Multiple Parameters Estimation Based on Transmitter Side Information in Wireless Power Transfer System

Abstract

Due to the electrical isolation nature of wireless power transfer (WPT) system, a method that can obtain the receiver side parameter only based on transmitter side information is desirable. However, typical estimation scheme assume that the coil inductance and compensation capacitance are constant, which will cause large estimation errors in high frequency system. Therefore, a multiple parameters estimation algorithm that can simultaneously identify load resistance, mutual inductance and receiver coil inductance is proposed in this paper, where only the input current and voltage are needed to be measured. Moreover, in order to cope with capacitor aging effect and manufacturing tolerance, compensation capacitance estimation algorithm is also presented. Mathematical model and algorithm procedure are depicted thoroughly and the gradient descent approach is adopted to obtain the optimal estimated parameter. The uniqueness of solution and the validity of this approach are strictly proved as well. Finally, a WPT experimental prototype with Class-D inverter is implemented and the experimental results are provided to verify the availability and accuracy of the proposed algorithm. INDEX TERMS Wireless power transfer, parameter estimation, gradient descent approach.

Wireless Power Supply Voltage Regulation Control of Implantable Devices Based on Primary Side MPC

“…Then, the output voltage U 0 is controlled by controlling I p . According to the analysis above, the output voltage estimation Equation ( 13) is obtained by combining Equations ( 10)- (12).…”

“…From the established identification model, the identification result is obtained, but it increased the control complexity and size of the WPT system. In [12], a multi-parameter estimation algorithm is proposed to identify the load resistance and mutual inductance from the transmitter information, and more accurate estimated parameters are obtained. However, it also increased the difficulty of the controller design.…”

Steady-State Multiple Parameters Estimation of the Inductive Power Transfer System

“…One other study suggests load identification by employing a parity-time symmetry approach, which has the advantage of eliminating the need for the mutual inductance information [28]. In order to improve the estimation procedure, the algorithm that can simultaneously estimate load resistance, mutual inductance, and secondary-side coil inductance or compensation capacitance is proposed in [29]. Frequency sweeping in combination with gradient descent approach is adopted to obtain the estimation results.…”

“…Another disadvantage of existing methods in [23]- [27], [30]- [34], [36]- [40] is that the parameters of the secondary-side circuit are considered to be constant. In real working conditions, however, coil inductance may be subjected to uncontrolled electromagnetic environments, leading to its deviation from the rated value [29]. Similarly, the value of the compensation capacitors may differ from the measured value due to the ageing effect [29], [35], [42] and due to the ambient temperature [43].…”

“…In real working conditions, however, coil inductance may be subjected to uncontrolled electromagnetic environments, leading to its deviation from the rated value [29]. Similarly, the value of the compensation capacitors may differ from the measured value due to the ageing effect [29], [35], [42] and due to the ambient temperature [43]. These can significantly affect the control algorithm, leading to the incorrect regulation of the output voltage and/or current.…”