Method for calculating number of healthy strings of sodium-sulfur battery and failure detection method using same
AssigneeNGK Insulators, Ltd.
InventorsNaoki Hirai, Motohiro Fukuhara
Life of this patent
Estimating the term…
Abstract
A number (uo) of healthy strings of one block in a sodium-sulfur battery is determined according to expression (1), and a failure of the sodium-sulfur battery is detected on the basis of the determination of the value of the uo. This method makes it possible to properly determine a failure of the sodium-sulfur battery, which can be used to compensate for fluctuations of electric power generated by a renewable energy generating device. uo=(Qo/Qs)×us . . . (1) where Qs: used capacity of reference block; Qo: used capacity of target block; and us: number of healthy strings of reference block (us≦u).
Claims6
A method for calculating the number of healthy strings of a sodium-sulfur battery, comprising:
- forming a string of the sodium-sulfur battery by connecting an S number of electric cells, which is a plural number, in series;
- connecting a U number of the strings, which is a plural number, in parallel to form a block;
- connecting an N number of the blocks, which is a plural number, in series, and
- determining in a control unit a number uo of healthy strings of a block in a sodium-sulfur battery according to expression (1) given below:
- uo=(Qs/Qo)×us (1)
- where
- Qs:
- used capacity of reference block;
- Qo:
- used capacity of target block;
- and
- us:
- number of healthy strings of reference block (us≦u).
Dependencies are inferred from the claim text.