CN202535104U - Battery management system capable of automatically cutting off failure units in series-connected battery pack - Google Patents

Abstract

The utility model discloses a battery management system capable of automatically cutting off failure units in a series-connected battery pack. The battery management system capable of automatically cutting off the failure units in the series-connected battery pack is characterized by comprising a battery pack formed by a plurality of series-connected battery units, wherein two ends of each battery unit are connected with a battery unit detection module. A positive electrode and a negative electrode of each battery unit are respectively connected with a contact head of a two-circuit interlock switch, and an active end of the two-circuit interlock switch is connected with adjacent negative electrodes of battery units in order to enable the battery units to be connected in series. The battery unit detection module is connected with the two-circuit interlock switch and connected with a main control module through a communication line. The battery units are connected with the main control switch in series, the main control switch is connected with the main control module, and the main control module is connected with a host computer through a trunk. The battery management system can automatically cut the failure units near expiry in the series-connected battery units away from the whole series-connected return circuit; meanwhile, the battery units being cut off can also be reconnected to the series-connected return circuit when the battery units are needed, for example, when charging is needed. Therefore, the flexibility is high, and the battery consistency requirement is reduced.

Description

A battery management system that can automatically remove failed cells in a series battery pack

technical field

The utility model relates to a battery management device, in particular to a battery management system capable of automatically cutting out failure units in series battery packs.

Background technique

With the popularization of various battery-powered devices, the reliability and maintenance cost of battery systems have drawn more and more attention. Due to the low voltage of the battery cells, in order to meet the voltage level requirements of the electrical appliances, the battery cells need to be connected in series to achieve a higher voltage, which is convenient for directly driving the electrical appliances. For example, electric bicycles need a voltage of about 48v, and electric buses need a voltage of about 500v, and a certain number of batteries need to be used in series. However, the series battery system may cause the failure of the entire string of batteries due to the poor performance of a certain battery unit in the series circuit, causing losses to users. The more the number of series, the greater the probability of failure, and the difficulty of maintenance also increases.

Due to the individual differences of battery cells, the electrical parameters such as capacity, self-discharge, internal resistance and discharge platform of each battery cell cannot be exactly the same. Even if battery cells with similar initial states are combined in series to work together, after a period of use, there will often be an unbalanced phenomenon among the cells in the series system. Although adding a balancing circuit to the battery pack can alleviate the individual differences in the operation of the battery unit to a certain extent, if the battery unit fails for some reason, the battery pack will still fail. The traditional method can only treat the symptoms but not the root cause.

Utility model content

The purpose of this utility model is to overcome the deficiencies of the prior art and provide a battery management system that can automatically cut off the failed units in the series battery pack, which can automatically cut off the battery units that are about to fail in the series battery pack from the entire series circuit , and the disconnected battery unit can also be reconnected when needed, such as when charging. High flexibility. Greatly reduces the requirement for battery cell consistency.

The utility model is realized through the following technical solutions:

A battery management system that can automatically remove failed units in a series battery pack, which includes a battery pack composed of multiple battery units connected in series, and a battery unit detection module is connected to each battery unit through a photoelectric isolator at both ends; it also includes multiple a two-way interlock switch, the positive and negative poles of each battery are respectively connected to the two contacts of a two-way interlock switch, and the movable end of the two-way interlock switch is connected to the negative pole of the adjacent battery unit to connect the battery units in series; The battery unit detection module is connected with the two-way interlock switch, the battery unit detection module is connected with the main control module through the communication line and the photoelectric isolator; the battery pack is connected in series with the main control switch, the main control switch and the main control module are connected through the communication line, the main The control module is connected with the host computer through CAN bus or 485 bus.

Each battery unit is connected with a diode in parallel, the anode of the diode is connected with the negative pole of the battery unit, and the cathode of the diode is connected with the active end of the two-way interlock switch.

The battery unit detection module includes a battery state detection circuit and a PLC controller. The battery state detection circuit is connected to the PLC controller through a communication line, and the PLC controller is connected to the corresponding two-way interlock switch through a line. The main control The module is a PLC controller, and the upper computer is a PC.

The utility model has the advantages of:

1. It has the function of cutting off the battery cells that have reached the over-discharge threshold in the battery pack in real time during the discharge process, so as to ensure that the discharge voltage of the entire battery pack is stable; this structure can ensure that each battery cell in the battery pack is fully discharged, and at the same time It can ensure that each battery unit will not be damaged due to over-discharge, which greatly prolongs the service life and reliability of the battery pack;

2. It has the function of cutting off the battery cells that have reached the overcharge threshold in the battery pack in real time during the charging process, so as to ensure that the battery cells that have not been fully charged can be fully charged one by one. The charger fully charges the higher voltage battery pack;

3. It has the function of judging the faulty battery unit in the battery pack. If the voltage of the faulty battery unit is lower than the allowable minimum threshold value, the battery unit will be permanently removed from the battery pack, and the number and number of the faulty battery unit will be recorded by the host computer. Fault status, to facilitate the next repair work, and no longer connect to it;

4. The battery unit is connected in parallel with a diode, and the main control switch does not need to be disconnected at the moment of switching. The working current of the entire circuit will flow in the circuit through the diode to realize online cutting or connecting, and the output or input of the battery pack will not be interrupted. When there is a brief interruption of electricity;

5. The system has low static power consumption and can be connected to the battery pack for a long time.

Description of drawings

Fig. 1 is the structural block diagram of the utility model embodiment one;

Fig. 2 is a structural block diagram of the second embodiment of the utility model.

Detailed ways

The utility model will be further described below in conjunction with the accompanying drawings and embodiments, and the protection scope of the utility model is not limited to the following description.

Embodiment one:

As shown in Figure 1, a battery management system that can automatically remove failed units in a series battery pack includes a battery pack composed of multiple battery units connected in series, and each battery unit is connected to a battery unit through a photoelectric isolator Detection module; also includes a plurality of two-way interlock switches, the positive and negative poles of each battery unit are respectively connected to the two contacts of a two-way interlock switch, and the movable end of the two-way interlock switch is connected to the adjacent battery unit Negative connection connects the battery cells in series; the battery cell detection module is connected to the two-way interlock switch, the battery cell detection module is connected to the main control module through the communication line and the photoelectric isolator; the battery pack is connected in series with the main control switch, the main control switch and the main control The modules are connected through communication lines, and the main control module is connected with the host computer through CAN bus or 485 bus.

The battery unit detection module includes a battery state detection circuit and a PLC controller. The battery state detection circuit is connected to the PLC controller through a communication line. The battery state detection circuit can be operated to send a battery unit working state signal to the PLC controller. The PLC controller It is connected with the corresponding two-way interlock switch through the line, the main control module is a PLC controller, and the upper computer is a PC.

The battery state detection circuit in the battery unit detection module can dynamically detect the state of the battery unit, and send the state signal to the PLC controller. When the voltage is normal, the PLC controller controls the active end of the two-way interlock switch to connect to the positive pole of the battery unit. Keep the battery unit in a normal charging and discharging state. When the voltage of the battery unit is abnormal, or has reached the overcharge and overdischarge threshold voltage, the PLC controller controls the active end of the two-way interlock switch to connect to the negative pole of the battery unit, so that the battery unit is cut off and bypassed. In addition to the series system, the working status of the battery unit is transmitted to the main control module, and the main control module transmits the received information to the upper computer, and the upper computer records the serial number and status of the battery unit, so as to facilitate the next inspection of the faulty battery. repair work on the unit, and no longer connect the faulty battery unit.

In the entire series circuit, the main control module controls a main control switch that can withstand the current and voltage of the battery pack. When the battery unit is performing the switching action, the main control module controls the main control switch to temporarily disconnect the entire battery pack circuit, and then restarts. Insertion or removal of battery cells. After the operation is completed, the main control module controls the main control switch to close, thereby realizing zero-current switching, reducing the impact on the switching element, and improving its life and reliability.

Embodiment two:

As shown in Figure 2, this embodiment is improved on the basis of Embodiment 1, that is, each battery cell is connected in parallel with a diode, the anode of the diode is connected to the negative electrode of the battery cell, and the cathode of the diode is connected to the two-way interconnection The active end of the lock switch is connected. In this way, the main control switch does not need to be disconnected at the moment of switching, and the working current of the entire circuit will flow in the circuit through the diode to realize online cutting or connecting. The output or input of the entire battery system will not be interrupted, and it is suitable for use when a short interruption of power is not allowed.

Claims (3)

1. A battery management system that can automatically remove failed units in a series battery pack, characterized in that it includes a battery pack formed by connecting multiple battery cells in series, and each battery cell is connected to a battery cell through a photoelectric isolator at both ends detection module; It also includes a plurality of two-way interlock switches, the positive and negative poles of each battery are respectively connected to the two contacts of a two-way interlock switch, and the movable end of the two-way interlock switch is connected to the negative pole of the adjacent battery unit to connect the battery unit series; The battery unit detection module is connected to the two-way interlock switch, and the battery unit detection module is connected to the main control module through the communication line and the photoelectric isolator; The battery pack is connected in series with a main control switch, the main control switch and the main control module are connected through a communication line, and the main control module is connected with an upper computer through a CAN bus or a 485 bus. 2. A battery management system capable of automatically removing failed units in a series battery pack according to claim 1, wherein each battery unit is connected in parallel with a diode, and the anode of the diode is connected to the negative pole of the battery unit. The cathode of the diode is connected with the movable end of the two-way interlock switch. 3. A battery management system capable of automatically removing failed units in a series battery pack according to claim 1 or 2, wherein the battery unit detection module includes a battery state detection circuit and a PLC controller, and the battery state The detection circuit is connected with the PLC controller through the communication line, and the PLC controller is connected with the corresponding two-way interlock switch through the line. The main control module is a PLC controller, and the upper computer is a PC.

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