Method and apparatus for diagnosing fault of negative contactor of battery pack

摘要

The present invention discloses an apparatus and method for diagnosing a short circuit accident occurring in a negative contactor of a battery pack. The apparatus for diagnosing a negative contactor of a battery pack according to the present invention is a device for diagnosing a negative contactor of a battery pack including a positive contactor on a charge/discharge path connected to a positive terminal and a negative contactor on a charge/discharge path connected to a negative terminal. , a positive terminal of a battery module provided in the battery pack and one end of the positive contactor are connected between a first node and a ground to which the first node is commonly connected to measure a first measurement voltage applied between the first node and the ground a first voltage measuring unit provided for; A second voltage connected between a second node and a ground to which the negative terminal of the battery module and one end of the negative contactor are commonly connected, and provided to measure a second measurement voltage applied between the second node and the ground measuring unit; a positive protection capacitor positioned between the positive terminal of the battery pack and the ground; a negative electrode protection capacitor located between the negative terminal of the battery pack and the ground; and a third node in which the first node, the second node, the other end of the positive contactor and one end of the positive electrode protection capacitor are commonly connected, and the other end of the negative contactor and one end of the negative electrode protection capacitor are commonly connected. a first diagnostic voltage applied between the third node and the second node, and a second diagnostic circuit applied to the positive electrode protection capacitor, comprising a plurality of diagnostic circuits configured to selectively connect two points among four nodes and a ground; A diagnostic voltage and a third diagnostic voltage applied to the cathodic protection capacitor are measured, and the first measured voltage, the second measured voltage, the first diagnostic voltage, the second diagnostic voltage, and the third diagnostic voltage are used to measure the diagnostic voltage and the third diagnostic voltage. and a diagnostic unit for diagnosing whether the negative contactor is short-circuited.