Tuning device and tuning method for inductive power transfer system using measuring coil technology

Abstract

The invention discloses a tuning device and a tuning method for an inductive power transmission system using measuring coil technology. When the secondary side loop resonates, the phase difference between the voltage at both ends of the measuring coil and the current of the primary side coil is zero to dynamically adjust the primary side. The operating frequency of the side inverter. The invention avoids the difficulty of measuring the induced voltage of the secondary coil, saves the high-speed communication process, reduces the output current of the inverter and the power loss of the primary circuit, improves the efficiency of power transmission of the system, and makes the tuning more accurate and reliable. The method of the invention can realize higher-precision tuning, make the secondary circuit closer to the ideal resonance state, and better improve the transmission efficiency of the wireless power transmission equipment.

Description

technical field [0001] The invention relates to the field of inductive power transmission, in particular to a tuning device and a tuning method in inductive power transmission equipment. Background technique [0002] As a new type of energy transmission, inductive power transmission can effectively overcome the problems of easy contact sparks, carbon deposition and environmental influence in traditional power transmission methods. Based on the advantages of inductive power transmission, this technology has been adopted It is widely used in mobile phone equipment charging, indoor equipment charging, rail transit and other fields, and has attracted extensive attention from experts and scholars at home and abroad. [0003] The inductive power transmission system is composed of primary side and secondary side. The direct current is input to the primary side, and the direct current is inverted through the inverter bridge to obtain high-frequency alternating current. The high-freq...

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Problems solved by technology

However, due to the influence of load change, component parameter change, air gap distance change and external environment, the secondary circuit presents a non-resonant state, and the load partial voltage in the circuit becomes smaller. In order to keep the load voltage constant, a larger principle is required. The side loop current increases the loss of the primary side loop and reduces the energy transmission efficiency of the system

[0005] One of the existing efficiency optimization methods is to add a dynamic tuning device to the secondary side. By controlling the equivalent impedance of the secondary side, the secondary side circuit can reach a resonance state. However, this method needs to add redundant controllers and tuning devices. It increases the complexity of the system, and when the system is working normally, it is difficult to directly measure the induced voltage of the secondary coil, and it is difficult to judge whether the secondary circuit is in a resonant state

The other is to optimize the efficiency of the system with multi-parameter changes based on the perturbation-observation method, and search for the maximum efficiency operating point of the system in real time by continuously adjusting the conduction angle of the converter. However, due to the large number of inductance and capacitance parameters in the system, multiple If there is a resonance point, it is easy to cause the phenomenon of frequency bifurcation, and the phenomenon that the disturbance does not reach the resonance point; and when the comparison of system efficiency between resonance and non-resonance conditions is not obvious, it is difficult for the controller to distinguish the resonance state and it is difficult to reach the resonance state.

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