Dynamically tuning device and tuning method for sending terminal of wireless electric energy transmission device

Abstract

The present invention discloses a dynamically tuning device and a tuning method for the sending terminal of a wireless electric energy transmission device, and relates to the technical field of wireless electric energy transmission. The primary side of the dynamically tuning device is provided with a phase detection device PD, a BUCK circuit, a control unit CU and a rectifier bridge. According to the detected phase difference state, the resonant state is judged. Meanwhile, the real-time tuning is realized through adjusting the equivalent output resistance of the BUCK circuit. As a result, the primary side can be maintained to run at a minimum voltage phase difference and a minimum current phase difference. That means, a primary side circuit is closer to the completely resonant state, so that the active power of the sending terminal is improved. Furthermore, the transmission power and the transmission efficiency of the wireless electric energy transmission device are improved.

Description

technical field [0001] The invention relates to the technical field of wireless power transmission, in particular to a dynamic tuning device and a tuning method for a sending end of a wireless power transmission device. Background technique [0002] The research on wireless power transmission technology first started in the early 1970s. In recent years, it has rapidly become a hot spot pursued by major research institutions, and has attracted the close attention of many domestic and foreign scholars and industrial circles. Initially, this technology was mainly used for medical electronic devices implanted in the human body, such as providing non-contact power supply for artificial cardiac pacemakers. Later, scientists successively used wireless power transmission technology for non-contact power supply of electric vehicles and rail transit wireless power supply systems. Some breakthroughs have been made, and they are gradually developing in the direction of high-power applic...

AI Technical Summary

Problems solved by technology

However, there is a large air gap between the receiving coil and the sending coil, which makes the leakage inductance of the sending coil and the receiving coil very large. In addition, factors such as load, temperature and humidity will cause the impedance of the line to change; As the work power increases, the voltage of the receiving coil decreases, which reduces the transmission power and transmission efficiency of electric energy

In order to improve the transmission power and transmission efficiency of electric energy, the tuning device generally tunes the leakage inductance of the sending coil or receiving coil by switching the capacitor, that is, the capacitor and the sending coil or receiving coil form an LC resonant oscillation circuit, which improves the sending coil and the receiving coil. The active power of the receiving coil; however, most of the existing tuning devices at the sending end are based on impedance measurement and change the number of switching capacitors for dynamic compensation to realize the tuning of the leakage inductance of the sending end coil of the wireless energy transfer system. However, due to the operation of the wireless energy transfer system Due to factors such as changes in working conditions and the external environment, the inductance and circuit impedance of the coils at the sending end and receiving end will change. This change is difficult to measure in real time, which makes the parameters of the wireless power transmission system change, which in turn leads to resonance between the sending end and the receiving end. When the frequency changes, the tuning device cannot tune in real time and accurately, and the system is not in a state of resonance, which affects the effective transmission of system power and reduces the power supply capacity of the system; there is also an additional phase-controlled inductance circuit connected in parallel at the sending end, and the dynamic tuning method is used for real-time adjustment The equivalent natural resonant frequency of the transmitting end is used to ensure the stability of the working resonant frequency, but it also has limitations. Only after the load range is determined can a tuning circuit that keeps the system frequency stable can be designed.

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