Voltage measuring apparatus, voltage measuring method, voltage control apparatus, and voltage control method

Abstract

A voltage measuring apparatus that individually measures voltages of n-pieces (2≤n) of power storage elements B() to B(n) connected in series includes: first to n-th voltage detecting units that respectively individually measure voltages of the power storage elements; a switching circuit that switches a connection state between the power storage elements and the first to n-th voltage detecting units; a SW control unit that drives the switching circuit; and an operation processing unit. The power storage elements are arranged in order so that potential becomes higher as n increases. The switching circuit includes a capacitor connected in parallel to the power storage element B(). In the switching circuit, the negative terminals of the power storage elements are connected to a first terminal of the capacitor via respective corresponding first switches. The positive terminals of the power storage elements are connected to a second terminal of the capacitor via respective corresponding second switches. A third switch SWis interposed between the first voltage detecting unit and the first terminal. When the first switch and the second switch corresponding to the power storage element B(j) (j is any of 1 to n) are respectively switches SWjand SWj, the SW control unit closes the switches SWjand SWjand opens other first and second switches according to an instruction of the operation processing unit, so that the capacitor is connected in parallel to the power storage element B(j).