Method for measuring current of switch integrated into power module

Abstract

The invention relates to a method for measuring current of a switch integrated into a power module. A current sensor used in the method comprises a Rogowski coil and a processing circuit. The two Rogowski coils are integrated in the power module to form a differential Rogowski coil, the processing circuit is located outside the power module, the output ends of the two Rogowski coils are connected with the input end of the processing circuit, and the grounding ends of the two Rogowski coils are connected with the grounding end of the processing circuit; the Rogowski coil is etched on an island structure of a copper layer on a DBC substrate of an internal packaging structure of the power module in a plane mode, the Rogowski coil is not electrically connected with the copper layer on the DBC substrate, and a current-carrying conductor of a tested switching current of the power module is located above the Rogowski coil and is not in contact with the Rogowski coil. The two Rogowski coils are symmetrically located on the two sides of the current-carrying conductor. On the premise that an existing packaging structure of the power module is not changed, the Rogowski coil is integrated into the power module only by changing partial structural layout, and the problem that an existing Rogowski coil broadband and a current sensor are difficult to integrate is solved.

Description

technical field [0001] The invention belongs to the technical field of switch current measurement, in particular to a switch current measurement method integrated into a power module. Background technique [0002] Current sensors play a vital role in modern power electronic systems, and the switching current information of power devices is a common key information required for power electronic fault protection, health monitoring and control. At present, extensive research work has been carried out on current sensing technology in power electronic systems, which can measure current through shunts, current transformers, Rogowski coils, Hall sensors, and magnetoresistive sensors. [0003] Shunts are the most cost-effective, and although their operation is simple based on Ohm's law, practical current shunts have inherent inductance, which limits their measurement accuracy and bandwidth (from DC to tens of MHz); furthermore, at high frequencies Due to the influence of the skin e...

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Problems solved by technology

[0005] Aiming at the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a switching current measurement method integrated into the power module, the Rogowski coil is integrated into the power module, and the output terminal of the Rogowski coil is connected to the processing outside the power module Circuit connection, designed to solve the problem of difficult integration of existing Rogowski coil broadband and current sensors

The traditional Rogowski coil is wound on a non-magnetic skeleton, and there are problems such as uneven winding and large volume. In this application, two Rogowski coils are used to form a differential Rogowski coil, which can well solve the problem of uneven winding, and Small size, compact structure and easy integration, which improves the anti-interference performance of the current sensor

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