An identification method of primary side capacitance and inductance parameters in a resonant wireless charging system

Abstract

The present invention provides a method for identifying primary side capacitance and inductance parameters in a resonant wireless charging system, which includes the following steps: aiming at the typical structure of a resonant wireless charging system, according to the equivalent circuit diagram, establishing a resonant circuit primary side current effective value equation; The current RMS equation, establishes the frequency constraint equation of the input signal that makes the primary side current of the resonant circuit reach the peak value of the RMS; detects the real-time waveform of the primary side current of the resonant circuit, and obtains two characteristic quantities, which are the steady state RMS value of the primary side current and The frequency of the input signal that can make the current effective value reach the peak value; through the system identification method, the unknown quantities in the current effective value equation and the frequency constraint equation, that is, the primary side capacitance and inductance of the resonant circuit, are parameterized to obtain the capacitance and inductance values. Compared with the prior art, the invention has less detection amount and high identification accuracy, and has reference significance for fault diagnosis and early warning, frequency tracking and impedance matching of the wireless charging system.

Description

technical field [0001] The invention relates to the technical field of electric vehicles and wireless charging, in particular to a method for identifying primary side capacitance and inductance parameters in a resonant wireless charging system. Background technique [0002] With the continuous progress of society, the world's automobile industry has developed rapidly. However, traditional fuel vehicles have problems such as large oil consumption and serious exhaust emissions, which have brought considerable pressure to the world's energy and environment. As a new energy vehicle, electric vehicles are powered by electric energy and driven by motors. Compared with fuel vehicles, electric vehicles are more energy-saving and environmentally friendly during operation, so electric vehicles are also vigorously promoted by countries all over the world. [0003] There are two methods of contact charging and non-contact charging for electric vehicles. The technology of contact chargin...

AI Technical Summary

Problems solved by technology

However, since the primary side coil of the resonant circuit of the wireless charging system is buried underground, it is subjected to various stresses for a long time, and its coil inductance and compensation capacitance parameters will inevitably drift. At this time, the wireless charging system deviates from the resonance state. When the parameters change to a certain extent, the reactive power consumption will increase, and the charging efficiency will not meet the charging requirements. Therefore, it is very valuable to obtain the inductance and compensation capacitance of the primary side coil of the resonant circuit of the wireless charging system in time to ensure the efficient operation of the system.

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