Battery health state estimation method and device based on on-line alternating current impedance

Abstract

The invention provides a battery health state estimation method and device based on on-line alternating current impedance, and solves the problem that a current battery health state estimation methodis only suitable for an off-line state of a battery and is not suitable for dynamic characteristics of the battery. The embodiment of the invention provides a battery health state estimation method and device based on online alternating-current impedance. The method comprises the steps of: measuring the online alternating-current impedance of a battery; converting the online alternating-current impedance into an equivalent element parameter; and obtaining the health state of the battery based on the association relationship between the equivalent element parameters and the health state.

Description

technical field

[0001] The invention relates to the field of battery technology, in particular to a battery health state estimation method and device based on online AC impedance. Background technique

[0002] In recent years, the electrochemical energy storage technology represented by lithium-ion batteries has developed rapidly, and the technical and economical efficiency has been significantly improved. Under the joint promotion of global energy storage policies, technologies and markets, according to the statistics of the global energy storage project database of Zhongguancun Energy Storage Industry Technology Alliance (CNESA), as of the end of 2019, the cumulative installed capacity of global energy storage systems was 13.6GW (excluding pumped storage units). ), among which the installed capacity of electrochemical energy storage is 9520.5MW. Among various electrochemical energy storage technologies, the cumulative installed capacity of lithium-ion batteries is the larg...

Examples

Embodiment 1

[0034] figure 1 Shown is a schematic flowchart of a method for estimating the state of health of a battery based on online AC impedance provided by an embodiment of the present invention.

[0035] figure 1 Said, the battery state of health estimation method based on the online AC impedance described in the present invention includes:

[0036] Step S01: Measure the online AC impedance of the battery. Wherein, optionally, the battery may be a lithium battery.

[0037] Step S02: converting the online AC impedance into equivalent element parameters.

[0038] Step S03: Obtain the state of health of the battery based on the equivalent element parameters and the association relationship with the state of health.

[0039] figure 2 What is shown is a schematic flowchart of a method for establishing an association relationship between an equivalent element and a battery health state provided by an embodiment of the present invention.

[0040] Such as figure 2 As shown, before o...

Embodiment 2

[0049] Step 1: Select a total of 21 frequencies within the range of online AC impedance frequency from 1000Hz to 0.1Hz, and superimpose these 21 frequencies into a waveform;

[0050] Step 2: Put the lithium-ion battery in a constant temperature environment of 25°C, let it stand for one hour, perform a 1C charge-discharge cycle on the lithium-ion battery, and calibrate the battery once every 100 cycles. Optionally, you can follow the "GB / T36276-2018 Lithium-ion Batteries for Electric Power Storage" for calibration, and record the calibrated capacity.

[0051] Step 3: After the calibration in step 2, during the battery charging process, use the waveform in step 1 to stimulate the battery, and measure the online AC impedance data at 60% state of charge;

[0052] Step 4: Construct an equivalent circuit diagram, use the equivalent circuit to fit the online AC impedance data of different cycle times in step 3 to equivalent component parameters, and extract the charge transfer inter...

Embodiment 3

[0057] The device 100 for estimating the state of health of a battery includes a measurement module 10 , a conversion module 20 and conversion of AC impedance into equivalent component parameters. Wherein, the measurement module 10 is configured to measure the online AC impedance of the battery; the conversion module 20 is configured to convert the online AC impedance into equivalent element parameters; The relationship gets the state of health of the battery.

[0058] After the measurement module 10 measures the online AC impedance of the battery, the conversion module 20 converts the online AC impedance into equivalent element parameters, and then the processing module 30 obtains the battery health status.

[0059] The processing module 30 is further configured to: charge the battery after each calibration; during the charging process, apply the excitation signal to the battery in a preset charge state or energy state, and obtain the online AC impedance data.

[0060] The...

technical field

[0001] The invention relates to the field of battery technology, in particular to a battery health state estimation method and device based on online AC impedance. Background technique

[0002] In recent years, the electrochemical energy storage technology represented by lithium-ion batteries has developed rapidly, and the technical and economical efficiency has been significantly improved. Under the joint promotion of global energy storage policies, technologies and markets, according to the statistics of the global energy storage project database of Zhongguancun Energy Storage Industry Technology Alliance (CNESA), as of the end of 2019, the cumulative installed capacity of global energy storage systems was 13.6GW (excluding pumped storage units). ), among which the installed capacity of electrochemical energy storage is 9520.5MW. Among various electrochemical energy storage technologies, the cumulative installed capacity of lithium-ion batteries is the larg...

Examples

Embodiment 1

[0034] figure 1 Shown is a schematic flowchart of a method for estimating the state of health of a battery based on online AC impedance provided by an embodiment of the present invention.

[0035] figure 1 Said, the battery state of health estimation method based on the online AC impedance described in the present invention includes:

[0036] Step S01: Measure the online AC impedance of the battery. Wherein, optionally, the battery may be a lithium battery.

[0037] Step S02: converting the online AC impedance into equivalent element parameters.

[0038] Step S03: Obtain the state of health of the battery based on the equivalent element parameters and the association relationship with the state of health.

[0039] figure 2 What is shown is a schematic flowchart of a method for establishing an association relationship between an equivalent element and a battery health state provided by an embodiment of the present invention.

[0040] Such as figure 2 As shown, before o...

Embodiment 2

[0049] Step 1: Select a total of 21 frequencies within the range of online AC impedance frequency from 1000Hz to 0.1Hz, and superimpose these 21 frequencies into a waveform;

[0050] Step 2: Put the lithium-ion battery in a constant temperature environment of 25°C, let it stand for one hour, perform a 1C charge-discharge cycle on the lithium-ion battery, and calibrate the battery once every 100 cycles. Optionally, you can follow the "GB / T36276-2018 Lithium-ion Batteries for Electric Power Storage" for calibration, and record the calibrated capacity.

[0051] Step 3: After the calibration in step 2, during the battery charging process, use the waveform in step 1 to stimulate the battery, and measure the online AC impedance data at 60% state of charge;

[0052] Step 4: Construct an equivalent circuit diagram, use the equivalent circuit to fit the online AC impedance data of different cycle times in step 3 to equivalent component parameters, and extract the charge transfer inter...

Embodiment 3

[0057] The device 100 for estimating the state of health of a battery includes a measurement module 10 , a conversion module 20 and conversion of AC impedance into equivalent component parameters. Wherein, the measurement module 10 is configured to measure the online AC impedance of the battery; the conversion module 20 is configured to convert the online AC impedance into equivalent element parameters; The relationship gets the state of health of the battery.

[0058] After the measurement module 10 measures the online AC impedance of the battery, the conversion module 20 converts the online AC impedance into equivalent element parameters, and then the processing module 30 obtains the battery health status.

[0059] The processing module 30 is further configured to: charge the battery after each calibration; during the charging process, apply the excitation signal to the battery in a preset charge state or energy state, and obtain the online AC impedance data.

[0060] The...

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