PARAMETER ESTIMATION DEVICE USING FILTER

• US 20130185008A1
• Filed: 07/14/2011
• Published: 07/18/2013
• Est. Priority Date: 09/16/2010
• Status: Active Grant

• Current Assignee: Calsonic Kansei Corporation
• Original Assignee: Calsonic Kansei Corporation
• Inventors: Itabashi, Kinnosuke, Teranishi, Nozomu
• Granted Patent: US 9,784,794 B2
• Time in Patent Office: Days
• US Class Current: 702/63
• CPC Class Codes: G01R 31/36 Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
• CPC Class Codes: G01R 31/367 Software therefor, e.g. for battery testing using modelling or look-up tables
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: G01R 31/392 Determining battery ageing or deterioration, e.g. state of health
• CPC Class Codes: H01M 10/486 for measuring temperature
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A parameter estimation device using a filter has a preprocessing computing means 6, a state estimating means 7 and a state-of-charge estimating means 9. A low-pass filter 61 of the preprocessing computing means 6 transfers voltage preprocessing value V_p and current preprocessing value I_p from inputted discharge-and-charge current value I and terminal voltage value V, respectively. The state estimating means 7 estimates parameters of a state equation of a battery equivalent model 7A based on the battery equivalent model 7A containing a resistance and a capacitor from the voltage preprocessing value and the current preprocessing value inputted from the means 6. The state-of-charge estimating means 9 estimates the state of charge from state quantity obtained by the means 7. The time constant varies in such a way that the higher the temperature and the state of charge SoC becomes the smaller the time constant becomes.

Claims

1. A parameter estimation device using a filter comprising:

a discharge-and-charge current detecting means that detects a discharge-and-charge current value of a battery;

a terminal voltage detecting means that detects a terminal voltage value of the battery;

a temperature detecting means that detects a temperature of the battery;

a stage-of-health detecting means that detects a state of health of the battery;

a preprocessing computing means that transfers the discharge-and-charge current value detected by the discharge-and-charge current detecting means and the terminal voltage value detected by the terminal voltage detecting means to a current preprocessing value and a voltage preprocessing value, respectively, by inputting the discharge-and-charge current value and the terminal voltage value to a low-pass filter;

a state estimating means that estimates parameters of a state equation expressing a battery equivalent circuit model from the voltage preprocessing value and the current preprocessing value obtained by the preprocessing computing means, based on the battery equivalent circuit model containing a resistance and a capacitor; and

a state-of-charge estimating means that estimates a state of charge of the battery based on a state quantity obtained by the state estimating means, wherein

the low-pass filter has a time constant that is set to vary in such a way that the higher the temperature detected by the battery temperature detecting means the smaller time constant becomes, and in such a way that the higher the state of health detected by the state-of-health detecting means becomes the smaller time constant becomes, and such that the higher the state of charge detected by the state-of-charge detecting means becomes the smaller time constant becomes.

2. The parameter estimation device using the filter according to claim 1, wherein

the battery equivalent circuit model has one resistance corresponding to a feedthrough term including an electrolytic resistance, a wire-connection resistance and a charge-transfer resistance, the one resistance being connected to a parallel circuit consisting of a resistance and a capacitance to correspond to a diffusional resistance of the battery.

3. The parameter estimation device using the filter according to claim 2, wherein

the parallel circuit comprises two parallel circuits that are connected to each other in series.