Vehicle-mounted-charger reverse connection prevention method

Abstract

The invention discloses a vehicle-mounted-charger reverse connection prevention method and belongs to the automobile manufacturing technology field. In the method, a reverse connection prevention circuit of a vehicle-mounted charger is used. The circuit comprises a branch formed through connecting in series a pre-charge resistor and a pre-charge relay. The reverse connection prevention method comprises the following steps that when receiving a charging command, a cell management system makes a first relay and the pre-charge relay simultaneously close; at this moment, the cell management system detects a voltage of two ends of the pre-charge resistor and compares a detected voltage value and a preset voltage scope value in predetermined time; if the detected voltage value exceeds the preset voltage scope value, a vehicle-mounted charger circuit is in a reversal connection state; and at this moment, the cell management system makes the pre-charge relay and the first relay disconnect. By using the method, problems that conduction losses of an existing vehicle-mounted charger reverse connection prevention circuit are large and a traditional reverse connection prevention circuit reduces whole machine efficiency can be solved.

Description

technical field [0001] The invention relates to the technical field of automobile manufacturing, in particular to a method for preventing reverse connection of a vehicle charger. Background technique [0002] The on-board charger refers to the charger fixedly installed on the electric vehicle, which has the ability to fully charge the power battery of the electric vehicle safely and automatically. figure 1 The vehicle-mounted charger shown includes a charging unit 11 electrically connected to the battery management system 12. The charging unit 11 has a rectification and filtering circuit 121, and the negative terminal HV- of the high-voltage bus of the rectification and filtering circuit 121 is connected to the battery management system 12 through a MOS tube. The second relay RL2 and the first relay RL1 are connected in series to the positive pole of the battery voltage, and the positive terminal HV+ of the high-voltage bus bar of the rectification and filtering circuit 121 ...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide an anti-reverse connection method for on-board chargers, which can solve the problems of large conduction loss of the anti-reverse connection circuit of existing on-board chargers and the lower efficiency of the whole machine caused by traditional anti-reverse connection circuits

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