Dynamic improvement of inductive power transfer systems with maximum energy efficiency tracking using model predictive control : analysis and experimental verification
- Authors: Liu, Shunpan , Mai, Ruikun , Zhou, Li , Li, Yong , Hu, Jiefeng , He, Zhengyou , Yan, Zhaotian , Wang, Shiqi
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Transactions on Power Electronics Vol. 35, no. 12 (2020), p. 12752-12764
- Full Text: false
- Reviewed:
- Description: For inductive power transfer (IPT) systems, loads and system input voltages are subject to change, which affects system efficiency and stability. This article presents a perturbation and observation (P&O) method for maximum energy efficiency tracking (MEET) with a model predictive control (MPC) scheme for improving the dynamic performance of series-series compensated IPT systems. In the IPT system, the inverter at the primary side incorporates the P&O method and phase shift modulation (PSM) to minimize system input power. Meanwhile, the rectifier at the secondary side is controlled by MPC control based PSM to improve the dynamic response of the output voltage. Simulated and experimental results show that, compared to the PI controller, the MPC controller, based on a simple but accurate mathematical model, has a better dynamic response to load and input voltage variations. With the MPC controller, the settling time of the output voltage is reduced by 85.7%, which indicates a particularly stable power supply to the load. Furthermore, MEET adopting the P&O method in the IPT system can promote the system efficiency by 1.85% on average when the output voltage is regulated by the MPC controller. © 1986-2012 IEEE.
A new coupling structure and position detection method for segmented control dynamic wireless power transfer systems
- Authors: Li, Xiaofei , Hu, Jiefeng , Wang, Heshou , Dai, Xin , Sun, Yue
- Date: 2020
- Type: Text , Journal article
- Relation: IEEE Transactions on Power Electronics Vol. 35, no. 7 (2020), p. 6741-6745
- Full Text: false
- Reviewed:
- Description: In this letter, a new coupling structure for dynamic wireless power transfer (DWPT) systems is proposed. Bipolar coils are symmetrically placed on the transmitter unipolar coils, resulting in natural decoupling between the bipolar coils and the unipolar coils. This special structure can mitigate the self-couplings between the adjacent unipolar transmitter coils and hence facilitate the design of the compensation circuit. Another remarkable advantage of this design is that it can lead to a stable mutual coupling between the transmitter array and the receiver when the receiver moves along the transmitter, making it a natural fit for DWPT applications. Furthermore, to reduce the electromagnetic interference and power loss, an automatic segmented control scheme is implemented, and a position detection method by monitoring the primary current is developed. The feasibility of the proposed coupling structure and the position detection method are verified on a laboratory prototype with 72-V output voltage. The experimental results show that the power fluctuation is within ±2.5%, and system efficiency is around 90%. (This letter is accompanied by a video demonstrating the experimental test). © 2020 IEEE.
Extension of ZVS region of series-series WPT systems by an auxiliary variable inductor for improving efficiency
- Authors: Li, Yong , Liu, Shunpan , Zhu, Xia , Hu, Jiefeng , Zhang, Min , Mai, Ruikun , He, Zhengyou
- Date: 2021
- Type: Text , Journal article
- Relation: IEEE Transactions on Power Electronics Vol. 36, no. 7 (2021), p. 7513-7525
- Full Text: false
- Reviewed:
- Description: To maintain a stable output voltage under various operating conditions without introducing extra dc/dc converters, phase-shift (PS) control is usually adopted for wireless power transfer (WPT) systems. By using this method, however, zero-voltage switching (ZVS) operation cannot be guaranteed, especially in light-load conditions. To achieve high efficiency and reduce electromagnetic interference, it is significant for WPT systems to achieve ZVS operation of all switching devices in the whole operation range. In this article, an auxiliary variable inductor, of which the equivalent inductance can be controlled by adjusting the dc current in its auxiliary winding, is designed for series-series-compensated WPT systems under PS control to mitigate the loss arising from hard switching. As a result, a wide ZVS operation range of all switching devices can be achieved. A laboratory prototype is built to verify the theoretical analysis. The experimental results show that, under load and magnetic coupling variations, ZVS operation at fixed operation frequency as well as a constant dc output voltage can be maintained. Compared to the conventional method with only PS control, the proposed WPT can achieve higher overall efficiency in a wider load range owing to the wide ZVS operation range. © 1986-2012 IEEE.
High-efficiency WPT system for CC/CV charging based on double-half-bridge inverter topology with variable inductors
- Authors: Zhu, Xiao , Zhao, Xing , Li, Yong , Liu, Shunpan , Yang, Huanyu , Tian, Jihao , Hu, Jiefeng , Mai, Ruikun , He, Zhengyou
- Date: 2022
- Type: Text , Journal article
- Relation: IEEE Transactions on Power Electronics Vol. 37, no. 2 (2022), p. 2437-2448
- Full Text: false
- Reviewed:
- Description: Efficiency remains a key challenge in wireless charging in academia and industry. In this article, a new wireless power transfer (WPT) system based on a double-half-bridge (DHB) inverter with two variable inductors (VIs) is proposed. Compared with conventional full-bridge (FB) inverters, the DHB inverter can reduce the current through the mosfets under the same output power and thus, reduce the conduction loss. Next, by adjusting the inductances of the VIs instead of using phase shift (PS) method, the output voltage or current can be controlled, while the circulating current can be eliminated and wide-range zero voltage switching operation can be achieved. Consequently, the power loss can be further reduced. Circuit analysis, VI design, as well as hardware implementation, are provided in detail. A laboratory prototype is built to verify the feasibility of the proposed method. Close agreement is obtained between simulation and experimental results. The maximum efficiency can reach 92.4%, which is 3.65% higher than traditional PS control. © 1986-2012 IEEE.