KR20210014343A - A control method for uniform charing battery on serial connet to EV - Google Patents

Abstract

The present invention relates to an equalized charging apparatus for a serial connection battery cell for an electric vehicle and an equalized charging control method using the same. The equalized charging apparatus includes: a battery part including a plurality of battery unit cells connected in series for the equalized charging of a battery cell; an analogue multiplexer setting a plurality of serially connected batteries of the battery part as a unit battery module to sequentially measure a sequential switching operation of the corresponding battery module and a corresponding voltage value; a decoder decoding the voltage value of the unit battery module measured through the analogue multiplexer to store corresponding state information in the storage part; a voltage sensing module formed with a circuit algorithmized to confirm a corresponding state value by recognizing a voltage state of the battery to sense a voltage for the connected battery by including one single voltage sensing circuit for the analogue multiplexer and the decoder; a voltage balancing module provided to be matched with one single voltage sensing module to adjust the balancing of the corresponding battery such that an equalized charging procedure can proceed in regard to the voltage of the battery sensed through the voltage sensing module by being algorithmized; and the storage part measuring a corresponding voltage state for batteries set by unit battery module in accordance with the operation of the analogue multiplexer to sequentially store the measured value.

Description

[A control method for uniform charing battery on serial connet to EV]

The present invention relates to a method for equally charging control of a series-connected battery cell for an electric vehicle, and by setting a plurality of battery cells connected in series as one unit module, the voltage of the unit module is sequentially switched to an ADC (Analog to Digital sensor). The present invention relates to a device for equalizing charging of a series-connected battery cell for an electric vehicle for a voltage battery pack used in an electric vehicle and an energy storage system by measuring, and a method for controlling equal charging using the same.

In general, transport vehicles are widely used as a means for transporting various articles and heavy objects. Electric carriers are driven by electricity by installing batteries, motors, controllers, mechanical devices, and control devices on existing carriers. Currently, devices using batteries are used in many places. In a situation where items using batteries such as portable electronic devices such as smartphones and laptops, and electric vehicles that can be recharged using batteries are being used, the performance of the battery becomes a measure by which the performance of the entire device can be measured.

In order to use a large-capacity battery, a battery cell or pack is used as a secondary battery in the form of a battery pack through multiple serial and parallel connections. The method of configuring the battery pack includes spot welding by attaching a nickel electrode plate to the positive and negative terminals of the battery cell, and connecting the positive terminal between the battery cell and the structure that can fix the battery cells. In some cases, a battery pack including battery cells is manufactured by fixing it.

Typically, a secondary battery is a battery capable of charging and discharging, unlike a primary battery that cannot be charged. The secondary battery is used in the form of a single battery depending on the type of external device to be applied, or it is used in the form of a battery module that connects multiple batteries and bundles them into one unit. In spite of the characteristics and frequent starting, the charging and discharging characteristics must be maintained robustly and a long life must be guaranteed. However, the conventional lead-acid battery has a problem that charging and discharging characteristics deteriorate and cannot be used for a long time as the engine is frequently stopped and restarted under the ISG system. Therefore, the use of lithium-ion secondary batteries for batteries required for ISG systems is increasing, and the use of lithium-ion secondary batteries capable of high output is increasing.

In general, lithium-ion batteries are a hybrid electric vehicle that is one of the concerns of today's automotive market due to its high energy density per unit volume, low self-discharge, and very long life cycle. (Hybrid Electric Vehicle) is often used as a battery that provides electrical energy.

In particular, hybrid electric vehicles require a high voltage energy source, so numerous lithium ion battery cells are connected in series and used. The plurality of lithium-ion battery cells used at this time form different charges between the battery cells due to the different discharge rates and internal chemical characteristics formed by frequent charging/discharging and the temperature difference between the external cells. Charge Imbalance). Charge imbalance can cause certain battery cells to charge during charging and overdischarge during discharge as well. In addition, it leads to a decrease in the total storage capacity and the life cycle of the battery.

On the other hand, one battery pack is used for the electric drive device. These battery packs display the currently available capacity based on the current voltage, and if a problem occurs without a separate warning of a failure situation, it leads to an abrupt stop of the electric drive system. If such a phenomenon occurs in electric vehicles, etc., it may lead to human accidents.

In particular, unlike batteries connected in parallel, in the case of batteries connected in series, there may be differences in individual voltages of each battery. Therefore, it is necessary to monitor the voltage difference between each individual battery and perform a balancing operation to eliminate the difference.

Accordingly, the present invention is proposed to propose a method for efficient operation of a battery and extending battery life by measuring a voltage value of a battery module connected in series through a voltage measuring sensor.

1. Equal cell control method of battery pack for electric vehicle (Patent Publication No. 10-2013-0075279) 2. Battery cell voltage equalization control device and control method (Patent Publication No. 10-2014-0132085) 3. Battery cell voltage equalization control device and control method (Patent Registration No. 10-1720027)

The present invention has been conceived to solve the above problem, and the object is to set a plurality of battery cells connected in series as one unit module and sequentially switch to an ADC (Analog to Digital sensor) to measure the voltage of the unit module to generate electricity. It is to provide an equalizing charging device for a series-connected battery cell for an electric vehicle for a voltage battery pack used in a vehicle and an energy storage system, and an equalizing charging control method using the same.

In addition, the present invention is a battery pack used in an electric vehicle and an energy storage system, in order to solve the problem of explosion and life if the battery voltage and capacity of each battery are not equal, since tens to hundreds of batteries are connected in series. In order to compensate for the disadvantages of measuring the voltage of individual battery cells for electric vehicles, a number of battery cells connected in series are set as unit modules and sequentially switched through ADC to measure the voltage of the battery cells and charge the cells of the battery pack for electric vehicles. An object of the present invention is to provide an equalizing charging device and an equalizing charging control method using the same.

In order to achieve the above object, the apparatus for equalizing charging of a series-connected battery cell for an electric vehicle according to an embodiment of the present invention includes a battery unit including a plurality of battery unit cells connected in series for equalizing charging of the battery cells, a plurality of series An analog multiplexer that sequentially measures a corresponding voltage value by setting the battery of the connected battery unit as a unit battery module, and corresponding state information by decoding the voltage value of the unit battery module measured through the analog multiplexer A decoder that stores the data in the storage unit, an algorithmized circuit that recognizes the voltage state of the battery and checks the corresponding state value, and includes an analog multiplexer and one voltage sensing circuit for the decoder to measure the voltage for the connected battery. Voltage sensing module for sensing, voltage balancing provided to correspond to one voltage sensing module in order to adjust the balancing of the corresponding battery so that the charging procedure is performed evenly with respect to the voltage of the battery sensed through the algorithmized voltage sensing module It characterized in that it comprises a module and a storage unit for sequentially storing the measured value by measuring the voltage state of the battery set for each unit battery module according to the operation of the analog multiplexer.

In addition, the voltage balancing module of the equalizing charging device of a series-connected battery cell for an electric vehicle according to an embodiment of the present invention monitors the voltage difference between each individual battery for the voltage difference occurring in each battery individual voltage of the battery connected in series. And performing a balancing operation to remove the difference or to keep the voltage of individual batteries equal.

In order to achieve the above object, a method for controlling equal charging of a series-connected battery cell for an electric vehicle according to another embodiment of the present invention includes: a first step of setting a unit battery module for a plurality of battery cells connected in series; A second step of switching the set unit battery module to sequentially measure a battery voltage using an analog multiplexer; A third step of decoding the measured voltage value of the unit battery module measured by being switched through a decoder and storing corresponding state information; A fourth step of sensing a voltage of a battery connected through a voltage sensing module configured with an algorithmic circuit by recognizing a voltage state of the battery based on the measured voltage value; And a fifth step of adjusting the balancing of the corresponding battery for each unit battery module so as to equally charge the voltages of the plurality of batteries connected in series with respect to the sensed voltage of the battery.

In addition, when the battery voltage measured by switching through an analog multiplexer is lower than the voltage of other series connected battery in the method for equalizing charge control of a series-connected battery cell for an electric vehicle according to an embodiment of the present invention, a capacitor module and a DC converter are added to the corresponding battery. It characterized in that it is configured to supplement the switching voltage by connecting.

The equalizing charging device for a series-connected battery cell for an electric vehicle according to the present invention and the equalizing charging control method using the same are configured by sequentially switching to an ADC (Analog to Digital sensor) by setting a plurality of series-connected battery cells as one unit module. By measuring the voltage of the module, it can be used in electric vehicles and energy storage systems to provide an even battery cell.

In addition, the equal charging device for a series-connected battery cell for an electric vehicle according to the present invention and a method for controlling equal charging using the same include tens to hundreds of batteries connected in series to a battery pack used for an electric vehicle and an energy storage system. By maintaining the voltage and capacity of each battery equally, it solves the problem of explosion and life, and solves the shortcomings of measuring the voltage of individual battery cells for electric vehicles through sequential switching procedure through ADC by setting the battery unit module And can provide even voltage measurement and charging of battery cells.

In addition, the equalizing charging device for a series-connected battery cell for an electric vehicle according to the present invention and the equalizing charging control method using the same are used to monitor the voltage difference between each individual battery of the battery connected in series, and to solve the difference, analog for each unit battery module. By performing the battery voltage sensing and balancing operation with the multiplexer, it is possible to reduce material cost by not having a separate equipment for the balancing procedure.

1 is an internal circuit diagram for battery measurement of a conventional series-connected battery cell
2 is a configuration diagram of an equal charging device for a series-connected battery cell for an electric vehicle according to the present invention
3 is a circuit diagram showing the configuration of a unit battery module for equally charging 12 batteries according to an embodiment of the present invention
4 is a circuit diagram for equally charging control for unit modules of 12 batteries according to FIG. 3
5 is an internal configuration diagram showing the configuration of an analog multiplexer of the battery cell equalizing charging device according to FIG. 2
6 is an internal configuration diagram showing the configuration of a decoder of the battery cell equalizing charging device according to FIG. 2
7 is a flow chart showing a method for controlling equal charging of a series-connected battery cell for an electric vehicle according to the present invention
8 is a block diagram of 96 batteries for equally charging control of a series-connected battery cell according to the present invention
9 is a configuration diagram showing a connection state of a resistor and a converter for equalizing charge control of the series-connected battery cell according to FIG. 7

Hereinafter, a detailed description of a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

2 is a block diagram showing a configuration diagram of an equalizing charging device for a series-connected battery cell for an electric vehicle of the present invention. Looking at the configuration, a battery unit 10, an analog multiplexer 20, a decoder 30, and voltage sensing It consists of a module 40, a voltage balancing module 50 and a storage unit 60. Looking at its operation, the battery unit 10 is configured to include a plurality of battery unit cells connected in series for equal charging of the battery cells.

The battery unit 10 provides power for driving an electric vehicle, and is set by variably applying battery unit cells connected in series according to the type and characteristic of the driving electric vehicle.

That is, in the case of an electric vehicle using a high voltage, the battery unit 10 connects 90 or more batteries in series and connects 90 or more signal lines, which is the number of batteries, to a battery management system (BMS) for monitoring and balancing.

Conventionally, when 96 batteries are connected in series, 96 voltage measurement sensors, 96 switches, and 96 resistors are provided to measure the voltage of the batteries connected in sequence, or an IC that monitors 12 batteries for monitoring and balancing is used. Therefore, 8 or more expensive dedicated ICs were used to monitor them and perform a balancing procedure according to voltage.

The analog multiplexer 20 sets a plurality of series-connected battery cells as a unit battery module and sequentially measures a corresponding voltage value for a sequential switching operation of the corresponding battery module.

That is, when 96 batteries are connected in series as shown in FIG. 3, 12 are set as one unit battery module, and as shown in FIG. 5, the unit battery module is connected to the unit battery module through the analog multiplexer 20. For this, the voltage status of each battery is checked through eight switching operations by measuring the corresponding voltage value eight times through sequential switching operations. If six analog multiplexers 20 are used, voltage can be measured through six switching operations by setting 16 units for 96 batteries connected in series as one unit battery module.

The decoder 30 decodes the voltage value of the unit battery module measured through the analog multiplexer 20 and stores the corresponding state information in the storage unit 60.

That is, when the 96 battery packs are connected in series, a decoder for dividing into 12 by 8 and selecting 12 is required. As shown in FIG. 6, the decoder 30 is operated with the number of decoders set as unit battery modules for the connected battery.

The voltage sensing module 40 is composed of an algorithmized circuit to recognize the voltage state of the battery and check the corresponding state value, and one voltage sensing circuit is provided for the analog multiplexer 20 and the decoder 30. It senses the voltage of the connected battery.

The voltage balancing module 50 corresponds to one voltage sensing module by adjusting the balancing of the corresponding battery so that an algorithmicized battery voltage sensed through the voltage sensing module 40 can be evenly charged. Equipped with one voltage balancing module.

In other words, in the case of batteries connected in series, a difference may occur in the individual voltage of each battery, so the voltage difference between each individual battery is monitored and the difference is eliminated, or a balancing operation is performed to keep the voltage of each individual battery equal. must do it.

According to the operation of the analog multiplexer 20, the storage unit 60 measures a corresponding voltage state of a battery set for each unit battery module and stores the measured value.

FIG. 7 is a flowchart showing a method for controlling equal charging of a series-connected battery cell for an electric vehicle according to the present invention. With reference to FIGS. 2 to 7 attached, a method for controlling equal charging of a series-connected battery cell according to the present invention is shown. Looking at, first, a plurality of battery cells connected in series are set as a unit battery module for equal charging and control of the battery cells (step S100), and then the battery cells set as the unit battery modules are set as an analog multiplexer. As shown in Fig. 8, a switching operation is performed to sequentially measure the corresponding battery voltage (step S200).

At this time, when the switched and measured battery voltage is lower than that of other series connected battery voltages, as shown in FIG. 9, a capacitor module and a DC converter are connected and supplemented to supplement the switching voltage to provide an equal battery voltage. do.

The measured voltage value of the unit battery module switched and measured by the above procedure is decoded through a decoder to store the corresponding state information (step S300), and the voltage value of the battery is decoded through the decoder and measured based on the measured voltage value. Recognizes the voltage state and senses the voltage of the connected battery through a voltage sensing module composed of an algorithmic circuit (step S400).

Thereafter, balancing of the corresponding battery is adjusted for each unit battery module so that voltages of a plurality of batteries connected in series are equally charged using a voltage balancing module with respect to the sensed voltage of the battery (step S500).

In general, a plurality of series-connected battery cells is set as a unit battery module.For example, for 96 series-connected battery cells, 12 battery cells are set as one unit battery module, and an analog multiplexer sensor (ADC) is set as a bundle of 12. It is possible to measure the voltage of 96 batteries by measuring the voltage 8 while switching sequentially.

Meanwhile, if 6 battery cells are set as one unit battery module, 96 battery voltages can be measured by switching 16 times using 6 analog multiplexer sensors (ADCs).

When a plurality of series-connected battery cells are configured, in general, a voltage sensing circuit is operated to measure the constant voltage in a state where 96 are always bitten.The present invention has one voltage sensing module equipped with one sensing circuit, and a switching combination Measure the voltage by connecting a voltage measurement circuit to both ends of (+) and (-) of the first battery (B1) and store it in the CPU. In the same way, measure the voltage of the second battery (B2) and store it in the CPU. By measuring the voltage of the battery (B3) and storing it in the CPU, all the voltages of 96 batteries connected in series in the CPU, that is, the storage unit are sequentially stored.

At this time, the high voltage battery is supplied with power from the cell power supply module (consisting of a capacitor + DC/DC converter) and supplemented by connecting a switch connected with a resistor as shown in FIG. 9 to conduct current. Transfer is possible.

As described above, in the present specification and drawings, a preferred embodiment of the present invention has been disclosed, and although specific terms are used, this is only used in a general meaning to easily explain the technical content of the present invention and to aid understanding of the invention. , It is not intended to limit the scope of the present invention. In addition to the embodiments disclosed herein, it is apparent to those of ordinary skill in the art that other modified examples based on the technical idea of the present invention may be implemented.

10: battery part
20: analog multiplexer (ADC)
30: decoder (DECODER)
40: voltage sensing module
50: voltage balancing module
60: storage

Claims (4)

A battery unit 10 comprising a plurality of battery unit cells connected in series for equal charging of the battery cells,
An analog multiplexer (20) for sequentially measuring the corresponding voltage value by setting the batteries of the plurality of series-connected battery units 10 as unit battery modules,
A decoder 30 that decodes the voltage value of the unit battery module measured through the analog multiplexer 20 and stores the corresponding state information in the storage unit 60,
The voltage for sensing the voltage of the connected battery by having one voltage sensing circuit for the analog multiplexer 20 and decoder 30 composed of an algorithmized circuit to recognize the voltage state of the battery and to check the corresponding state value Sensing module 40,
A voltage balancing module 50 provided to correspond to one voltage sensing module in order to adjust the balancing of the corresponding battery so that the algorithmized and charged voltage of the battery sensed through the voltage sensing module 40 can be uniformly performed. ), and
Serial for electric vehicle, characterized in that it comprises a storage unit 60 for sequentially storing the measured value by measuring the voltage state of the battery set for each unit battery module according to the operation of the analog multiplexer 20 Equal charging device for connected battery cells.
The method of claim 1,
The voltage balancing module 50 is
It is recommended to monitor the voltage difference between each individual battery for the voltage difference that occurs in the individual voltages of each battery in series connected batteries and to eliminate the difference, or to perform a balancing operation to keep the voltage of individual batteries equal. Equivalent charging device for series-connected battery cells for electric vehicles, characterized in that.
A first step of setting a unit battery module for a plurality of battery cells connected in series;
A second step of switching the unit battery module set in the first step to sequentially measure the battery voltage using an analog multiplexer;
A third step of decoding the measured voltage value of the unit battery module measured by being switched in the second step through a decoder and storing corresponding state information;
A fourth step of sensing a voltage of a battery connected through a voltage sensing module configured with an algorithmic circuit by recognizing a voltage state of the battery based on the voltage value measured through the third step; And
Equal charging of a series-connected battery cell for an electric vehicle comprising; a fifth step of adjusting the balancing of the corresponding battery for each unit battery module so as to equally charge the voltages of the plurality of batteries connected in series with respect to the sensed voltage of the battery. Control method.
The method of claim 3,
In the case where the battery voltage measured by switching in the second step is lower than the voltage of other series connected battery, the capacitor module and the DC converter are connected to the corresponding battery to supplement the switching voltage. Equal charge control method of battery cells.

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