Hybrid supercapacitor modeling method

Abstract

The invention discloses a hybrid supercapacitor modeling method. Models mainly comprise a charge state model, an open-circuit voltage model, an internal resistance characteristic model, a temperature characteristic model and an output voltage model of a hybrid supercapacitor. The invention relates to the technical field of super capacitor modeling, and has the beneficial effects that the complete model building of a hybrid super capacitor electrical system is realized, and the real simulation of the charge state, the working voltage and current, the internal resistance change, the heating condition and the output voltage of the hybrid super capacitor when the electrical system works in reality is realized.

Description

Technical Field

[0001] The invention relates to the field of hybrid supercapacitor modeling, and in particular to a hybrid supercapacitor modeling method. Background Art

[0002] The early energy storage systems of new energy power systems had the problem of a single energy storage method. They mainly used single methods such as electrochemical energy storage, pumped storage, and flywheel energy storage, but the actual effect was not ideal. In order to meet the comprehensive needs of the new power system for large-scale, multi-scale power-energy balance, a variety of energy storage technologies should be used in combination to effectively achieve the multi-time scale balance of power-energy in the new power system and obtain the best technical and economic benefits. For example, in a high-proportion new energy environment, the flexible application of energy storage systems to provide stable energy and power at the same time has become the focus of research. Hybrid supercapacitors are a new type of energy storage device that combines the advantages of supercapacitors and batteries. They have both high power density and energy density, and their energy-power ratio is more optimized, the charging rate and efficiency are high, the operating temperature range is wide, the safety is high, it is not restricted by geographical address conditions, and the cycle life is long. They are suitable for occasions with high requirements for energy storage density and power performance. Therefore, hybrid supercapacitors can be used as an energy source for grid-type energy storage to promote the energy balance of the system and support the safety and stability of the system. Therefore, a hybrid supercapacitor modeling method is built to more effectively study the electrical characteristics of hybrid supercapacitors and the energy storage performance of hybrid supercapacitors in new power systems. Summary of the invention

[0003] The purpose of the present invention is to solve the above problems and to design a hybrid supercapacitor modeling method.

[0004] To achieve the above-mentioned purpose, the technical solution of the present invention is a hybrid supercapacitor modeling method, which models the electrical characteristics of the hybrid supercapacitor, and the model mainly includes a state of charge model, an open circuit voltage model, an internal resistance characteristic model, a temperature characteristic model and an output voltage model of the hybrid supercapacitor;

[0005] The present invention is implemented as follows: a hybrid supercapacitor modeling method comprises the following steps:

[0006] Step 1, setting the initial state of charge SOC0 and initial temperature T0 of the hybrid supercapacitor model;

[0007] Step 2, measure the current value flowing through the hybrid supercapacitor model, and record the current value as I;

[0008] Step 3, sending the initial state of charge SOC0 in step 1 and the current value I recorded in step 2 into the state of charge model to calculate the state of charge SOC(t) of the hybrid supercapacitor model;

[0009] Step 4: Send the initial temperature T0 in step 1 and the state of charge SOC(t) calculated in step 3 to the internal resistance characteristic model to calculate the internal resistance Z of the hybrid supercapacitor model. sc ;

[0010] Step 5: Substitute the initial temperature T0 in step 1 and the internal resistance Z calculated in step 4 sc The temperature T of the hybrid supercapacitor model is calculated by sending it into the temperature characteristic model;

[0011] Step 6: Input the state of charge SOC(t) calculated in step 3 and the temperature T calculated in step 5 into the open circuit voltage model to calculate the open circuit voltage value U of the hybrid supercapacitor model. OCV ;

[0012] Step 7: Substitute the current value I recorded in step 2 and the internal resistance Z calculated in step 4. sc and the open circuit voltage U calculated in step 6 OCV The output voltage value U of the hybrid supercapacitor model is calculated by sending it to the output voltage model. out .

[0013] The state of charge model, the main input of which is the current flowing through the hybrid supercapacitor in the circuit in which the hybrid supercapacitor is currently located, can calculate the state of charge of the hybrid supercapacitor according to the current under different working conditions. When the hybrid supercapacitor model is working, its state of charge SOC(t) can be expressed as:

[0014] SOC(t)=SOC0-∫I(t)dt / Q n

[0015] Where SOC0 is the initial state of charge of the hybrid supercapacitor; I(t) is the current value (A) flowing through the port of the hybrid capacitor; Q n is the charge of the hybrid capacitor (C).

[0016] The open circuit voltage model, which combines the state of charge SOC(t) calculated by the state of charge model of the hybrid supercapacitor and the temperature T calculated by the temperature characteristic model, can obtain the open circuit voltage U of the hybrid supercapacitor model. OCV It can be expressed as:

[0017] U OCV =f(SOC(t),T)

[0018] Where U OCV As a function of SOC(t) and T, U can be calculated by the open circuit voltage model. OCV value.

[0019] The internal resistance characteristic model, which combines the state of charge SOC(t) calculated by the state of charge model and the temperature T of the hybrid supercapacitor calculated by the temperature characteristic model, can obtain the internal resistance Z of the hybrid supercapacitor model. sc It can be expressed as:

[0020] Z sc =g(SOC(t),T)

[0021] In the formula, Z sc As a function of SOC(t) and T, Z can be calculated using the temperature characteristic model. sc value.

[0022] The temperature characteristic model combines the current flowing through the hybrid supercapacitor model and the internal resistance characteristic model to calculate the heating condition and temperature change of the hybrid supercapacitor, and obtains the real-time temperature change of the hybrid supercapacitor model.

[0023] Temperature calculation:

[0024] T=T0+(Q 热 -Q 散 ) / (m·c)

[0025] Q 热 =I 2 ·Z sc

[0026] Q 散 =∫h·A·(TT e )dt

[0027] Where, T is the real-time temperature of the hybrid supercapacitor (℃); T0 is the initial temperature of the hybrid supercapacitor (℃); T e is the ambient temperature (℃); Q 热 is the heat generated by the hybrid supercapacitor during operation (J); Q 散 is the heat dissipated during the operation of the hybrid supercapacitor (J); m is the mass of the hybrid supercapacitor (kg); c is the overall specific heat capacity of the hybrid supercapacitor (J / kg·K); I is the current flowing through the hybrid supercapacitor (A); Z sc is the internal resistance of the hybrid supercapacitor (Ω); A is the contact area between the hybrid supercapacitor and the air (m 2 ), h is the air convection heat transfer coefficient.

[0028] The output voltage model, which combines the current I flowing through the hybrid supercapacitor model and the open circuit voltage U calculated by the open circuit voltage model OCV The internal resistance Z calculated by the internal resistance characteristic model sc, and the output voltage value U of the hybrid supercapacitor model is obtained out It can be expressed as:

[0029] U out =U OCV -I·Z sc

[0030] A hybrid supercapacitor modeling method produced by utilizing the technical solution of the present invention realizes the construction of a complete model of the hybrid supercapacitor electrical system, and realizes the true simulation of the charge state, working voltage and current, internal resistance change and heating conditions, and output voltage of the hybrid supercapacitor when working in the electrical system in reality. The use of the hybrid supercapacitor model for power system simulation can better fit the actual working conditions of the hybrid supercapacitor in the power system, and provides benefits for the development of energy storage systems of new power systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is the overall model diagram of the hybrid supercapacitor model;

[0032] Figure 2 It is the charge state model diagram in the hybrid supercapacitor model;

[0033] Figure 3 This is the open circuit voltage model diagram in the hybrid supercapacitor model;

[0034] Figure 4 This is the internal resistance characteristic model diagram in the hybrid supercapacitor model;

[0035] Figure 5 This is the temperature characteristic model diagram of the hybrid supercapacitor model;

[0036] Figure 6 This is the output voltage model diagram in the hybrid supercapacitor model.

[0037] In the figure, 1. open circuit voltage model diagram; 2. open circuit voltage model diagram; 3. internal resistance characteristic model diagram; 4. temperature characteristic model diagram; 5. output voltage model diagram. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention more clear, the technical solutions of the present invention will be further described in detail below in conjunction with the accompanying drawings of the present invention.

[0039] A hybrid supercapacitor modeling approach is based on actual hybrid supercapacitors.

[0040] The electrical characteristics of the hybrid supercapacitor were simulated in Matlab / Simulink software. Figure 1The structure of the hybrid supercapacitor model shown is constructed, and this model mainly includes the charge state model, open circuit voltage model, internal resistance characteristic model, temperature characteristic model and output voltage model of the hybrid supercapacitor.

[0041] The simulation modeling of the hybrid supercapacitor in Simulink includes the following steps:

[0042] Step 1, setting the initial state of charge SOC0 and initial temperature T0 of the hybrid supercapacitor model;

[0043] Step 2, measure the current value flowing through the hybrid supercapacitor model, and record the current value as I;

[0044] Step 3, sending the initial state of charge SOC0 in step 1 and the current value I recorded in step 2 into the state of charge model to calculate the state of charge SOC(t) of the hybrid supercapacitor model;

[0045] Step 4: Send the initial temperature T0 in step 1 and the state of charge SOC(t) calculated in step 3 to the internal resistance characteristic model to calculate the internal resistance Z of the hybrid supercapacitor model. sc ;

[0046] Step 5: Substitute the initial temperature T0 in step 1 and the internal resistance Z calculated in step 4 sc The temperature T of the hybrid supercapacitor model is calculated by sending it into the temperature characteristic model;

[0047] Step 6: Input the state of charge SOC(t) calculated in step 3 and the temperature T calculated in step 5 into the open circuit voltage model to calculate the open circuit voltage value U of the hybrid supercapacitor model. OCV ;

[0048] Step 7: Substitute the current value I recorded in step 2, the internal resistance Zsc calculated in step 4, and the open circuit voltage value U calculated in step 6. OCV The output voltage value U of the hybrid supercapacitor model is calculated by sending it to the output voltage model. out .

[0049] In Simulink, follow Figure 2 The model shown builds a state-of-charge model. The main input of this model is the current flowing through the hybrid supercapacitor in the circuit where the hybrid supercapacitor is currently located. The state of charge of the hybrid supercapacitor can be calculated according to the current under different working conditions. When the hybrid supercapacitor model is working, its state of charge SOC(t) can be expressed as:

[0050] SOC(t)=SOC0-∫I(t)dt / Q n

[0051] Where SOC0 is the initial state of charge of the hybrid supercapacitor; I(t) is the current value (A) flowing through the port of the hybrid capacitor; Q n is the charge of the hybrid capacitor (C), which is 28800C.

[0052] In Simulink, follow Figure 3 The model shown builds an open circuit voltage model. This model combines the state of charge SOC(t) calculated by the state of charge model of the hybrid supercapacitor and the temperature T calculated by the temperature characteristic model to obtain the open circuit voltage U of the hybrid supercapacitor model. OCV It can be expressed as:

[0053] U OCV =f(SOC(t),T)

[0054] Where U OCV As a function of SOC(t) and T, U can be calculated by the open circuit voltage model. OCV value.

[0055] In Simulink, follow Figure 4 The model shown builds an internal resistance characteristic model. This model combines the state of charge SOC(t) calculated by the state of charge model and the hybrid supercapacitor temperature T calculated by the temperature characteristic model to obtain the internal resistance Z of the hybrid supercapacitor model. sc It can be expressed as:

[0056] Z sc =g(SOC(t),T)

[0057] In the formula, Z sc As a function of SOC(t) and T, Z can be calculated using the temperature characteristic model. sc value.

[0058] In Simulink, follow Figure 5 The model shown builds a temperature characteristic model. This model combines the current flowing through the hybrid supercapacitor model and the internal resistance characteristic model to calculate the heating and temperature changes of the hybrid supercapacitor, and obtains the real-time temperature changes of the hybrid supercapacitor model.

[0059] Temperature calculation:

[0060] T=T0+(Q 热 -Q 散 ) / (m·c)

[0061] Q 热 =I 2 ·Z sc

[0062] Q 散 =∫h·A·(TT e )dt

[0063] Where, T is the real-time temperature of the hybrid supercapacitor (℃); T0 is the initial temperature of the hybrid supercapacitor (℃); T e is the ambient temperature (℃); Qheat is the heat generated by the hybrid supercapacitor during operation (J); Qdissipation is the heat dissipated during the operation of the hybrid supercapacitor (J); m is the mass of the hybrid supercapacitor (kg); c is the overall specific heat capacity of the hybrid supercapacitor (J / kg·K); I is the current flowing through the hybrid supercapacitor (A); Z sc is the internal resistance of the hybrid supercapacitor (Ω); A is the contact area between the hybrid supercapacitor and the air (m 2 ), h is the air convection heat transfer coefficient.

[0064] In Simulink, follow Figure 6 The model shown builds an output voltage model, which combines the current I flowing through the hybrid supercapacitor model and the open circuit voltage U calculated by the open circuit voltage model OCV The internal resistance Z calculated by the internal resistance characteristic model sc , and the output voltage value U of the hybrid supercapacitor model is obtained out It can be expressed as:

[0065] U out =U OCV -I·Z sc

[0066] The Matlab / Simulink simulation method of the present invention can truly and reliably simulate the electrical characteristics of the hybrid supercapacitor, can be more in line with the actual working conditions of the hybrid supercapacitor in the power system, and provides benefits for the development of energy storage systems of new power systems.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A hybrid supercapacitor modeling method, characterized in that: The model mainly includes the charge state model (1), open circuit voltage model (2), internal resistance characteristic model (3), temperature characteristic model (4) and output voltage model (5) of the hybrid supercapacitor.

2. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The following steps are involved: Step 1, setting the initial state of charge SOC0 and initial temperature T0 of the hybrid supercapacitor model; Step 2, measure the current value flowing through the hybrid supercapacitor model, and record the current value as I; Step 3, sending the initial state of charge SOC0 in step 1 and the current value I recorded in step 2 into the state of charge model (1) to calculate the state of charge SOC(t) of the hybrid supercapacitor model; Step 4: Send the initial temperature T0 in step 1 and the state of charge SOC(t) calculated in step 3 to the internal resistance characteristic model (3) to calculate the internal resistance Z of the hybrid supercapacitor model. sc ; Step 5: Substitute the initial temperature T0 in step 1 and the internal resistance Z calculated in step 4 sc The temperature T of the hybrid supercapacitor model is calculated by inputting the temperature characteristic model (4); Step 6: Input the state of charge SOC(t) calculated in step 3 and the temperature T calculated in step 5 into the open circuit voltage model (2) to calculate the open circuit voltage value U of the hybrid supercapacitor model. OCV ; Step 7: Substitute the current value I recorded in step 2 and the internal resistance Z calculated in step 4. sc and the open circuit voltage U calculated in step 6 OCV The output voltage value U of the hybrid supercapacitor model is calculated by sending it to the output voltage model. out .

3. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The state of charge model (1) is mainly inputted by the current flowing through the hybrid supercapacitor in the circuit in which the hybrid supercapacitor is currently located. The state of charge of the hybrid supercapacitor can be calculated according to the current under different working conditions. When the hybrid supercapacitor model is working, its state of charge SOC(t) can be expressed as: SOC(t)=SOC0-∫I(t)dt / Q n Where SOC0 is the initial state of charge of the hybrid supercapacitor; I(t) is the current value (A) flowing through the port of the hybrid capacitor; Q n is the charge of the hybrid capacitor (C).

4. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The open circuit voltage model (2) is combined with the state of charge SOC (t) calculated by the state of charge model (1) of the hybrid supercapacitor and the temperature T calculated by the temperature characteristic model (4), and the open circuit voltage U of the hybrid supercapacitor model can be obtained. OCV It can be expressed as: U OCV =f(SOC(t),T) Where U OCV As a function of SOC(t) and T, U can be calculated by the open circuit voltage model. OCV value.

5. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The internal resistance characteristic model (3) is combined with the state of charge SOC (t) calculated by the state of charge model (1) and the temperature T of the hybrid supercapacitor calculated by the temperature characteristic model (4), and the internal resistance Z of the hybrid supercapacitor model can be obtained. sc It can be expressed as: Z sc =g(SOC(t),T) In the formula, Z sc As a function of SOC(t) and T, Z can be calculated by the temperature characteristic model (4): sc value.

6. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The temperature characteristic model (4) is used to calculate the heating condition and temperature change of the hybrid supercapacitor by combining the current flowing through the hybrid supercapacitor model and the internal resistance characteristic model (3), thereby obtaining the real-time temperature change of the hybrid supercapacitor model; Temperature calculation: T=T0+(Q 热 -Q 散 ) / (m·c) Q 热 =I 2 ·Z sc Q 散 =∫h·A·(T-T e )dt Where, T is the real-time temperature of the hybrid supercapacitor (℃); T0 is the initial temperature of the hybrid supercapacitor (℃); T e is the ambient temperature (℃); Q 热 is the heat generated by the hybrid supercapacitor during operation (J); Q 散 is the heat dissipated during the operation of the hybrid supercapacitor (J); m is the mass of the hybrid supercapacitor (kg); c is the overall specific heat capacity of the hybrid supercapacitor (J / kg·K); I is the current flowing through the hybrid supercapacitor (A); Zsc is the internal resistance of the hybrid supercapacitor (Ω); A is the contact area between the hybrid supercapacitor and the air (m 2 );h is the air convection heat transfer coefficient.

7. A hybrid supercapacitor modeling method according to claim 1, characterized in that: The output voltage model (5) is a model that combines the current I flowing through the hybrid supercapacitor model and the open circuit voltage U calculated by the open circuit voltage model (2). OCV The internal resistance Z calculated by the internal resistance characteristic model (3) sc , and the output voltage value U of the hybrid supercapacitor model is obtained out It can be expressed as: U out =U OCV -I·Z sc。

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