Static longitudinal end effect caused by truncated iron and coil windings is the inherent characteristic of linear motors. For multisegment long primary double-sided linear induction motors (DLIMs), subsection power supply mode results in longer iron than excited coil windings, which aggravates the static longitudinal end effect. First, the characteristics of the DLIM impedance matrix are researched through experiments. The impedance matrix is calculated by the measured amplitude and phase of the three-phase voltage and current. Unlike the traditional rotating induction motor, the matrix of DLIM is not a traditional cyclic symmetric matrix. Positive-sequence impedance, which is defined and obtained based on the impedance matrix, could be used to measure parameters by open-circuit and short-circuit experiments. The parameters measurement method is validated more accurate than the traditional average phase impedance. The research results, which are validated by test data from the long primary DLIM system capable of producing 400 kN of force, operating at the 100-MW peak power level, could be the reference for accurate description of the dynamics motor model and parameter measurement.

The soft-switching characteristics of double-sided LCC wireless power transmission systems are susceptible to system parameter disturbances. In order to improve the stability of zero voltage switches in constant-current and constant-voltage charging modes, this paper synthesizes eight resonant conditions which make the system realize constant-current/constant-voltage and Zero Phase Angle. The influence of compensating capacitance parameter disturbance on system impedance angle is studied under constant current/constant voltage operation mode. The parameter configuration methods of compensated capacitance realized by zero voltage switches under the influence of third-order harmonic in constant current/constant voltage operation mode are also given. The system’s experimental prototype verifies the theoretical analysis’s accuracy with capacitive and inductive input impedance.

In this paper, an array multi-transmitter multi-mode wireless power transfer system is proposed. The system realizes the joint modulation of three transmitter coil working modes of single transmitter coil, dual transmittercoil and four transmitter coils in the wireless power transfer system through PI closed-loop control, which can realize the stable output of WPT system in three different transmitter coil work modes. It effectively compensates for the shortcomings of the single working mode of a single transmitter coil and the limited range of effective working areas, and improves the robustness of the wireless power transfer system.

In this paper, an exact linearization algorithm and nonlinear control scheme of the inductive power transfer (IPT) system for electric vehicles (EVs) are proposed, considering a variation in system operating point. For ease of modeling, the secondary side of IPT system is equivalent to a reflected reactor and resistor on primary side at different operating frequencies. By utilizing the exact linearization method, the nonlinear model is accurately transformed into a linear one at whole operating points. Besides, to acquire constant currentnvoltage (CV/CC) charging and zero voltage switching (ZVS) operating for EVs, the controllers are designed and optimized in the linear space, and then inverse mapped to the nonlinear space. This avoids designing different controllers for each operating point. Compared with a traditional PI controller, the nonlinear control scheme suggested in this paper enables the system to obtain a fixed dynamic response even if the operating point of the IPT system changes. Finally, practical results obtained from a hardware prototype are included. They confirm the performances of the system and indicate that the proposed nonlinear control scheme can automatically maintain CCnCV output and ZVS operation with a constant response time of 10 ms.

There are several resonance frequencies points in the high-order resonant network to realize constant current/constant voltage output, but the disturbance of the resonant network parameters will affect the output characteristics of the system. Therefore, selecting the appropriate resonant frequency is necessary to achieve stable output characteristics of wireless power transmission. This paper analyzes the influence of sensitivity of the double-sided LCC compensation network parameters on resonance point and output characteristics. Moreover, this paper proposes a design method to realize load-independent constant current and constant voltage output under two ZPA frequencies, and the resonance parameters are optimized for the realization of ZVS. Under constant current and constant voltage output resonant points, the transmission efficiency of the double-sided LCC IPT system reaches 88.9% and 88.5%, respectively.

This paper proposes a position recognition method for the receiver coil by the secondary coil current. Based on the practical value of the current of the receiver coil, the position recognition of the receiver coil in the WPT system is realized. This paper proposes a 3×3 array multi-transmitter coil grouping and control logic. The mathematical model of mutual inductance between the receiver and transmitter coil at different positions on the X-Y plane is established. A method for identifying the position of the receiver coil according to the current of the receiver coil is proposed. Compared with the traditional position recognition method of the receiver coil, this method does not need to add a detection coil and position sensor and can realize the position recognition of the receiver coil on the 2D plane.