Estimation device and estimation method
This estimation device is provided with: an acquiring unit which acquires a measurement result from a temperature sensor for measuring temperature at a specific location to which heat generated by an electrical storage device is transmitted; and an observer which, in accordance with input of the measurement result, estimates the temperature at a location where the temperature sensor has not performed measurement.
1 . An estimation device comprising:
an acquisition unit that acquires a measurement result from a temperature sensor that measures a temperature at a specific position to which heat generated from a plurality of energy storage elements within an energy storage device is transferred;
an observer that estimates a temperature at a position where the temperature sensor does not measure a temperature in response to input of the measurement result and based, in part, thereon and on an environmental temperature of the energy storage device; and
an arithmetic unit that calculates a speed as to a degradation of the plurality of energy storage elements based upon the measurement result, the estimate, and a change of one or more characteristics of the plurality of energy storage elements.
2 . The estimation device according to claim 1 , wherein the observer estimates a temperature at a position where the temperature sensor does not measure a temperature by deriving a state variable based on a state equation simulating heat conduction in the energy storage device and an observation equation expressing a relationship between the state variable in the state equation and an observation variable observable by the temperature sensor.
3 . The estimation device according to claim 2 , wherein the observer includes an internal parameter designed in such a manner that an estimated temperature by the observer and a measured temperature by the temperature sensor asymptotically approach each other.
4 . The estimation device according to claim 1 , wherein the observer includes an internal parameter designed in such a manner that an estimated temperature by the observer and a measured temperature by the temperature sensor asymptotically approach each other.
5 . The estimation device according to claim 1 , wherein:
the temperature sensor is provided in the energy storage device, and
the observer estimates a temperature outside the energy storage device based on a temperature of the energy storage device measured by the temperature sensor.
6 . The estimation device according to claim 1 , wherein in the observer, an observer gain is formulated by a Kalman filter.
7 . The estimation device according to claim 1 , wherein the estimation device is configured as a server device disposed separately from the energy storage device.
8 . The estimation device according to claim 1 , wherein the simulation of the degradation prediction of the energy storage device is simulation based on a physical model of the energy storage device.
9 . An estimation method comprising the steps of:
acquiring a measurement result from a temperature sensor that measures a temperature at a specific position to which heat generated from a plurality of energy storage elements within an energy storage device is transferred;
estimating a temperature at a position where the temperature sensor does not measure a temperature based upon an environmental temperature of the energy storage device and by inputting the measurement result to an observer that estimates a state variable based on a state equation simulating heat conduction in the energy storage device and an observation equation expressing a relationship between the state variable in the state equation and an observation variable observable by the temperature sensor; and
calculating a speed as to a degradation of the plurality of energy storage elements based upon the measurement result, the estimate, and a change of one or more characteristics of the plurality of energy storage elements.