KR101997398B1 - Method and apparatus for predicting inrush current of parallel-connected battery modules - Google Patents

Abstract

An embodiment of the present invention relates to a method for anticipating a rush current of a battery module in a battery system in which N+1 battery modules (N is a natural number) are arranged in parallel. To this end, provided is a first circuit configuration, wherein a first battery module to be connected to a direct current (DC) link is modelled as a first circuit model in which a first open circuit voltage (OCV) source and a first resistance are connected in series in a starting state, and N second battery modules connected to the DC link are modelled as an integrated circuit model in which an integrated OCV source and an integrated resistance are connected in series in the starting state, wherein a load is connected to the integrated circuit model. Further provided is the method for anticipating a rush current of a battery module, including: a step of estimating the integrated OCV by substituting the voltage of the load (a load voltage), the current of the load (a load current) and the integrated resistance into the first circuit configuration; and a step of, in a second circuit configuration in which the load is connected to the first circuit model connected in parallel and the integrated circuit model, estimating a second rush current which is outputted by the first battery module to the DC link, and a second rush current which is outputted by each of the second battery modules to the DC link on average, by substituting the first OCV, the integrated OCV, the first resistance, the integrated resistance, and the load current into the second circuit configuration.

Description

TECHNICAL FIELD The present invention relates to a method and an apparatus for predicting inrush current of a battery module connected in parallel,

The present embodiment relates to a technique for predicting a rush current of a battery module connected in parallel.

Renewable energy and environmentally friendly electric vehicles are being activated to reduce environmental pollution and increase the efficiency of energy use, and the use of large capacity battery system is continuously increasing.

The large-capacity battery system generally has a structure in which two or more high-voltage battery modules, in which a plurality of battery cells are connected in series, are connected in parallel.

On the other hand, when connecting a high voltage battery module to a DC (direct current) link, the energy charge between the battery modules must be within a similar range to avoid excessive inrush currents in the high power relay for parallel connection.

In addition, when the battery module is being used, if the battery module that has been previously shut down is newly inserted or replaced (hot-swapped), if the size of the load current and the state of each battery module are not taken into consideration, Or the battery module may fail.

In view of the foregoing, an object of the present embodiment is to provide, in one aspect, a technique for predicting an inrush current of a battery module. In another aspect, the object of the present embodiment is to provide a control technique for limiting the inrush current of the battery module to within a safe range.

In order to achieve the above object, an embodiment of the present invention provides a method for predicting an inrush current of a battery module in a battery system in which N + 1 battery modules are arranged in parallel (N is a natural number) The first battery module to be connected to the DC link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series, and N second battery modules connected to the DC link, (Load voltage), the current (load current) of the load, the current of the load (load current), and the load current are modeled by an integrated circuit model in which an integrated OCV source and an integrated resistance are connected in series. And estimating the integrated OCV by inserting the integrated resistance into the first circuit configuration; And a second circuit configuration in which the load is connected to the first circuit model and the integrated circuit model connected in parallel, the first OCV, the integrated OCV, the first resistor, the integrated resistor, 2 circuit configuration so as to estimate a first inrush current that the first battery module outputs to the DC link and a second inrush current that each of the second battery modules output to the DC link on average A method of predicting inrush current of a battery module is provided.

The method may further include confirming the first OCV with the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link.

The method may further include measuring the first resistance with a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module.

The method includes measuring an internal resistance of the first battery module by a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module, And measuring the first resistance by adding the connection resistance between the first resistance and the internal resistance.

The method may further include estimating the integrated resistance with a variation amount of the terminal voltage of the N second battery modules with respect to the variation amount of the terminal currents of the N second battery modules in a time period in which the amount of current change per unit time is equal to or greater than a predetermined value.

The method may further include calculating the integrated resistance by connecting the resistors (second resistors) included in the circuit models of the N second battery modules in parallel.

When the first inrush current and the second inrush current are smaller than a maximum output current of the battery module and less than a maximum allowable current of the switch connecting the battery module and the DC link, And connecting the battery module to the DC link.

In this method, in the step of estimating the integrated OCV, the integrated OCV can be estimated by adding the load voltage to the value obtained by multiplying the load current by the integrated resistance.

The first inrush current may be calculated by Equation (1).

[Equation 1]

Is1 = ((Vocv1 - Vocvt) + Rt * Iload) / (R1 + Rt)

Is1: first inrush current, Vocv1: first OCV, Vocvt: integrated OCV, Rt: integrated resistance, Iload: load current, R1:

In another embodiment, a method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel, includes: a first battery module to be connected to a DC Wherein a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series is modeled as a first circuit model, and the N second battery modules connected to the DC link are modeled as an integrated OCV source and an integrated resistor Verifying the value of the first resistor, modeled in an integrated circuit model connected in series; Confirming the value of the integrated resistor; Checking a voltage (load voltage) of a load connected to the battery system and a current (load current) of the load; Estimating the integrated OCV using the integrated circuit model, the integrated resistor, the load current, and the load voltage; Confirming the first OCV; Wherein the first circuit module and the integrated circuit model are connected in parallel and the first inrush current outputted from the first battery module to the DC link is supplied to the first OCV, Estimating using an integrated resistance, the load current, and the first resistor; Estimating an integrated inrush current of the N second battery modules by subtracting the first inrush current at the load current; And estimating a second inrush current output from each of the second battery modules by dividing the integrated inrush current by N. The inrush current predicting method of the battery module includes:

The method may further include measuring an internal resistance of the first battery module by a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module, The connection resistance between the first battery module and the DC link may be combined with the internal resistance to measure the first resistance.

In this method, in the step of checking the integrated resistance, the integrated resistance may be calculated by connecting the resistors (second resistors) included in the circuit models of the N second battery modules in parallel.

In this method, the first OCV can be identified by the terminal voltage of the first battery module measured in a state where the first battery module is not connected to the DC link in the step of checking the first OCV.

In another embodiment, there is provided an apparatus for predicting inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel, comprising: a first battery module Is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a startup state, and N second battery modules connected to the DC link are modeled as an integrated OCV source and an integrated resistor A parameter verifying unit modeled as an integrated circuit model connected in series and identifying a value of the first resistor and the integrated resistor; (Load voltage) of the load connected to the battery system and the load current (load current), and detects a terminal voltage of the first battery module and a terminal voltage of the N second battery modules Verification unit; An OCV verifying unit for verifying the first OCV with a terminal voltage of the first battery module and estimating the integrated OCV using the integrated circuit model, the integrated resistor, the load current, and the load voltage; And a first inrush current output from the first battery module to the DC link in a state where the first circuit model and the integrated circuit model are connected in parallel and the load current is maintained, Estimating an integrated inrush current of the N second battery modules by subtracting the first inrush current at the load current using the integrated resistance, the load current, and the first resistance, N, and estimating a second rush current output from each of the second battery modules. The inrush current estimating apparatus includes:

The parameter checking unit may measure the first resistor and the integrated resistor using a step current.

The OCV checking unit can identify the first OCV by the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link.

When the first inrush current and the second inrush current are smaller than a maximum output current of the battery module and less than a maximum allowable current of the switch connecting the battery module and the DC link, To the DC link.

When the first inrush current and the second inrush current are equal to or greater than the maximum output current of the battery module or the maximum allowable current of the switch connecting the battery module and the DC link, And further insert an auxiliary resistor in the module and the DC link to connect the first battery module to the DC link.

As described above, according to the present embodiment, the inrush current of the battery module can be predicted, and the inrush current of the battery module can be limited within a safe range.

1 is a configuration diagram of a battery system according to an embodiment.
2 is a configuration diagram of a battery module according to an embodiment.
3 is a circuit model of a battery module according to an embodiment.
4 is a circuit model of a battery system according to one embodiment.
Fig. 5 is a circuit model in which the circuit model of Fig. 4 is simplified.
6 is a configuration diagram of an inrush current predicting apparatus according to an embodiment.
7 is a flowchart of a first example method for predicting inrush current in one embodiment.
8 is a diagram showing a first circuit configuration in which the first battery module is not connected to the DC link.
9 is a diagram showing a second circuit configuration in which a first battery module is connected to a DC link;
10 is a diagram for explaining the measurement of the internal resistance by the step current.
11 is a diagram for explaining measurement of internal resistance with some current / voltage waveform during operation.
12 is a flowchart of a second exemplary method for predicting inrush current in one embodiment.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

In describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected to or connected to the other component, It should be understood that an element may be "connected," "coupled," or "connected."

1 is a configuration diagram of a battery system according to an embodiment.

Referring to FIG. 1, N + 1 (N is a natural number) battery modules 110 may be arranged in parallel in the battery system 100.

One terminal of the N + 1 battery modules 110 may be electrically connected to the DC link 120 while the other terminal is connected to the ground link 130. One terminal of the battery module 110 connected to the DC link 120 is referred to as a module positive terminal and the other terminal of the battery module 110 connected to the ground link 130 is referred to as a module negative terminal .

The DC link 120 may be connected to one terminal STP of the battery system 100 and the ground link 130 may be connected to the other terminal STN of the battery system 130. [ One terminal STP of the battery system 100 is referred to as a system plus terminal STP and the other terminal STN is referred to as a system negative terminal STN.

A load 140 may be connected to the system plus terminal STP and the system minus terminal STN.

One battery module 110 of the N + 1 battery modules 110 may be separated from the DC link 120 and reconnected to the DC link 120. Or one battery module 110 of the N + 1 battery modules 110 may be added to increase the capacity of the battery system 100 or may be to replace an existing battery module.

As described above, in the battery system 100, the N battery modules 110 are connected to the DC link 120, and one battery module 110 is newly connected to the DC link 120, When one battery module 110 is newly connected to the DC link 120, it may be a problem that the current (inrush current) flowing in each battery module 110 exceeds the allowable range.

The device 150 included in the battery system 100 predicts an inrush current flowing through each battery module 110 and when the inrush current is within the permissible range, the battery module 110 is added to the DC link 120 So that the battery system 100 can be controlled.

The permissible range of the inrush current is determined by the maximum output current of the battery module 110 or the switch-battery module 110 and the DC link 120, which are included in the battery module 110 or connected to the outside of the battery module 110, The maximum allowable current of the switch that controls the connection of the switch. The output current of the battery cell included in the battery module 110 may be limited to a certain value. When the current exceeds the predetermined value, the inside of the battery cell may be deformed or the safety of the battery cell may be deteriorated. If a current exceeding the maximum allowable current flows through the switch, the switch may be broken or the switch may not be turned off.

2 is a configuration diagram of a battery module according to an embodiment.

Referring to FIG. 2, the battery module 110 may include a plurality of battery cells 210, a serial switch SWS, a bypass switch SWP, and a bypass resistor RP.

The plurality of battery cells 210 may be connected in series or in parallel. The battery cells 210 may be connected in series to increase the voltage of the battery module 110 and the battery cells 210 may be connected in parallel to increase the capacity of the battery module 110. [

A serial switch SWS may be disposed between the battery cell 210 and the module positive terminal MTP. When the serial switch SWS is turned on, the current of the battery cell 210 may be output to the module plus terminal MTP.

The bypass switch SWP may be connected in series with the bypass resistor RP. The bypass switch SWP and the bypass resistor RP may be connected in parallel with the serial switch SWS. When the serial switch SWS is turned off and the bypass switch SWP is turned on, the current of the battery cell 210 is passed through the bypass switch SWP and the bypass resistor RP to the module plus terminal MTP Can be output.

The module negative terminal MTN may be connected to the battery cell 210 on the other side of the module plus terminal MTP and may be connected to a ground link external to the battery module 110.

3 is a circuit model of a battery module according to an embodiment.

Referring to FIG. 3, the battery module may be circuit modeled with an OCV (open circuit voltage) source (OCVS), an internal resistance Ri, a double layer resistance Rd, and a double layer capacitor Cd. Here, OCV may mean the voltage of the OCV source (OCVS).

The OCV is a voltage measured in the absence of current flowing into the module plus terminal (MTP) and the module minus terminal (MTN), which is highly related to the state-of-charge (SoC) of the battery module.

The internal resistance Ri can be connected in series with the OCV source (OCVS) between the OCV source (OCVS) and the module positive terminal (MTP). The internal resistance Ri represents an electrical resistance state inside the battery module in which the current flowing into the battery module is experienced.

The double layer resistance Rd and the double layer capacitor Cd may be connected in parallel to form one RC ladder. The RC ladder may be connected in series with the internal resistance Ri between the internal resistor Ri and the module positive terminal MTP.

On the other hand, the inrush current Is flows in the form of a step current. Since this step current has a large amount of change per hour, the current flows from the RC ladder to the double layer capacitor Cd without flowing into the double layer resistor Rd. Then, the double-layer capacitor Cd can be recognized as a very low impedance with respect to a current having a large change amount per unit time.

According to this principle, in the state in which the inrush current Is flows, the circuit model of the battery module as shown in Fig. 3 (a) can be simplified as shown in Fig. 3 (b).

When the circuit model (FIG. 3 (b)) of the battery module is applied to the battery system, the circuit model shown in FIG. 4 can be obtained.

4 is a circuit model of a battery system according to one embodiment.

4, a first battery module to be connected to the DC link 120 may be modeled as a first circuit model 111 in which a first OCV source OCV1 and a first resistor R1 are connected in series in a startup state have. The N second battery modules connected to the DC link 120 are respectively connected to the second OCV sources OCVS2a, OCVS2b, ..., OCVS2n and the second resistors R2a, R2b, ..., R2n in the starting state, 112n, ..., 112n that are connected in series.

The first circuit model 111 may further include a first serial switch SWS1 for controlling the connection with the DC link 120 and the first serial switch SWS1 may be modeled as having the initial state turned off have. On the other hand, there may be a resistor in a portion connected to the DC link 120 in the first serial switch SWS1 and the first battery module, and this resistance may be called a first connection resistance. The first connection resistance and the internal resistance of the first battery module described with reference to FIG. 3 may be combined and modeled as the first resistor R1.

The second circuit models 112a, 112b, ..., 112n may further include second serial switches SWS2a, SWS2b, ..., SWS2n for controlling the connection with the DC link 120, The switches SWS2a, SWS2b, ..., SWS2n may be modeled as having the initial state turned on. On the other hand, there may be a resistance in a portion of the second serial switch SWS2a, SWS2b, ..., SWS2n and the second battery module connected to the DC link 120, which may be referred to as a second connection resistance . This second connection resistance and the internal resistance of the second battery module described with reference to FIG. 3 may be combined and modeled as the second resistors R2a, R2b, ..., R2n.

The N second battery modules may be integrated and modeled. An integrated circuit model incorporating portions of the second circuit models 112a, 112b, ..., 112n is shown in FIG.

Fig. 5 is a circuit model in which the circuit model of Fig. 4 is simplified.

5, the N second battery modules connected to the DC link 120 can be modeled as an integrated circuit model 512 in which the integrated OCV source OCVSt and the integrated resistor Rt are connected in series in the startup state . The integrated circuit model 512 may further include an integrated serial switch SWSt for controlling the connection with the DC link 120. [

The integrated resistor Rt may be calculated by connecting a second resistor included in the second circuit model of each of the N second battery modules in parallel. If a second resistance for each of the second battery modules is previously measured or confirmed, the integrated resistance Rt can be calculated in such a way that these second resistors are connected in parallel.

On the other hand, since the second series switches are all modeled in the turn-on state, the integrated serial switch SWSt modeled by the parallel connection of the second series switches can also be modeled into the turn-on state.

The voltage Vocvt of the integrated OCV source OCVSt can be estimated by the device (see 150 in Fig. 1). Battery modules that are connected in parallel are similarly balanced in OCV because their charge states are similarly balanced. In the same manner, the second OCV of each of the second battery modules connected in parallel is also similar, and the voltages of the second OCV and the integrated OCV (Vocvt) are also similar. Thus, the device (see 150 in FIG. 1) can estimate the integrated OCV (Vocvt) and estimate the second OCV of each of the second battery modules to the same value as this voltage.

Since the initial state of the first series switch SWS1 of the first battery model is modeled as turn-off, the first OCV (Vocv1) of the first battery module can be identified as the terminal voltage of the first battery module. The output current I1 of the first battery module may be 0 A in accordance with the turn-off of the first serial switch SWS1.

The output current It of the integrated circuit model may be equal to the current Iload of the load 140. [

An apparatus for predicting inrush current (see 150 in FIG. 1) can predict the inrush current of each battery module using this circuit model.

6 is a configuration diagram of an inrush current predicting apparatus according to an embodiment.

6, the apparatus 150 may include a parameter check unit 610, a voltage current check unit 620, an OCV check unit 630, an inrush current estimating unit 640, a controller 650, have.

The parameter verifying unit 610 can confirm the value of the integrated resistance of the integrated circuit model and the first resistance of the first circuit model. The parameter verifying unit 610 can confirm the value of the first resistor and the integrated resistor with the value input by the user setting. The parameter verifying unit 610 may be measured using a first resistor and a current input to and output from the integrated resistor and a voltage varying corresponding to the current.

For example, the parameter verifying unit 610 may measure the first resistance using the step current input to or output from the first battery module. The parameter verifying unit 610 measures the internal resistance of the first battery module by the variation amount of the terminal voltage of the first battery module with respect to the step current applied to the first battery module, Can be combined with the internal resistance to measure the first resistance.

The parameter verifying unit 610 can measure the integrated resistance of the N second battery modules based on the amount of variation of the terminal voltage of the second battery module with respect to the step current inputted to or outputted from the N second battery modules. The parameter verifying unit 610 determines whether or not the N number of the second battery modules in the time interval having the waveform of the time- The integrated resistance can be estimated from the variation amount of the terminal voltage to the variation amount of the terminal current of the second battery modules.

The voltage / current checking unit 620 can check the terminal voltage of each battery module, the terminal current, the current input / output to / from the terminal of each battery module, the load voltage, and the load current. The voltage and current checking unit 620 can check voltages and currents through the voltage sensor and the current sensor, and can confirm terminal voltages and terminal currents measured by the respective battery modules through communication with the battery modules.

The OCV checking unit 630 can measure or estimate the first OCV of the first circuit model and the integrated OCV of the integrated circuit model.

The OCV verifying unit 630 can confirm the first OCV based on the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link.

The OCV checking unit 630 can estimate the integrated OCV using the integrated circuit model, the integrated resistance, the load current, and the load voltage.

The inrush current estimating unit 640 can estimate the inrush current (first inrush current) of the first battery module and the inrush current (second inrush current) of the second battery module.

The inrush current estimating unit 640 estimates the first inrush current output from the first battery module to the DC link in the state where the first circuit model and the integrated circuit model are connected in parallel and the load current is maintained, An integrated resistance, a load current, and a first resistance. The inrush current estimator 640 estimates the integrated inrush current of the N second battery modules by subtracting the first inrush current from the load current, divides the integrated inrush current by N, The second inrush current can be estimated.

The controller 650 can control the switches of the respective battery modules such that the first inrush current and the second inrush current are within the permissible range.

When the first inrush current and the second inrush current are smaller than the maximum output current of the battery module and less than the maximum allowable current of the series switch connecting the battery module and the DC link, the controller 650 controls the first battery module to be connected to the DC link Can be connected. When the first inrush current and the second inrush current are equal to or greater than the maximum output current of the battery module or the maximum allowable current of the series switch connecting the battery module and the DC link, So that the first battery module can be connected to the DC link. Here, the auxiliary resistor may be a bypass resistor. The controller 650 may turn off the serial switch and turn on the bypass switch to allow the inrush current to flow through the bypass resistor to the DC link.

8 is a diagram showing a first circuit configuration in which a first battery module is not connected to a DC link, and FIG. 9 is a diagram showing a first example of a method of predicting an inrush current according to an embodiment of the present invention. And a second circuit connected to the DC link.

The first circuit configuration shown in FIG. 8 and the second circuit configuration shown in FIG. 9 are first described to improve understanding of the first exemplary method shown in FIG.

8, in the battery system, the load 140 is connected to the integrated circuit model 512 in which the first circuit model 111 is not connected to the DC link 120 and the N second battery modules are modeled A first circuit arrangement 810 is shown.

9, when the first series switch SWS1 is turned on, a startup state is formed. The load 140 is connected to the first circuit model 111 and the integrated circuit model 512, which are connected in parallel in the startup state, Lt; RTI ID = 0.0 > 910 < / RTI >

Referring to FIG. 7, based on the first circuit configuration 810 and the second circuit configuration 910, the device may be configured such that the terminal of the first battery module, which is measured in a state where the first battery module is not connected to the DC link, The first OCV can be identified by the voltage (S700).

Since the first circuit model 111 has the current I1 flowing to the first resistor R1 of 0A in the state that the first series switch SWS1 is turned off, the terminal voltage of the first battery module becomes the first OCV (Vocv1). According to this principle, the device can identify the first OCV with the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link.

The apparatus substitutes the load voltage Vload, the load current Iload and the integrated resistance Rt into the first circuit configuration 810 in a first circuit configuration 810 in which the load is connected to the integrated circuit model, Vocvt) (S702).

In the first circuit configuration 810, an equation of Vocvt = Vload + Rt * Iload is established according to Kirchhoff's law. Since the load voltage (Vload), the load current (Iload) and the integrated resistance (Rt) are both measurable or verifiable values, the device can estimate the integrated OCV (Vocvt) using these values.

The device is connected to the second circuit arrangement 910 in a second circuit arrangement 910 by connecting a first OCV (Vocvl), an integrated OCV (Vocvt), a first resistor R1, an integrated resistor Rt and a load current Iload The first inrush current Is1 output from the first battery module to the DC link 120 can be estimated.

According to the Kirchhoff's law for the second circuit configuration 910, the first inrush current Is1 can be calculated by [Equation (1)].

[Equation 1]

Is1 = ((Vocv1 - Vocvt) + Rt * Iload) / (R1 + Rt)

Is1: first inrush current, Vocv1: first OCV, Vocvt: integrated OCV, Rt: integrated resistance, Iload: load current, R1:

The device can estimate the integrated inrush current Ist of the N second battery modules by subtracting the first inrush current Is1 from the load current Iload. The apparatus can then estimate the second inrush current, which the second battery module outputs on average, by dividing the integrated inrush current Ist by N. [

10 is a diagram for explaining the measurement of the internal resistance by the step current.

Referring to FIG. 10, when the current 1010 is applied to the battery module in steps, it can be seen that the terminal voltage 1020 of the battery module fluctuates in steps. Since the capacitors are recognized as low impedance with respect to the step current, It can be estimated that the variation amount? V of the voltage 1020 is determined by a value obtained by multiplying the internal resistance or the connection resistance by the step current (the amount of current fluctuation? I). In this context, the device can measure the resistance of the battery module with the amount of variation (? V) of the terminal voltage of the battery module with respect to the step current (current fluctuation amount? I) applied to the battery module.

11 is a diagram for explaining measurement of internal resistance with some current / voltage waveform during operation.

11, the waveform of the current 1110 applied to the battery module may be such that the current change amount? I of the current per unit time in the portion 1112 is equal to or larger than a predetermined value. The device can estimate the resistance by the amount of variation (? V) of the terminal voltage to the variation (? I) of the terminal current of the battery module - or the battery modules.

12 is a flowchart of a second exemplary method for predicting inrush current in one embodiment.

Referring to FIG. 12, the apparatus can confirm the value of the first resistor (S1200). The first resistor may be measured and verified by user input. Alternatively, the apparatus may measure the internal resistance of the first battery module by a variation amount of the terminal voltage of the first battery module with respect to the step current applied to the first battery module, and measure a connection resistance between the first battery module and the DC link, The first resistance can be measured.

The device can confirm the value of the integrated resistance (S1202). The integrated resistance can be measured and verified by user input. Alternatively, the apparatus can calculate the integrated resistance by connecting the resistors (second resistors) included in the circuit models of the N second battery modules in parallel.

The device can check the voltage of the load connected to the battery system and the current of the load. The device can check the load voltage and load current through measurement.

The device can estimate the integrated OCV using the integrated circuit model, integrated resistance, load current, and load voltage (S1206).

The device can confirm the first OCV (S1208). The apparatus can identify the first OCV with the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link.

The apparatus includes a first inrush current output from the first battery module to the DC link in a state where the first circuit model and the integrated circuit model are connected in parallel and the load current is maintained is referred to as a first OCV, an integrated OCV, And may be estimated using the first resistance (S1210).

The apparatus estimates the integrated inrush current of the N second battery modules by subtracting the first inrush current at the load current, divides the combined inrush current by N, and estimates the second inrush current output by each second battery module (S1212).

According to the embodiment described above, the inrush current of the battery module can be predicted, and the inrush current of the battery module can be limited within a safe range.

It is to be understood that the terms "comprises", "comprising", or "having" as used in the foregoing description mean that the constituent element can be implanted unless specifically stated to the contrary, But should be construed as further including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (20)

A method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
(Load voltage), the load current (load current), and the integrated resistance into the first circuit configuration in a first circuit configuration in which the load is connected to the integrated circuit model, ; And
The first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, And estimating a first inrush current that the first battery module outputs to the DC link and a second inrush current that each of the second battery modules outputs to the DC link on average,
Further comprising the step of identifying the first OCV with the terminal voltage of the first battery module measured while the first battery module is not connected to the DC link. The method according to claim 1,
And calculating the integrated resistance by connecting the resistors (second resistors) included in the circuit model of each of the N second battery modules in parallel. The method according to claim 1,
Measuring the first resistance with a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module. The method according to claim 1,
Wherein the internal resistance of the first battery module is measured by a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module, And measuring the first resistance in combination with the internal resistance. A method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
(Load voltage), the load current (load current), and the integrated resistance into the first circuit configuration in a first circuit configuration in which the load is connected to the integrated circuit model, ; And
The first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, And estimating a first inrush current that the first battery module outputs to the DC link and a second inrush current that each of the second battery modules outputs to the DC link on average,
Estimating the integrated resistance with a variation amount of a terminal voltage with respect to a variation amount of a terminal current of the N second battery modules in a time interval in which the amount of current change per unit time is equal to or greater than a predetermined value. delete A method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
(Load voltage), the load current (load current), and the integrated resistance into the first circuit configuration in a first circuit configuration in which the load is connected to the integrated circuit model, ; And
The first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, And estimating a first inrush current that the first battery module outputs to the DC link and a second inrush current that each of the second battery modules outputs to the DC link on average,
Wherein when the first inrush current and the second inrush current are less than a maximum output current of the battery module and less than a maximum allowable current of the switch connecting the battery module and the DC link, To the inductance of the battery module. 8. The method of claim 7,
In the step of estimating the integrated OCV,
And estimating the integrated OCV by adding the load voltage to a value obtained by multiplying the load current by the integrated resistance. A method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
(Load voltage), the load current (load current), and the integrated resistance into the first circuit configuration in a first circuit configuration in which the load is connected to the integrated circuit model, ; And
The first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, the first OCV, And estimating a first inrush current that the first battery module outputs to the DC link and a second inrush current that each of the second battery modules outputs to the DC link on average,
Wherein the first inrush current is calculated by Equation (1).
[Equation 1]
Is1 = ((Vocv1 - Vocvt) + Rt * Iload) / (R1 + Rt)
Is1: first inrush current, Vocv1: first OCV, Vocvt: integrated OCV, Rt: integrated resistance, Iload: load current, R1: A method for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
Confirming the value of the first resistor;
Confirming the value of the integrated resistor;
Checking a voltage (load voltage) of a load connected to the battery system and a current (load current) of the load;
Estimating the integrated OCV using the integrated circuit model, the integrated resistor, the load current, and the load voltage;
Confirming the first OCV;
Wherein the first circuit module and the integrated circuit model are connected in parallel and the first inrush current outputted from the first battery module to the DC link is supplied to the first OCV, Estimating using an integrated resistance, the load current, and the first resistor;
Estimating an integrated inrush current of the N second battery modules by subtracting the first inrush current at the load current; And
Dividing the integrated inrush current by N and estimating a second inrush current output by each of the second battery modules
And estimating an inrush current of the battery module. 11. The method of claim 10,
In determining the value of the first resistor,
Wherein the internal resistance of the first battery module is measured by a variation amount of a terminal voltage of the first battery module with respect to a step current applied to the first battery module, And measuring the first resistance together with the internal resistance. 11. The method of claim 10,
In the step of checking the integrated resistance,
And calculating the integrated resistance by connecting the resistors (second resistors) included in the circuit models of the N second battery modules in parallel. 11. The method of claim 10,
In the step of identifying the first OCV,
And determining the first OCV with the terminal voltage of the first battery module measured when the first battery module is not connected to the DC link. 11. The method of claim 10,
In the step of estimating the first inrush current,
Wherein the first inrush current is calculated by Equation (1).
[Equation 1]
Is1 = ((Vocv1 - Vocvt) + Rt * Iload) / (R1 + Rt)
Is1: first inrush current, Vocv1: first OCV, Vocvt: integrated OCV, Rt: integrated resistance, Iload: load current, R1: An apparatus for predicting an inrush current of a battery module in a battery system in which N + 1 (N is a natural number) battery modules are arranged in parallel,
A first battery module to be connected to a DC (direct current) link is modeled as a first circuit model in which a first OCV (open circuit voltage) source and a first resistor are connected in series in a start state, The modules are modeled as an integrated circuit model in which the integrated OCV source and the integrated resistor are connected in series in the activated state,
A parameter verifying unit for verifying a value of the first resistor and the integrated resistor;
(Load voltage) of the load connected to the battery system and the load current (load current), and detects a terminal voltage of the first battery module and a terminal voltage of the N second battery modules Verification unit;
An OCV verifying unit for verifying the first OCV with a terminal voltage of the first battery module and estimating the integrated OCV using the integrated circuit model, the integrated resistor, the load current, and the load voltage; And
Wherein the first circuit module and the integrated circuit model are connected in parallel and the first inrush current outputted from the first battery module to the DC link is supplied to the first OCV, Estimating an integrated inrush current of the N second battery modules by subtracting the first inrush current at the load current using the integrated resistance, the load current and the first resistance, A second inrush current estimating unit for estimating a second inrush current output from each of the second battery modules,
And an inrush current predicting device of the battery module. 16. The method of claim 15,
Wherein the parameter checking unit comprises:
Wherein the first resistor and the integrated resistor are measured using a step current. 16. The method of claim 15,
The OCV checking unit,
Wherein the first OCV is determined based on a terminal voltage of the first battery module measured while the first battery module is not connected to the DC link. 16. The method of claim 15,
Wherein the inrush current estimating unit comprises:
Wherein the first inrush current is calculated by Equation (1).
[Equation 1]
Is1 = ((Vocv1 - Vocvt) + Rt * Iload) / (R1 + Rt)
Is1: first inrush current, Vocv1: first OCV, Vocvt: integrated OCV, Rt: integrated resistance, Iload: load current, R1: 16. The method of claim 15,
Wherein when the first inrush current and the second inrush current are less than a maximum output current of the battery module and less than a maximum allowable current of the switch connecting the battery module and the DC link, And a control unit connected to the inrush current estimating unit. 20. The method of claim 19,
Wherein,
When the first inrush current and the second inrush current are equal to or more than a maximum output current of the battery module or a maximum allowable current of the switch connecting the battery module and the DC link, And an auxiliary resistor is further inserted to connect the first battery module to the DC link.

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