Method and apparatus for estimating maximum power of battery by using internal resistance of the battery

Abstract

Disclosed is a method for estimating the maximum power of a battery, which can inexpensively perform an estimation of the maximum power of a battery in a relatively simple manner of using the internal resistance of the battery, which has a correlation with and a largest effect on the maximum power of the battery. The method includes the steps of: measuring an internal resistance and a temperature of the battery and estimating a state of charge, if an estimation of the maximum power of the battery is requested; and reading a value of the maximum power of the battery, which corresponds to the measured temperature, the estimated state of charge, and the measured internal resistance, from a table in which the internal resistances and the maximum powers of the battery are mapped according to the temperatures and states of charge.

1 . A method of estimating a maximum power of a battery, comprising the steps of: 
 measuring an internal resistance and a temperature of the battery and estimating its state of charge, if an estimation of the maximum power of the battery is requested; and    reading a value of the maximum power of the battery, which corresponds to the measured temperature, the estimated state of charge, and the measured internal resistance, from a table in which the values of the internal resistance and the maximum power of the battery are mapped according to temperatures and states of charge.    
     
     
         2 . The method as claimed in  claim 1 , further comprising the steps of: 
 measuring the internal resistances and maximum powers of the battery according to the temperatures and states of charge; and    storing in a memory the table in which the internal resistances and maximum powers of the battery have been measured according to the temperatures and states of charge.    
     
     
         3 . The method as claimed in  claim 2 , wherein the measurements of the internal resistance and maximum power of the battery taken in order to form the table, are actually carried out in a range of an operational temperature and an operational state of charge.  
     
     
         4 . The method as claimed in  claim 1 , wherein the internal resistance is calculated by measuring the electric current and voltage of the battery.  
     
     
         5 . The method as claimed in  claim 1 , wherein the internal resistance is calculated by measuring voltage and electric current of the battery for a preset time, while a certain device having the battery is driven.  
     
     
         6 . An apparatus for estimating a maximum power of a battery, comprising: 
 a memory for storing a table in which internal resistances and maximum powers of the battery are mapped according to temperatures and states of charge;    a sensor for sensing temperature;    an estimation unit for estimating the state of charge of the battery;    a measurement unit for measuring voltage and electric current of the battery; and    a controller for measuring the temperature through the temperature sensor, estimating a state of charge through the estimation unit, measuring the voltage and electric current of the battery through the measurement unit so as to calculate the internal resistance of the battery, and reading the value of the maximum power of the battery, which corresponds to the measured temperature, the estimated state of charge, and the calculated internal resistance, from the table, when an estimation of the maximum power of the battery is requested.    
     
     
         7 . The apparatus as claimed in  claim 6 , wherein the controller measures the real-time voltage and electric current of the battery for a preset time, and calculates the internal resistance using the measured current and voltage.