KR102475285B1 - Multiple battery module integrated safety management system - Google Patents

Abstract

A multiple battery module integrated safety management system of the present invention comprises: a main sensor; an auxiliary sensor having a larger number of turns than the main sensor; and an arc reading unit which receives an induced current signal generated by the magnetic field change from the main sensor and auxiliary sensor when an arc occurs, converts the induced current signal into a voltage signal, and compares the two converted voltage signals to read whether an arc has occurred on a DC line. Accordingly, it is possible to accurately detect whether the arc is generated by comparing two voltage signals without a complicated calculation process such as DWT analysis. Therefore, DWT analysis is omitted, and a system can be configured simply in terms of software and hardware, thereby reducing system construction costs.

Description

Multiple battery module integrated safety management system {Multiple battery module integrated safety management system}

The present invention relates to an integrated safety management system for a plurality of battery modules.

In general, secondary batteries can be used as one battery module by bonding a plurality of unit secondary battery cells in environments requiring high capacity such as electric vehicles, energy storage systems, and uninterruptible power supplies. Accordingly, a plurality of battery modules may be joined and used.

When a plurality of battery modules are used together, the battery module overheats due to abnormal operations such as overcurrent and overvoltage, and as a result, problems such as swelling and damage of the battery module may occur.

In order to compensate for this problem, when multiple battery modules are connected and used, technology is required to measure and monitor various status information such as voltage, current, and temperature of each individual module and prevent overcharging or overdischarging of unit cells. do.

In order to solve this problem, a conventional battery safety management system acquires status information such as current, voltage, and temperature for each battery, and transmits the obtained status information to a remote terminal unit (RTU) located outside the battery safety management system. and the RTU diagnoses the presence or absence of an abnormality of the battery based on the received battery status information. However, conventionally, there is a limitation in that a plurality of battery states must be integrated and sensed through a single battery state monitoring system.

In addition, in some cases, one battery condition monitoring system is placed in each battery, but in this case, as the battery condition monitoring system and the RTU communicate by wire, the signal line wiring is very complicated and maintenance costs are high. there was.

In addition, when the battery is repeatedly charged and discharged and a non-constant voltage is applied, there is a very high possibility of arcing. In addition, if current flows abnormally due to a ground fault, excess battery capacity, contact with other objects, etc., arcs may repeatedly occur at contact points between busbars, cables, wires, and terminal contacts inside the power control facility. Arcing can lead to fire or explosion. Therefore, it is important for the battery safety management system to quickly and accurately detect arc occurrence to prevent fire or explosion.

An arc detection device installed in a conventional battery safety management system uses an arc detection method based on high frequency characteristics of a current transformer. That is, the arc was detected through amplification and FFT (Fast Fourier Transform) analysis by filtering only the high-frequency characteristics that appear when an arc was generated by receiving a voltage signal according to the amount of current change from a current sensor connected to a power line connecting the source and the load. At this time, DWT (Discrete Wavelet Transform) analysis is performed for accurate arc detection. This is because non-arc cases, such as inverter operation, can be mistaken for arcs without DWT analysis. However, in order to perform DWT analysis, a high-spec battery safety management system is required, and a lot of software and hardware costs are required to build such a high-spec system.

Korea Patent Publication (10-2019-0012718)

An object of the present invention is to provide a plurality of battery module integrated safety management system that can solve the above problems.

A plurality of battery module integrated safety management systems for achieving the above object,

It is implemented in the form of a PCB (Printed Circuit Board) board coupled and attached to the output terminal of each battery cell, and the battery cell's power (voltage, current), battery cell +/- terminal temperature, SOC (State of charge), SOH (State Of Health), a plurality of BMS (Battery Management System) that measures internal resistance and outputs it in a short-range wireless communication method;

Measurement data obtained and transmitted by each of the plurality of BMSs is received and stored for each channel, and battery cell output, battery cell voltage, charge/reverse current, charge/discharge rate, charge energy, minimum and maximum temperature, minimum and RTU (Remote Terminal Unit), which additionally extracts additional information such as maximum voltage, total system voltage, battery cell internal resistance average, maximum temperature, battery cell temperature/position, and communication status, and then guides the user with measurement data for each channel;

a router that forms and operates a private network through which the plurality of BMSs can access and communicate with the RTU; and

An arc detector installed on a DC line connected between the router and the RTU to detect an arc generated in a DC line of a battery system,

The arc detector,

Main sensor through which the DC line passes;

An auxiliary sensor through which a DC line passes, disposed side by side with the main sensor and spaced apart from the main sensor; and

An arc reading unit that receives an induced current signal generated by a change in magnetic field when an arc is generated from the main sensor and the auxiliary sensor, converts it into a voltage signal, and compares the two converted voltage signals to read whether an arc has occurred on the DC line. It is characterized by including.

The present invention receives a main sensor, an auxiliary sensor having a larger number of turns than the main sensor, and an induced current signal generated due to a magnetic field change when an arc is generated from the main sensor and the auxiliary sensor, respectively, and converts them into voltage signals, and converts the two voltage signals into two converted voltage signals. Equipped with an arc reading unit that compares and reads whether an arc has occurred in the DC line. Due to this, it is possible to accurately detect whether an arc is generated by comparing two voltage signals without a complicated calculation process such as DWT analysis. Therefore, DWT analysis is omitted, and the system can be configured simply in terms of software and hardware, thereby reducing system construction costs.

The present invention is implemented in the form of a printed circuit board (PCB) board coupled to +/- terminals of a battery cell and proposes a BMS having a short-range wireless communication function, through which each of a plurality of battery cells provided in a battery system It allows for more detailed and efficient monitoring of conditions.

In addition, by enabling the BMS to additionally measure and monitor the internal resistance of each of a plurality of battery cells, more diverse and detailed battery condition monitoring operations can be performed.

In addition, measurement data for each channel and data for a system unit are provided together through one screen, but measurement data for each channel can be provided in multiple stages in summary information and detailed information status using a plurality of battery icons. That is, while increasing the visibility of information provision, it is possible to maximize the level of information provision.

1 is a diagram showing a plurality of battery module integrated safety management system according to an embodiment of the present invention.
2 is a diagram showing a detailed configuration of a BMS according to an embodiment of the present invention.
3 is a diagram showing a detailed configuration of a cell balancing unit according to an embodiment of the present invention.
4 is a diagram for explaining a driving principle of an internal resistance meter according to an embodiment of the present invention.
5 is a diagram illustrating an example of a monitoring screen provided to an RTU according to an embodiment of the present invention.
6 is a diagram showing a detailed configuration of an arc detector according to an embodiment of the present invention.
7 is a photograph showing an actual screen of an oscilloscope showing a voltage signal L1 obtained from a main sensor and a voltage signal L2 obtained from an auxiliary sensor when an arc occurs.

Hereinafter, a plurality of battery module integrated safety management system according to an embodiment of the present invention will be described in detail.

As shown in Figure 1, a plurality of battery module integrated safety management system according to an embodiment of the present invention, BMS (Battery Management System) 110, router 120, RTU ((Remote Terminal Unit) (130) ), and an arc detector 140.

[BMS(110)]

The BMS 110 is coupled and attached to each of a plurality of battery cells provided in a battery system.

Each of the BMSs 110 measures and reports the battery cell's power (voltage, current), battery cell +/- terminal temperature, battery cell aging state (SOC; State of Charge, SOH; State Of Health), internal resistance, In addition, a cell balancing operation is performed.

In particular, as shown in FIG. 2, the BMS 110 of the present invention is implemented in the form of a PCB (Printed Circuit Board) board coupled to the +/- terminals of the battery cell, thereby reducing the system volume increase due to the BMS. to be minimized. In addition, by allowing measurement data to be transmitted in a wireless communication method, additional complicated signal line wiring is not required at all.

The BMS 110 of the present invention includes a power sensor 111, first and second temperature sensors 112 and 113, a battery cell aging state measuring unit 114, a cell balancing unit 115, and an internal resistance meter 116 and a BMS control unit 117 and the like.

In addition, the BMS 110 of the present invention mounts the components and is implemented in the form of a PCB board coupled and attached to the +/- terminals of the battery cells, so that the increase in system volume by the BMS 110 can be minimized. do.

At this time, the signal terminal of the PCB board and the +/- terminal of the battery cell are in contact with each other, but the distance between the signal terminals in the PCB board is larger than the distance between the +/- terminals of the battery cell by about 0.5 mm. This is because when the PCB board is bonded and attached to the battery, the PCB board is slightly bent and a tensile force is generated in which the signal terminal in the PCB board is pushed toward the +/- terminal of the battery cell, which causes the signal terminal in the PCB board and the +/- terminal of the battery cell - This is to ensure that the clamping state between terminals can be maintained more stably for a longer period of time.

<Power sensor 111, first and second temperature sensors 112 and 113, battery cell aging state measuring unit 114>

The power sensor 111 measures and reports the voltage and current of the battery cell to which it is coupled and attached through a power sensor and a current sensor.

The first and second temperature sensors 112 and 113 are disposed on the PCB board so as to be adjacent to the + and - terminals of the battery cell to which they are bonded, and the temperatures of the + and - terminals of the battery cell are measured through them, respectively. Measure and notify.

The battery cell aging state measuring unit 114 has an SOC and SOH measurement algorithm, through which the SOC and SOH of the battery cell are measured and notified.

<Cell balancing unit 115>

Under the control of the RTU 130, the cell balancing unit 115 forcibly drops the output voltages of battery cells outputting higher voltage values than the average voltage, so that the outputs of all battery cells have a constant value.

As shown in FIG. 3 (a), the cell balancing unit 115 of the present invention is a capacitor (C) connected in series between the + terminal and - terminal of the battery cell, inserted between the + terminal of the battery cell and one side of the capacitor It is configured to include a first transistor (TR1), a second transistor (TR2) inserted between the negative terminal of the battery cell and the other side of the capacitor, and a resistor (R) connected in parallel to the capacitor (C).

In this case, the RTU 130 of the present invention collects and analyzes all the output voltages of each battery cell to calculate the battery cell average voltage (or battery cell minimum voltage), and calculates the voltage excess of each battery cell based on this. do.

In addition, by generating and providing control signals based on PWM for the RTU 130, the duty width of the control signals is adjusted based on the voltage excess of each battery cell while minimizing heat generation due to cell balancing, and accordingly, the battery cell voltage In proportion to the excess amount, the cell balancing performance section of each BMS 110 can be increased. As a result, the excess battery cell voltage is more safely discharged through the cell balancing unit 115, so that the final outputs of all the battery cells can have the same voltage value.

Accordingly, when the RTU 130 generates and outputs a control signal having an adjusted duty width for cell balancing, each of the cell balancing units 115 generates first and second transistors TR1 according to the control signal as shown in FIG. 3(b). ,2) is temporarily operated, and the operated first and second transistors TR1 and 2 apply an excess battery cell voltage to the capacitor C to be charged.

And, as shown in FIG. 3(c), when the first and second transistors TR1 and 2 are in the inactive period, the first and second transistors TR1 and 2 block the connection with the battery cell, and the capacitor (C ) so that the battery cell voltage excess charged in ) is all discharged through the resistor (R).

As described above, the present invention proposes a new cell balancing method in which an active method of charging excess battery cell voltage to a capacitor through a transistor and a passive method of discharging all of the excess voltage through a resistor are combined.

In particular, the cell balancing method proposed in the present invention blocks the connection between the resistor and the battery cell signal line while the resistor discharges the excess battery cell voltage, so that leakage current occurs and insulation resistance increases. to block in advance. That is, the leakage current and the possibility of erroneous detection of insulation failure are prevented in advance by the load resistance of the cell balancing circuit.

<Internal resistance meter (116)>

The internal resistance meter 116 measures and reports the internal resistance of the battery cell.

As shown in FIG. 4 , the internal resistance meter 116 sets the load resistance by the cell balancing unit 115 to R and sets the battery cell output voltage to Voc.

In addition, a voltage drop due to cell balancing occurs minutely, and the amount of voltage drop at this time is set as Vload.

Then, after subtracting the amount of voltage drop from the battery cell output voltage, multiplying the load resistance R, and dividing this value by the amount of voltage drop Vload, the internal resistance Rbat of the battery cell is calculated.

[Equation 1]

Rbat(MΩ)= (Voc-Vload) * R / Vload

<BMS control unit 117>

The BMS control unit 117 includes a wireless communication module supporting short-range wireless communication such as Wi-Fi, and collects data acquired through the components and outputs them in a short-range wireless communication method or a control signal transmitted in a short-range wireless communication method. is received and transmitted to the related component.

That is, by transmitting and receiving signals using short-distance wireless communication, it is unnecessary to add signal wires for transmitting and receiving signals with external devices.

In addition, an LED indicator is provided, through which the operating state of the BMS can be visually guided. For example, by providing guidance on BMS normal operation status, reception error status, cell balancing performance status, failure status, etc. through LED light emission color, the user can immediately grasp the operating status of the BMS by checking the exterior of the BMS. .

As such, the BMS of the present invention can measure the power (voltage, current) of the battery cell, the temperature of the +/- terminal of the battery cell, and the aging state of the battery cell without increasing the system volume and adding a signal line.

In particular, the BMS of the present invention additionally acquires and provides new information called internal resistance, thereby allowing the degree of aging of the battery cell to be grasped based on the resistance value.

[Router (120)]

The router 120 serves as a point for wireless communication network access, and after automatically assigning a virtual IP address or private IP address to each BMS 110, based on this, a plurality of BMSs 110 Form and operate a private network that enables access and communication with one RTU (130).

[RTU(130)]

The RTU 130 receives and stores measurement data acquired and transmitted by each of the plurality of BMSs 110 for each channel, and at the same time, from the measurement data for each channel, the battery cell output, battery cell voltage, charge/discharge current, charge/discharge rate, and charge energy. , minimum and maximum temperature, minimum and maximum voltage, overall system voltage, battery cell internal resistance average, maximum temperature, battery cell temperature/position, and additional information such as communication status are additionally extracted.

In addition, a leakage monitoring sensor, an insulation resistance meter, and the like may be provided, and the insulation resistance and leakage current amount of the battery system may be measured through these.

The RTU 130 includes a user interface means such as a keyboard and a monitor, through which a user accesses a pre-registered web page or executes a monitoring program to search and view measurement data, additional information, and measurement information for each channel. make it possible

The monitor terminal is implemented as a laptop, desktop, smart phone, tablet PC, etc., through which the user accesses the above web page or executes a monitoring program to obtain and upload channel-specific measurement data and additional information to the RTU 130. , it makes it possible to search and view measurement information.

As shown in Figure 5, in the present invention, the monitoring screen is divided into two screens.

After generating a plurality of battery cell icons corresponding to each of the plurality of battery cells and firstly guiding the main measurement data of the related battery cell, they are displayed through the first split screen.

At this time, the measurement data is the power (voltage, current) of the battery cell measured and provided by the BMS, battery cell +/- terminal temperature, battery cell aging state (SOC; State of charge, SOH; State Of Health), internal resistance, It may be whether or not cell balancing is performed, and allows a user to select and display at least one of the measurement data as main measurement data.

In addition, by collecting and analyzing the measurement data acquired and transmitted by each of the plurality of BMS 110, battery cell output, battery cell voltage, charge/reverse current, charge/discharge rate, charge energy, minimum and maximum temperature, minimum and maximum voltage, system Additional information such as total voltage, average battery cell internal resistance, maximum temperature, battery cell temperature/position, and communication status is additionally extracted and displayed through a second split screen.

In addition, if necessary, the insulation resistance of the DC line additionally measured through a leakage monitoring sensor, an insulation resistance meter, etc., and the amount of leakage current can also be displayed through the second split screen.

In addition, whether an arc is generated in the DC line determined by the arc detector 140 can also be displayed through the second split screen.

In addition, by detecting an abnormal battery state based on temperature, output, communication status, etc., and changing the icon display color of the battery whose battery abnormality is confirmed, it is possible to confirm that a specific battery has an abnormal state through the icon.

In addition, by diversifying the icon display color according to the cause of the abnormality, it is possible to guide which battery has a problem with only the icon display color.

As described above, the present invention enables to provide more diverse information to the user more efficiently by displaying the state of each battery cell individually through one monitoring screen and simultaneously acquiring and providing system-level monitoring information.

In addition, based on the icon, only the main measurement data of each battery cell is guided first, but when the user selects one of a plurality of icons, a page that guides all of the measurement data of the related battery cell can be additionally configured and provided. .

That is, the present invention provides summary information and detailed information in multiple stages using icons, thereby increasing the visibility of information provision and maximizing the level of information provision.

[Arc detector 140]

The arc detector 140 is installed on a DC line connected between the router 120 and the RTU 130 and detects an arc generated in the DC line of the battery system.

As shown in FIG. 6 , the arc detector 140 includes a main sensor 141 , an auxiliary sensor 142 , and an arc reading unit 143 .

<Main sensor 141, auxiliary sensor 142>

The main sensor 141 and the auxiliary sensor 142 are arranged side by side, separated by a predetermined interval.

Each of the main sensor 141 and the auxiliary sensor 142 has a sensor body 141a and 142a through which a DC line passes, and a sensor line 141b wound with a predetermined number of turns around the entire sensor body 141a and 142a. 142b).

The sensor bodies 141a and 142a are made of ferrite material. The sensor bodies 141a and 142a have a ring shape with an open center, and a DC line passes through the center of the sensor bodies 141a and 142a. In this embodiment, the sensor lines 141b and 142b are formed of copper wires.

When an arc is generated, a magnetic field around the sensor bodies 141a and 142a is changed due to a change in current flowing in the DC line. When the magnetic field changes, an induced current flows in the sensor lines 141b and 142b. Depending on the number of windings and impedance, the magnitude of the induced current varies.

The number of windings of the sensor line 142b of the auxiliary sensor 142 is greater than the number of windings of the sensor line 141b of the main sensor 141 . Also, the impedance is different. In this embodiment, the main sensor 141 has a winding number of 100 N and an impedance of 100 μH, and the auxiliary sensor 142 has a winding number of 1220 N and an impedance of 19.46 mH. The margin of error for each winding is ±5%.

The larger the number of windings, the better the voltage response (voltage resolution) when the induced current is converted into a voltage signal. In particular, when an arc occurs and the DC line burns, the voltage signal obtained from the current signal of the main sensor 141 is saturated and the voltage response is significantly reduced, but the voltage signal obtained from the current signal of the auxiliary sensor 142 is still saturated. voltage response is good.

<Arc reading unit 143>

The arc reading unit 143 receives an induced current signal from the main sensor 141 and an induced current signal from the auxiliary sensor 142 . The arc reading unit 143 determines whether the current signal and the current signal are within a set range, and reads whether an arc has occurred in the DC line. The arc reading unit 143 transfers the read whether arc occurs to the RTU 130 .

The induced current signals received from the main sensor 141 and the auxiliary sensor 142 are converted into voltage signals and amplified in the arc reading unit 143, respectively. Due to this, the arc reading unit 143 may obtain a primary voltage signal from the main thin line 141 and a secondary voltage signal from the auxiliary sensor 142 , respectively.

The arc reading unit 143 compares and analyzes two voltage signals (a primary voltage signal and a secondary voltage signal) to read whether an arc has occurred, an arc generation time and an end time, a change trend during arc progress, and the like.

For example, referring to FIG. 7 , it is possible to suspect whether an arc has occurred by looking at the voltage signal L1 obtained from the main sensor 141, but based on this alone, whether such a voltage change is caused by an arc or an arc such as an inverter operation It is caused by other factors, but it is difficult to distinguish. For this reason, in the prior art, in order to accurately read whether or not an arc was generated, DWT analysis was inevitably performed.

However, since the present invention observes the voltage signal L2 obtained from the auxiliary sensor 142 having good voltage response along with the voltage signal L1 to accurately read arc generation, DWT analysis is not required.

110: BMS 120: router
130: RTU 140: arc detector
141: main sensor 142: auxiliary sensor
143: arc reading unit

Claims (5)

delete It is implemented in the form of a PCB (Printed Circuit Board) board coupled and attached to the output terminal of each battery cell, and the battery cell's power (voltage, current), battery cell +/- terminal temperature, SOC (State of charge), SOH (State Of Health), a plurality of BMS (Battery Management System) that measures internal resistance and outputs it in a short-range wireless communication method; Measurement data obtained and transmitted by each of the plurality of BMSs is received and stored for each channel, and battery cell output, battery cell voltage, charge/reverse current, charge/discharge rate, charge energy, minimum and maximum temperature, minimum and RTU (Remote Terminal Unit), which additionally extracts additional information such as maximum voltage, total system voltage, battery cell internal resistance average, maximum temperature, battery cell temperature/position, and communication status, and then guides the user with measurement data for each channel; a router that forms and operates a private network through which the plurality of BMSs can access and communicate with the RTU; And an arc detector installed on a DC line connected between the router and the RTU to detect an arc generated in a DC line of a battery system,
The arc detector includes a main sensor through which a DC line passes; An auxiliary sensor through which a DC line passes, disposed side by side with the main sensor and spaced apart from the main sensor; And when an arc occurs, the induced current signal generated by the change in the magnetic field is received from the main sensor and the auxiliary sensor, respectively, and converted into a voltage signal, and the converted two voltage signals are compared to read whether an arc has occurred on the DC line. including wealth,
Each of the main sensor and the auxiliary sensor,
A sensor body through which a DC line passes; and a sensor line wound with a predetermined number of windings around the entire sensor body, wherein the number of windings of the auxiliary sensor is greater than the number of windings of the main sensor. According to claim 2,
The number of windings of the main sensor is 100 N error range ± 5%, the plurality of battery module integrated safety management system, characterized in that the number of windings of the auxiliary sensor is 1220 N error range ± 5%. The method of claim 2, wherein the BMS,
a power sensor that measures and reports the output voltage and current of the battery cell;
first and second temperature sensors for measuring and notifying the + terminal temperature and - terminal temperature of the battery cell;
Battery cell aging state measuring unit for measuring and notifying SOC and SOH of the battery cell;
a cell balancing unit performing a cell balancing operation under the control of the RTU; and
A plurality of battery module integrated safety management system, characterized in that it comprises an internal resistance meter for measuring and reporting the internal resistance of the battery cell. The method of claim 4, wherein the cell balancing unit,
A capacitor connected in series between the + terminal and - terminal of the battery cell;
a resistor connected in parallel to the capacitor;
A first transistor inserted between the + terminal of the battery cell and one side of the capacitor; and
A second transistor inserted between the - terminal of the battery cell and the other side of the capacitor,
The first and second transistors charge the capacitor with the output of the battery cell when operating, and discharge the charged power of the capacitor through the resistor when not operating. management system.

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