Mutual inductance estimation method and system based on ac/dc converter multi-source wireless charging

Abstract

The invention discloses a mutual inductance estimation method and system based on AC / DC transformer multi-source wireless charging. Each transmitting coil is composed of n coils with the same resonance frequency, an independent alternating current voltage source provides electrical energy for each transmitting coil, and each voltage source can generate an alternating current of any amplitude and phase; an MOS switching tube is mounted on each transmitting coil and used for connecting or disconnecting the voltage sources and the transmitting coils; a voltage / current detection probe is mounted on each transmitting coil and used for monitoring the voltage / current value on each transmitting coil in real time; receiving coils have the same resonant frequency as the transmitting coils; and the receiving coils are connected with a two-way AC / DC voltage regulating transformer and then connected with a battery pack. The mutual inductance estimation system has the advantages that mutual inductance between the receiving / transmitting coils is estimated quickly, accurately and safely, and thus the situation that a multiple transmitting end / single receiving end wireless charging system efficiently charges an electric vehicle becomes possible.

Description

technical field [0001] The invention relates to the field of static wireless charging of electric vehicles, in particular to a mutual inductance estimation method and system for wireless charging of stationary pure electric vehicles. Background technique [0002] In the existing pure electric vehicle wireless charging technology, usually a single transmitting coil is fixedly installed on the ground parking space, and the electric vehicle must be accurately parked at the specified position, so that the receiving coil on the chassis of the electric vehicle and the transmitting coil on the ground are in the right position. to charge. However, this one-to-one wireless charging system is very sensitive to the relative position between the coils. When the two coils are not aligned coaxially, the transmission power and transmission efficiency will be greatly reduced. [0003] As a result, more and more wireless systems use multiple transmit coils to power the receive coils. The ...

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Problems solved by technology

However, the internal resistance of the transmitting coil is very small. When there is under-coupling between the receiving / transmitting coils, a large current may be generated even if a small voltage is applied to the transmitting coil, causing the transmitting coil to be overloaded and causing safety hazards.

In car wireless charging, when the car is far away from the charging position, the transmitting coil is in an unloaded state, and the receiving / transmitting coil is in a zero-coupling state at this time. If the driving voltage of the transmitting coil is added blindly at this time, an overload current will be generated and the circuit will be burned. , causing a safety accident

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