CN214626461U - Charging control circuit capable of realizing simultaneous charging and independent power supplement of double battery packs - Google Patents

Abstract

The utility model relates to a low-speed electric motor car technical field that charges, a can realize that the double cell package charges simultaneously and mends the charge control circuit of electricity alone, the defect that several kinds of charge control circuit to present low-speed electric motor car exist, a can realize that the double cell package charges simultaneously and mends the charge control circuit of electricity alone, control logic is simple, high reliability, can charge simultaneously when two battery package lack of electricity, also can realize reaching the uniformity of voltage and capacity through the mode of mending the electricity alone when two battery package voltage and capacity appear mismatching, the advantage that control logic is simple and reliability is high has, create the advantage for the series-parallel operation of on-vehicle battery package, great using value has.

Description

Charging control circuit capable of realizing simultaneous charging and independent power supplement of double battery packs

Technical Field

The utility model relates to a low-speed electric motor car technical field that charges, in particular to can realize that double cell package charges simultaneously and mends charge control circuit of electricity alone.

Background

At present, low-speed electric vehicles represented by old-age mobility scooter occupy a large market share among three-line and four-line cities, small towns and villages by virtue of the advantages of being good in price, flexible, convenient, practical and easy to maintain, besides, low-speed electric vehicles for fields such as golf cars, police cruisers, scenic sightseeing vehicles and the like are also popular in the market, although the development of the low-speed electric vehicles is only ten years of sightseeing, the low-speed electric vehicles become important components of a traffic system at present, and the market volume also develops from tens of thousands of starting vehicles to millions of sales vehicles.

The consumer groups of the low-speed electric vehicles generally have low income and do not enjoy national subsidies, so the low-speed electric vehicles are different from new energy electric vehicles (subsidy vehicles) in terms of safety technical requirements and cost control. Different market positions determine that the low-speed electric vehicle is necessarily different from a new energy electric vehicle in the aspects of power configuration and electric control design. The power source of the low-speed electric vehicle is generally selected from a lithium ion battery, the power number is generally 5-10 KWh, the working voltage platform mainly comprises 48Vdc, 60Vdc, 72Vdc, 96Vdc and the like, and if a lithium iron phosphate battery is adopted, the maximum number of the lithium iron phosphate batteries is 30; and if lithium cobaltate, lithium manganate or a ternary lithium battery is adopted, the number of the lithium cobaltate, lithium manganate or ternary lithium battery is 27 at most. In practical application, in order to facilitate connection and installation, and facilitate maintenance, battery replacement and other after-sales maintenance, the lithium ion battery pack is generally divided into battery packs or connected in series or in parallel, the series connection is used for improving a direct-current voltage platform, the parallel connection is used for increasing the battery capacity, and the final purpose is to improve the vehicle endurance mileage and the vehicle-mounted electrical power performance.

However, the series connection or the parallel connection of the battery packs are not combined randomly, even the battery packs with the same specification cannot be connected in series and in parallel randomly, and the series connection and the parallel connection can be carried out only when the voltage platforms of the two battery packs are equal and the capacity of the two battery packs is equal, or the voltage platforms and the capacity of the two battery packs are controlled within a certain tolerance range. If the voltage platforms or capacities of the two battery packs are different, the two battery packs are in series connection forcibly, so that the two battery packs are unbalanced in the charging and discharging processes, namely, the pressure difference and the capacity difference are gradually increased, and finally, the phenomena of insufficient charging and insufficient discharging of the whole battery pack are caused, so that the discharging performance of the battery and the endurance mileage of the whole vehicle are reduced seriously; the forced parallel connection can cause the discharge and ignition phenomena of two battery packs in the parallel connection moment, the high-voltage and high-capacity battery packs can discharge short-time heavy current to the low-voltage and low-capacity battery packs, the socket connector or the connecting contact can be directly ablated and aged, the lithium ion battery can be irreversibly damaged, and the cycle number and the service life of the battery can be shortened.

Different from new energy electric vehicles, the charging mode of the low-speed electric vehicle is only slow charging, and the low-speed electric vehicle has the characteristics of low charging voltage, small charging current and long charging time, and is generally used for going out in the daytime and charging at night. Fig. 1 is a schematic diagram of a charging control circuit for charging a dual battery pack in series and independently compensating power, and fig. 2 is a schematic diagram of a charging control circuit for charging a dual battery pack simultaneously, which are widely used and have certain representativeness.

In the circuits shown in fig. 1 and fig. 2, a low-speed electric vehicle with a 48Vdc operating voltage platform is selected as an example, 16 strings of lithium iron phosphate batteries are connected in series to form a group, each 8 strings of batteries are a battery pack, and two battery packs are divided in total: a 1# battery pack and a 2# battery pack. The two battery packs are uniformly charged by a battery management system BMS for voltage acquisition and charging logic control so as to ensure the charging safety of the batteries.

The charging control circuit shown in fig. 1 can realize series charging and individual power supplement of two battery packs through corresponding control logics, logic control pins CO 1-CO 4 are output by a battery management system BMS, MOS transistors QT 1-QT 4 are charging control switches, when gate control levels CO 1-CO 4 output high levels, corresponding MOS transistors are closed, and when gate control levels CO 1-CO 4 output low levels, corresponding MOS transistors are opened. The external charger adopts a constant-current constant-voltage working mode, the output voltage range covers the voltage of a single battery pack and the total voltage of two battery packs connected in series, the external charger is in butt joint with a vehicle-mounted battery pack through a charging port JP1 and charges the vehicle-mounted battery pack, and the control logic is described as follows:

(1) when CO2 and CO3 output high levels and CO1 and CO4 output low levels, MOS (metal oxide semiconductor) tubes QT3 and QT2 are closed, MOS tubes QT1 and QT4 are disconnected, and the charger charges the two battery packs in series;

(2) when CO1 and CO2 output high levels and CO3 and CO4 output low levels, MOS (metal oxide semiconductor) tubes QT1 and QT3 are closed, MOS tubes QT2 and QT4 are disconnected, and the charger independently supplements power for the 1# battery pack;

(3) when CO3 and CO4 output high levels and CO1 and CO2 output low levels, MOS (metal oxide semiconductor) tubes QT2 and QT4 are closed, MOS tubes QT1 and QT3 are disconnected, and the charger independently supplements power for the 2# battery pack;

(4) in the charging process, when the battery overvoltage, overtemperature, overcurrent or short-circuit protection threshold is triggered, the charging loop of the corresponding battery pack can be cut off by controlling the grid level of the corresponding MOS tube;

(5) when the two battery packs are ready to be used in series or in parallel, if the voltages of the two battery packs are inconsistent, the control logic of the step (2) or the step (3) is used for independently supplementing the battery packs with low voltages, and the series-parallel operation can not be carried out until the voltages of the two battery packs are completely equal.

The charging control circuit shown in fig. 2 can only realize the simultaneous charging of two battery packs, the logic control pins CT1 and CT2 are output by the battery management system BMS, the MOS transistors QN1 and QN2 are charging control switches, the diodes DD1 to DD4 are reflux diodes, when the gate control levels CT1 and CT2 output high levels, the corresponding MOS transistors are closed, and when the gate control levels CT1 and CT2 output low levels, the corresponding MOS transistors are opened. The external charger adopts a constant-current constant-voltage working mode, the output voltage range covers the voltage of a single battery pack, the external charger is in butt joint with a vehicle-mounted battery pack through a charging port JP1 and charges the vehicle-mounted battery pack, and the control logic is described as follows:

(1) when the CT1 and the CT2 output high levels, the MOS tubes QN1 and QN2 are closed, and the charger charges the two battery packs simultaneously;

(2) the charging path of the 1# battery pack is as follows: a positive electrode of the charging port JP1 → QN1 → DD1 → 1# battery pack → DD3 → QN2 → a negative electrode of the charging port JP 1;

(3) the charging path of the 2# battery pack is as follows: a positive electrode of the charging port JP1 → QN1 → DD2 → 2# battery pack → DD4 → QN2 → a negative electrode of the charging port JP 1;

(4) in the charging process, when the battery overvoltage, overtemperature, overcurrent or short-circuit protection threshold is triggered, the charging loop of the corresponding battery pack can be cut off by controlling the grid level of the corresponding MOS tube.

Although the charge control circuit shown in fig. 1 can realize series charging and separate power supplement of two battery packs, the requirements on the control logic time sequence of the charge control switches QT 1-QT 4 are very strict, and if MOS transistors QT3 and QT4 are closed simultaneously in the control process, the 1# battery pack is directly short-circuited; if the MOS tubes QT1 and QT2 are closed simultaneously in the control process, the 2# battery pack is directly short-circuited, and the instant burning of a charge control circuit is inevitably caused. An unknown or uncertain output level state can occur in input/output (I/O) pins of a microprocessor (CPU) in a battery management system BMS in modes of power-on, Bootloader (Bootloader), Reset (Reset) and the like, the phenomenon of upper and lower bridge arm direct connection of QT1/QT2 or QT3/QT4 can easily occur at the moment, and a safety accident of charging, smoking and firing can be caused in serious cases.

The charging control circuit shown in fig. 2 has two reflux diodes on the charging loop of each battery pack, and due to the pipe voltage drop, a large heating loss is generated during charging, the charging efficiency is low, and meanwhile, separate power supplement of the two battery packs cannot be realized.

In view of this, the to-be-solved technical problem of the utility model is to provide a control logic is simple, the reliability is high to can realize that the double cell package charges simultaneously and mends the charge control circuit of electricity alone.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a control logic is simple, the reliability is high and can realize that the double cell package charges simultaneously and mends the charge control circuit of electricity alone, aims at realizing charging simultaneously when two battery package insufficient voltage, also can realize reaching the uniformity of voltage and capacity through the mode of mending the electricity alone when two battery package voltage and capacity appear not matching, creates the advantage for the series-parallel operation of on-vehicle battery package.

To achieve the above object, the present invention provides a charging control circuit capable of simultaneously charging and separately charging a dual battery pack, comprising a 1# battery pack, a 2# battery pack, a battery management system BMS, a MOS transistor QM1, a MOS transistor QM2, a MOS transistor QM3, a MOS transistor QM4, a reflux diode DE1, a reflux diode DE2, a high frequency transformer T1, a high frequency transformer T2 and a charging port JP1, wherein the 1# battery pack and the 2# battery pack are electrically connected to the battery management system BMS respectively, the battery management system BMS is provided with logic control pins PWM1 to PWM4, the positive and negative electrodes of the 1# battery pack are electrically connected to the MOS transistor QM1 and the high frequency transformer T1 respectively, the two ends of the reflux diode DE1 are electrically connected to the high frequency transformer T1 and the MOS transistor QM1 respectively, one end of the high frequency transformer T1 is electrically connected to the positive electrode of the charging port JP1, and the other end of the high frequency transformer T1 is electrically connected to the charging port 1 and the charging port JP 2 in series in turn, the logic control pins PWM1 and PWM2 are electrically connected to the MOS transistor QM1 and MOS transistor QM3, respectively, the MOS transistor QM3 is electrically connected to the reverse flow diode DE2, high frequency transformer T2, MOS transistor QM4, and the negative electrode of the charging port JP1 in series, the high frequency transformer T1 and high frequency transformer T2 are electrically connected to the positive electrode of the charging port JP1, the positive and negative electrodes of the # 2 battery pack are electrically connected to the MOS transistor QM3 and high frequency transformer T2, respectively, and the logic control pins PWM3 and PWM4 are electrically connected to the MOS transistor QM2 and MOS transistor QM4, respectively.

Further, MOS transistor QM2 and MOS transistor QM4 are primary side signal excitation input terminals of high-frequency transformer T1 and high-frequency transformer T2, and MOS transistor QM1 and MOS transistor QM3 are secondary side signal output control terminals of high-frequency transformer T1 and high-frequency transformer T2.

Further, the phase of the pulse width modulation signals output by the logic control pins PWM1 and PWM3 are complementary, and the phase difference is 180 degrees.

Further, the phase of the pulse width modulation signals output by the logic control pins PWM2 and PWM4 are complementary, and the phase difference is 180 degrees.

Further, the phases of the pulse width modulation signals output by the logic control pins PWM3 and PWM4 are the same.

Adopt the technical scheme of the utility model, following beneficial effect has:

1. the utility model provides a charge control circuit comprises 4 MOS pipes QM1, QM2, QM3, QM4 and 2 diodes DE1, DE2, and 2 high frequency transformers T1, T2, MOS pipe QM1 ~ QM4 is the charge control switch, QM2 and QM4 are used as the excitation of the primary side signal of high frequency transformer, QM1 and QM3 are used as the output control of the secondary side signal of high frequency transformer; diodes DE1 and DE2 are reflux diodes, and two flyback switching power supplies are formed by high-frequency transformers T1 and T2 and MOS transistors QM 1-QM 4 and are respectively used for charging the 1# battery pack and the 2# battery pack;

2. the utility model provides a logic control pin PWM 1-PWM 4 is exported by battery management system BMS among the control circuit that charges, is pulse width modulation signal, and wherein the pulse width modulation signal phase complementation of PWM1 and PWM3 output, the difference is 180 degrees; the phases of the pulse width modulation signals output by the PWM2 and the PWM4 are complementary and are different by 180 degrees, and the phases of the pulse width modulation signals output by the PWM3 and the PWM4 are the same;

3. the utility model provides a charge control circuit control logic is simple, and the reliability is high, can charge simultaneously when two batteries package insufficient voltage, also can realize reaching the uniformity of voltage and capacity through the mode of mending the electricity alone when two batteries package voltage and capacity appear not matching.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic diagram of a charging control circuit for charging a dual battery pack in series and independently compensating the charging current used in the prior art;

FIG. 2 is a schematic diagram of a charging control circuit for charging two battery packs at the same time;

fig. 3 is a schematic diagram of a charging control circuit for simultaneously charging and individually compensating the dual battery packs according to the present invention;

fig. 4 is a timing waveform diagram of the logic control pins PWM 1-PWM 4 in the charging control circuit according to the present invention.

The objects, features and advantages of the present invention will be further described with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

It should be noted that all the directional indicators (such as upper, lower, left, right, front and rear … …) in the embodiment of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the technical solutions in the embodiments may be combined with each other, but it must be based on the realization of those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should not be considered to exist, and is not within the protection scope of the present invention.

The utility model provides a can realize that double cell package charges simultaneously and mends charge control circuit of electricity alone.

As shown in fig. 3 and 4, in an embodiment of the present invention, the charging control circuit capable of simultaneously charging and separately recharging two battery packs includes a 1# battery pack, a 2# battery pack, a battery management system BMS, a MOS transistor QM1, a MOS transistor QM2, a MOS transistor QM3, a MOS transistor QM4, a reflux diode DE1, a reflux diode DE2, a high frequency transformer T1, a high frequency transformer T2 and a charging port JP1, wherein the 1# battery pack and the 2# battery pack are electrically connected to the battery management system BMS respectively, the battery management system BMS is provided with logic control pins PWM1 to PWM4, the positive and negative electrodes of the 1# battery pack are electrically connected to the MOS transistor QM1 and a high frequency transformer T1 respectively, the two ends of the reflux diode DE1 are electrically connected to the high frequency transformer T1 and the MOS transistor QM1 respectively, one end of the high frequency transformer T1 is electrically connected to the positive electrode of the charging port JP1, the other end of the high frequency transformer T4642 is electrically connected to the charging port JP1 in series, the logic control pins PWM1 and PWM2 are electrically connected to the MOS transistor QM1 and MOS transistor QM3, respectively, the MOS transistor QM3 is electrically connected to the reverse flow diode DE2, high frequency transformer T2, MOS transistor QM4, and the negative electrode of the charging port JP1 in series, the high frequency transformer T1 and high frequency transformer T2 are electrically connected to the positive electrode of the charging port JP1, the positive and negative electrodes of the # 2 battery pack are electrically connected to the MOS transistor QM3 and high frequency transformer T2, respectively, and the logic control pins PWM3 and PWM4 are electrically connected to the MOS transistor QM2 and MOS transistor QM4, respectively.

Specifically, the MOS transistor QM2 and the MOS transistor QM4 are primary signal excitation input terminals of the high-frequency transformer T1 and the high-frequency transformer T2, the MOS transistor QM1 and the MOS transistor QM3 are secondary signal output control of the high-frequency transformer T1 and the high-frequency transformer T2, and the reflux diode DE1 and the reflux diode DE2, the high-frequency transformer T1, the high-frequency transformer T2, and the MOS transistors QM1 to QM4 form a two-way flyback switching power supply, which is respectively used for charging the 1# battery pack and the 2# battery pack.

The logic control pins PWM 1-PWM 4 are output by a battery management system BMS and are pulse width modulation signals, wherein the phases of the pulse width modulation signals output by the logic control pin PWM1 and the logic control pin PWM3 are complementary and have a phase difference of 180 degrees; the phase of the pulse width modulation signals output by the logic control pin PWM2 and the logic control pin PWM4 are complementary and different by 180 degrees, and the phase of the pulse width modulation signals output by the logic control pin PWM3 and the logic control pin PWM4 is the same. FIG. 4 is a timing waveform of BMS logic control pins PWM 1-PWM 4, defined according to coil dotted terminals, when logic control pins PWM3 and PWM4 output high level pulse "H", the two flyback switching power supplies have no output; when the logic control pins PWM3 and PWM4 output low-level pulses L, the two flyback switching power supplies start to output power and respectively charge the two battery packs; if the logic control pin PWM1 continuously outputs low level and the MOS tube QM1 is disconnected, the charging loop of the 1# battery pack can be completely turned off; if the logic control pin PWM2 continuously outputs low level and the MOS transistor QM3 is turned off, the charging loop of the # 2 battery pack can be completely turned off, so that when a certain battery pack needs to be charged alone, the charging loop can be implemented by turning off the corresponding output control switch of another battery pack. The external charger adopts a constant-current constant-voltage working mode, the output voltage range covers the voltage of the single battery pack, and the external charger is in butt joint with the vehicle-mounted battery pack through a charging port JP1 and charges the vehicle-mounted battery pack.

The utility model provides a charge control circuit can realize that the double cell package charges simultaneously and mends the electricity alone, combines the circuit schematic diagram shown in fig. 3, and its working process and control logic describe as follows:

(1) when the logic control pin PWM3 and the logic control pin PWM4 output pulse width modulation signals with the same phase, and the logic control pin PWM1 and the logic control pin PWM2 output pulse width modulation signals with complementary phases corresponding to the logic control pin PWM3 and the logic control pin PWM4, the charger charges two battery packs simultaneously;

(2) when the logic control pin PWM3 and the logic control pin PWM4 output pulse width modulation signals with the same phase, the logic control pin PWM1 continuously outputs high level, and the logic control pin PWM2 continuously outputs low level, the charger independently supplements power for the 1# battery pack;

(3) when the logic control pin PWM3 and the logic control pin PWM4 output pulse width modulation signals with the same phase, the logic control pin PWM2 continuously outputs high level, and the logic control pin PWM1 continuously outputs low level, the charger independently supplements power for the 2# battery pack;

(4) in the charging process, when the battery overvoltage, overtemperature, overcurrent or short-circuit protection threshold is triggered, the logic control pin PWM1 and the logic control pin PWM3 continuously output low levels, the MOS tube QM1 and the MOS tube QM2 are disconnected, and the 1# battery pack can stop charging; the logic control pin PWM2 and the logic control pin PWM4 continuously output low level, the MOS tube QM3 and the MOS tube QM4 are disconnected, and the 2# battery pack can stop charging;

(5) when the two battery packs are ready to be used in series or in parallel, if the voltages of the two battery packs are inconsistent, the control logic of the step (2) or the step (3) is used for independently supplementing the battery packs with low voltages, and the series-parallel operation can not be carried out until the voltages of the two battery packs are completely equal.

Specifically, the technical scheme of the utility model defects that several kinds of charge control circuit exist to present low-speed electric motor car, a can realize that the double cell package charges simultaneously and mends the charge control circuit of electricity alone, control logic is simple, the reliability is high, can charge simultaneously when two battery package insufficient voltage, also can realize reaching the uniformity of voltage and capacity through the mode of mending the electricity alone when two battery package voltage and capacity appear not matching, the advantage that control logic is simple and the reliability is high has, create the advantage for the series-parallel operation of on-vehicle battery package, great using value has.

The above only be the preferred embodiment of the utility model discloses a not consequently restriction the utility model discloses a patent range, all are in the utility model discloses a conceive, utilize the equivalent structure transform of what the content was done in the description and the attached drawing, or direct/indirect application all is included in other relevant technical field the utility model discloses a patent protection within range.

Claims (5)

1. A charging control circuit capable of realizing simultaneous charging and separate power compensation of dual battery packs is characterized by comprising a 1# battery pack, a 2# battery pack, a battery management system BMS, a MOS pipe QM1, a MOS pipe QM2, a MOS pipe QM3, a MOS pipe QM4, a reflux diode DE1, a reflux diode DE2, a high-frequency transformer T1, a high-frequency transformer T2 and a charging port JP1, wherein the 1# battery pack and the 2# battery pack are respectively electrically connected with the battery management system BMS, the battery management system BMS is provided with logic control pins PWM 1-PWM 4, the positive pole and the negative pole of the 1# battery pack are respectively electrically connected with the MOS pipe QM1 and the high-frequency transformer T8, the two ends of the reflux diode DE1 are respectively electrically connected with the high-frequency transformer T1 and the MOS pipe QM1, one end of the high-frequency transformer T1 is electrically connected with the positive pole of the charging port JP1, the other end of the high-frequency transformer T1 is sequentially electrically connected with the negative pole of the charging port JP1, the logic control pins PWM1 and PWM2 are electrically connected to the MOS transistor QM1 and MOS transistor QM3, respectively, the MOS transistor QM3 is electrically connected to the reverse flow diode DE2, high frequency transformer T2, MOS transistor QM4, and the negative electrode of the charging port JP1 in series, the high frequency transformer T1 and high frequency transformer T2 are electrically connected to the positive electrode of the charging port JP1, the positive and negative electrodes of the # 2 battery pack are electrically connected to the MOS transistor QM3 and high frequency transformer T2, respectively, and the logic control pins PWM3 and PWM4 are electrically connected to the MOS transistor QM2 and MOS transistor QM4, respectively.

2. The charging control circuit of claim 1, wherein the MOS transistors QM2 and QM4 are primary side signal excitation inputs of the high-frequency transformer T1 and the high-frequency transformer T2, and the MOS transistors QM1 and QM3 are secondary side signal outputs of the high-frequency transformer T1 and the high-frequency transformer T2.

3. The charging control circuit capable of realizing simultaneous charging and separate power compensation of two battery packs according to claim 1, wherein the phase of the pulse width modulation signals output by the logic control pins PWM1 and PWM3 are complementary and differ by 180 °.

4. The charging control circuit capable of realizing simultaneous charging and separate power compensation of two battery packs according to claim 1, wherein the phase of the pulse width modulation signals output by the logic control pins PWM2 and PWM4 are complementary and differ by 180 °.

5. The charging control circuit capable of realizing simultaneous charging and separate power compensation of two battery packs according to claim 1, wherein the phases of the pulse width modulation signals output by the logic control pins PWM3 and PWM4 are the same.

Images