Chargepoint, Inc.

Ivan Baranov

David R Sunderland

An open-loop fluxgate-type current sensor is described. The current sensor includes a single winding around a core that combines drive and sense that is used as both an excitation source and a feedback element to measure current through a primary winding. The current sensor further includes an H-bridge driver to impress voltage to the single winding to cause current to saturate the core, the voltage being impressed with opposing polarities repeatedly causing the core to saturate at opposing polarities. The current sensor further includes an analog transconductance integrator that continuously integrates the current to infer magnetizing force being driven into the core at the opposing polarities. The current sensor further includes a microcontroller unit (MCU) that calculates residual current based on the inferred magnetizing force being driven into the core at the opposing polarities and cause remedial action to be taken when the calculated residual current exceeds a threshold.

Single winding core-insensitive fluxgate current sensor

An integrated meter in an electric vehicle supply equipment (EVSE) is described. Input power is received at input terminal of the EVSE and carried through a conductor that passes through an opening of a current transformer coil of the meter. The input power is split into a main path and an auxiliary path. The main path is for charging an electric vehicle (EV). The auxiliary path provides power to the meter to the EVSE itself. The auxiliary path passes through the opening of the current transformation coil in a reverse direction before being passed to a power supply of the meter and to a power supply of the EVSE to remove any current not for charging the EV from current measurements. The meter calculates energy measurements that do not include current drawn by the meter and the EVSE and transmits them to a processor of the EVSE.

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San Francisco, CA, United States of America

Ivan Baranov