Voltage-type wireless power supply system load identification method

Abstract

The invention discloses a voltage-type wireless power supply system load identification method. The voltage-type wireless power supply system load identification method comprises the following steps: establishing an inductively power transfer (IPT) system, a primary side circuit sampling circuit obtains 2N primary side resonance current peak values and system working frequency sampling values in a free resonance state and computes total active wear portion RX generated by a secondary side circuit. Whether a non-mutual-inductance-coupling value M exists or not can be judged by comparison of the RX with a primary side coil internal resistance value Rp. If the non-mutual-inductance-coupling value M exists, a load resistance value Re q can be computed. The voltage-type wireless power supply system load identification method has the obvious advantages of being capable of detecting changes of oscillation frequency and the primary side resonance current peak values in a period of a free resonance mode by utilizing two basic modes, namely energy filling and free resonance, and therefore whether load exists or not and power grades of the load when the load exists can be identified.

Description

technical field [0001] The invention belongs to a load identification technology of an IPT system, in particular to a load identification method of a voltage-type wireless power supply system. Background technique [0002] Inductively Power Transfer (IPT) technology is a new type of safe power supply technology based on Faraday's electromagnetic induction principle, which uses high-frequency alternating magnetic field to realize wireless transmission of electric energy between a completely electrically insulated power system and a movable load. This technology has been widely used in fields such as electric vehicles, rotating electrical equipment, biomedicine, home appliances and mobile electronic devices. Due to the large power nature and level span of the load carried by the IPT system (several milliwatts to thousands of watts), if the nature and power of the load are not identified, the stability and reliability of the IPT system will be greatly reduced. Therefore, befor...

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Problems solved by technology

[0003] However, these traditional identification technologies mainly use the phase difference between the primary side resonant voltage and current to identify the load. Too many variables need to be detected, which makes the control system very complicated and difficult to implement.

[0004] For a voltage-type IPT system, if a wireless communication module is used to realize load identification, due to the presence of high-frequency magnetic fields of power transmission and wireless communication at the same time, the mutual interference between the two may reduce the reliability of energy transmission and wireless communication

[0005] If the identification method based on reflected impedance and detection of resonance voltage and current phase difference is adopted, although the load size can be accurately identified in theory, in practice, due to the detection of current peak value, voltage peak value and the phase difference between the two

The hardware circuit is extremely complex, and too many detected quantities are likely to affect the accuracy of actual load identification

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