Multi-level battery active equalization circuit

Abstract

The utility model discloses a multi-level battery active equalization circuit, which is provided with a controller, a switch control unit and an energy transfer unit, the controller is connected with the switch control unit, and the energy transfer unit is respectively connected with a first to-be-equalized target, a second to-be-equalized target and the switch control unit; the controller is used for collecting first voltage information of a first to-be-balanced target and second voltage information of a second to-be-balanced target and then controlling the working state of the switch control unit to transmit electric energy of the first to-be-balanced target to the second to-be-balanced target through the energy transfer unit. Or the electric energy of the second to-be-balanced target is transmitted to the first to-be-balanced target through the energy transfer unit, so that the preset states of the first to-be-balanced target and the second to-be-balanced target are the same, and the preset state balance between the first to-be-balanced target and the second to-be-balanced target is realized; the technical problems of high energy consumption, high cost and poor applicability during equalization between battery modules or between battery PACKs in the prior art are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery equalization technical field especially is related to a multilevel battery initiative equalization circuit. BACKGROUND

[0002] As an important means of safe use and maintaining the service life of the battery, the battery equalization in the related art, when the power supply system is a multilevel battery system, the battery equalization adopts the mode including 1, resistance discharge equalization, 2, DCDC power supply charge (discharge) equalization. In the above two equalization modes, there are corresponding technical defects respectively, the first equalization mode converts the electric heating into heat energy and then dissipates, and the energy-saving effect is poor, the second equalization mode needs to introduce an external power supply, and requires that the power of the external power supply is adapted to the current battery system, leading to poor standardization and poor applicability of the battery system.

[0003] Therefore, how to solve the technical problems of high energy consumption, high cost and poor applicability in the battery equalization in the related art becomes a technical problem to be solved by the person skilled in the art. CONTENT OF THE UTILITY MODEL

[0004] The utility model provides a multilevel battery initiative equalization circuit to solve the technical problems of high energy consumption, high cost and poor applicability in the battery equalization in the related art.

[0005] A multilevel battery initiative equalization circuit in the utility model, it includes:

[0006] A controller is used to collect the first voltage information of a first target to be equalized and the second voltage information of a second target to be equalized, and the first target to be equalized and the second target to be equalized are battery modules in the same battery PACK, or the first target to be equalized and the second target to be equalized are battery PACKs respectively.

[0007] A switch control unit is connected with the controller, and its working state is controlled by the control signal sent by the controller.

[0008] An energy transfer unit is connected with the first target to be equalized, the second target to be equalized and the switch control unit respectively, and is used to receive the electric energy of the first target to be equalized and transfer it to the second target to be equalized, or receive the electric energy of the second target to be equalized and transfer it to the first target to be equalized, so that the preset states of the first target to be equalized and the second target to be equalized are the same.

[0009] The multilevel battery initiative equalization circuit has at least the following beneficial effects:

[0010] The utility model discloses a kind of multi-level battery active equalization circuits, be provided with controller, switch control unit and energy transfer unit, controller is connected with switch control unit, energy transfer unit is connected with first target to be equalized, second target to be equalized, switch control unit respectively;Wherein, controller is used to collect the first voltage information of first target to be equalized and the second voltage information of second target to be equalized, then the working state of switch control unit is controlled to transmit the electric energy of first target to be equalized to second target to be equalized by energy transfer unit, or the electric energy of second target to be equalized is transmitted to first target to be equalized by energy transfer unit, so that the preset state of first target to be equalized and second target to be equalized is identical, realize the preset state equalization between first target to be equalized and second target to be equalized, solve the technical problem of high energy consumption, high cost and poor applicability when battery module or battery PACK is equalized in relevant technology;Multi-level battery active equalization circuit provided in the utility model embodiment not only realizes low energy consumption equalization by energy transmission mode, and the equalization between battery module or battery PACK is realized by directly introducing controller to control switch control unit, improve equalization efficiency, while the utility model embodiment reduces battery equalization cost without introducing external charging power supply, improve the applicability of circuit.

[0011] According to multi-level battery active equalization circuit of some other embodiments of the utility model, the energy transfer unit includes current monitoring unit and energy storage unit;

[0012] The first end of the current monitoring unit is connected with the negative pole of the first target to be equalized, the positive pole of the second target to be equalized and the current monitoring first interface of the controller respectively, the second end of the current monitoring unit is connected with the first end of the energy storage unit and the current monitoring second interface of the controller respectively, and the second end of the energy storage unit is connected to the switch control unit.

[0013] According to multi-level battery active equalization circuit of some other embodiments of the utility model, the current monitoring unit includes a first resistor; and the energy storage unit includes a first inductor.

[0014] According to multi-level battery active equalization circuit of some other embodiments of the utility model, the switch control unit includes a first switch circuit and a second switch circuit.

[0015] The first end of the first switch circuit is connected with the positive pole of the first target to be equalized, the second end of the first switch circuit is connected with the first end of the second switch unit and the energy transfer unit respectively, the second end of the second switch circuit is connected with the negative pole of the second target to be equalized, and the control end of the first switch circuit and the control end of the second switch circuit are connected with the controller respectively.

[0016] According to the multi-level battery active balancing circuit of some other embodiments of the present application, the first switch circuit comprises a first switch tube and a second switch tube; the second switch circuit comprises a third switch tube and a fourth switch tube;

[0017] The first end of the first switch tube is connected to the positive pole of the first target to be balanced, the second end of the first switch tube is connected to the second end of the second switch tube, the first end of the second switch tube is connected to the connection point of the first end of the third switch tube and the energy storage unit, the second end of the third switch tube is connected to the second end of the fourth switch tube, the first end of the fourth switch tube is connected to the negative pole of the second target to be balanced; the control end of the first switch tube, the control end of the second switch tube, the control end of the third switch tube and the control end of the fourth switch tube are respectively connected to the controller.

[0018] According to the multi-level battery active balancing circuit of some other embodiments of the present application, further comprising a first overcurrent protection unit, a second overcurrent protection unit and a third overcurrent protection unit;

[0019] The first overcurrent protection unit is arranged between the first target to be balanced and the switch control unit;

[0020] The first end of the second overcurrent protection unit is connected to the energy transfer unit, and the second end of the second overcurrent protection circuit is connected to the connection point of the negative pole of the first target to be balanced and the positive pole of the second target to be balanced;

[0021] The third overcurrent protection unit is arranged between the second target to be balanced and the switch control unit.

[0022] According to the multi-level battery active balancing circuit of some other embodiments of the present application, further comprising a first filter voltage stabilizing unit and a second filter voltage stabilizing unit;

[0023] The first end of the first filter voltage stabilizing unit is connected to the connection point of the first overcurrent protection unit and the switch control unit, and the second end of the first filter voltage stabilizing unit is connected to the connection point of the second overcurrent protection unit and the energy transfer unit;

[0024] The first end of the second filter voltage stabilizing unit is connected to the connection point of the second overcurrent protection unit and the energy transfer unit, and the second end of the second filter voltage stabilizing unit is connected to the connection point of the third overcurrent protection unit and the switch control unit.

[0025] According to the multi-level battery active balancing circuit of some other embodiments of the present application, the controller outputs a PWM control signal to control the working state of the switch control circuit. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a first embodiment module composition schematic view of the utility model of a multi-level battery active equalization circuit;

[0027] Figure 2 is a second embodiment module composition schematic view of the utility model of a multi-level battery active equalization circuit;

[0028] Figure 3 is a third embodiment module composition schematic view of the utility model of a multi-level battery active equalization circuit;

[0029] Figure 4 is a fourth embodiment module composition schematic view of the utility model of a multi-level battery active equalization circuit;

[0030] Figure 5 is a fifth embodiment module composition schematic view of the utility model of a multi-level battery active equalization circuit;

[0031] Figure 6 is a specific embodiment circuit composition structure schematic view of the utility model of a multi-level battery active equalization circuit;

[0032] Figure 7 is a specific embodiment application schematic diagram of the utility model of a multi-level battery active equalization circuit. DETAILED DESCRIPTION

[0033] The utility model's conception and the technical effect that generates will be described clearly, completely below with the embodiment, to fully understand the purpose, characteristics and effect of the utility model. Obviously, the described embodiment is only a part of the embodiment of the utility model, and not all embodiments, based on the embodiment of the utility model, the other embodiments obtained by the skilled in the art without creative labor are all within the scope of the utility model protection.

[0034] In the description of the embodiment of the utility model, if "several" is involved, its meaning is more than one, if "multiple" is involved, its meaning is more than two, if "greater than", "less than", "exceeds" are involved, should be understood as not including the number, if "above", "below", "within" are involved, should be understood as including the number. If "first", "second" are involved, should be understood as being used to distinguish technical features, and can not be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0035] Refer to Figure 1The utility model embodiment provides a kind of multilevel battery initiative equalization circuit, it includes controller, switch control unit and energy transfer unit;Wherein, first target to be equalized and second target to be equalized are two adjacent battery modules in same battery PACK, or first target to be equalized and second target to be equalized are adjacent battery PACK.In this embodiment, controller is connected with first target to be equalized, second target to be equalized, switch control unit respectively, energy transfer unit is connected with first target to be equalized, second target to be equalized and switch control unit respectively, switch control unit is connected with first target to be equalized, second target to be equalized respectively.In this embodiment, for collecting the first voltage information of first target to be equalized and the second voltage information of second target to be equalized, determine the direction of energy transfer, i.e., the equalization process is to transfer the electric energy of first target to be equalized to second target to be equalized, or to transfer the electric energy of second target to be equalized to first target to be equalized;Controller determines the direction of energy transfer, and realizes that the electric energy of first target to be equalized is transmitted to second target to be equalized by energy transfer unit by the on-off of switch control unit, so that the preset state of both is same to realize equalization process, or the electric energy of second target to be equalized is transmitted to first target to be equalized by energy transfer unit by the on-off of switch control unit, so that the preset state of both is same to realize equalization process.The multilevel initiative equalization circuit provided in the utility model embodiment is equalized by the mode of energy transfer, avoids the high energy consumption in the related art by converting electric energy into heat energy, and realizes the equalization of battery system without introducing external power supply, reduces the cost of battery equalization, and improves the applicability of battery system.

[0036] In some embodiments, the utility model embodiment equalization is completed to make the preset state of first target to be equalized and second target to be equalized same includes any one or more of the following preset values same: voltage value same, SOC same, SOE same, etc.

[0037] Refer to Figure 2In some embodiments, during the battery equalization process, the charge / discharge current of each level of battery needs to be monitored in real time to prevent the occurrence of unexpected events caused by excessive charge / discharge current and safety accidents. To achieve current monitoring during the equalization process, the energy transfer unit includes a current monitoring unit and an energy storage unit; wherein the first end of the current monitoring unit is connected with the negative electrode of the first target to be equalized, the positive electrode of the second target to be equalized, and the current monitoring first interface of the controller, respectively; the second end of the current monitoring unit is connected with the first end of the energy storage unit and the current monitoring second interface of the controller, respectively; and the second end of the energy storage unit is connected to the switch control unit. In this embodiment, the current monitoring unit is provided to monitor the charge / discharge current of the first target to be equalized and the second target to be equalized in real time through the controller during the equalization process, and then when the monitored charge / discharge current exceeds the preset value, the controller controls the working state of the switch control unit to stop the equalization process, and can be connected with external equipment to realize the alarm prompt when the current exceeds the preset value, thereby ensuring the safety of the equalization process.

[0038] With reference to Figure 3 In some embodiments, to achieve accurate control of the switch control unit to equalize the first target to be equalized and the second target to be equalized, the switch control unit includes a first switch circuit and a second switch circuit in this embodiment. Specifically, the first end of the first switch circuit is connected with the positive electrode of the first target to be equalized, the second end of the first switch circuit is connected with the first end of the second switch circuit and the energy transfer unit, respectively, the second end of the second switch circuit is connected with the negative electrode of the second target to be equalized, and the control end of the first switch circuit and the control end of the second switch circuit are connected with the controller, respectively. After forming a loop through the first switch circuit, the energy transfer unit and the first target to be equalized, the energy output by the first target to be equalized is stored in the energy transfer unit, or the energy stored in the energy transfer unit is used to charge the first target to be equalized. By forming a loop through the second switch circuit, the energy transfer unit and the second target to be equalized, the energy stored in the energy transfer unit is used to charge the second target to be equalized, or the energy output by the second target to be equalized is stored in the energy transfer unit.

[0039] With reference to Figure 4In some embodiments, in order to prevent the instantaneous current from being too large in the balancing process and thus burning the devices in the circuit, in the embodiment, a first overcurrent protection unit, a second overcurrent protection unit and a third overcurrent protection unit are arranged; wherein the first overcurrent protection unit is arranged between the first target to be balanced and the switch control unit, and is used to protect the first target to be balanced from being burned when the first target to be balanced is charging or discharging, and prevent the line current between the first target to be balanced and the switch control unit from being too large; the first end of the second overcurrent protection unit is connected to the energy transfer unit, and the second end of the second overcurrent protection unit is connected to the connection point of the negative electrode of the first target to be balanced and the positive electrode of the second target to be balanced, and is used to prevent the line current between the energy transfer unit and the first target to be balanced and the second target to be balanced from being too large; and the third overcurrent protection unit is arranged between the second target to be balanced and the switch control unit, and is used to prevent the line current between the second target to be balanced and the switch control unit from being too large.

[0040] Referring to Figure 5 In some embodiments, in order to stabilize the voltage of the first target to be balanced and the second target to be balanced during the charging and discharging in the balancing process, a first filter voltage stabilizing unit and a second filter voltage stabilizing unit are further arranged; specifically, the first end of the first filter voltage stabilizing unit is connected to the connection point of the first overcurrent protection unit and the switch control unit, the second end of the first filter voltage stabilizing unit is connected to the connection point of the second overcurrent protection unit and the energy transfer unit, that is, the two ends of the first filter voltage stabilizing unit are arranged at the positive and negative electrodes of the first target to be balanced, and then the first target to be balanced is charged or discharged after being filtered and stabilized by the first filter voltage stabilizing unit, thereby protecting the circuit; the first end of the second filter voltage stabilizing unit is connected to the connection point of the second overcurrent protection unit and the energy transfer unit, the second end of the second filter voltage stabilizing unit is connected to the connection point of the third overcurrent protection unit and the switch control unit, that is, the two ends of the second filter voltage stabilizing unit are arranged at the positive and negative electrodes of the second target to be balanced, and then the second target to be balanced is charged or discharged after being filtered and stabilized by the second filter voltage stabilizing unit, thereby protecting the circuit.

[0041] Referring to Figure 6 The following will illustrate the specific implementation mode of the multi-level active balancing circuit provided by the embodiment of the utility model through a specific embodiment, and it should be noted that the embodiment is only a specific embodiment, and no creative improvement is made on the embodiment, and only simple changes still belong to the protection scope of the multi-level active balancing circuit provided by the embodiment of the utility model.

[0042] In the embodiment, U1 and U2 represent first and second target to be balanced, which can be adjacent battery modules in the same battery PACK or adjacent battery PACKs. The first switch circuit includes first and second switch tubes, and the second switch circuit includes third and fourth switch tubes. In the embodiment, each switch tube is implemented by a MOS tube, but each MOS tube can be replaced by other switch tubes with equivalent functions, such as IGBT, GaN, etc. Specifically, the first switch circuit includes first and second MOS tubes Q1 and Q2, the second switch circuit includes third and fourth MOS tubes Q3 and Q4, the current monitoring unit includes a first resistor R, the energy storage unit includes a first inductor L, the first, second and third overcurrent protection units correspond to fuses F1, F2 and F3, respectively, the first filter and voltage stabilizing unit includes a first capacitor C1, and the second filter and voltage stabilizing unit includes a second capacitor C2. In the embodiment, the controller is connected to the first and second target to be balanced U1 and U2 to collect voltage information of the two targets. If the voltage information of the two targets is inconsistent, energy balancing needs to be performed. In the embodiment, energy is transferred from the first target to be balanced to the second target to be balanced. Specifically, the battery balancing is realized by controlling the switch control unit. In the embodiment, the source of the first MOS tube Q1 (i.e. the second end of the first switch tube) is connected to the source of the second MOS tube Q2 (i.e. the second end of the second switch tube), the drain of the first MOS tube (i.e. the first end of the first MOS tube) is connected to the positive electrode of the first target to be balanced U1, the first fuse F1 is arranged on the connection line between the drain of the first MOS tube and the positive electrode of the first target to be balanced U1 for protection, the first capacitor C1 is connected in parallel across the positive and negative electrodes of the first target to be balanced U1 for filtering and voltage stabilization, the drain of the second MOS tube Q2 (i.e. the first end of the second switch tube) is connected to one end of the first inductor L and the drain of the third MOS tube Q3 (i.e. the first end of the third switch tube), the other end of the first inductor L is connected to one end of the first resistor R, the other end of the first resistor R is connected to the connection point of the first and second targets to be balanced U1 and U2, the second fuse F2 is arranged between the first resistor R and the first and second targets to be balanced U1 and U2 for protection, the second capacitor C2 is connected in parallel across the positive and negative electrodes of the second target to be balanced U2 for filtering and voltage stabilization, the source of the third MOS tube Q3 (i.e. the second end of the third switch tube) is connected to the source of the fourth MOS tube Q4 (i.e. the second end of the fourth switch tube), the drain of the fourth MOS tube Q4 (i.e. the first end of the fourth switch tube) is connected to the negative electrode of the second target to be balanced U2, the third fuse F3 is arranged on the connection line between the drain of the fourth MOS tube Q4 and the negative electrode of the second target to be balanced U2 for overcurrent protection.The controller is connected with the gate (control end) of the first MOS tube Q1, the gate (control end) of the second MOS tube Q2, the gate (control end) of the third MOS tube Q3 and the gate (control end) of the fourth MOS tube Q4 respectively, and the controller controls the on-off state of the first MOS tube Q1, the second MOS tube Q2, the third MOS tube Q3 and the fourth MOS tube Q4 through the output PWM control signal. Under normal circumstances, each MOS tube is in an off state. When the controller monitors that the first target to be balanced U1 needs to transmit power to the second target to be balanced U2 to realize the balancing process, the controller outputs the PWM control signal to make the first MOS tube Q1 and the second MOS tube Q2 conductive. At this time, the loop of the first target to be balanced U1 and the first inductor L is conductive, and the power on the first target to be balanced U1 is transmitted to the first inductor L. Then the first MOS tube Q1 and the second MOS tube Q2 are controlled to be off, and the third MOS tube Q3 and the fourth MOS tube Q4 are controlled to be on. At this time, the loop of the second target to be balanced U2 and the first inductor L is conductive, and the power on the first inductor L is transferred to the second target to be balanced. Through the continuous control of the on-off state of the first MOS tube Q1, the second MOS tube Q2, the third MOS tube Q3 and the fourth MOS tube Q4, the voltage value, SOC or SOE of the first target to be balanced U1 and the second target to be balanced U2 is finally consistent, and the balancing process is completed. The two ends of the first resistor R are connected to the current monitoring first interface and the current monitoring second interface of the controller respectively, for monitoring the size of the current in real time during the balancing process. When the current is too large, the controller can stop the balancing process and communicate with the external device to issue an alarm prompt. In this embodiment, in order to ensure the stable and safe work of each device during the balancing process, the voltage withstand level of the first MOS tube Q1, the second MOS tube Q2, the third MOS tube Q3 and the fourth MOS tube Q4 is designed to be twice that of the first target to be balanced U1 or the second target to be balanced U2.

[0043] Reference Figure 7The following is a specific application example of the multi-level battery active equalization circuit proposed in the embodiments of the present application. In this embodiment, the multi-level battery active equalization circuit is applied to a battery system including a plurality of battery PACKs and battery modules, wherein each battery PACK includes a plurality of battery modules, and each battery module includes a plurality of battery monomers. Further, the multi-level battery active equalization circuit is connected to adjacent two battery modules and adjacent two battery PACKs, and when the battery equalization between adjacent battery modules or battery PACKs is performed, the multi-level battery active equalization circuit proposed in the embodiments of the present application is used to realize active equalization, and in the case of not consuming a large amount of energy, not introducing an external power supply, not introducing different isolation level devices due to high and low system working voltage, the equalization process between battery modules or battery PACKs is realized, and the technical problems of high energy consumption, high cost, complex electrical isolation and poor applicability in the related art when equalizing between battery modules or battery PACKs are solved.

[0044] The embodiments of the present application are described in detail above in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the purpose of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A multi-level battery active balancing circuit, characterized in that, include: The controller is used to collect the first voltage information of the first target to be balanced and the second voltage information of the second target to be balanced. The first target to be balanced and the second target to be balanced are battery modules in the same battery pack, or the first target to be balanced and the second target to be balanced are battery packs respectively. A switch control unit is connected to the controller, and its operating state is controlled by control signals issued by the controller. An energy transfer unit is connected to the first target to be balanced, the second target to be balanced, and the switch control unit, respectively. Used to receive electrical energy from the first target to be balanced and transfer it to the second target to be balanced, or to receive electrical energy from the second target to be balanced and transfer it to the first target to be balanced, so that the preset states of the first target to be balanced and the second target to be balanced are the same.

2. The multi-level battery active balancing circuit according to claim 1, characterized in that, The energy transfer unit includes a current monitoring unit and an energy storage unit; The first end of the current monitoring unit is connected to the negative terminal of the first target to be balanced, the positive terminal of the second target to be balanced, and the first current monitoring interface of the controller. The second end of the current monitoring unit is connected to the first end of the energy storage unit and the second current monitoring interface of the controller. The second end of the energy storage unit is connected to the switch control unit.

3. The multi-level battery active balancing circuit according to claim 2, characterized in that, The current monitoring unit includes a first resistor; the energy storage unit includes a first inductor.

4. The multi-level active equalization circuit according to claim 2 or 3, characterized in that, The switch control unit includes a first switch circuit and a second switch circuit; The first terminal of the first switching circuit is connected to the positive terminal of the first target to be balanced, the second terminal of the first switching circuit is connected to the first terminal of the second switching circuit and the energy transfer unit, the second terminal of the second switching circuit is connected to the negative terminal of the second target to be balanced, and the control terminals of the first switching circuit and the second switching circuit are connected to the controller.

5. The multi-level active equalization circuit according to claim 4, characterized in that, The first switching circuit includes a first switching transistor and a second switching transistor; the second switching circuit includes a third switching transistor and a fourth switching transistor. The first end of the first switching transistor is connected to the positive terminal of the first target to be balanced; the second end of the first switching transistor is connected to the second end of the second switching transistor; the first end of the second switching transistor is connected to the connection point between the first end of the third switching transistor and the energy storage unit; the second end of the third switching transistor is connected to the second end of the fourth switching transistor; and the first end of the fourth switching transistor is connected to the negative terminal of the second target to be balanced. The control terminals of the first, second, third, and fourth switching transistors are respectively connected to the controller.

6. The multi-stage active equalization circuit according to any one of claims 1 to 3, characterized in that, It also includes a first overcurrent protection unit, a second overcurrent protection unit, and a third overcurrent protection unit; The first overcurrent protection unit is disposed between the first target to be balanced and the switch control unit; The first end of the second overcurrent protection unit is connected to the energy transfer unit, and the second end of the second overcurrent protection circuit is connected to the connection point between the negative terminal of the first target to be balanced and the positive terminal of the second target to be balanced. The third overcurrent protection unit is located between the second target to be balanced and the switch control unit.

7. The multi-level active equalization circuit according to claim 6, characterized in that, It also includes a first filtering and voltage regulation unit and a second filtering and voltage regulation unit; The first end of the first filtering and voltage regulating unit is connected to the connection point between the first overcurrent protection unit and the switch control unit, and the second end of the first filtering and voltage regulating unit is connected to the connection point between the second overcurrent protection unit and the energy transfer unit. The first end of the second filter and voltage regulator unit is connected to the connection point between the second overcurrent protection unit and the energy transfer unit, and the second end of the second filter and voltage regulator unit is connected to the connection point between the third overcurrent protection unit and the switch control unit.

8. The multi-level active equalization circuit according to any one of claims 1 to 3, characterized in that, The controller outputs a PWM control signal to control the operating state of the switch control circuit.

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