Patent ID: 8212571
Filing Date: 2012-07-03
Classification: B60L,H02J,Y02T

Abstract:
1. A vehicle power supply device, comprising: a lithium battery module that is constituted with a plurality of serially connected lithium battery cell groups, each group including a plurality of serially connected lithium battery cells; a first control device that includes a plurality of integrated circuits each disposed in correspondence to the plurality of lithium battery cells; a plurality of voltage detection harnesses that are disposed for inputting terminal voltages at the individual lithium battery cells included in the corresponding lithium battery cell group to the plurality of integrated circuits; a second control device that controls all of the plurality of lithium battery cells; and a signal transmission path that is disposed between the first control device and the second control device so that signals are transmitted between the first control device and the second control device, wherein: each of the plurality of integrated circuits comprises: a selection circuit that selects and outputs in a predetermined order the terminal voltages at the individual lithium battery cells that are input from the corresponding lithium battery cell group via the voltage detection harnesses; a voltage measurement circuit that detects the terminal voltages output from the selection circuit; a plurality of balancing switches used to discharge the individual lithium battery cells included in the corresponding lithium battery cell group; a balancing switch control circuit that controls open/close of the balancing switches; and a diagnosis circuit that diagnoses disconnection in the voltage detection harnesses via which the terminal voltages at the individual lithium battery cells included in the corresponding lithium battery cell group are input, and wherein: when measuring the terminal voltages at the individual battery cells included in the corresponding lithium battery cell group, the control circuit of each of the integrated circuits closes the balancing switch corresponding to a measurement target lithium battery cell, and then opens the balancing switch corresponding to the measurement target lithium battery cell; when measuring the terminal voltages at the individual battery cells included in the corresponding lithium battery cell group, the voltage measurement circuit of each of the integrated circuits inputs via the selection circuit and detects the terminal voltage at the measurement target lithium battery cell during a period that the balancing switch corresponding to the measurement target lithium battery cell remains opened; the diagnosis circuit of each of the integrated circuits compares the terminal voltage detected by the voltage measurement circuit with a predetermined threshold and, based upon the result of the comparison, diagnoses an abnormality whether or not disconnection has occurred in the voltage detection harness corresponding to the measurement target lithium battery cell; and each of the integrated circuits executes cyclically a measurement of the terminal voltages at the individual lithium battery cells included in the corresponding lithium battery cell group and a diagnosis of abnormal disconnection in the voltage detection harnesses via which the terminal voltages at the individual lithium battery cells included in the corresponding lithium battery cell group are input, transmits the measurement result of the terminal voltages to the second control device through the signal transmission path, and, if the diagnosis result of abnormal disconnection indicates an abnormality, transmits a signal indicating an abnormality to the second control device through the signal transmission path.