IMPEDANCE MEASUREMENT DEVICE, DIAGNOSIS DEVICE, AND MEASUREMENT METHOD OF IMPEDANCE MEASUREMENT DEVICE

摘要

PROBLEM TO BE SOLVED: To suppress a reduction in the accuracy of measuring the impedance of a layer-built cell by a simple configuration.SOLUTION: An impedance measurement device of the present invention outputs an AC current to a positive electrode and a negative electrode of a layer-built cell, with a midway point of the layer-built cell serving as a point of reference, and detects at least one of a positive electrode-side potential difference between the positive electrode and the midway point and a negative electrode-side potential difference between the negative electrode and the midway point. The impedance measurement device adjusts the AC current on the basis of the detected potential difference and computes the impedance of the layer-built cell on the basis of the magnitude of the AC current and the detected potential difference. The impedance measurement device further determines whether or not the AC current is leaking to a load of the layer-built cell on the basis of the resistance ratio of the positive electrode-side internal resistance from the positive electrode of the layer-built cell to the midway point and the negative electrode-side internal resistance from the midway point to the negative electrode, and when it is determined that the AC current is leaking to the load, executes processing for balancing the AC current and computes the impedance.SELECTED DRAWING: Figure 10