and hence its magnetic components and EMI filters can be optimized. And efficiencies and volumes of the two-stage bidirectional converters are compared according to configuration of isolated and non-isolated parts and a two-stage topology suitable for low voltage and high current applications is proposed. A 12kW(12V, 1000A) prototype of the proposed converter has been built and tested to verify the validity of the proposed operation.

Practical Design Methodology of Dual Active Bridge Converter as Isolated Bi-directional DC-DC Converter for Solid State Transformer (Solid State Transformer를 위한 양방향 Dual Active Bridge DC-DC 컨버터의 설계 기법)

  • Choi, Hyun-Jun;Lee, Won-Bin;Jung, Jee-Hoon
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.22 no.2
    • /
    • pp.102-108
    • /
    • 2017
  • Proper design guides are proposed for a practical dual-active bridge (DAB) converter based on the mathematical model on the steady state. The DAB converter is popular in bidirectional application due to its zero-voltage capability and easy bidirectional operation for seamless control, high efficiency, and performance. Some design considerations are taken to overcome the limitation of the DAB converter. The practical design methodology of power stage is discussed to minimize the conduction and switching losses of the DAB converter. Small-signal model and frequency response are derived and analyzed based on the generalized average method, which considers equivalent series resistance, to improve the dynamics, stability, and reliability with voltage regulation of the practical DAB converter. The design of closed-loop control is discussed by the derived small-signal model to obtain the pertinent gain and phase margin in steady-state operation. Experimental results of a 3.3 kW prototype of DAB converter demonstrate the validity and effectiveness of the proposed methods.