Identification method of load and mutual inductance of sp type icpt system

Abstract

The invention discloses a load and mutual inductance identification method of an SP type ICPT system. The steps include: constructing an equivalent circuit of the SP type ICPT system, determining the parameters of components and obtaining the primary side coil L p The resonant current I p The effective value and resonant frequency ω, according to the formula to construct a system of equations to solve the equivalent load R and mutual inductance M, and finally calculate the load R L , where the component parameters include E dc , L p , R p 、C p , L s , R s and C s , this method is based on reflection impedance analysis and energy transfer equation derivation, establishes the identification model of mutual inductance and load parameters, and realizes the identification of system load and mutual inductance by detecting the current frequency of the primary side coil and its effective value during steady-state operation, without adding additional With additional circuit, the calculation process is simple, the obtained data has small error, high precision 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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