Non-vehicle-mounted charger insulation detection starting judgment method and circuit

Abstract

The invention discloses a non-vehicle-mounted charger insulation detection starting judgment method and a circuit. An insulation detection starting judgment circuit is added between a positive bus anda negative bus of a contactor of the off-board charger, and after the off-board charger and a battery interface of the electric vehicle are physically connected and handshake of the two parties succeeds, the non-vehicle-mounted charger starts to detect whether the voltage of the outer side of the contactor output by direct current of the off-board charger is smaller than 10 V; if yes, performingcharging strictly according to the control guidance logic required by the new national standard, if it is detected that the voltage on the outer side of the contactor is larger than or equal to 10 V,judging whether the voltage on the outer side of the contactor is virtual voltage, if yes, the insulation detection starting judgment circuit is started directly or after waiting for set time, and ifnot, ending the charging time sequence and reporting faults. By judging the voltage attribute and quickly reducing the virtual voltage, the system can be charged according to the requirements of the national standard, the false alarm problem caused by the simple application of the national standard method is avoided, and whether the vehicle relay is adhered can be judged more accurately.

Description

technical field [0001] The invention relates to an off-vehicle charger insulation detection start-up judgment method and a circuit, belonging to the field of power supply of vehicle auxiliary devices. [0002] technical background [0003] The current popularization of electric vehicles has driven the demand for research and development and construction of charging devices, and relevant national standards have been issued one after another. The formulation of the new national standard GB / T 27930-2015 regulates the communication protocol between the electric vehicle off-board conductive charger and the battery management system. This standard clearly stipulates that after the handshake between the two parties is successful, the off-board charger starts to detect the main contactors K1 and K2 of its own DC output and judge whether the voltage outside the contactors is less than 10V. If it is detected that the voltage outside the contactor is ≥10V, the charging sequence ends an...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a method and circuit for determining the start-up of insulation detection of off-board chargers in view of the current problem of false alarms in off-board chargers, so as to reduce the probability of system false alarm failures and improve the reliability of off-board chargers. To ensure safety and expand the range of vehicles using off-board chargers

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