Isolated BMS without CPU in the battery block

Abstract

An isolated BMS without a CPU in the battery cell portion according to the present invention is an isolated battery management system comprising a control portion and a battery portion acting as a slave of the control portion, wherein the battery portion includes a balancing portion that performs balancing operations and a monitoring portion that performs monitoring, wherein the balancing portion and the monitoring portion communicate with a pair of LEDs and detectors (DET) to be physically separated from the control portion, and wherein a code is assigned to each battery cell to recognize the battery cell, and the assigned code is transmitted together when measuring the battery cell voltage.

Description

Technology Field

[0001] The present invention relates to an isolated battery management system without a CPU in the battery unit. Background Technology

[0002] Generally, electric vehicles use a high voltage of 400 to 700 V by connecting multiple battery cells of 3.6 to 3.7 V in series. In a battery pack composed of multiple cells, if the voltage of a cell becomes higher than that of other cells, it can become overloaded, which can lead to a battery explosion; conversely, if the voltage of a battery cell is lower than that of other cells, it can overload the other cells, which can also lead to an explosion.

[0003] Therefore, it is important to accurately monitor the voltage of the battery cells, and overcharging, over-discharging, and abnormal temperatures must be carefully managed. To this end, the accurate battery voltage of each battery cell must be measured to ensure normal battery operation, and battery balancing operations must be performed as necessary to ensure stable battery operation.

[0004] While monitoring the battery status of multiple battery cells and balancing the battery cells is performed based on the CPU, the high-voltage battery voltage is overloaded onto the CPU control board operating at low voltage, making control impossible and causing battery malfunction, which ultimately leads to an accident resulting in a battery explosion.

[0005] In conventional isolated BMS structures, the high-voltage battery and low-voltage control board are separated, and the structure is complex due to the use of multiple LEDs (light-emitting diodes), DETs (detectors), and wireless devices for wireless control corresponding to the number of battery cells; furthermore, differences in temperature characteristics among LEDs cause errors in voltage recognition for each battery cell.

[0006] In addition, differences in the mounting structure of each LED cause differences in the light intensity of the LEDs and DETs mounted within the module, which in turn causes errors in voltage recognition for each battery cell. To solve this, a guide member (shield) with a through hole for each LED is used to prevent interference between LEDs, thereby enabling accurate monitoring of the voltage for each battery cell.

[0007] Even if one bears the burden of having to install these guide components precisely, errors exist, and even if errors are minimized by mounting them accurately, errors in accurate voltage monitoring of battery cells occur due to differences in characteristics of each LED. Prior art literature

[0008] Korean Registered Patent No. 10-2312942 The problem to be solved

[0009] The present invention aims to solve the above-mentioned problems by providing a battery cell monitoring and battery cell balancing system that operates without a CPU in the battery section of an isolated battery management system. means of solving the problem

[0010] The isolated BMS without a CPU in the battery cell section according to the present invention for the above-mentioned problem to be solved is an isolated battery management system comprising a control section and a battery section acting as a slave of the control section, wherein the battery section includes a balancing section that performs balancing operations and a monitoring section that performs monitoring, wherein the balancing section and the monitoring section communicate with a pair of one LED and a detector (DET) to be physically separated from the control section, and each battery cell is assigned a code to recognize the battery cell transmitting the LED signal, and the assigned code is transmitted together when measuring the battery cell voltage.

[0011] The monitoring unit comprises: a diode array connected in series for each battery cell; a switch that switches the diode array signal by a first control signal (CRTL0-0x); a signal generator that generates a second control signal (CTRL1-0 / 1) and a battery cell code for each first control signal; and the LED that sequentially outputs the code signal of the battery cell and the output voltage of the diode array output through the switch as an optical signal.

[0012] The above signal generator includes: an oscillator for generating a first control signal (CRTL0-0x), a second control signal (CTRL1-0 / 1), and a code signal; a counter block for outputting a first frequency and a second frequency; a PS register for outputting a parallel signal as a serial signal; a distribution counter for distributing frequencies equal to the number of battery cells; and an encoder for converting the output voltage of a diode array into a control signal to operate a switch so that the switch is selected.

[0013] The above first frequency is characterized by being a frequency obtained by multiplying the second frequency by the number of battery cells (N) to output a code for each selected battery cell. Effects of the invention

[0014] The isolated BMS without a CPU in the battery cell section according to the present invention can safely manage the battery by physically isolating the high-voltage battery section and the CPU control section operating at low voltage using LEDs for monitoring the battery status of the battery cells and the battery cell balancing operation.

[0015] The present invention provides a simple structure and is easy to manage by eliminating all circuits that used multiple LEDs and DETs and wireless signals to control them, as in conventional inventions. Brief explanation of the drawing

[0016] FIG. 1 is a block diagram of an isolated battery management system without a CPU in the battery section according to the present invention. FIG. 2 is a detailed block diagram of a monitoring unit according to the present invention. FIG. 3 is a block diagram of a signal generator that generates a first control signal, a second control signal, and a code according to the present invention. Specific details for implementing the invention

[0017] The present invention will be described below with reference to specific embodiments and drawings for implementation. The embodiments of the present invention are intended to illustrate a single invention, and the scope of the rights is not limited to the illustrative embodiments. Furthermore, the illustrative drawings should not be interpreted as being limited to the drawings, as they only illustrate the essential details and omit incidental details for the clarity of the invention.

[0018] In an isolated battery management system (BMS) structure, the high and low voltage batteries and the low-voltage control board are separated. The structure is complex due to the use of multiple LEDs (Light Emitting Diodes), DETs (Detectors), and wireless devices for wireless control corresponding to the number of battery cells, and differences in temperature characteristics among LEDs cause errors in voltage recognition for each battery cell.

[0019] In addition, differences in the mounting structure of each LED cause differences in the light intensity of the LEDs and DETs mounted within the module, which in turn causes errors in voltage recognition for each battery cell. To solve this, a guide member (shield) with a through hole for each LED is used to prevent interference between LEDs, thereby enabling accurate monitoring of the voltage for each battery cell.

[0020] Even if one bears the burden of having to install these guide components precisely, errors exist; and even if mounted accurately to minimize errors, discrepancies occur in the voltage monitoring of battery cells due to differences in characteristics among LEDs.

[0021] To fundamentally solve this, all battery cells use a single LED and DET to recognize all battery cell voltages, thereby obtaining a constant battery cell voltage and simultaneously resolving the voltage recognition error caused by the error between the LED and DET.

[0022] To achieve this operation, all battery cells are configured to sequentially select and operate LEDs and DETs. A code is assigned to each battery cell to recognize which battery cell's voltage is operating as an LED. By transmitting this code along with the sequential measurement of battery cell voltages, it is possible to identify which battery cell's voltage is being measured, thereby enabling accurate monitoring of the voltages of all battery cells. Consequently, a simple structure is achieved by using multiple LEDs and DETs and eliminating all wireless signal circuits required to control them.

[0023] FIG. 1 is a block diagram of a CPU-free isolated BMS according to the present invention, which is composed of a control unit (10) acting as a master and a battery unit (20) acting as a slave, and performs balancing operations, overvoltage / overcurrent monitoring, temperature monitoring, SoC (state of charge), SoH (state of health) monitoring, etc., and ensures safe battery operation.

[0024] The above battery unit is composed of a balancing unit (21) that performs balancing operations and a monitoring unit (22) that performs monitoring. The balancing unit and the monitoring unit are isolated structures that are physically separated from the control unit containing the CPU using LEDs and DETs.

[0025] During the monitoring process for each battery cell, if a battery cell is determined to have a problem, the CPU is commanded to perform balancing operations.

[0026] The control unit through the CPU performs a balancing operation by transmitting a cell code defined for each battery cell to the battery unit to perform the balancing operation, thereby turning on the switch corresponding to the battery cell in the battery unit. At this time, the battery cell code value obtained from the control unit is received by the decoder of the battery unit for decoding, and the decoded value is implemented as an operation to turn on the switch of the corresponding battery cell.

[0027] In balancing, since it operates in a logic form, it is not sensitive to LED and DET operation errors, so even if multiple units are used, it can operate without significant difficulty due to temperature changes and LED characteristic errors.

[0028] It is important to ensure the safe operation of the voltage of each battery cell within the battery pack. The present invention uses LEDs and DETs to physically separate the high-voltage battery section and the low-voltage control board, enabling operation in an isolated structure.

[0029] It is important that the monitoring voltage operates accurately and without error. Battery cell voltages have errors depending on the characteristic errors of the LED and DET structures, as well as the layout structure and temperature characteristics.

[0030] In order to accurately obtain the battery cell voltage without errors due to characteristic errors of the LED and DET structures used in each battery cell or due to the arrangement structure in such an isolated structure, the present invention operates with a single LED-DET pair so that the voltage of all battery cells is monitored under the same conditions.

[0031] As shown in Fig. 1, a diode array is formed for each cell, and the diode array is configured as a switch array that sequentially connects the diode array to an LED-DET pair. Then, a code for the corresponding battery cell is generated so that it is possible to know which battery cell's diode array is connected to an LED to output voltage.

[0032] For detailed operation, a code generator is required to determine which battery cell is selected and outputs voltage to the LED; a first control signal (CTRL0-0x) is used to operate the corresponding switch in the switch array, and a second control signal (CTRL1-0 / 1) is used to recognize the voltage and code of the battery cell selected by the switch.

[0033] The above diode array consists of multiple diode arrays connected in series, with a certain number of diode arrays. The number of diode arrays is determined by the number of battery cells and the number of temperature sensors.

[0034] The output voltage of the diode array, input via the battery voltage, is applied in the forward direction and input to the LED as it is lowered by the threshold voltage for each diode. The LED is configured with a diode array structure consisting of a fixed number of forward diodes so that the minimum voltage is applied within the range where the DET is recognized.

[0035] FIG. 2 is a detailed view of the monitoring unit, comprising a battery array (23) composed of N-1 battery cells, an array of diode arrays (24) connected to each battery cell to sequentially operate the battery cells, a switch array (25), a diode array output switch (26), a code generation signal (29), a code generation signal switch (28), and a temperature compensation unit (32).

[0036] Temperature compensation operation is also implemented by processing M Temp_0 / 1 / ..M signals along with the voltages of the battery cells.

[0037] LEDs and diodes exhibit significant variations in operation due to temperature characteristics. When recognizing battery voltage, errors occur where the same battery voltage is recognized as different depending on the temperature. For this reason, a temperature compensation circuit is required.

[0038] To overcome this, multiple TEMP01, TEMP02, TEMPNM voltages, which are reference voltages that do not change with temperature (voltages obtained through a regulator, etc.), are input and passed through the same diode array circuit to compare with the battery voltage, thereby enabling accurate recognition of the battery voltage even in a changing temperature environment.

[0039] In other words, since the reference voltage is obtained by passing through a diode array and an LED, which are circuits with the same reference voltage, it operates in an environment with temperature changes such as battery voltage, and can accurately recognize the battery voltage based on the known reference voltage even if it changes with temperature.

[0040] A first control signal (CRTL0-0x) is generated to sequentially obtain the voltages of the battery cells through switch control, and a second control signal (CTRL1-0 / 1) is generated for each first control signal so that the battery cell code of the diode array selected by the first control signal and the output voltage of the diode array output through the switch are sequentially output to the LED (30).

[0041] FIG. 3 is a block diagram of a signal generator that generates a first control signal (CRTL0-0x, 25), a second control signal (CTRL1-0 / 1, 26, 28) and a code signal (29).

[0042] The above signal generator is composed of an oscillator (41) for generating a first control signal (CRTL0-0x), a second control signal (CTRL1-0 / 1), and a code signal, a counter block (42), a PS register (43) for outputting a parallel signal as a serial signal, a distribution counter (CNT_N, 44), and an encoder (45).

[0043] The counter block is a block that outputs a suitable frequency and outputs frequencies f1 and f2. Here, f2 is a frequency obtained by dividing the frequency of f1 by the number of battery cells (N).

[0044] The distribution counter is a circuit that distributes frequencies equal to the number of batteries. Based on the signal obtained through the distribution counter, it outputs the code of the selected battery cell as a serial signal through the PS register, and sequentially generates a first control signal (CRTL0-0x) through the encoder to operate the switch so that the selected battery cell of the battery pack is output to the diode array. That is, it performs an operation of simultaneously generating the code of the selected battery cell along with the first control signal (CRTL0-0x) that is sequentially selected for each battery cell. Since the code generated at this time must be output for each selected battery cell, the PS register is operated by generating frequency f1 by multiplying f2 by the number of batteries (N).

[0045] In order to transmit voltage to the control board via LEDs for each selected battery cell, a first control signal is generated at voltage f2 so that the control board can retrieve the corresponding battery cell voltage while recognizing the battery cell code whenever the corresponding battery cell is selected. That is, a second control signal is generated for every N battery cells in accordance with the sequentially generated first control signal, thereby recognizing the code of the selected battery cell and monitoring the battery voltage.

[0046] In this invention, the diode array and the switch array can be operated as a single diode array and switch, but the structure of operating in a parallel structure is maintained for the reliable operation of the battery pack. Explanation of the symbols

[0047] 10: Control unit 20: Battery unit 21: Balancing Department 22: Monitoring Department 23: Battery cell array 24: Array of diode arrays 25: Switch array 26: First control signal 27: Resistance block 28: Second control signal 29: Code signal 30: LED 31: Detector

Claims

Claim 1 An isolated battery management system comprising a control unit (10) and a battery unit (20) acting as a slave of the control unit, wherein the battery unit comprises a balancing unit (21) that performs balancing operations and a monitoring unit (22) that performs monitoring, wherein the balancing unit and the monitoring unit communicate via a pair of LEDs (30) and detectors (DET) (31) to be physically separated from the control unit, and the monitoring unit comprises: a diode array (24) connected in series for each battery cell (23); a switch (25) that outputs the output voltage of the diode array by a first control signal (26, CRTL0-0x); a signal generator (29) that generates a code for each battery cell and a second control signal (28, CTRL1-0 / 1) for each first control signal; and the LED that sequentially outputs the code signal of the battery cell and the output voltage of the diode array output through the switch as an optical signal. Claim 2 delete Claim 3 An isolated battery management system according to claim 1, wherein the signal generator comprises: an oscillator for generating a first control signal (CRTL0-0x), a second control signal (CTRL1-0 / 1), and a code signal; a counter block for outputting the frequency generated by the oscillator as a first frequency and a second frequency; a PS register for outputting a parallel signal of the first frequency as a serial code signal; a distribution counter for counting the number of battery cells at the second frequency; and an encoder for converting the output voltage of a diode array selected according to the code signal of the PS register and the counting of the distribution counter into a first control signal so that the output voltage is selected through a switch. Claim 4 An isolated battery management system according to claim 3, wherein the first frequency is a frequency obtained by multiplying the second frequency by the number of battery cells (N) to output a code for each selected battery cell.

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