CN207067363U - A kind of series battery cells information detection - Google Patents

Abstract

The utility model relates to a battery information detection circuit of a series battery pack, comprising: a single battery voltage detection module, a current detection module, and a power supply module, wherein: the number of the single battery voltage detection modules is the same as the number of the series batteries, each Each battery cell is connected to a single cell voltage monitoring module; the sampling resistance of the current detection module is milliohm level, the power supply module is a three-terminal voltage stabilizing device, and the voltage or part of the voltage of the series battery pack is used as an input. The output stable voltage supplies power for the single battery voltage detection module and current detection module. The battery information detection circuit of the battery pack provided by the utility model uses the detection battery itself to supply power to the working chip, and through the high-precision differential mode amplifier chip, the accurate single voltage and working current of each battery in the battery pack can be obtained and provided to control chip. The circuit does not need an external power supply, and the battery information obtained by detection is highly accurate.

Description

A battery information detection circuit of a series battery pack

technical field

The utility model belongs to the field of electronic technology, in particular to a battery information detection circuit of a series battery pack.

Background technique

In a battery energy storage system, it is generally necessary to connect battery packs in series and parallel to achieve the required voltage level and capacity level. Since the battery cannot ensure uniform battery characteristic parameters during the production and processing process, the difference in working conditions during the charging and discharging process will also Exacerbate the inconsistency between the individual battery cells in the series battery pack. Batteries that work under inconsistent conditions for a long time will accelerate aging, reduce the terminal voltage, and lose the discharge capacity. Therefore, an effective battery management system (BMS) is safe for the battery pack. Efficient long-term operation is essential.

In the current battery management system, for the information of the single cells in the battery pack, especially the collection of the voltage of the single cells, the common-mode measurement method of resistive voltage division or the differential-mode measurement method of flying capacitors and switch arrays are mostly used. The measurement accuracy of the former is Low, the latter detection speed is slow and the cost is high. Inaccurate voltage measurement will weaken the management effect of the entire battery management system, thus failing to achieve the intended purpose. Therefore, accurately measuring the voltage of the battery pack is a key issue for efficient battery management.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the prior art and provide a battery information detection circuit of a series battery pack.

The utility model solves its technical problem and realizes by taking the following technical solutions:

A battery information detection circuit for a series battery pack, comprising: a single battery voltage detection module, a current detection module, and a power supply module, wherein:

The number of the single cell voltage detection modules is the same as the number of batteries connected in series, and each battery cell is connected to a single cell voltage monitoring module;

The sampling resistance of the current detection module is milliohm level, which has little influence on the battery working circuit; the parallel current monitor has the following characteristics: it can detect bidirectional current, has large internal gain, and low operating current;

The power supply module is a three-terminal voltage stabilizing device, which uses the voltage or part of the voltage of the series battery pack as input, and outputs a stable voltage to supply power for the voltage detection module and the current detection module of the single battery.

Moreover, the single battery voltage detection module is composed of voltage acquisition terminals, differential mode voltage amplification chips (U1-Un), voltage dividing resistors (Rx1 and Rx2), and output terminals. The two ends of each single battery are connected to the voltage acquisition terminal, and the two ends of the voltage acquisition terminal are connected to two input pins of the differential mode voltage amplifier chip. The output pin of the differential mode voltage amplifying chip is connected to a voltage dividing resistor, and after being divided by the resistor, it is connected to an output terminal for subsequent circuit processing.

Moreover, the differential-mode voltage amplifying chip in the single battery voltage monitoring module needs to have the following characteristics: it can withstand high common-mode voltage, has a high common-mode voltage rejection ratio, integrates precision resistors inside, and has low operating current.

Moreover, the current detection module is composed of a sampling resistor (Rs), a parallel current monitor (U0), a voltage dividing resistor (R01 and R02), and an output terminal. The sampling resistor is connected in series to the main circuit of the battery, and the two ends are connected to the two input pins of the parallel current monitor, and the output pin of the parallel current monitor is connected to the voltage divider, and connected to the output terminal after the resistance divider, for subsequent circuit processing .

The utility model has the advantages of:

The battery information detection circuit of the battery pack provided by the utility model uses the detection battery itself to supply power to the working chip, and through the high-precision differential mode amplifier chip, the accurate single voltage and working current of each battery in the battery pack can be obtained and provided to control chip. The circuit does not need an external power supply, and the battery information obtained by detection is highly accurate.

Description of drawings

Fig. 1 is a circuit diagram of the utility model.

Detailed ways

The utility model will be further described in detail below in conjunction with the accompanying drawings and through specific embodiments. The following embodiments are only descriptive, not restrictive, and cannot limit the protection scope of the utility model.

FIG. 1 is a schematic structural diagram of an embodiment of a battery information detection circuit for a series battery pack provided by the present invention. As shown in FIG. 1 , the battery information detection circuit of the series battery pack in this embodiment includes: a single battery voltage detection module, a current detection module, and a power supply module. The single battery voltage detection module is composed of voltage acquisition terminals, differential mode voltage amplifier chips (U1~Un), voltage divider resistors (Rx1 and Rx2, where x is 1~n), and output terminals. The current detection module consists of a sampling resistor (Rs), a parallel current monitor (U0), a voltage divider resistor (R01 and R02), and an output terminal. The power supply module consists of a three-terminal voltage regulator.

As shown in Figure 1, n battery cells B1~Bn are connected in series to form a battery pack, and the rated voltage of a single battery is 12V, which are connected in series in the main working circuit and are in the state of charging or discharging. Each battery cell is equipped with a cell voltage detection module, and the two ends of each cell are connected to the voltage acquisition terminals of the cell voltage detection module through wires. Both ends of the voltage acquisition terminal are connected to the input pins of the differential mode voltage amplifier. Preferably, the differential mode amplifier is INA148. Its internal integrated calibration resistor does not require external circuits, and the output voltage is the differential mode voltage value at both ends of the input pin, with high accuracy. The voltage output by the differential mode amplifier is divided by the voltage dividing resistor and then connected to the output terminal for subsequent circuit processing, such as AD conversion. If the number of battery cells in series is large, the number of battery voltage detection modules is also large. At this time, an analog switch can be added to the subsequent circuit to gate n output terminals.

In the current detection module, the sampling resistor Rs is connected in series to the main circuit of the battery, and the working current flows through the sampling resistor to generate a potential difference. In order not to affect the normal operation of the main circuit, the resistance value of the sampling resistor is generally small, at the milliohm level. Therefore, the potential difference between its two ends is also small. The two ends of the sampling resistor are connected with two input pins of the parallel current monitor, and the parallel current monitor detects the current by amplifying the differential mode voltage at both ends of the sampling resistor. Preferably, the parallel current monitor is INA282. It allows bidirectional input, and the output voltage varies linearly with the input differential mode voltage, with high accuracy. The voltage output by the parallel current monitor is divided by the voltage dividing resistor and then connected to the output terminal for subsequent circuit processing.

The voltage stabilizing chip in the power supply module is preferably a 7805 linear voltage stabilizing chip. Since its input voltage does not exceed 36V, the voltage of two batteries in series at the low end is selected as the input, and the positive pole of the second battery is connected to the input pin of the chip. Output 15V stable voltage, the output pin is connected with the power supply pin of the differential mode voltage discharger and the parallel current monitor.

Although the embodiments and drawings of the utility model are disclosed for the purpose of illustration, those skilled in the art can understand that various replacements, changes and modifications can be made without departing from the spirit and scope of the utility model and the appended claims. It is possible, therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims (3)

1. a kind of series battery cells information detection, including：Monomer battery voltage detection module, current detection module, Power supply module, wherein：

The quantity of described monomer battery voltage detection module is identical with series-connected cell quantity, each battery cell and a monomer Battery voltage monitoring module is connected；

The sampling resistor of the current detection module is milliohm rank；

Power supply module is Three-end voltage stabilizer, steady by the use of series battery voltage in itself or portion voltage as input, output Fixed voltage is that monomer battery voltage detection module is powered with current detection module.

2. series battery cells information detection according to claim 1, it is characterised in that：The cell electricity Detection module is pressed by voltage acquisition terminal, differential mode voltage amplification chip (U1~Un), divider resistance (Rx1 and Rx2), lead-out terminal Composition, each cell both ends are connected with voltage acquisition terminal, voltage acquisition terminal both ends connection differential mode voltage amplification chip Two input pins, differential mode voltage amplification chip output pin connection divider resistance, lead-out terminal is connected after electric resistance partial pressure, For subsequent conditioning circuit processing.

3. series battery cells information detection according to claim 1, it is characterised in that：The current detecting mould Block is made up of sampling resistor (Rs), parallel-current monitor (U0), divider resistance (R01 and R02), lead-out terminal, sampling resistor The main circuit of battery work is sealed in, both ends connect two input pins of parallel-current monitor, the output of parallel-current monitor Pin connects the short rent of partial pressure, and lead-out terminal is connected after electric resistance partial pressure, for subsequent conditioning circuit processing.