JPWO2018047258A1 - Simulation method and simulation apparatus - Google Patents

Abstract

The simulation method includes the step S04 of calculating the current flowing through the equivalent circuit model, the step S51 of setting at least one of the resistance value of the resistor and the capacitance value of the capacitor according to the current calculated in step S04, Step S52 of calculating the polarization voltage generated in the storage device using the calculation result in S04 and the setting result in step S51, and step S07 of calculating the terminal voltage of the storage device using the calculation result in step S52 And.

Description

  The present invention relates to a simulation method and a simulation apparatus.

  BACKGROUND Storage devices such as lead batteries, lithium ion batteries and lithium ion capacitors may be mounted on vehicles such as electric vehicles and hybrid vehicles. The terminal voltage of the storage device may be used to calculate the fuel consumption of the vehicle in which the storage device is mounted. For example, a storage device model for calculating a terminal voltage of the storage device is used to estimate the terminal voltage of the storage device. An example of the storage device model is an equivalent circuit model.

  The terminal voltage of the storage device may include a polarization voltage generated in the storage device. For example, Patent Document 1 discloses a method of representing a voltage generated in an RC parallel circuit as a polarization voltage using an equivalent circuit model including an RC parallel circuit.

Japanese Patent Publication No. 2016-508214 gazette

  There are cases where it is not possible to obtain an accurate value of the polarization voltage simply by representing the polarization voltage by the voltage generated in the RC parallel circuit as in Patent Document 1. This causes the impediment to improving the accuracy of simulation of the terminal voltage of the storage device.

  Various aspects of the present invention provide a simulation method and simulation apparatus capable of improving the estimation accuracy of a terminal voltage of a storage device.

  A simulation method according to one aspect of the present invention estimates a terminal voltage of a storage device using an equivalent circuit model of the storage device including a resistor and a capacitor connected in parallel for representing a polarization voltage generated in the storage device. It is a simulation method which a simulation apparatus performs. The simulation method comprises the steps of: calculating a current flowing through the equivalent circuit model; setting at least one of the resistance value of the resistor and the capacitance value of the capacitor according to the current calculated in the calculating step; Calculating the polarization voltage generated in the storage device using the calculation result in the setting step and the setting result in the setting step, and using the calculation result in the step of calculating the polarization voltage, the terminal voltage of the storage device Calculating

  According to the above simulation method, the equivalent circuit model includes a resistor and a capacitor connected in parallel for representing a polarization voltage generated in the storage device. At least one of the resistance value of the resistor and the capacitance value of the capacitor is set according to the current flowing in the equivalent circuit model. Thus, unlike in the case where the resistance value of the resistor and the capacitance value of the capacitor are constant regardless of the current flowing through the equivalent circuit, at least one of the resistor and the capacitor Have. As a result, the calculation accuracy of the polarization voltage is improved as compared to the case where neither the resistor nor the capacitor has the above-mentioned non-linear characteristic. Therefore, it is possible to improve the estimation accuracy of the terminal voltage.

  In the setting step, at least one of the resistance value of the resistor and the capacitance value of the capacitor may be set according to the value of the current flowing through the resistor and the capacitor. As described above, at least one of the resistor and the capacitor can be provided with the non-linear characteristic with the value of the current as an argument. Also, by setting the value of the current flowing through the resistor and capacitor as an argument, it is possible to set the resistance value of the resistor only according to the value of the current flowing through the resistor, or according to only the value of the current flowing through the capacitor The polarization voltage can be calculated more accurately than when the capacitance value of the capacitor is set.

  In the setting step, the resistance value of the resistor may be set using a value obtained from the Butler-Volmer equation using the value of the current flowing through the resistor and the capacitor as a variable. Thereby, the polarization voltage can be calculated more accurately.

  The simulation method further includes the step of calculating a DC resistance voltage which is a voltage generated in the DC resistance component of the equivalent circuit model, and in the step of calculating the terminal voltage, the terminal voltage is calculated based on the DC resistance voltage The resistance component includes a linear DC resistance component and a nonlinear DC resistance component connected in series with the linear DC resistance component, and the nonlinear DC resistance component may have a resistance value that changes in accordance with the current.

  In the storage device, in addition to the fixed DC resistance component, a variable DC resistance component due to an electrolytic solution or the like is included. In order to simulate this variable DC resistance component, the DC resistance component of the equivalent circuit model includes a nonlinear DC resistance component connected in series with the linear DC resistance component, and the nonlinear DC resistance component changes in accordance with the current It has a resistance value. In this equivalent circuit model, since the resistance value of the DC resistance component is determined to be one value according to the state of the storage device, the calculation accuracy of the DC resistance voltage is improved. As a result, it is possible to improve the estimation accuracy of the terminal voltage of the storage device.

  The simulation method further includes the step of calculating a DC resistance voltage which is a voltage generated in the DC resistance component of the equivalent circuit model, and in the step of calculating the terminal voltage, the terminal voltage is calculated based on the DC resistance voltage The resistance component includes a linear DC resistance component and a gassing portion connected in series with the linear DC resistance component, and the gassing portion includes a capacitor and a switching element connected in parallel to calculate a DC resistance voltage. In the step, a first voltage which is a voltage generated in the linear DC resistance component and a second voltage which is a voltage generated in the gassing portion are calculated, and a DC resistance voltage is calculated based on the first voltage and the second voltage. It is also good.

  The gassing generated in the storage device can be regarded as a direct current resistance component. In order to simulate the DC resistance component due to this gassing, the DC resistance component of the equivalent circuit model includes a gassing portion connected in series with the linear DC resistance component, and the gassing portion has a capacitor and a switching element connected in parallel. ing. Since the DC resistance component based on the gassing is simulated by such a simple circuit, it becomes possible to simplify the calculation of the terminal voltage of the storage device.

  In the setting step, the time constant determined from the resistance value of the resistor and the capacitance value of the capacitor may be set to different values depending on whether the power storage device is in the charged or discharged state or in the inactive state. Good.

  In this case, the time constant determined from the resistance value of the resistor and the capacitance value of the capacitor 22 is set to different values depending on whether the power storage device is in the charged or discharged state and in the inactive state. Thus, by changing the value of the time constant in the charged or discharged state and in the inactive state, polarization is more than when the same time constant is used in the charged or discharged state and the inactive state. The voltage can be calculated accurately. This makes it possible to improve the estimation accuracy of the terminal voltage of the storage device.

  A simulation apparatus according to another aspect of the present invention estimates a terminal voltage of a storage device using an equivalent circuit model of the storage device including a resistor and a capacitor connected in parallel for representing a polarization voltage generated in the storage device. A simulation device for calculating at least one of the resistance value of the resistor and the capacitance value of the capacitor according to the current calculated by the current calculation unit. Using the setting unit and the calculation result of the current calculation unit and the setting result of the setting unit, the polarization voltage calculation unit that calculates the polarization voltage generated in the storage device, and the calculation result of the polarization voltage calculation unit And a terminal voltage calculation unit that calculates a terminal voltage of the device. This simulation apparatus also makes it possible to improve the estimation accuracy of the terminal voltage of the storage device, as in the above-described simulation method.

  According to various aspects of the present invention, it is possible to improve the estimation accuracy of the terminal voltage of the power storage device.

It is a figure which shows schematic structure of a fuel-consumption calculation apparatus. It is a figure which shows the equivalent circuit model for calculating the voltage of an electrical storage device. It is a figure which shows schematic structure of the electrical storage device simulator which concerns on one Embodiment. It is a figure which shows the example of the hardware constitutions of the electrical storage device simulator of FIG. It is a figure which shows the example of a detailed structure of a direct current resistance calculation part. It is a figure which shows the example of a detailed structure of a polarization calculation part. It is a figure which shows the example of calculation by a polarization calculation part. It is a figure which shows the example of calculation by a polarization calculation part. It is a flowchart which shows the example of the process performed in the electrical storage device simulator of FIG. It is a flowchart which shows the example of calculation processing of the electric current and direct current | flow resistance voltage of FIG. It is a flowchart which shows the example of calculation processing of the polarization voltage of FIG. It is a figure which shows the example of the presumed result (simulation result) of the terminal voltage of the electrical storage device by an electrical storage device simulator. It is a figure which shows the change of the terminal voltage of a halt condition.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements will be denoted by the same reference symbols, without redundant description.

  The simulation apparatus according to one embodiment is used, for example, in calculation of fuel consumption of a vehicle equipped with a power storage device. The storage device mounted on a vehicle adopting a so-called μHEV (Hybrid Electric Vehicle) system may be a sub storage device provided separately from the main storage device. In that case, in the fuel consumption calculation, the power storage device is used to cover the consumption current of the 12V auxiliary equipment mounted on the vehicle.

[Summary of fuel consumption calculation device]
FIG. 1 is a diagram showing a schematic configuration of a fuel consumption calculation device that performs the above-described fuel consumption calculation. As shown in FIG. 1, the fuel consumption calculation device 90 includes an input unit 91, a control unit 92, and an output unit 93 as its functional blocks.

  The input unit 91 inputs data necessary for fuel consumption calculation. An example of the input data is a traveling pattern of the vehicle. Besides that, parameters that determine the characteristics of various devices such as an engine mounted on a vehicle, types of control methods of charging and discharging of a storage device, configuration of a storage device, power consumption of accessories mounted on a vehicle, and a vehicle Data such as the weight of can be input.

  The control unit 92 performs fuel consumption calculation using the data input by the input unit 91. Although the specific method of fuel consumption calculation is not particularly limited, for example, the following procedure is performed.

  First, based on the traveling pattern and the like input by input unit 91, control unit 92 requires, for example, power required for the vehicle to travel (hereinafter simply referred to as "required power") and consumption current of auxiliary equipment for each section. Calculate The sections include a stop section, an acceleration section, a constant speed travel section, and a deceleration section. The required power is relatively large in the acceleration section and relatively small in the constant speed traveling section. The required power may be zero in the stop section and the deceleration section. The consumption current of the accessory varies depending on the type of accessory. For example, the magnitude of the current consumption of an accessory that is continuously used, such as an audio device, is substantially constant regardless of the section. On the other hand, the magnitude of the consumption current of accessories temporarily used such as the ignition device of the engine becomes large only at the time of use.

  Next, the control unit 92 calculates the output of the engine for each section. The output of the engine is, for example, 0 when the engine is stopped in the stop section, and is set to a predetermined output in the other sections. Of the output of the engine, an output exceeding the required power is converted into power by the alternator and supplied from the alternator to the accessory and the storage device. When the power supplied from the alternator exceeds the power consumption of the accessory, current flows from the alternator to the storage device to charge the storage device. When the power supplied from the alternator falls below the power consumption of the accessory, a current flows from the storage device to the accessory, and the storage device is discharged. Here, the terminal voltage of the storage device depends on the state of charge (SOC) of the storage device, the magnitude of the charge / discharge current, and the like. The terminal voltage of the storage device is estimated, for example, using an equivalent circuit model for calculating the terminal voltage of the storage device. Details of the estimation of the terminal voltage will be described later. The control unit 92 also calculates the charge / discharge power of the storage device for each section from the charge / discharge current of the storage device and the terminal voltage of the storage device.

  Thereafter, control unit 92 calculates the integrated value of the output of the engine and the charge / discharge power of the storage device in all the sections. The integrated value of the output of the engine in all sections indicates the amount of energy that the engine will consume when the vehicle travels in the travel pattern input by the input unit 91. The integrated value of the charge / discharge power of the storage device in the entire section indicates the magnitude of the amount of energy that would increase or decrease in the storage device when the vehicle travels in the travel pattern input by the input unit 91. The amount of energy that the engine will consume, the amount of energy that will decrease in the power storage device, and the total amount of energy become the amount of energy required to drive the vehicle in the travel pattern input by the input unit 91. Since the travel distance of the vehicle is also known from the travel pattern, based on the travel distance and the amount of energy required for it, the control unit 92 calculates the travelable distance per predetermined amount of energy as the fuel consumption.

  The output unit 93 outputs the fuel consumption calculated by the control unit 92. As a result, the result of the fuel consumption calculation based on the traveling pattern and the like input by the input unit 91 can be obtained.

  As described above, in the fuel consumption calculation, the terminal voltage of the storage device is estimated. Since the accuracy of the fuel consumption calculation is also improved by improving the estimation accuracy of the terminal voltage of the storage device, the simulation device (the storage device simulator) according to the embodiment is used for the purpose of improving the calculation accuracy of the fuel consumption, for example. It is also good. In the following description, a single lead storage battery is used as the storage device. The storage device is not limited to the lead storage battery, and may be another storage device, or may be a composite storage device in which a plurality of storage devices are combined.

  In the present embodiment, the storage device simulator estimates the terminal voltage of the storage device using the storage device model for calculating the terminal voltage of the storage device. In this embodiment, an equivalent circuit model of the storage device is used as the storage device model. First, an example of the equivalent circuit model will be described with reference to FIG.

[Equivalent circuit model of storage device]
In the example shown in FIG. 2, the equivalent circuit model 40 includes connected in series between the opposite polarity of the node N ₁ and the node N ₂ to each other, the circuit 10, a circuit 20, and a constant voltage source 30.

Node N ₁ and the node N ₂ is an external element and portions electrically connected in the electric storage device, providing a voltage generated in the equivalent circuit model 40. The voltage generated in the equivalent circuit model 40 is the terminal voltage V (t) of the storage device. Node N ₁ is an anode, providing a current I (t) flowing into the power storage device. In addition, (t) etc. may be added to a code indicating time-varying physical quantity such as voltage and current, but the physical quantity indicated in this way shall mean the value of the physical quantity at time t. Further, time t is an integer of 0 or more and indicates an elapsed time from the start time of estimation of the terminal voltage V (t). Time t = 0 is a start time of estimation of the terminal voltage V (t).

[Circuit 10 and DC resistance voltage Vdc (t)]
The circuit 10 is a DC resistance unit that simulates the DC impedance (DC resistance component) of the storage device. Circuit 10 includes a resistor. In the present embodiment, the circuit 10 further includes capacitors and switching elements connected in parallel. In the example shown in FIG. 2, the resistor 11, the resistor 12, and the capacitor 13 and the switching element 14 connected in parallel are connected in series.

The resistor 11 simulates the linear DC resistance component of the storage device. The linear DC resistance component includes the resistance of the electrode. The resistance value R ₀ of the resistor 11 is a constant. The resistor 12 simulates the non-linear DC resistance component of the storage device. The non-linear direct current resistance component includes liquid resistance. The resistance value R (I) of the resistor 12 is variable. The resistance value R (I) changes in accordance with the current I (t), and differs, for example, between charging and discharging. The gassing unit, which is a circuit in which the capacitor 13 and the switching element 14 are connected in parallel, simulates a DC resistance component based on the gassing in the power storage device. The capacitance value C of the capacitor 13 is variable. The switching element 14 is an element that can switch electrical switching. That is, between the both ends of the switching element 14 is switched to a closed state which is a conductive state and an open state which is a blocked state. One end of the switching element 14 is connected to one end of the capacitor 13 on the node N ₁ side, and the other end of the switching element 14 is connected to the other end of the capacitor 13 on the node N ₂ side. As described later, when the terminal voltage V (t) is larger than the threshold voltage Vth, the switching element 14 is in the open state, and when the terminal voltage V (t) is lower than the threshold voltage Vth, the switching element 14 is It will be closed.

For example, a diode can be used as switching element 14. In this case, the cathode of the diode is connected to one end of the capacitor 13 on the node N ₁ side, and the anode of the diode is connected to the other end of the capacitor 13 on the node N ₂ side. The diode has infinite resistance when the voltage applied between the anode and the cathode is less than the diode's forward voltage, and the voltage applied between the anode and the cathode is greater than or equal to the diode's forward voltage. Is an ideal diode with a resistance value of zero. As described later, when the terminal voltage V (t) is larger than the threshold voltage Vth, the voltage applied between the anode and the cathode is less than the forward voltage of the diode, and the terminal voltage V (t) is When the threshold voltage is equal to or lower than the threshold voltage Vth, the voltage applied between the anode and the cathode is equal to or higher than the forward voltage of the diode.

  That is, the DC resistance component simulated by the circuit 10 is a linear DC resistance component simulated by the resistor 11, a non-linear DC resistance component simulated by the resistor 12, a gussing simulated by the capacitor 13 and the switching element 14. Department and. The impedance of the circuit 10 is determined by the resistance value of each resistor in the circuit 10, the capacitance value C of the capacitor 13 and the threshold voltage Vth of the switching element 14. If the impedance of the circuit 10 is determined, when the current I (t) flows in the equivalent circuit model 40, the current I (t) also flows in the circuit 10, the current I (t) and the impedance of the circuit 10 From this, the voltage generated in the circuit 10 can be calculated. The voltage generated in the circuit 10 is illustrated as a direct current resistive voltage Vdc (t).

DC resistance voltage Vdc is a voltage (first voltage) generated in resistor 11, a voltage (second voltage) generated in resistor 12, and a voltage (third voltage) generated in capacitor 13 and switching element 14 The total voltage of The voltage generated in the resistor 11 is illustrated as a voltage Vdc1 (t). The voltage generated at the resistor 12 is illustrated as a voltage Vdc2 (t). The voltage generated in the capacitor 13 and the switching element 14 is referred to as a voltage Vg (t) and illustrated. That is, in the circuit 10, the following relational expression (1) is established.

[Circuit 20 and Polarization Voltage Vpol]
The circuit 20 is a polarization model unit that simulates the polarization impedance component of the storage device. The circuit 20 includes a resistor and a capacitor (RC parallel circuit) connected in parallel. In the example shown in FIG. 2, three RC parallel circuits are connected in series. Specifically, the resistor 21 and the capacitor 22 (first RC parallel circuit) connected in parallel, the resistor 23 and the capacitor 24 (second RC parallel circuit) connected in parallel, and the resistor connected in parallel 25 and capacitor 26 (third parallel circuit) are connected in series. The resistance value of the resistor 21 and the capacitance value of the capacitor 22 constituting the first RC parallel circuit are variable. The resistor 21 simulates the polarization resistance component (first polarization resistance component) of the storage device, and the capacitor 22 simulates the polarization capacitance component (first polarization capacitance component) of the storage device. The resistance value of the resistor 23 and the capacitance value of the capacitor 24 constituting the second RC parallel circuit are constants. The resistor 23 simulates the polarization resistance component (second polarization resistance component) of the storage device, and the capacitor 24 simulates the polarization capacitance component (second polarization capacitance component) of the storage device. The resistance value of the resistor 25 and the capacitance value of the capacitor 26 constituting the third RC parallel circuit are constants. The resistor 25 simulates the polarization resistance component (third polarization resistance component) of the storage device, and the capacitor 26 simulates the polarization capacitance component (third polarization capacitance component) of the storage device.

  In the example shown in FIG. 2, the circuit 20 includes first to third three RC parallel circuits, but the circuit 20 includes at least a first RC parallel circuit (resistor 21 and capacitor 22). It should just be. Also, the circuit 20 may include four or more RC parallel circuits.

  The resistance value of each resistor in the circuit 20 and the capacitance value of each capacitor determine the impedance of the circuit 20. If the impedance of the circuit 20 is determined, when the current I (t) flows in the equivalent circuit model 40, the current I (t) also flows in the circuit 20, the current I (t) and the impedance of the circuit 20 From this, the voltage generated in the circuit 20 can be calculated. The voltage generated in the circuit 20 is illustrated and referred to as a polarization voltage Vpol (t).

The polarization voltage Vpol is a total voltage of the voltage generated in the resistor 21 and the capacitor 22, the voltage generated in the resistor 23 and the capacitor 24, and the voltage generated in the resistor 25 and the capacitor 26. The voltage generated in the resistor 21 and the capacitor 22 is illustrated as a first polarization voltage Vp1 (t). The voltage generated in the resistor 23 and the capacitor 24 is illustrated as a second polarization voltage Vp2 (t). The voltage generated in the resistor 25 and the capacitor 26 is illustrated and referred to as a third polarization voltage Vp3 (t). That is, in the circuit 20, the following relational expression (2) is established.

  Here, assuming that the time constant of the first RC parallel circuit including the resistor 21 and the capacitor 22 is a time constant τ1, the time constant τ1 is obtained by multiplying the resistance value of the resistor 21 by the capacitance value of the capacitor 22. It is determined as a value. The time constant τ1 is reflected in the time change of the first polarization voltage Vp1 (t) generated in the resistor 21 and the capacitor 22. For example, as the time constant τ1 is larger, the time change of the first polarization voltage Vp1 (t) becomes slower. Similarly, assuming that the time constant of the second RC parallel circuit configured of resistor 23 and capacitor 24 is time constant τ 2, time constant τ 2 is the second polarization voltage Vp 2 generated in resistor 23 and capacitor 24 (t It is reflected in the time change of). Assuming that the time constant of the third RC parallel circuit configured of the resistor 25 and the capacitor 26 is the time constant τ 3, the time constant τ 3 is the time of the third polarization voltage Vp 3 (t) generated in the resistor 25 and the capacitor 26 It is reflected in the change. The time constant τ1, the time constant τ2, and the time constant τ3 may be set to different values. When the circuit 20 includes an RC parallel circuit having a plurality of different time constants, the time change of the polarization voltage Vpol (t) can be more accurately represented. Each time constant may be set, for example, such that time constant τ1 <time constant τ2 <time constant τ3.

[Constant voltage source 30 and open circuit voltage Vocv (t)]
The constant voltage source 30 has a constant direct current (DC) voltage. The voltage of the constant voltage source 30 is an open circuit voltage (OCV: Open Circuit Voltage) of the storage device. The impedance of the constant voltage source 30 is zero. The open circuit voltage of the storage device is illustrated as open circuit voltage Vocv (t). The open circuit voltage Vocv (t) is determined, for example, from the SOC of the storage device. In that case, the open circuit voltage Vocv (t) is a function having the SOC as an argument. The temperature of the storage device may be included in the argument.

Between the DC resistance voltage Vdc (t) generated in the circuit 10 described above, the polarization voltage Vpol (t) generated in the circuit 20, and the open voltage Vocv (t) of the constant voltage source 30 and the terminal voltage V (t) The following relational expression (3) is established between them.

  The storage device simulator according to the embodiment estimates the terminal voltage V (t) of the storage device using the equivalent circuit model 40 of the storage device described above.

[Storage Device Simulator]
FIG. 3 is a diagram showing a schematic configuration of a power storage device simulator according to an embodiment. The storage device simulator 1 includes, as its functional blocks, the input unit 2, the SOC calculation unit 3, the parameter setting unit 4, the DC resistance calculation unit 5, the polarization calculation unit 6, the OCV calculation unit 7, and terminal voltage calculation. And 8 are included. The storage device simulator 1 is configured by, for example, the hardware shown in FIG.

  FIG. 4 is a diagram showing an example of a hardware configuration of the storage device simulator of FIG. 3. As illustrated in FIG. 4, the storage device simulator 1 physically includes one or more central processing units (CPUs) 101, a random access memory (RAM) 102 as a main storage device, and a read only memory (ROMs). Computer, a communication module 104 which is a data transmission / reception device, an auxiliary storage device 105 such as a hard disk and a flash memory, an input device 106 which accepts user input such as a keyboard, and an output device 107 such as a display. Is configured as. Each function of the storage device simulator 1 shown in FIG. 3 is controlled by the communication module 104 under the control of the CPU 101 by causing one or more predetermined computer software to be read on hardware such as the CPU 101 and the RAM 102. This is realized by operating the output device 107 and reading and writing data in the RAM 102 and the auxiliary storage device 105. Although the above description is described as the hardware configuration of the storage device simulator 1, the fuel consumption calculation device 90 includes the main storage device such as the CPU 101, the RAM 102 and the ROM 103, the communication module 104, the auxiliary storage device 105, the input device 106, and the output It may be configured as a normal computer system including the device 107 and the like.

  Referring to FIG. 3 again, details of each function of the storage device simulator 1 will be described. The input unit 2 is a part for inputting a designated value (bat_demand) to the power storage device. The designated values include, for example, the magnitude of the charge / discharge current, the magnitude of the charge / discharge power, etc. required of the storage device in the fuel consumption calculation by the fuel consumption calculation device 90 described above. The input unit 2 outputs the input designated value to the DC resistance calculation unit 5.

The SOC calculation unit 3 is a part that calculates the SOC of the power storage device. For example, SOC (t) of the power storage device is calculated from the initial SOC (0) of the power storage device and the charge / discharge power amount of the power storage device thereafter. The value of the initial SOC (0) of the storage device is not particularly limited, and may be set as appropriate. The charge / discharge power amount of the storage device can be obtained by integrating the charge / discharge power of the storage device by the charge / discharge time. The storage device charge / discharge power is obtained based on the current flowing through the storage device and the full charge capacity s of the storage device. In the calculation of SOC (t) at time t, the current I flowing from time 0 to time t-1 in the equivalent circuit model 40 can be used as the current flowing to the storage device. In this case, SOC calculation unit 3 calculates SOC (t) according to, for example, the following equation (4). The SOC calculating unit 3 outputs the calculated SOC (t) to the parameter setting unit 4, the polarization calculating unit 6, and the OCV calculating unit 7.

The parameter setting unit 4 is a portion that sets values of various parameters necessary for estimation of the terminal voltage of the power storage device. Examples of parameters are coefficient V ₀ , resistance value R ₀ of linear DC resistance component, coefficient I ₀ , coefficient α, capacitance value C, and constant y. The resistance value R ₀ is the resistance value of the resistor 11 (see FIG. 2). The capacitance value C is the capacitance of the capacitor 13 (see FIG. 2). For the capacitance value C, its reciprocal 1 / C can be used as a parameter. The value of each parameter is changed according to the SOC of the power storage device. For example, the capacitance value C increases as the SOC decreases. The coefficient V ₀ , the coefficient I ₀ , and the coefficient α are used in Equations (6) to (9) and Equation (17) described later, and these applications will be described later.

  The parameter setting unit 4 sets the value of each parameter by, for example, referring to a lookup table that describes the value of each parameter. A look-up table is provided for each parameter. The look-up table is, for example, a table in which the SOC is associated with the value of each parameter. In this case, the parameter setting unit 4 obtains the value of each parameter associated with the SOC (t) received from the SOC calculation unit 3 by referring to each lookup table, and obtains the obtained value for each parameter. Set to a value.

  Each look-up table may be prepared for each temperature T of the storage device. In that case, the value of each parameter is set in consideration of the temperature T of the storage device. Moreover, the value of each parameter may be predetermined. The parameter setting unit 4 outputs the values of the set parameters to the DC resistance calculation unit 5 and the polarization calculation unit 6.

  The DC resistance calculation unit 5 is a part that calculates a DC resistance voltage Vdc (t) generated in the circuit 10 in the equivalent circuit model 40. Further, the DC resistance calculation unit 5 is also a part that calculates the current I (t) flowing through the equivalent circuit model 40 from the designated value (bat_demand) input by the input unit 2. As shown in FIG. 5, the DC resistance calculation unit 5 includes, as its functional blocks, a current calculation unit 51, a voltage calculation unit 52, and a mode determination unit 53. The current calculator 51 calculates the current I (t) flowing through the equivalent circuit model 40. The voltage calculation unit 52 calculates a DC resistance voltage Vdc (t) generated in the DC resistance component (circuit 10) of the equivalent circuit model 40. The calculation method of the current I (t) and the DC resistance voltage Vdc (t) differs depending on the charge mode of the storage device. Hereinafter, an example of a method of calculating DC resistance voltage Vdc (t) and current I (t) will be described for each charge and discharge mode of the power storage device.

[Example of calculation of DC resistance voltage Vdc (t) in CC mode]
First, a constant current (CC: Constant Current) mode will be described. The CC mode is a mode in which a constant current flows regardless of the terminal voltage V (t). Therefore, in the CC mode, the current calculation unit 51 sets the designated current I_cmd received from the input unit 2 as the current I (t). The current calculation unit 51 outputs the current I (t) to the voltage calculation unit 52.

The voltage calculator 52 calculates the voltage Vdc1 (t), the voltage Vdc2 (t), and the voltage Vg (t) based on the current I (t) calculated by the current calculator 51, and calculates the voltage Vdc1 (t). The DC resistance voltage Vdc (t) is calculated based on the voltage Vdc2 (t) and the voltage Vg (t). Specifically, voltage calculation unit 52 multiplies resistance value R ₀ received from parameter setting unit 4 by current I (t) received from current calculation unit 51, as shown in equation (5). Thus, the voltage Vdc1 (t) is calculated.

The voltage calculation unit 52 sets the resistance value R (I) of the nonlinear DC resistance component using a value obtained from the Butler-Volmer equation (butler-volmer equation) with the value of the current I (t) as a variable. The resistance value R (I) is the resistance value of the resistor 12 (see FIG. 2). Specifically, as shown in the equations (6) to (9), the voltage calculation unit 52 uses the coefficient V ₀ , the coefficient I ₀ , and the coefficient α received from the parameter setting unit 4 to set the resistance value. Calculate R (I). The coefficient V ₀ is used to make the dimensions of the resistance value R (I) and the current I (t) uniform. The factor I ₀ is used to normalize the current I (t). The factor α is used to specify the Butler-Volmer equation.

F is expressed as a solution of equation (7), that is, a solution of the Butler-Volmer equation, where x is the argument (I (t) / I ₀ ).

Here, the Butler-Volmer equation can be solved by obtaining x that satisfies Equation (8), given a constant y and a coefficient α.

For example, x may be determined by the Newton method. That is, the value of x at which the value of f (x) becomes 0 in the equation (9) (actually, a sufficiently small value, for example, f (x) ≦ 10 ⁻⁶ ) is obtained by the Newton method. In the formulas (8) and (9), x is different from x in the formula (7), and x in the formula (7) is y in the formulas (8) and (9). In Equation (8) and Equation (9), F is x.

The voltage calculation unit 52 calculates the voltage Vdc2 (t) by multiplying the resistance value R (I) by the current I (t), as shown in the equation (10).

  The voltage calculation unit 52 calculates the voltage Vg (t) based on the capacitance value C received from the parameter setting unit 4 and the current I (t−1) one time before. As shown in equation (11), voltage calculation unit 52 satisfies the condition that current I (t-1) is larger than 0 and terminal voltage V (t-1) is larger than threshold voltage Vth. It is determined whether the This condition is a condition under which gassing occurs. The threshold voltage Vth is set to a terminal voltage at which gassing starts to occur, and is set to 13.6 V, for example.

In the description using the equivalent circuit model 40, switching is satisfied when the condition that the current I (t-1) is larger than 0 and the terminal voltage V (t-1) is larger than the threshold voltage Vth is satisfied. The element 14 is set to the open state. When the storage device is discharged or the current I (t-1) is zero, the switching element 14 is set to the closed state, and the charge amount of the capacitor 13 is reset to zero. That is, when the battery device is charged and the terminal voltage V (t-1) is larger than the threshold voltage Vth, the voltage calculator 52 calculates a value obtained by integrating the current I (t-1). Divide by C, and let the result of the division be a voltage Vg (t). Further, voltage calculation unit 52 determines that voltage Vg (t) is lower when current I (t-1) is 0 or less, that is, when the storage device is discharged or current I (t-1) is 0. And 0).

  The voltage calculation unit 52 adds the voltage Vdc1 (t), the voltage Vdc2 (t) and the voltage Vg (t) as shown in the above equation (1), and sets the total voltage as the DC resistance voltage Vdc (t). calculate.

[Example of calculation of DC resistance voltage Vdc (t) in CV mode]
The constant voltage (CV: Constant Voltage) mode will be described. The CV mode is a mode in which the storage device is charged in a state where the output voltage of a voltage source (for example, an alternator) for charging the storage device is constant. In the CV mode, it is assumed that changes in the polarization voltage Vpol (t) and the open circuit voltage Vocv (t) are relatively slow, and the voltage calculation unit 52 calculates the DC resistance voltage Vdc (t) by the following equation (12). calculate. The voltage Va is a CV voltage and indicates the upper limit voltage of a voltage source (for example, an alternator). This voltage Va is preset. For example, when an alternator having an upper limit voltage of 14 V is used, the voltage Va is set to 14 V.

  Voltage calculation unit 52 determines voltage Vg (t) based on capacitance value C received from parameter setting unit 4 and current I (t−1) one time ago, as shown in equation (11) described above. Calculate). The voltage calculation unit 52 outputs the calculated DC resistance voltage Vdc (t) and the voltage Vg (t) to the current calculation unit 51.

The current calculator 51 calculates the current I (t) based on the DC resistance voltage Vdc (t) calculated by the voltage calculator 52. Specifically, the current calculation unit 51 obtains x by solving the following non-linear equation (13), where (V / V ₀ ) is x.

Formula (13) sets V ₀ / (I ₀ × R ₀ ) as A, and sets (Vdc (t) −Vg (t)) / (I ₀ × R ₀ ) as B, and the following formula (14) is It can be solved by finding x that satisfies. For example, x may be determined by the Newton method.

Specifically, current calculation unit 51 determines that the value of f (x) in equation (15) is 0 (in practice, the value is sufficiently small, for example, f (x) ≦ 10 ⁻⁶ ). Is determined by the Newton method.

The current calculator 51 calculates the current I (t) using x as shown in equation (16).

  Mode determination unit 53 determines the charge / discharge mode of the power storage device, and causes current calculation unit 51 and voltage calculation unit 52 to calculate DC resistance voltage Vdc (t) and current I (t) according to the charge / discharge mode. Mode determination unit 53 determines the charge / discharge mode, for example, by comparing terminal voltage V (t−1) one time before with voltage Va. Specifically, when the terminal voltage V (t−1) is smaller than the voltage Va, the mode determination unit 53 determines that the mode is the CC mode. When the terminal voltage V (t−1) reaches the voltage Va (equal to or higher than the voltage Va), the mode determining unit 53 determines that the mode is the CV mode. Current calculation unit 51 calculates current I (t) according to the charge / discharge mode determined by mode determination unit 53, and outputs the calculated current I (t) to SOC calculation unit 3 and polarization calculation unit 6, respectively. . Voltage calculation unit 52 calculates DC resistance voltage Vdc (t) according to the charge / discharge mode determined by mode determination unit 53, and outputs the calculated DC resistance voltage Vdc (t) to terminal voltage calculation unit 8.

  Although DC resistance calculation unit 5 calculates current I (t) and DC resistance voltage Vdc (t), it is not limited thereto. The storage device simulator 1 further includes a functional block having the same function as the direct current resistance calculation unit 5, and after the functional block calculates the current I (t), the direct current resistance calculation unit 5 calculates the current I (t) The DC resistance voltage Vdc (t) may be calculated based on

  Referring back to FIG. 3, the description of the functional blocks of the storage device simulator 1 will be continued. The polarization calculator 6 is a part that calculates the polarization voltage Vpol (t) generated in the circuit 20 in the equivalent circuit model 40. Here, the functional block of the polarization calculator 6 will be described with reference to FIG. As shown in FIG. 6, the polarization calculation unit 6 includes, as its functional blocks, a setting unit 6a and a polarization voltage calculation unit 6b.

  The setting unit 6 a is a unit that sets characteristic parameters of the circuit 20. As modes of setting of the characteristic parameter, there are the first mode and the second mode. The setting unit 6a sets the characteristic parameter of the circuit 20 in at least one of the first aspect and the second aspect. Both the first aspect and the second aspect may be used. Hereinafter, the first aspect and the second aspect will be described in order.

[First Aspect of Setting Characteristic Parameters of Circuit 20]
In the first aspect, the setting unit 6a sets at least one of the resistance value of the resistor 21 and the capacitance value of the capacitor 22 according to the current I (t) flowing through the equivalent circuit model 40. Specifically, this will be described with reference to FIG. In FIG. 7, the current flowing through the resistor 21 is illustrated as a current I ₁ (t). The current flowing through the capacitor 22 is illustrated and referred to as a current I ₂ (t). The sum of the currents I ₁ (t) and I ₂ (t) is equal to the current I (t). Hereinafter, the resistance value of the resistor 21 is referred to as a resistance value Rp, and the capacitance value of the capacitor 22 is referred to as a capacitance value Cp.

For example, the setting unit 6a may set the resistance value Rp of the resistor 21 in accordance with the value of the current I ₁ (t). In this case, the resistance value Rp is represented by a function having the value of the current I ₁ (t) as an argument.

The setting unit 6a may set the resistance value Rp in accordance with the value of the total current of the current I ₁ (t) and the current I ₂ (t), that is, the value of the current I (t). In this case, the resistance value Rp is represented by a function having the value of the current I (t) as an argument.

The setting unit 6a may set the capacitance value Cp in accordance with the value of the current I ₂ (t). In this case, the capacitance value Cp is represented by a function having the value of the current I ₂ (t) as an argument.

  The setting unit 6a may set the capacitance value Cp in accordance with the value of the current I (t). In this case, the capacitance value Cp is represented by a function having the value of the current I (t) as an argument.

  The setting unit 6a may set only the resistance value Rp according to the current as described above, or may set only the capacitance value Cp as described above. When the setting unit 6a sets only the resistance value Rp in accordance with the current, the capacitance value Cp can be set to a predetermined value. When the setting unit 6a sets only the capacitance value Cp according to the current, the resistance value Rp can be a predetermined value. Further, the setting unit 6a may set the values of both the resistance value Rp and the capacitance value Cp according to the current as described above.

  Here, an example of setting of the resistance value Rp of the resistor 21 by the setting unit 6a and an example of setting of the capacitance value Cp of the capacitor 22 will be described.

式（１７）の右辺は上述の式（６）の右辺と同じである。よって、先に説明したように式中のＦ（Ｉ（ｔ）／Ｉ_０）をバトラーボルマーの式を解くことによって求めることで、抵抗値Ｒｐを計算することができる。[Example of setting resistance value Rp of resistor 21]
An example of setting of the resistance value Rp of the resistor 21 will be described. For example, setting unit 6a sets resistance value Rp using a value obtained from the Butler-Volmer equation (butler_volmer equation) using the value of current I (t) as a variable. Specifically, the setting unit 6a calculates the resistance value Rp using the coefficient V ₀ , the coefficient I ₀ , and the coefficient α received from the parameter setting unit 4 as shown in equation (17).

The right side of equation (17) is the same as the right side of equation (6) described above. Therefore, the resistance value Rp can be calculated by finding F (I (t) / I ₀ ) in the equation as described above by solving the Butler-Volmer equation.

[Example of setting of capacitance value Cp of capacitor 22]
An example of setting of the capacitance value Cp of the capacitor 22 will be described. For example, setting unit 6a uses a value of current I (t) as a variable, such as a spline function, a piecewise linear function, a function that is linear with respect to the value of current I (t) but is positive, and a Gaussian function The capacitance value Cp can be set using FIG. 8 shows the behavior of the capacitance value Cp represented by a Gaussian function as an example. In this example, the value of capacitance value Cp becomes maximum when value I of current I (t) is near 0, and the value of capacitance value Cp becomes smaller as the value I of current I (t) decreases or increases therefrom Become.

Or more in the various aspects of setting the resistance value Rp and capacitance Cp explained, than when setting depending only on the value of the resistance Rp currents I _{1 (t),} current I _{1 (t)} and current I ₂ By setting according to the value of the total current of (t), that is, the value of the current I (t), it is possible to more accurately represent the first polarization voltage Vp1 (t) and hence the polarization voltage Vpol (t). The following can be considered as the reason. That is, when the argument of the function representing the resistance value Rp is only the value of the current I ₁ (t), for example, the time constant is initially large when the step response (time change of voltage at transient response) is observed. After that, since the time constant suddenly decreases, the voltage generated in the resistor 21 and the capacitor 22 gradually rises and then is fixed to a substantially constant value at a certain timing and does not change. A step response having such a discontinuity can not reproduce the actual step response completely. On the other hand, by setting the argument of the function representing the resistance value Rp to the value of the current I (t), the step response is improved so that the above-mentioned discontinuity is eliminated, and as a result, the actual step response is more accurate. Can be reproduced in

  The above is the first mode of setting of parameters related to the circuit 20. Next, a second mode of setting of parameters for the circuit 20 will be described.

[Second Aspect of Setting Characteristic Parameters of Circuit 20]
Returning to FIG. 6, in the second embodiment, the setting unit 6a pauses when the power storage device is in a charged state or a discharged state as described above, which is determined from the resistance value of the resistor 21 and the capacitance value of the capacitor 22. In the case of the state, set different values. Here, in the inactive state, no charge / discharge current is generated in the storage device (the charge / discharge current is 0), but storage in each capacitor in the circuit 20 is caused by charge / discharge of the previous storage device. This means that the polarization voltage Vpol (t) changes with time by discharging the stored charge.

For example, the direction, the value, and the current I (t) of the current I (t) flowing through the equivalent circuit model 40 determine whether the storage device is in the charged state, the discharged state, or the inactive state. The setting unit 6a makes a determination based on the time elapsed since the time t. With reference again to FIG. 2, in the example of FIG. 2, current I (t) from the node N _1, are shown as current flowing in the circuit 10, circuit 20, and the constant voltage source 30. In this case, when the value of the current I (t) is positive, the current I (t) is a charging current of the storage device, and the storage device is in a charging state. When the value of the current I (t) is negative, the current I (t) is a discharge current of the storage device, and the storage device is in a discharge state. When the value of the current I (t) is 0, the storage device is in a floating state in which neither charging nor discharging is performed. The floating, the node N ₁ and the node N _2, transfer of current between the external elements of the power storage device does not exist. However, even in the floating state, there is a period in which the voltage across each capacitor changes due to the charge stored in each capacitor in the circuit 20 being discharged or the like. This period corresponds to a period in which the power storage device is in the inactive state. For example, the period of time when the value of the current I (t) becomes zero may be determined as a pause state during a predetermined period. The predetermined period may be set, for example, from several seconds to several tens of seconds.

  For example, setting unit 6a sets time constant τ1 such that the time constant is larger when the storage device is in the inactive state than when the storage device is in the charged state and in the discharged state (charge / discharge state). It is also good. According to this setting, it is possible to make the time change of the polarization voltage Vpol (t) in the idle state slower than the time change of the polarization voltage Vpol (t) in the charge and discharge state.

  The setting unit 6a may set the time constant τ1 so that the time constant becomes smaller in the inactive state than in the charged and discharged state. According to this setting, it is possible to make the time change of the polarization voltage Vpol (t) in the quiescent state steeper than the time change of the polarization voltage Vpol (t) in the charge and discharge state.

  The setting unit 6a may set the time constant τ1 so that the time constant becomes larger in the discharged state than in the charged state. According to this setting, it is possible to make the time change of the polarization voltage Vpol (t) in the discharge state slower than the time change of the polarization voltage Vpol (t) in the charge state.

  The setting unit 6a may set the time constant τ1 so that the time constant becomes smaller in the discharged state than in the charged state. According to this setting, it is possible to make the time change of the polarization voltage Vpol (t) in the discharge state steeper than the time change of the polarization voltage Vpol (t) in the charge state.

  When the power storage device is in the inactive state, setting unit 6a further discharges the state immediately before the power storage device when the state immediately before the power storage device is in the inactive state (the state immediately before) is in the charge state. The time constant .tau.1 may be set to a different value depending on the case.

  As the time constant τ1 in the pause state, the setting unit 6a sets the time constant so that the time constant becomes larger when the immediately preceding state is the discharged state than when the immediately previous state is the charged state. The constant τ1 may be set. According to this setting, the temporal change of the polarization voltage Vpol (t) in the pause state when the immediately preceding state is the discharge state, the polarization voltage Vpol in the pause state when the immediately previous state is the charge state It can be made slower than the time change of (t).

  The setting unit 6a may set the time constant τ1 such that the time constant is smaller when the immediately preceding state is the discharged state than when the immediately previous state is the charged state. According to this setting, the temporal change of the polarization voltage Vpol (t) in the pause state when the immediately preceding state is the discharge state, the polarization voltage Vpol in the pause state when the immediately previous state is the charge state It can be made steeper than the time change of (t).

Specifically, the time constant τ1 is set by setting the resistance value and the capacitance value such that the product of the resistance value of the resistor 21 and the capacitance value of the capacitor 22 becomes the time constant τ1. In addition, the time constant in the inactive state may be changed according to the time T _U during which the power storage device has been used, or the charge integration amount ∫ | i | dt. In this case, the time constant function of quiescent polarization may be determined in advance by testing with a storage device. An example of a time constant function when current flows (not charged) but not in quiescent state is {( _Ad / | I−B _d |) + C _d }. Here, I is the value of the current (a negative value during discharge), and A _d , B _d and C _d are constants. This function, for example, Pb0 reaction time constant of ₂ and PbSO ₄ is guided by the reciprocal of the current-dependent, based on the finding that. A _d , B _d and C _d may have different values depending on the sign of I.

  As mentioned earlier, both the first and second aspects of the setting of the characteristic parameters of circuit 20 may be used. In this case, setting unit 6a uses the first aspect to set the resistance value of resistor 21 and the capacitance value of capacitor 22 to the current I (when the power storage device is other than in the inactive state (such as charge and discharge)). It may be set according to t), and when the power storage device is in the inactive state, the second embodiment may be used to set the time constant τ1. For example, in this way, both the first aspect and the second aspect can be used in combination.

The polarization voltage calculation unit 6 b is a part that calculates the polarization voltage Vpol (t) using the calculation result of the DC resistance calculation unit 5 and the setting result of the setting unit 6 a. Specifically, polarization voltage calculation unit 6b uses current I (t) calculated by DC resistance calculation unit 5, and the resistance value of resistor 21 and the capacitance value of capacitor 22 set by setting unit 6a. , And calculate the first polarization voltage Vp1 (t). The first polarization voltage Vp1 (t) can be calculated as a voltage generated in the resistor 21 or the capacitor 22. The calculation method of the voltage is not particularly limited, and various known methods can be used. For example, the voltage generated in the resistor 21 is obtained from the magnitude of the current I ₁ (t) flowing in the resistor 21 and the resistance value Rp of the resistor 21. The voltage generated in the capacitor 22 is obtained from the charge amount stored in the capacitor 22 and the capacitance value of the capacitor 22. The currents I ₁ (t) and I ₂ (t) flowing through the resistor 21 and the capacitor 22 have a resistance value Rp of the resistor 21 under the condition that the total current flowing through both becomes the current I (t). , The capacitance value Cp of the capacitor 22 and the charge amount stored in the capacitor 22. The same applies to the second polarization voltage Vp2 (t) and the third polarization voltage Vp3 (t). Then, as shown in the above-mentioned equation (2), the polarization voltage calculation unit 6b generates the first polarization voltage Vp1 (t), the second polarization voltage Vp2 (t), and the third polarization voltage Vp3 (t). The total voltage is calculated as the polarization voltage Vpol (t).

  The polarization voltage Vpol (t) calculated by the polarization voltage calculator 6b of the polarization calculator 6 is output to a terminal voltage calculator 8 described later.

  Returning to FIG. 3, the description of the functional blocks of the storage device simulator 1 will be continued. The OCV calculator 7 is a part that calculates the open circuit voltage Vocv (t) of the power storage device. As described above, the open circuit voltage Vocv (t) is obtained from the SOC of the storage device. For example, a table in which the value of each SOC is associated with the value of open circuit voltage Vocv is prepared in advance. The OCV calculator 7 calculates the open circuit voltage Vocv (t) from the SOC (t) received from the SOC calculator 3 by referring to the table. The above-described table may be prepared for each temperature T, and in this case, the open circuit voltage Vocv (t) is calculated in consideration of the temperature T of the storage device.

  The terminal voltage calculation unit 8 is a part that calculates the terminal voltage V (t) of the storage device. As described above, the DC resistance voltage Vdc (t) calculated by the DC resistance calculation unit 5, the polarization voltage Vpol (t) calculated by the polarization calculation unit 6, and the open circuit voltage calculated by the OCV calculation unit 7 Vocv (t) is sent to the terminal voltage calculator 8. The terminal voltage calculation unit 8 calculates a terminal voltage V (t) based on the DC resistance voltage Vdc (t), the polarization voltage Vpol (t), and the open circuit voltage Vocv (t). Specifically, terminal voltage calculation unit 8 adds DC resistance voltage Vdc (t), polarization voltage Vpol (t), and open circuit voltage Vocv (t) as shown in the above equation (3), and The total voltage is calculated as the terminal voltage V (t). Terminal voltage calculation unit 8 outputs the calculated terminal voltage V (t) to the outside of power storage device simulator 1 and to DC resistance calculation unit 5.

  Next, calculation processing (simulation method) of the terminal voltage V (t) performed by the power storage device simulator 1 will be described with reference to FIGS. 9 to 11. FIG. 9 is a flow chart showing an example of calculation processing of the terminal voltage V (t) executed by the power storage device simulator 1. FIG. 10 is a flowchart showing an example of the calculation process of the current and DC resistance voltage of FIG. FIG. 11 is a flowchart showing an example of the calculation process of the polarization voltage of FIG. The process of the flowchart shown in FIG. 9 is executed, for example, when estimating the terminal voltage of the storage device at a certain time t in the fuel consumption calculation of the fuel consumption calculation device 90.

  First, the input unit 2 inputs a designated value (bat_demand) (step S01). For example, input unit 2 receives the designated value from the external device of power storage device simulator 1 to input the designated value. Then, the input unit 2 outputs the input designated value to the DC resistance calculation unit 5.

  Then, SOC calculation unit 3 calculates the SOC of the storage device (step S02). The SOC calculation unit 3 calculates the SOC (t) using, for example, the equation (4) described above. Then, the SOC calculating unit 3 outputs the calculated SOC (t) to the parameter setting unit 4, the polarization calculating unit 6, and the OCV calculating unit 7.

Subsequently, the parameter setting unit 4 sets each parameter of the equivalent circuit model 40 (step S03). The parameters set in step S03 are, for example, a coefficient V ₀ , a resistance value R ₀ , a coefficient I ₀ , a coefficient α, and a capacitance value C. The parameter setting unit 4 acquires and acquires the value of each parameter associated with the SOC (t) received from the SOC calculation unit 3 by referring to, for example, a lookup table that describes the value of each parameter. Set the value to the value of each parameter. Then, the parameter setting unit 4 outputs the set parameter to the DC resistance calculation unit 5 and the polarization calculation unit 6.

  Subsequently, DC resistance calculation unit 5 calculates current I (t) and DC resistance voltage Vdc (t) (step S04). In the process of step S04, as shown in FIG. 10, the mode determination unit 53 first determines the charge / discharge mode of the power storage device (step S41). When it is determined in step S41 that the charge / discharge mode is the CC mode (step S41; CC), the current calculator 51 calculates the current I (t) flowing through the equivalent circuit model 40 (step S42). In step S42, the current calculation unit 51 sets the designated current included in the designated value inputted by the input unit 2 to the current I (t).

Then, in step S43 to step S46, the voltage calculation unit 52 calculates the voltage Vdc1 (t), the voltage Vdc2 (t), and the voltage Vg (t) based on the current I (t), and calculates the voltage Vdc1 (t). The DC resistance voltage Vdc (t) is calculated based on the voltage Vdc2 (t) and the voltage Vg (t). First, the voltage calculation unit 52 calculates the voltage Vdc1 (t) (step S43). Specifically, as shown in the above-mentioned equation (5), voltage calculation unit 52 receives resistance value R ₀ received from parameter setting unit 4 and current I (t) received from current calculation unit 51. Calculate the voltage Vdc1 (t) by multiplying.

  Subsequently, the voltage calculation unit 52 calculates the voltage Vdc2 (t) (step S44). Specifically, voltage calculation unit 52 calculates voltage Vdc2 (t) using the Butler-Volmer equation in which the value of current I (t) is a variable. More specifically, the voltage calculation unit 52 calculates the voltage Vdc2 (t) using the equations (6) to (10) described above.

  Subsequently, the voltage calculator 52 calculates the voltage Vg (t) (step S45). The calculation of step S45 will be described using equivalent circuit model 40. The condition that current I (t-1) is larger than 0 and terminal voltage V (t-1) is larger than threshold voltage Vth is satisfied. When the switching element 14 is in the open state, When the storage device is discharged or current I (t-1) is 0 (that is, when current I (t-1) is 0 or less), switching element 14 is set to the closed state, and the capacitor The charge amount of 13 is reset to 0.

  Specifically, as shown in the above-mentioned equation (11), voltage calculation unit 52 has current I (t-1) larger than 0 (that is, the battery device is charged), and the terminal When the voltage V (t-1) is larger than the threshold voltage Vth, a value obtained by integrating the current I (t-1) is divided by the capacitance value C, and the division result is taken as a voltage Vg (t). Further, voltage calculation unit 52 determines that voltage Vg (t) is lower when current I (t-1) is 0 or less, that is, when the storage device is discharged or current I (t-1) is 0. And 0).

  Subsequently, the voltage calculation unit 52 calculates the DC resistance voltage Vdc (t) (step S46). Specifically, the voltage calculation unit 52 adds the voltage Vdc1 (t), the voltage Vdc2 (t) and the voltage Vg (t) as shown in the above equation (1), and adds the total voltage to the DC resistance voltage. Calculated as Vdc (t). Then, current calculation unit 51 outputs current I (t) to SOC calculation unit 3 and polarization calculation unit 6, and voltage calculation unit 52 outputs DC resistance voltage Vdc (t) to terminal voltage calculation unit 8. . Then, the process of step S04 ends.

  On the other hand, when it is determined in step S41 that the charge / discharge mode is the CV mode (step S41; CV), the voltage calculation unit 52 calculates the DC resistance voltage Vdc (t) (step S47). In step S47, the voltage calculation unit 52 calculates the DC resistance voltage Vdc (t) using the above-described equation (12). Also, the voltage calculation unit 52 calculates the voltage Vg (t) using the above-described equation (11). Then, the voltage calculation unit 52 outputs the calculated DC resistance voltage Vdc (t) and the voltage Vg (t) to the current calculation unit 51.

  Subsequently, the current calculator 51 calculates the current I (t) flowing through the equivalent circuit model 40 (step S48). In step S48, the current calculator 51 calculates the current I (t) based on the DC resistance voltage Vdc (t) calculated by the voltage calculator 52. Specifically, the current calculation unit 51 calculates the current I (t) using the above-described equations (13) to (16). Then, current calculation unit 51 outputs current I (t) to SOC calculation unit 3 and polarization calculation unit 6, and voltage calculation unit 52 outputs DC resistance voltage Vdc (t) to terminal voltage calculation unit 8. . Then, the process of step S04 ends.

  Subsequently, the polarization calculation unit 6 calculates the polarization voltage Vpol (t) (step S05). In the process of step S05, as shown in FIG. 11, first, in step S51, the polarization calculation unit 6 sets the characteristic parameter of the circuit 20. For example, when the characteristic parameter of circuit 20 is set using the above-described first aspect, setting unit 6a of polarization calculating unit 6 calculates the current I (t) calculated in step S42 or step S48. In accordance with the value of V, at least one of the resistance value of the resistor 21 and the capacitance value of the capacitor 22 is set as described above. Further, when the characteristic parameter of the circuit 20 is set by using the second aspect described above, the setting unit 6a described above according to the state of the power storage device (charge or discharge state or pause state). Set the time constant τ1 as follows. When both the first aspect and the second aspect are used, setting unit 6a sets the resistance value of resistor 21 according to the value of current I (t) when the power storage device is not in the inactive state. And at least one of the capacitance values of the capacitor 22 are set. When the power storage device is in the inactive state, the time constant τ1 is set to a value different from the time constant in any other state than the inactive state.

  In step S52, the polarization calculation unit 6 calculates the polarization voltage. Specifically, the polarization voltage calculation unit 6b of the polarization calculation unit 6 calculates the first polarization voltage Vp1 (t) using the resistance value of the resistor 21 and the capacitance value of the capacitor 22 set in the previous step S51. Do. The polarization voltage calculation unit 6b also calculates the second polarization voltage Vp2 (t) and the third polarization voltage Vp3 (t). The polarization voltage calculation unit 6b calculates the sum of the first polarization voltage Vp1 (t), the second polarization voltage Vp2 (t), and the third polarization voltage Vp3 (t) as the polarization voltage Vpol (t). Do. Then, the process of step S05 ends.

  Subsequently, the OCV calculator 7 calculates the open circuit voltage Vocv (t) (step S06). For example, OCV calculation unit 7 calculates open circuit voltage Vocv (t) from SOC (t) received from SOC calculation unit 3 by referring to a table in which the value of each SOC is associated with the value of open circuit voltage Vocv. Do. Then, the OCV calculator 7 outputs the calculated open circuit voltage Vocv (t) to the terminal voltage calculator 8.

  Subsequently, terminal voltage calculation unit 8 calculates terminal voltage V (t) (step S07). Specifically, terminal voltage calculation unit 8 includes DC resistance voltage Vdc (t) calculated by DC resistance calculation unit 5, polarization voltage Vpol (t) calculated by polarization calculation unit 6, and OCV calculation unit 7. Based on the calculated open circuit voltage Vocv (t), the terminal voltage V (t) is calculated. More specifically, terminal voltage calculation unit 8 adds DC resistance voltage Vdc (t), polarization voltage Vpol (t), and open circuit voltage Vocv (t) as shown in the above equation (3). The total voltage is calculated as the terminal voltage V (t). Then, terminal voltage calculation unit 8 outputs the calculated terminal voltage V (t) to the outside of power storage device simulator 1 and to DC resistance calculation unit 5. As described above, the process of calculating the terminal voltage V (t) at time t ends.

  The process of step S01 and the processes of step S02 and step S03 may be performed in parallel, or the order of implementation may be reversed. Further, the process of step S05 and the process of step S06 may be performed in parallel, or the order of implementation may be reversed. Also, the processing of step S43 to step S45 may be performed in parallel, or the order of implementation may be reversed.

  In the power storage device simulator 1 and the simulation method executed by the power storage device simulator 1 described above, the equivalent circuit model 40 of the power storage device including the DC resistance component (circuit 10) is used. The storage device includes a fixed direct current resistance component such as an electrode and a variable direct current resistance component caused by an electrolytic solution and the like. In order to simulate this variable DC resistance component, the DC resistance component (circuit 10) of the equivalent circuit model 40 is a linear DC resistance component simulated by the resistor 11 and a nonlinear DC resistance component simulated by the resistor 12 And the resistor 11 and the resistor 12 are connected in series. The non-linear DC resistance component (resistor 12) has a resistance value R (I) that changes in accordance with the current I (t). In this equivalent circuit model 40, since the resistance value of the DC resistance component (circuit 10) is determined to one value according to the state of the storage device, the calculation accuracy of the DC resistance voltage Vdc (t) is improved. As a result, it is possible to improve the estimation accuracy of the terminal voltage V (t) of the storage device. In particular, it is possible to improve the estimation accuracy of the terminal voltage V (t) at the time of cranking and at the time of CV charging. The estimation of the terminal voltage V (t) using a non-linear DC resistance component is useful, for example, for determining the life of the storage device based on the terminal voltage V (t) at the time of cranking.

  When the storage device is in the CC mode, since the current I (t) flowing through the storage device is constant, the designated current is set to the current I (t) (step S42 in FIG. 10), based on the current I (t). The voltage Vdc1 (t) generated in the linear DC resistance component (resistor 11) and the voltage Vdc2 (t) generated in the nonlinear DC resistance component (resistor 12) are calculated (steps S43 and S44 in FIG. 10). ). Then, the DC resistance voltage Vdc (t) is calculated based on the voltage Vdc1 (t) and the voltage Vdc2 (t) (step S46 in FIG. 10).

  When the storage device is in the CV mode, since the current I (t) flowing through the storage device is not constant, the DC resistance voltage Vdc (t) is first calculated (step S47 in FIG. 10), and then the DC resistance voltage Vdc (t) is calculated. Is used to calculate the current I (t) flowing through the storage device (step S48 in FIG. 10).

  Further, when the storage device is charged in a state where the SOC of the storage device is high, gassing may occur. Gassing can be regarded as a direct current resistance component. In order to simulate the direct current resistance component by this gassing, the direct current resistance component (circuit 10) of the equivalent circuit model 40 includes a gassing unit which simulates the direct current resistance component based on the gassing. Connected in series with the linear DC resistance component. The gassing unit is configured by a circuit in which the capacitor 13 and the switching element 14 are connected in parallel. Since the DC resistance component based on gassing is simulated by such a simple circuit, it becomes possible to simplify the calculation of the terminal voltage V (t) of the storage device.

  As the SOC of the storage device increases, the terminal voltage of the storage device also increases. That is, when the storage device is charged and the terminal voltage V (t-1) is larger than the threshold voltage Vth, gassing may occur. In such a case, by opening the switching element 14 of the gassing unit, the capacitor 13 simulates a DC resistance component due to the gassing. Thus, the voltage Vg (t) generated in the gassing portion can be calculated only by calculating the voltage applied to the capacitor 13. Therefore, the calculation of the terminal voltage V (t) of the storage device can be simplified. Become.

  When the storage device is discharged and when the current I (t) does not flow to the storage device, no gassing occurs. In such a case, by closing the switching element 14 of the gassing portion, the DC resistance component due to the gassing becomes zero. As a result, when no gassing occurs, the voltage Vg (t) generated in the gassing unit is set to 0. This makes it possible to simplify the calculation of the terminal voltage V (t) of the power storage device.

  The DC resistance component due to gassing changes in accordance with the SOC of the storage device. Therefore, the calculation accuracy of the voltage Vg (t) generated in the gassing portion can be improved by changing the capacitance value C of the capacitor 13 according to the SOC of the power storage device. This makes it possible to improve the estimation accuracy of the terminal voltage V (t).

  Further, according to the storage device simulator 1 and the simulation method executed by the storage device simulator 1, the equivalent circuit model 40 includes the resistor 21 connected in parallel for representing the polarization voltage Vpol (t) generated in the storage device and A capacitor 22 is included. At least one of the resistance value of the resistor 21 and the capacitance value of the capacitor 22 is set according to the current I (t) flowing through the equivalent circuit model 40 (step S51 in FIG. 11). Thus, unlike the case where the resistance value of the resistor and the capacitance value of the capacitor are constant regardless of the current flowing in the equivalent circuit, the nonlinear characteristic that the value of the element changes with current is One has. As a result, the calculation accuracy of the polarization voltage Vpol (t) is improved as compared to the case where neither the resistor nor the capacitor has the above-mentioned non-linear characteristic. Therefore, it is possible to improve the estimation accuracy of the terminal voltage V (t). In particular, since the influence of the polarization voltage Vpol (t) is large at the time of discharge of the power storage device (at the time of CC discharge), it is possible to improve the estimation accuracy of the terminal voltage V (t) at that time. At the time of discharge, the terminal voltage V (t) decreases, but at that time, whether the terminal voltage V (t) falls below the idling stop cancellation voltage affects the fuel consumption calculation result. By improving the calculation accuracy of the polarization voltage Vpol (t), it is possible to reproduce the change (falling) of the terminal voltage V (t) at the time of discharge, and it is possible to correctly determine the idling stop cancellation. Therefore, the calculation accuracy of the fuel consumption calculation is improved.

Depending on the values of current I ₁ (t) and current I ₂ (t) flowing through resistor 21 and capacitor 22 (that is, current I (t)), resistance value Rp of resistor 21 and capacitance value Cp of capacitor 22 At least one value may be set (step S51 in FIG. 11). For example, by setting resistance value Rp of resistor 21 according to the value of current I (t), the resistance value Rp is set according to the value of only current I ₁ (t) flowing through resistor 21. Also, the polarization voltage Vpol (t) can be more accurately represented. Also, setting the capacitance value Cp of the capacitor 22 according to the value of the current I (t) makes it possible to set the capacitance value Cp according to the value of only the current I ₂ (t) flowing through the capacitor 22 The polarization voltage Vpol (t) can be calculated more accurately.

  The resistance value Rp of the resistor 21 may be set using a value obtained from the Butler-Volmer equation with the value of the current I (t) as a variable (step S51 in FIG. 11). Thus, the polarization voltage Vpol (t) can be calculated more accurately.

  The capacitance value Cp of the capacitor 22 is a spline function, a piecewise linear function, a linear function with respect to the value of the current I (t) but a positive function, and a Gaussian function, with the value of the current I (t) as a variable It may be set using a function (step S51 in FIG. 11). Thus, the polarization voltage Vpol (t) can be calculated more accurately.

  In addition, time constant τ1 determined from resistance value Rp of resistor 21 and capacitance value Cp of capacitor 22 is set to different values depending on whether the storage device is in a charged or discharged state and in the inactive state. . Thus, by changing the value of the time constant τ1 between the charged or discharged state and the inactive state, the same time constant is used for the charged or discharged state and the inactive state, The polarization voltage Vpol (t) can be calculated accurately. This makes it possible to improve the estimation accuracy of the terminal voltage V (t). In particular, the current when the power storage device transitions from the inactive state to the charged state (CV charged state) is determined by the difference between open circuit voltage Vocv (t) and the voltage of the alternator, for example. t) affects the calculation of the charge charge. This also affects the fuel consumption calculation result. By improving the calculation accuracy of the quiescent polarization voltage Vpol (t), it becomes possible to correctly reproduce the quiescent terminal voltage V (t). Therefore, the calculation accuracy of the fuel consumption calculation is improved.

  When the power storage device is in the inactive state, furthermore, the state before the active power device is in the inactive state is the charging state, and the state before the active power device is in the inactive state is the discharging state And the time constant τ1 may be set to different values. Thus, the polarization voltage Vpol (t) in the idle state can be calculated more accurately than in the case where the same time constant is used regardless of the state before the energy storage device enters the idle state.

[Example of simulation result of terminal voltage of storage device]
FIG. 12 shows an example of a simulation result of the terminal voltage of the power storage device. In the graph of FIG. 12, the horizontal axis indicates time (seconds). The vertical axis represents the terminal voltage (V) of the storage device. In the graph, a curve indicated by a solid line shows the value of the terminal voltage V (t) actually measured. In the graph, a curve indicated by a broken line indicates the value of the terminal voltage V (t) by simulation. In the fuel consumption simulation, the running pattern (running state) of the vehicle changes with time, and accordingly, the storage device can take various states such as a charged state, a discharged state, or a state of neither charging nor discharging (resting state) . Thus, as shown in the graph of FIG. 12, the terminal voltage V (t) of the storage device changes every moment.

  As shown by a portion surrounded by an alternate long and short dash line in the graph, at the time of cranking, the current flowing through the power storage device largely changes, and the resistance value of the DC resistance component also largely changes. Further, as shown by a portion surrounded by a two-dot chain line in the graph, the current flowing through the storage device changes also during the CV charging, and the resistance value of the DC resistance component also changes. As indicated by the solid line in the graph, when the power storage device is near full charge (high SOC state), gassing occurs, so the resistance value of the DC resistance component also changes according to the gassing. . Due to the change in the resistance value, a change occurs in the DC resistance voltage Vdc (t), which appears as a change in the terminal voltage V (t). Further, as shown by the portion surrounded by a broken line in the graph, the storage device is discharged and the terminal voltage V is discharged from a state where the terminal voltage V (t) is high (about 14 V in this example). When (t) is decreasing, a change in the polarization voltage Vpol (t) of the storage device appears as a change in the terminal voltage V (t).

  (A) of FIG. 12 shows the simulation result of the terminal voltage V (t) of the storage device according to the comparative example. The simulation of the comparative example was performed using an equivalent circuit model including a linear DC resistance component and a linear polarization impedance component. In this case, since the DC resistance voltage Vdc (t) and the polarization voltage Vpol (t) can not be accurately represented, the value of the measured terminal voltage V (t) and the value and error of the terminal voltage V (t) by simulation Was great.

  (B) of FIG. 12 shows the result of simulation of the terminal voltage V (t) by the storage device simulator 1 in the same traveling pattern of the vehicle as that of (a) of FIG. In this case, since the DC resistance voltage Vdc (t) and the polarization voltage Vpol (t) can be accurately represented according to the above principle, comparison with the simulation result of the comparative example shown in FIG. The error between the measured terminal voltage V (t) and the terminal voltage V (t) by simulation is reduced.

  Specifically, cranking is performed because the circuit 10 of the equivalent circuit model 40 includes the resistor 12 and the resistance value R (I) of the nonlinear DC resistance component is considered in the calculation of the DC resistance voltage Vdc (t). The calculation accuracy of the terminal voltage V (t) (portion enclosed by the alternate long and short dash line in the graph) and the terminal voltage V (t) at the time of CV charging (portion enclosed by the alternate long and two short dash line in the graph) is improved . In addition, the circuit 10 of the equivalent circuit model 40 includes the capacitor 13 and the switching element 14, and the voltage Vg (t) is calculated in the calculation of the DC resistance voltage Vdc (t). The calculation accuracy of the terminal voltage V (t) in the SOC state (the portion surrounded by the solid line in the graph) was improved.

  Further, at least one of resistance value Rp of resistor 21 and capacitance value Cp of capacitor 22 of circuit 20 of equivalent circuit model 40 is set according to current I (t), so that a discharge state (during CC discharge) is obtained. The estimation accuracy of the terminal voltage V (t) of the power storage device (the portion surrounded by the broken line in the graph) was improved. This is because the change in the polarization voltage Vpol (t) appears as a change in the terminal voltage V (t) in the discharge state, but since the polarization voltage Vpol (t) is accurately calculated, The estimation accuracy of the terminal voltage V (t) of

  In addition, by setting the time constant τ1 determined from the resistance value of the resistor 21 and the capacitance value of the capacitor 22 to different values depending on whether the storage device is in the charged or discharged state or in the inactive state, the idle state is established. The polarization voltage Vpol (t) generated in the storage device can be accurately represented. As a result, the following effects are achieved.

  FIG. 13 is a diagram showing the change of the terminal voltage in the inactive state. This example shows that the power storage device is put in the inactive state before time t1, and shifted to the charge state (CV charge state) at time t1. In the graph, a curve A1 indicated by a solid line and a curve A2 indicated by a broken line show changes in two different terminal voltages V (t).

  As shown by curves A1 and A2, terminal voltage V (t) gradually decreases until time t1, and rises to the voltage value of CV charge at time t1. Here, since the terminal voltage V (t) indicated by the curve A1 and the terminal voltage V (t) indicated by the curve A2 are different in the steepness of the voltage change until the time t1, both of them at the time t1 The terminal voltage V (t) is different. Specifically, the terminal voltage V (t) indicated by the curve A1 has a steeper change in voltage than the terminal voltage V (t) indicated by the curve A2. Therefore, when both terminal voltages V (t) rise to the voltage of CV charging at time t1, the amount of change in both voltages at time t1 becomes the amount of voltage change ΔV1 and the amount of voltage change as shown in FIG. The magnitude is different from ΔV2 (in this example, ΔV1> ΔV2). When voltage change amount ΔV1 and voltage change amount ΔV2 are different, the magnitude of the charge of the power storage device is different even if the value of the current flowing through the power storage device is the same. This means that if the voltage value of terminal voltage V (t) in the inactive state is not accurately estimated, the magnitude of the charge of the storage device in the charged state (CV charged state) after the inactive state (ie, SOC Means that an error occurs. This error can affect the accuracy of the fuel consumption calculation.

  On the other hand, as described above, the time constant τ1 determined from the resistance value of the resistor 21 and the capacitance value of the capacitor 22 differs depending on whether the storage device is in the charged or discharged state or in the inactive state. By setting the value, the polarization voltage Vpol (t) generated in the storage device in the inactive state can also be accurately calculated. Therefore, the estimation accuracy of terminal voltage V (t) in the inactive state can be improved. As a result, the magnitude of the charge of the storage device in the charge state (CV charge state) after the pause state is also accurately estimated. Therefore, the accuracy of the fuel consumption calculation can be improved.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment. For example, the equivalent circuit model 40 can be changed according to the purpose. In the storage device simulator 1, the calculation in the above embodiment may be appropriately changed according to the configuration of the equivalent circuit model 40.

  For example, in order to improve the estimation accuracy of the portion affected by the DC resistance voltage Vdc (t) in the terminal voltage V (t), the configuration of the circuit 20 of the equivalent circuit model 40 is the same as that of the above embodiment. The configuration is not limited, and any configuration may be used. For example, only a parallel connection configuration of a resistor and a capacitor that simulates a linear polarization impedance may be provided. In this case, in the storage device simulator 1, the calculation regarding the resistance value of the resistor 21 and the capacitance value of the capacitor 22 and the calculation regarding the time constant τ1 may be omitted or changed as appropriate.

  In particular, in order to improve the estimation accuracy of the terminal voltage V (t) at the time of cranking and at the time of CV charging, the circuit 10 may include the resistor 11 and the resistor 12. In this case, in the power storage device simulator 1, the calculation regarding the gassing unit may be omitted or changed as appropriate. In addition, in order to improve the estimation accuracy of the terminal voltage V (t) in a state where the storage device is near full charge (high SOC state), the circuit 10 includes the resistor 11, the capacitor 13 and the switching element 14 It should be provided. In this case, in the storage device simulator 1, the calculation regarding the non-linear DC resistance component may be omitted or changed as appropriate.

  Further, in order to improve the estimation accuracy of the portion of the terminal voltage V (t) that is affected by the polarization voltage Vpol (t), the configuration of the circuit 10 of the equivalent circuit model 40 is the configuration of the above embodiment. The configuration is not limited to the above, and may have any configuration. For example, the circuit 10 may include only the resistor 11 that simulates a linear DC resistance component. In this case, in the power storage device simulator 1, the calculation regarding the non-linear DC resistance component and the calculation regarding the gassing unit may be omitted or changed as appropriate.

  Furthermore, the equivalent circuit model 40 of the storage device described above with reference to FIG. 2 may be an equivalent circuit model of a storage device of one cell. In a vehicle, for example, a lead battery (lead battery for automobile) in which 6-cell storage devices are connected in series is used. In this case, six equivalent circuit models 40 shown in FIG. 2 may be connected in series to represent the equivalent circuit model of the six-cell storage device. By doing this, for example, it is possible to cope with the case where an imbalance of 6 cells (a change in OCV between cells due to a variation in the electrolyte concentration, etc.) occurs while using an automotive lead battery (simulation (simulation) To be able to

  DESCRIPTION OF SYMBOLS 1 ... Electric storage device simulator (simulation apparatus), 2 ... Input part, 3 ... SOC calculation part, 4 ... Parameter setting part, 5 ... DC resistance calculation part, 51 ... Current calculation part, 52 ... Voltage calculation part, 53 ... Mode determination Part 6: 6 polarization calculation part 6a setting part 6b polarization voltage calculation part 7 OCV calculation part 8 terminal voltage calculation part 10 circuit (DC resistance component) 11 resistor (linear DC resistance Component) 12 Resistor (non-linear direct current resistance component) 13 Capacitor (gushing portion) 14 Switching element (gushing portion) 21, 23, 25 Resistor 20 Circuit 30 constant voltage source 40 ... equivalent circuit model, 51 ... current calculation unit, 52 ... voltage calculation unit, 90 ... fuel consumption calculation device.

Claims (14)

The simulation method is executed by a simulation apparatus for estimating a terminal voltage of the storage device using an equivalent circuit model of the storage device including a resistor and a capacitor connected in parallel for representing a polarization voltage generated in the storage device. ,
Calculating a current flowing through the equivalent circuit model;
Setting at least one of the resistance value of the resistor and the capacitance value of the capacitor according to the current calculated in the calculating step;
Calculating the polarization voltage generated in the storage device using the calculation result in the calculating step and the setting result in the setting step;
Calculating the terminal voltage of the storage device using the calculation result in the step of calculating the polarization voltage;
including,
Simulation method. The method further includes the step of calculating a DC resistance voltage which is a voltage generated in a DC resistance component of the equivalent circuit model,
In the step of calculating the terminal voltage, the terminal voltage is further calculated based on the DC resistance voltage,
The DC resistance component includes a linear DC resistance component and a nonlinear DC resistance component connected in series with the linear DC resistance component,
The non-linear direct current resistance component has a resistance value that changes according to the current.
The simulation method according to claim 1. The method further includes the step of calculating a DC resistance voltage which is a voltage generated in a DC resistance component of the equivalent circuit model,
In the step of calculating the terminal voltage, the terminal voltage is further calculated based on the DC resistance voltage,
The DC resistance component includes a linear DC resistance component and a gassing unit connected in series with the linear DC resistance component,
The gassing unit includes a capacitor and a switching element connected in parallel.
In the step of calculating the DC resistance voltage, a first voltage which is a voltage generated in the linear DC resistance component and a second voltage which is a voltage generated in the gassing portion are calculated, and the first voltage and the second voltage are calculated. Calculate the DC resistive voltage based on the voltage,
The simulation method according to claim 1. In the setting step, a time constant determined from the resistance value of the resistor and the capacitance value of the capacitor is different between when the power storage device is in a charged or discharged state and when the power storage device is in a resting state. Set to
The simulation method according to any one of claims 1 to 3. The DC resistance component further includes a gassing unit connected in series with the linear DC resistance component,
The gassing unit includes a capacitor and a switching element connected in parallel.
In the step of calculating the DC resistance voltage, a first voltage which is a voltage generated in the linear DC resistance component, a second voltage which is a voltage generated in the nonlinear DC resistance component, and a third voltage which is a voltage generated in the gassing portion Calculating a voltage, and calculating the DC resistive voltage based on the first voltage, the second voltage and the third voltage.
The simulation method according to claim 2. In the setting step, a time constant determined from the resistance value of the resistor and the capacitance value of the capacitor is different between when the power storage device is in a charged or discharged state and when the power storage device is in a resting state. Set to
The simulation method according to claim 5. In the setting step, at least one of the resistance value of the resistor and the capacitance value of the capacitor is set according to the value of the current flowing through the resistor and the capacitor.
The simulation method according to any one of claims 1 to 6. In the setting step, the resistance value of the resistor is set using a value obtained from a Butler-Volmer equation using the value of the current flowing through the resistor and the capacitor as a variable.
The simulation method according to claim 7. A simulation apparatus for estimating a terminal voltage of a storage device using an equivalent circuit model of the storage device including a resistor and a capacitor connected in parallel for expressing a polarization voltage generated in the storage device,
A current calculation unit that calculates a current flowing to the equivalent circuit model;
A setting unit configured to set at least one of the resistance value of the resistor and the capacitance value of the capacitor according to the current calculated by the current calculation unit;
A polarization voltage calculation unit that calculates the polarization voltage generated in the storage device using the calculation result of the current calculation unit and the setting result of the setting unit;
A terminal voltage calculation unit that calculates the terminal voltage of the storage device using the calculation result of the polarization voltage calculation unit;
Equipped with
Simulation equipment. It further comprises a voltage calculation unit for calculating a DC resistance voltage which is a voltage generated in a DC resistance component of the equivalent circuit model,
The terminal voltage calculation unit further calculates the terminal voltage based on the DC resistance voltage,
The DC resistance component includes a linear DC resistance component and a nonlinear DC resistance component connected in series with the linear DC resistance component,
The non-linear direct current resistance component has a resistance value that changes according to the current.
The simulation apparatus according to claim 9. It further comprises a voltage calculation unit for calculating a DC resistance voltage which is a voltage generated in a DC resistance component of the equivalent circuit model,
The terminal voltage calculation unit further calculates the terminal voltage based on the DC resistance voltage,
The DC resistance component includes a linear DC resistance component and a gassing unit connected in series with the linear DC resistance component,
The gassing unit includes a capacitor and a switching element connected in parallel.
The voltage calculation unit calculates a first voltage which is a voltage generated in the linear DC resistance component, and a second voltage which is a voltage generated in the gassing unit, based on the first voltage and the second voltage. Calculate the DC resistance voltage,
The simulation apparatus according to claim 9. The setting unit sets time constants determined from the resistance value of the resistor and the capacitance value of the capacitor to different values depending on whether the storage device is in a charged state or a discharged state and when the storage device is in a resting state. Do,
The simulation apparatus according to any one of claims 9 to 11. The DC resistance component further includes a gassing unit connected in series with the linear DC resistance component,
The gassing unit includes a capacitor and a switching element connected in parallel.
The voltage calculation unit includes a first voltage which is a voltage generated in the linear DC resistance component, a second voltage which is a voltage generated in the non-linear DC resistance component, and a third voltage which is a voltage generated in the gassing unit. Calculating and calculating the DC resistive voltage based on the first voltage, the second voltage and the third voltage,
The simulation apparatus according to claim 10. The setting unit sets time constants determined from the resistance value of the resistor and the capacitance value of the capacitor to different values depending on whether the storage device is in a charged state or a discharged state and when the storage device is in a resting state. Do,
The simulation apparatus according to claim 13.

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