SP type ICPT system load and mutual inductance identification method

Abstract

The invention discloses an SP type ICPT system load and mutual inductance identification method comprising steps: establishing an equivalent circuit of an SP type ICPT system, determining element parameters, and acquiring an effective value and resonant frequency omega of a resonant current Ip of a primary coil Lp, constituting an equation set according to a formula and calculating an equivalent load R and a mutual inductance M; Finally calculating a load RL, wherein the element parameters comprise Edc, Lp, Rp, Cp, Ls, Rs and Cs. The method of the invention is derived from a reflection impedance analysis and energy transmission equation, establishes an identification model of mutual inductance and load parameters; the system load and mutual inductance identification is realized by detecting the current frequency and effective value of a primary coil during stable operation without adding extra circuit; the calculation process is simple; data has a small error, high accuracy and high reliability.

Description

technical field [0001] The invention relates to the field of wireless power transmission systems, in particular to a load and mutual inductance identification method of an SP type ICPT system. Background technique [0002] At present, Inductively Coupled Power Transfer (ICPT) technology has become one of the mainstream technologies of wireless power transfer, and has been widely used in many fields such as electric vehicle charging, electronic product charging, biomedical power, and lighting systems. [0003] In the ICPT system, due to the change of the mutual inductance value and the load value between the coupling coils, the reflected impedance of the secondary circuit will have a corresponding change in the primary circuit, so that the resonant frequency of the primary circuit will drift and no longer match the natural operating frequency. , thus affecting the efficiency and power transmission capability of the system. For example, electric vehicles have different impedan...

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Problems solved by technology

[0003] In the ICPT system, due to the change of the mutual inductance value and the load value between the coupling coils, the reflected impedance of the secondary circuit will have a corresponding change in the primary circuit, so that the resonant frequency of the primary circuit will drift and no longer match the natural operating frequency. , thus affecting the efficiency and power transmission capability of the system. For example, electric vehicles have different impedance characteristics, and there are different mutual inductances due to their different chassis heights and positions. The switching of electric vehicles will affect the stability of its charging system and High efficiency, so the system needs to adjust the control mode of the energy transmitter according to the current situation. However, the high-order nonlinearity of the system makes the identification of load and mutual inductance a technical bottleneck. The system control is difficult, the calculation process is complicated, and the reliability is poor.

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