Impedance-Matching Range Extension Method for Maximum Power Transfer Tracking in IPT System

• Published in: IEEE transactions on power electronics Vol. 33; no. 5; pp. 4419 - 4428
• Main Authors: Dai, Xin, Li, Xiaofei, Li, Yanling, Hu, Aiguo Patrick
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.05.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Coefficient of variation; Coupling coefficients; Couplings; DC–DC converter; Discharge; Electronics; Impedance; Impedance matching; inductive power transfer (IPT); Inductors; Maximum power; Maximum power transfer; Power converters; Resistance; Resonant frequency; Topology; Tracking
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2017.2716968

Maximum power transfer is an important index for an inductive power transfer (IPT) system to make full use of its power transfer capability, and such a capability is usually realized by impedance matching. Traditionally, impedance matching is implemented by placing a power electronics converter such as a dc-dc converter at the secondary side of an IPT system. However, the power electronics converter and its operation mode directly affect its impedance-matching range, which is very limited if a traditional power converter only operates at continuous conduction mode (CCM). To extend the impedance-matching range, this paper proposes a novel impedance matching method based on combined CCM and discontinuous conduction mode (DCM) operation of an impedance matching converter. The impedance-matching range is fully analyzed for CCM and DCM operation, respectively, by taking variation of coupling coefficient into consideration. The analysis results show that the impedance-matching range can be extended by more than double that of the traditional impedance matching method. In addition, a maximum power transfer tracking method is developed using the proposed impedance-matching range extension method, and the experimental results have verified the feasibility of the tracking method.