CN206820489U - Intelligent balance charging device for battery packs in series - Google Patents

Abstract

The utility model discloses a kind of series battery intelligent equalization charging device; including Power Entry Module, charge control and detection protection module, equalizaing charge detection control module, CPU module; charge power supply automatically provides charging current with detection protection module by charge control through Power Entry Module, in the case where CPU module controls for battery pack to be charged, and CPU module and equalizaing charge detect control module and realize that the intelligent equalization for treating rechargeable battery set charges by detecting each monomer battery voltage of battery pack to be charged in real time.The beneficial effect of this patent is to use tandem type equalizaing charge and CPU module intelligent control, time for balance can effectively be shortened, the adaptation any number of cells of variety classes form battery pack, alleviate cell caused inconsistency during manufacture and use, improve the overall performance of series battery and the security reliability of charging.

Description

Intelligent balance charging device for battery packs in series

technical field

The utility model belongs to charging equipment for series battery packs, in particular to an intelligent equalizing charging device for series battery packs.

Background technique

With the rapid development of the new energy industry, whether it is new energy vehicles or large-scale energy storage applications, a large number of single batteries need to be used in series, but the inconsistency of the series of single batteries seriously affects the effective capacity of the power battery pack. Cycle life, safety and economy make it difficult for power pools to meet such requirements. The consistency of single cells determines the performance, life and safety of the series battery pack, that is, as long as the performance of one single cell deteriorates, the performance of the entire series battery pack will deteriorate. Common situations are: (1) The capacity of one of the single cells is low, and the result is that the single cell first reaches the upper limit cut-off voltage when charging, and first reaches the lower limit cut-off voltage when discharging, then the capacity of this single cell Determine the capacity of the entire series battery pack; (2) If the voltage of a single battery is low in the initial state, the single battery cannot reach the cut-off voltage and cannot be fully charged when charging, and the single battery first reaches the discharge cut-off when discharging. The single battery is not fully charged and is discharged ahead of time. The actual available power of the series battery pack is determined by the capacity of the single battery; (3) If the polarization impedance and internal resistance of a single battery are high, when charging The voltage rises quickly, and the voltage drops quickly during discharge. Judging from the performance of a certain test, the capacity of the single battery is insufficient, the load capacity decreases, and the temperature during charging and discharging is high.

It is still quite difficult to improve the consistency of single cells in the battery manufacturing process and requires a large investment and will greatly increase the manufacturing cost of the battery, resulting in high battery prices and not conducive to the rapid development of related industries. At present, battery manufacturers or battery combination factories use strict screening methods for battery matching to improve battery consistency. However, even a strictly matched battery will show visible differences at the beginning of the cycle or after multiple cycles, so the effectiveness of using battery matching is not satisfactory; the working conditions and environment of the battery will also have an impact on the consistency. The degree of change in consistency with the increase in the number of battery cycles is undetectable. Therefore, the consistency of a single battery is relative, too much emphasis on the consistency of the manufacturing process or the consistency of the environment during use can only be at the expense of increasing the cost of the power system.

How to ensure the safe and efficient use of power batteries in groups has become an urgent problem to be solved. In addition to working hard on the consistency of the battery itself, battery equalization technology, as one of the key technologies for the application of power batteries in groups, can effectively alleviate the inconsistency in the manufacturing process and use process, and improve the overall performance of the battery pack. In principle, equalization technology can not only solve the problem of battery consistency, but also prolong the life of the single battery with the worst performance in the series battery pack. At the same time, the improvement of battery performance will also improve battery safety, because battery performance As it gets worse, security also decreases. There are two main types of equalization circuits for series battery packs: one is the energy consumption type, which refers to the use of parallel resistors to dissipate the energy of the battery with more power in the battery pack until its state of charge reaches the average value. The second is the non-energy consumption type (energy transfer type), which uses energy storage elements such as capacitors and inductors to transfer energy between single cells or battery packs to keep the voltage of the battery pack consistent.

The energy-consuming equalization scheme uses power resistors as shunt elements. Its structure is simple and low in cost, which improves the imbalance of series battery packs, but the energy consumption is relatively high and wastes electric energy, which makes energy utilization low and the temperature rise reduces charging. The reliability of the equipment; in addition, because of the shunt of the resistance, the constant current charging method cannot be carried out, and only a small current can pass through the battery charging circuit, which greatly reduces the charging efficiency. On the basis of monitoring the voltage of the single battery, the energy transfer type unidirectional energy converter uses an optocoupler to control the energy conversion at both ends of the transformer, but the unidirectional equalization is not suitable for active equalization. The energy transfer type bidirectional energy converter directly converts energy from the high-voltage monomer to the low-voltage monomer, dynamically adjusts the input and output directions, and has the best balanced efficiency. However, because the energy converter uses a transformer, the structure is complex, the volume is large, and the cost Relatively high. Therefore, it is necessary to develop an efficient, simple and intelligent charging device suitable for equalizing charging of series battery packs.

Contents of the invention

Aiming at the consistency problem of the current serial battery pack itself and the shortcomings of the corresponding charging device, the utility model discloses an intelligent equalizing charging device for the serial battery pack.

The technical solution adopted by the utility model is: an intelligent balanced charging device for series battery packs, including a power input module, a charging control and detection protection module, a balanced charging detection control module, and a CPU module. Under the control, the charging control and detection protection module automatically provides the charging current for the battery pack to be charged, and the CPU module and the balanced charging detection control module detect the voltage of each single cell of the battery pack to be charged in real time to realize the intelligent balance of the battery pack to be charged Charge.

In the utility model, the power input module includes a power supply polarity judgment circuit composed of resistors R7, R8 and MOS tube VT1, bypass filter capacitors C2, C3, and C4 used to reduce the interference of noise on the power supply to the charging device Decoupling filter capacitor C1, resistors R9~R13, capacitor C10 and operational amplifier IC1A are used to reduce the noise generated by the charging device and interfere with the external power supply. C6~C9, diode D1, inductor L1 and integrated circuit IC2 form a step-down voltage regulator circuit to output the VDD voltage of the subsequent logic control circuit.

In the utility model, the charging control and detection protection module includes a Buck-Boost main circuit composed of MOS tubes VT2~VT3, diodes D2~D3, resistors R27~R30, capacitors C11~C12 and inductor L2, and a triode tube VT5~VT11 , the Buck-Boost control circuit composed of resistors R14~R26, operational amplifiers IC1C and IC1D, the charging voltage detection circuit composed of resistors R31~R33, capacitors C13~C14 and operational amplifier IC3C, and the resistors R42~R47, capacitors C19~C20 The charging current detection circuit composed of operational amplifier IC3A, the battery pack access detection and protection circuit composed of resistors R34~R41, capacitors C15~C18, triode tube VT12, MOS transistor VT4 and operational amplifier IC3D; Buck-Boost control circuit in Under the control of the CPU module output control signals PWM1, PWM2, KZXH1, the Buck-Boost main circuit automatically provides the charging current for the battery pack to be charged, and the charging voltage detection circuit and the charging current detection circuit feed back the charging voltage signals Adin1, The charging current signal Adin2, the charging circuit of the battery pack is only turned on when the battery pack to be charged is connected and the polarity is correct, and it can be turned on and off by the control signal KZXH2 of the CPU module.

In the utility model, the balanced charging detection control module includes a four-channel monomer battery terminal voltage detection circuit composed of resistors R48~R67, capacitors C21~C24 and operational amplifier IC4, and consists of resistors R68~R75, MOS tubes VTA1~ 4 and MOS tube VTB1~4, capacitor C25 composed of single battery voltage equalization switching circuit, the balanced switching control circuit composed of resistors R76~R83, photoelectric isolation driver IC5~IC6 and decoder IC7; each equalized charging detection control The module can realize the voltage balance of 4 single cells, and multiple balanced charging detection control modules can be cascaded to realize the application of more single cells; the positive pole of the charging power supply PWRin+ of the balanced charging detection control module, and the operating voltage VDD of the logic circuit , The reference ground GND is connected to the power input module, the four single battery connection terminals BAT0, BAT1, BAT2, BAT3, BAT4 are connected to the terminals of each single battery in the battery pack to be charged, and the voltage detection voltage BATin1 at both ends of the four single batteries , BATin2, BATin3, and BATin4 are connected to the A/D converter input of the CPU module, and the three balanced switching control signals KZM0, KZM1, and KZM2 are connected to the logic output of the CPU module; The positive pole of the charging power supply PWRin+, the operating voltage of the logic circuit VDD, and the reference ground GND are connected in parallel, the battery connection terminal BAT0 of the latter circuit is connected in parallel with the battery connection terminal BAT4 of the previous circuit, and the two ends of the four single batteries of each balanced charging detection control module The detection voltage BATin1, BATin2, BATin3, BATin4 and three balanced switching control signals KZM0, KZM1, KZM2 are respectively connected to the A/D converter input and logic output of the CPU module; the balanced charging detection control module detects the battery to be charged in real time The voltages BATin0~BATin n at both ends of multiple single batteries in the group are connected to the input terminal of the A/D converter of the CPU module, and the CPU module makes intelligent decisions according to the real-time terminal voltage of each single battery and outputs multiple control signals through the logic output terminal. The codes KZM0-KZM k control the work of the balanced charging detection control module to realize the intelligent balanced charging of the rechargeable battery pack.

In the utility model, the CPU module includes a CPU, a clock and a reset circuit, an ADC circuit, an output latch circuit, a PWM circuit, an LCD or LED display circuit, and a button circuit. The ADC circuit collects a charge control and detection protection module under the control of the CPU, The detection signal of the balanced charging detection control module is intelligently determined by the CPU, and the control signal is output by the output latch circuit and the PWM circuit to the charging control and detection protection module, and the balanced charging detection control module to realize the intelligence of the entire charging process, clock and reset The circuit is used to provide the CPU with a clock source and reset signal, the LCD or LED display circuit is used to display the charging status, parameters or curves, and the button circuit is used to set, view or modify the parameters of the battery pack to be charged.

The beneficial effect of the utility model is that: adopting cascaded equalization charging and CPU module intelligent control can effectively shorten the equalization time, adapt to battery packs composed of any number of single batteries of different types, and ease the process of single batteries in the process of manufacture and use. The resulting inconsistency improves the overall performance of the series battery pack and the safety and reliability of charging.

Description of drawings

Fig. 1 is a block diagram of the utility model;

Fig. 2 is a schematic diagram of an embodiment of a power input module of the present invention;

Fig. 3 is a schematic diagram of an embodiment of the charging control and detection protection module of the present invention;

4 is a schematic diagram of an embodiment of a balanced charging detection control module of the present invention;

Fig. 5 is a cascade schematic diagram of the balanced charging detection control module of the utility model;

Fig. 6 is the structural block diagram of CPU module of the utility model embodiment;

Fig. 7 is a curve diagram of charging current and voltage of the embodiment of the present invention.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Referring to the accompanying drawings, Fig. 1 is a block diagram of the utility model. An intelligent balanced charging device for series battery packs is composed of four parts: a power input module, a charging control and detection protection module, a balanced charging detection control module, and a CPU module. The positive pole PWRin+ and the negative pole PWRin- of the charging power supply are respectively connected to the power input module, and the power input module realizes the judgment of the polarity of the power supply, bypass and decoupling filtering, the power supply voltage detection output ADin0, and the voltage regulation output VDD for subsequent Logic control circuit; the working power supply, logic power supply, and reference ground of the charging control and detection protection module are respectively connected to PWRin+, VDD, and GND of the power input module, and are controlled by the output control signals PWM1, PWM2, KZXH1, and KZXH2 of the CPU module. The rechargeable battery pack automatically provides the charging current (the current flows from BATT+ to BATT-) and feeds back the charging voltage (approximate to the battery voltage) signal Adin1 and charging current signal Adin2 to the CPU module; A single battery BAT0, BAT1, BAT2, ..., BAT n terminal voltage is adjusted to connect BATin0, BATin1, BATin2, ..., BATin n to the CPU module, and the CPU module performs intelligent control according to the real-time terminal voltage of each single battery Make decisions and output control codes KZM0~KZM k to control the work of the balanced charging detection control module to realize the intelligent balanced charging of the rechargeable battery pack.

Fig. 2 is a schematic diagram of an embodiment of the power input module of the present invention. The power input module includes a power supply polarity judgment circuit composed of resistors R7, R8 and MOS tube VT1, which is used to reduce the noise on the power supply that interferes with the charging device. Bypass filter capacitors C2, C3, and C4 are used to reduce charging. The decoupling filter capacitor C1, resistors R9~R13, capacitor C10 and op amp IC1A, which generate noise from the device and interfere with the external power supply, are connected to the power supply voltage detection circuit and output ADin0 to the CPU module. Resistors R1~R6, capacitors C6~C9, diode D1, the inductor L1 and the integrated circuit IC2 form a step-down regulator circuit to output the VDD voltage of the subsequent logic control circuit. In Figure 2, the charging power supply is connected by the connector PWRin, the bypass filter capacitors C2, C3, and C4 are used to reduce the interference of the noise on the connected power supply to the charging device itself, and the decoupling filter capacitor C1 is used to reduce the noise generated by the charging device. The noise interferes with the external power supply. Resistors R7, R8 and MOS tube VT1 form an ideal diode circuit, which is connected to the ground loop of the charging device to prevent reverse connection of the charging power supply; when the power supply is connected correctly, there is a voltage between the gate and source of the MOS tube, and the MOS tube It can be turned on; when the power supply is reversed, there is no voltage between the gate and source of the MOS tube and it cannot be turned on, and the charging device will not work. MOS transistor VT1 is an N-channel enhancement type field effect transistor, which should be selected according to the charging voltage and current of the battery pack connected in series. P1103BVG, TM4422, etc.; take AO4468 as an example, it adopts SO8 package, specific parameters V _DS =30V, ID = _11.6A (V _GS =10V), R _DS(ON) <14mΩ (V _GS =10V), R _{DS (ON)} <22mΩ(V _GS =4.5V); in Figure 2, if R7=4.7KΩ, R8=200KΩ, and the voltage Vin=+15V between PWRin+ and PWRin-, V _GS =15*200/204.7 V ≈14.7 V; the advantage of this circuit instead of a diode is that the loss is small, because the diode has a forward voltage drop of 0.7V, and the MOS tube is resistive, generally it can be 10-30 milliohms, if the charging current is 2A Calculated, the diode consumes 1.4W, while the MOS tube is only 0.06W at most. Resistors R9~R13, capacitor C10 and op amp IC1A form a power supply voltage detection circuit and output ADin0 to the CPU module. Resistor R13 and capacitor C10 form a low-pass filter to filter out high-frequency interference on the signal ADin0. Resistor R9 ~R12 and operational amplifier IC1A form a non-inverting amplifier for detecting the access power supply voltage. The value range of resistors R9~R12 should be selected according to the access voltage Vin and the input voltage range of the A/D converter of the CPU module. If R9=R11=680KΩ, R10=R12=130KΩ, Vin=+15V, the operation Put the output V _ADin0 of IC1A =15*130/810 (1+130/680) V≈2.86 V; the low-pass filter composed of resistor R9 and capacitor C10, if R13=4.7KΩ, C10=1uF, then its cut-off Frequency = 1/2π*4.7K*1u≈33.86 Hz. Resistors R1~R6, capacitors C6~C9, diode D1, inductor L1 and integrated circuit IC2 form a step-down voltage regulator circuit to output the VDD voltage of the subsequent logic control circuit. IC2 in Figure 2 is produced by American Core Semiconductor Step-down converter MP1584, this part of the circuit can be implemented with other types of DC/DC converters, as long as the input and output meet the application requirements. The core of MP1584 is buck conversion, the input voltage range is 4.5-28V, and the output maximum current is 3A. In Figure 2, D1, L1, and C9 form a typical buck circuit. D1 is a Schottky diode SS34, R1= 100KΩ, R2= 51KΩ. To enable MP1584 from Vin, R3= 200KΩ is used to adjust the PWM frequency of the buck loop; in this embodiment, VDD=3.3V, take R4=68.1KΩ, R5= 124KΩ, R6= 40.2KΩ, C7=220pF, L1= 6.8uH, C9=22uF.

Fig. 3 is a schematic diagram of an embodiment of the charging control and detection protection module of the present invention. The charging control and detection protection module includes a Buck-Boost main circuit composed of MOS tubes VT2~VT3, diodes D2~D3, resistors R27~R30, capacitors C11~C12 and inductor L2, and a triode tube VT5~VT11, resistors R14~R26 , Buck-Boost control circuit composed of operational amplifier IC1C and IC1D, charging voltage detection circuit composed of resistors R31~R33, capacitors C13~C14 and operational amplifier IC3C, composed of resistors R42~R47, capacitors C19~C20 and operational amplifier IC3A The charging current detection circuit is a battery pack access detection and protection circuit composed of resistors R34~R41, capacitors C15~C18, triode tube VT12, MOS tube VT4 and operational amplifier IC3D; Buck-Boost control circuit outputs control signals in the CPU module Under the control of PWM1, PWM2, and KZXH1, the Buck-Boost main circuit automatically provides charging current for the battery pack to be charged, and the charging voltage detection circuit and charging current detection circuit feed back the charging voltage signal Adin1 and charging current signal Adin2 to the CPU module in real time, The charging circuit of the battery pack is only turned on when the battery pack to be charged is connected and the polarity is correct, and it can be turned on and off by the control signal KZXH2 of the CPU module. There are six main types of DC/DC converters used for charging, namely Buck DC/DC converter, Boost DC/DC converter, Buck Boost DC/DC converter. DC converters, Cuk DC/DC converters, Zeta DC/DC converters and SEPIC DC/DC converters; among them, Buck and Boost type DC/DC converters are basic, Buck-Boost, Cuk, Zeta, SEPIC type DC/DC converters are derived from it. In this embodiment, the working power supply, logic power supply, and reference ground of the charging control and detection protection module are respectively connected to PWRin+, VDD, and GND of the power input module. The Buck-Boost circuit composed of ~R30, capacitors C11~C12 and inductor L2 is controlled by a control circuit composed of triodes VT5~VT11, resistors R14~R26, operational amplifiers IC1C and IC1D. When the power is turned on, before the CPU works normally, the pull-up resistor R14 makes VT5 and VT7 turn on, and the MOS tubes VT2 and VT3 are all in the off state to ensure the safety of the circuit; after the CPU works normally, the output control signal KZXH1= 0 makes the circuit enter the working state; during the charging process, if overvoltage, overcurrent or other faults occur, the CPU module can output a control signal KZXH1=1 to turn off the MOS tubes VT2 and VT3. During the charging process, if it is detected that the charging current exceeds the set range, the MOS tube VT2 is turned off through the resistors R22~R23 and the triode tube VT6 to stop charging, so as to ensure the safety of the circuit and the battery. When the voltage of the rechargeable battery is lower than the supply voltage, Buck charging is used, and when the voltage of the rechargeable battery is higher than the supply voltage, Boost charging is used to ensure that the actual charging voltage is higher than the voltage of the battery to be charged. When working in the Buck mode, the operational amplifier IC1C is controlled by the PWM1 signal output by the CPU module, and its output drives the MOS tube VT2 to work through the triode tubes VT8 and VT9, resistors R25 and R27, the charging power supply PWRin+ is output through VT2-L2-D3, and VT2 is off D2 continues to flow when it is off; at this time, the PWM2 signal output by the CPU module at the same phase end of the operational amplifier IC1D remains at a low level, so that the Boost circuit part stops working; The charging voltage and current selection, the optional models in this embodiment are: AO4409, AO4467, TPC8107, TPC8108, P1003EVG, etc.; take AO4409 as an example, it adopts SO8 package, specific parameters V _DS =-30V, I _D =-15A , R _DS(ON) <7.5mΩ(V _GS =-10V), R _DS(ON) <12mΩ(V _GS =-4.5V). When working in Boost mode, the operational amplifier IC1D is controlled by the PWM2 signal output by the CPU module, and its output drives the MOS tube VT3 to work through the triode tubes VT10 and VT11, resistors R26 and R28, and the charging power supply PWRin+ is output through VT2-L2- VT3-D3, When VT3 is turned off, the voltage is boosted. At this time, the PWM1 signal output by the CPU module of the operational amplifier IC1C is kept at a high level to make the MOS transistor VT2 in the conduction state; the MOS transistor VT3 is an N-channel enhanced field effect transistor, which should be connected in series The charging voltage and current selection of the battery pack, the optional models in this embodiment are: IRF7413, AO4410, FSD6670, FDS6680, P0803BVG, etc.; taking IRF7413 as an example, it adopts SO8 package, and the specific parameters V _DS =30V, I _D =12A , R _DS(ON) <11mΩ (V _GS =10V). Diodes D2~D3 should choose Schottky (Schottky) diodes, also known as Schottky barrier diodes (SBD for short), such as: SS34, which is a low-power, ultra-high-speed semiconductor device; the most notable feature is the reverse The recovery time is extremely short (can be as small as a few nanoseconds), and the forward voltage drop is only about 0.4V; it is mostly used as high-frequency, low-voltage, high-current rectifier diodes, freewheeling diodes, and protection diodes. The inductance L2 cannot use an inductance with a magnet that is too small (the energy cannot be stored), or whose wire diameter is too thin (the pulse current is large, and the wire loss will be large). Regardless of whether the charging circuit of the present invention works in Buck mode or Boost mode, its charging process is essentially an energy transfer process of an inductance. First, the inductance L2 absorbs energy, and then the inductance L2 releases energy. If the capacity of the capacitor C12 is large enough, then A stable voltage can be maintained at the output; if this process is repeated, a stable charging voltage can be obtained across the capacitor. In order to improve the conversion efficiency of the charging device of the utility model, it is generally necessary to start from three aspects: (1) reduce the impedance of the circuit when the switch tube is turned on as much as possible, so that the electric energy can be converted into magnetic energy as much as possible; (2) reduce as much as possible The impedance of the load circuit allows the magnetic energy to be converted into electrical energy as much as possible, while the loss of the circuit is the lowest; (3) Reduce the consumption of the control circuit as much as possible, because for the charging device, the consumption of the control circuit is a waste in a sense , cannot be converted into energy on the battery pack. Since the utility model charging device works in the switching state, and the switching frequency of PWM control is relatively high, it will inevitably form high-frequency ripple interference on the capacitor C12, so the ripple composed of resistors R29~R30 and capacitor C11 is introduced Sink circuit. The CPU module realizes the automatic adjustment of the charging process by detecting the charging current and voltage in real time and controlling the output of the PWM; the charging device of the utility model includes a charging device composed of resistors R31~R33, capacitors C13~C14 and operational amplifier IC3C. The voltage detection circuit is a charging current detection circuit composed of resistors R42~R47, capacitors C19~C20 and operational amplifier IC3A; the principle of the charging voltage detection circuit is basically the same as that of the power supply voltage detection circuit in Figure 2, and the charging current detection circuit Among them, resistor R42, capacitor C19, resistor R45, and capacitor C20 respectively form two low-pass filters to filter the input and output signals, R46 and R47 are two 0.1Ω parallel sampling resistors, R43= 1.5KΩ, R44= 10KΩ, the amplification factor of operational amplifier IC3A is 1+10/1.5=7.7 times, if the maximum current is 6A, the maximum output voltage is 0.05*6*7.7=2.3V. The battery pack access detection and protection circuit composed of resistors R34~R41, capacitors C15~C18, triode tube VT12, MOS tube VT4 and operational amplifier IC3D; capacitors C15~C18 are connected to both ends of the battery pack to be charged to form a π-type filter The network is used to filter out the ripple interference formed at both ends of the battery pack during the charging and equalization process; resistors R34~R38 and operational amplifier IC3D form a comparison circuit to detect the connection and polarity of the battery pack, when a battery pack is connected and When the polarity is correct, the MOS tube VT4 is turned on and enters the normal charging state. When no battery pack is connected or the polarity is wrong, the MOS tube VT4 turns off the charging circuit; The pull-up resistor R40 makes VT12 turn on, and the MOS tube VT4 is turned off to ensure the safety of the circuit and the battery pack; after the CPU works normally, the output control signal KZXH2=0 makes the circuit enter the charging working state; In case of overvoltage, overcurrent or other failure phenomena, the CPU module can output a control signal KZXH2=1 to shut down the charging circuit.

Fig. 4 is a schematic diagram of an embodiment of the balanced charging detection control module of the present invention, and Fig. 5 is a cascade schematic diagram of the balanced charging detection control module of the present invention. The balanced charging detection control module includes a four-channel monomer battery terminal voltage detection circuit composed of resistors R48~R67, capacitors C21~C24 and op amp IC4. The single battery voltage balance switching circuit composed of resistors R76~R83, photoelectric isolation driver IC5~IC6 and decoder IC7 is a balanced switching control circuit; each balanced charging detection control module can realize the voltage of 4 single batteries Balanced, multiple balanced charge detection control modules can be cascaded to realize the application of more single batteries; PWRin+, VDD, GND of the balanced charge detection control module are connected to the power input module, BAT0, BAT1, BAT2, BAT3, BAT4 Connect to the terminals of each single battery in the battery pack to be charged, the voltage detection outputs of the single battery terminals BATin1, BATin2, BATin3, BATin4 are connected to the A/D converter input of the CPU module, and the balance switching control signals KZM0, KZM1, KZM2 are connected to The logic output terminal of the CPU module; when cascading, the PWRin+, VDD, and GND of each balanced charging detection control module are connected in parallel, the BAT0 of the latter circuit is connected in parallel with the BAT4 of the previous circuit, BATin1, BATin2, BATin3, BATin4, KZM0, KZM1, KZM2 is respectively connected to the CPU module; the balanced charging detection control module detects the voltage at both ends of each single battery of the battery pack to be charged in real time and adjusts BATin0~BATin n to connect to the CPU module. The voltage makes intelligent decisions and outputs control codes KZM0~ KZMk to control the work of the balanced charging detection control module to realize the intelligent balanced charging of the battery pack to be recharged. When multiple cells are used in series, due to the different characteristics of the batteries, they will be fully charged first when charging. If they are recharged, the batteries will be damaged. Therefore, it is necessary to stop charging the fully charged batteries and continue charging the unfulfilled ones. This is the balance Charge. One of the purposes of equalization is to prolong the life of the battery to reduce its use cost. The non-dissipative equalization method will be the future development direction. The key is to shorten the time required for equalization as much as possible; among them, the capacitive equalization circuit with capacitors as energy storage elements has Advantages of low cost, small size, and low energy loss. The four-channel monomer battery terminal voltage detection circuit composed of resistors R48~R67, capacitors C21~C24 and operational amplifier IC4 has the same detection principle for each channel, and its essence is a subtraction circuit. The resistors R48~R52, capacitors The first channel detection circuit composed of C21 and operational amplifier IC4A is an example: set the terminal voltage V _BAT+ -V _BAT- =4.2V of the single battery, take R48=R51=510KΩ, R49=R52=270KΩ, then V _BATin1 = R49 / R48*(V _BAT+ -V _BAT- )=2.224V, which meets the input requirements of the A/D converter. Resistor R50 and capacitor C21 form a low-pass filter to filter out high-frequency interference components in the circuit; In the circuit, the op-amp IC4 selects a general-purpose op-amp whose operating voltage meets the requirements, the resistor selects a metal film resistor with a small temperature drift, and the capacitor selects a ceramic capacitor with better high-frequency characteristics. In the single battery voltage balance switching circuit composed of resistors R68~R75, MOS transistors VTA1~4 and VTB1~4, and capacitor C25, the sources of the four MOS transistors VTB1~VTB4 whose drains are connected to the positive terminal of capacitor C25 are respectively connected to The sources of the four MOS transistors VTA1~VTA4 whose drains are connected to the negative terminals of the capacitor C25 are respectively connected to the low potential terminals of the four single cells to the high potential terminals of the four single cells, as long as the high potential terminals and the low potential terminals The control codes of the terminal MOS tubes are the same and only one MOS tube is turned on each time, which can ensure that the two ends of a single battery are selected to be turned on each time; the selection of the capacitor C25 and the MOS tube is related to the switching frequency, and the switching frequency The higher the value, the smaller the capacitance value, and the smaller the conduction current of the MOS tube. In this embodiment, the capacitor C25 is a 100uF tantalum capacitor, and the MOS tubes are all IRF7314 except VTA1. IRF7314 uses SO8 to package two P-channel field effect transistors. Specific parameters V _DS =-20V, I _D =-5.3A, R _DS(ON) <0.049Ω(V _GS =-4.5V), R _DS(ON) <0.082Ω(V _GS =-2.7V), VTA1 It is an N-channel field effect transistor, and the basic parameters are similar to those of IRF7314. In order to make the equalizing capacitor C25 connect to the two ends of a single battery each time during the charging or discharging process, the control of the MOS tube is composed of resistors R76~R83, photoelectric isolation drivers IC5~IC6 and decoder IC7 IC5 and IC6 are four-channel photoelectric isolators, together with the anode current limiting resistors R76~R83 on the input diode side and R68~R75 on the collector pull-up resistors on the output transistor side, they form a drive circuit for 8 MOS transistors. When the control level of the cathode on the side of the two light-emitting diodes is "1", the diode does not emit light, and the phototransistor is in an open state. When the level is "0", the diode lights up, the phototransistor is in the conduction state, and the gate of the MOS transistor is low to make the MOS transistor in the conduction state; the decoder IC7 is composed of two 2-wire → 4-wire decoding units, and the decoding The outputs are respectively connected to the cathodes on the control LED side corresponding to the 8 MOS transistors. The decoder is enabled by the control signal KZM2. When KZM2 = "1", the 2*4 decoding output signals are all "1". When KZM2="0", the output signals of the two decoding units are determined by the levels of the control codes KZM1 and KZM0, when [KZM1, KZM0]=00, the output [Y3, Y2, Y1, Y0]=1110, [KZM1 , KZM0]=01, output [Y3, Y2, Y1, Y0]=1101, [KZM1, KZM0]=10, output [Y3, Y2, Y1, Y0]=1011, [KZM1, KZM0]=11 , the output [Y3, Y2, Y1, Y0] = 0111, thus ensuring that the balancing capacitor C25 is connected to the two terminals of a single battery each time switching. The PWRin+, VDD, and GND of the balanced charging detection control module are connected to the power input module, BAT0, BAT1, BAT2, BAT3, and BAT4 are connected to the terminals of each single battery in the battery pack to be charged, and the voltage detection outputs of the single battery terminals are BATin1, BATin2, BATin3 and BATin4 are connected to the A/D converter input of the CPU module, and the balanced switching control signals KZM0, KZM1 and KZM2 are connected to the logic output of the CPU module. In order to ensure the rapidity of equalized charging, each equalized charging detection control module in this embodiment only realizes the voltage equalization of four single cells, but multiple equalized charging detection control modules can be cascaded to meet the needs of more Application of battery packs composed of single cells. As shown in Figure 5, when cascading, PWRin+, VDD, and GND of each balanced charging detection control module are connected in parallel, BAT0 of the latter circuit is connected in parallel with BAT4 of the previous circuit, BATin1, BATin2, BATin3, BATin4, KZM0, KZM1, KZM2 is connected to the CPU module respectively. In this way, the utility model can charge a battery pack composed of any number of single cells. During the charging process, the balanced charging detection control module detects the voltage at both ends of each single cell of the battery pack to be charged in real time and adjusts BATin0 to BATin n is connected to the CPU module, and the CPU module makes intelligent decisions according to the real-time terminal voltage of each single battery and outputs control codes KZM0~KZM k to control the work of the balanced charging detection control module to realize the intelligent balanced charging of the battery pack to be recharged.

Fig. 6 is a structural block diagram of the CPU module of the embodiment of the utility model, and Fig. 7 is a curve diagram of charging current and voltage of the embodiment of the utility model. The CPU module includes CPU, clock and reset circuit, ADC circuit, output latch circuit, PWM circuit, LCD or LED display circuit, and button circuit. Among them, the clock and reset circuit is used to provide a clock source and a reset signal to the CPU, so that the CPU can enter a normal working state after being powered on. Commonly used accumulator types have lead-acid accumulator, cadmium-nickel accumulator, iron-nickel accumulator, metal oxide accumulator, zinc-silver accumulator, zinc-nickel accumulator, hydrogen-nickel accumulator, lithium-ion accumulator etc.; LCD or LED display circuit, button circuit, LCD or LED display circuit is used to display the charging status, parameters or curves, and the button circuit is used to set, consult or modify the parameters of the battery pack to be charged, so that the utility model can be adjusted by changing the parameter settings. Adapt to the balanced charging of different types of batteries and can observe the charging status in real time. This embodiment introduces the charging method with a nominal 3.7V lithium battery. The termination voltage of a nominal 3.7V lithium battery can reach up to 4.2V. Because the internal structure of the lithium battery determines that it has special properties, the lithium battery cannot be overcharged. If the lithium battery is overcharged, the battery will be damaged due to too much loss of Li+, and the lithium battery must be charged by a specific constant current and constant voltage charging device; first, the lithium battery is charged with a constant current, When the overall voltage of the battery reaches 4.2V, keep the constant voltage state and continue charging. During constant voltage charging, if the current is less than 100mA, you need to stop immediately; the charging current is 1.0 to 1.5 times the battery capacity, such as the theoretical capacity of a lithium battery If the charging current is 1470mAh, then its charging current should be between 1470-2205mA. If 1.5 times the capacity of the lithium battery is used as the charging current, it needs to be charged for 2-3 hours. Conventional charging methods include: constant voltage charging, constant current charging, and constant current/constant voltage staged charging improved on this basis. The utility model adopts a mixed constant current/constant voltage charging method. The charging process of the hybrid constant current/constant voltage charging method is carried out in sections. In order to save the overall time of the charging process, a constant current is first used; when the battery voltage rises to the corresponding threshold, a constant voltage of the threshold value is used; The current will gradually decrease until it drops to 1/10 or 1/20 of the battery capacity, and the charging process ends; that is, when the charging current value is less than 1/10 of the battery capacity, the battery recovers about 90% of its capacity; In the remaining stage, the battery capacity does not change significantly, but the required time increases significantly. The voltage and current curves during the charging process are shown in Figure 7; It is one of the best charging methods for lithium batteries; in order to reduce the damage to the battery caused by overcharging, a segmented constant current charging method is also used if necessary; different voltage values are set at different stages so that the current gradually When the voltage reaches a predetermined value, the constant current charging is gradually reduced; when the voltage rises to the next predetermined value, the current continues to decrease; and so on, from the beginning to the end of the charging process, the current decreases At the same time, the voltage increases; although this method can reduce the impact of overcharging on the battery itself, the charging time is longer and the current is prone to sudden changes; the selection should be based on different types of batteries and parameters. The ADC circuit of the utility model collects the detection signals of the charging control and detection protection module and the balanced charging detection control module under the control of the CPU, and the CPU performs intelligent decision-making according to the characteristics and parameters of the battery, and then outputs the control signal through the output latch circuit and the PWM circuit. The signal is sent to the charging control and detection protection module, and the balanced charging detection control module to realize the intelligence of the entire charging process. The CPU of the utility model can be any one of embedded microprocessors such as single-chip microcomputer, DSP, ARM, FPGA, etc., preferably the embedded microprocessor with internal integrated clock and reset, ADC, PWM and I/O port lines meeting application requirements, The CPU module structure of the utility model can be simplified to improve system reliability.

The beneficial effect of the utility model is that: adopting cascaded equalization charging and CPU module intelligent control can effectively shorten the equalization time, adapt to battery packs composed of any number of single batteries of different types, and ease the process of single batteries in the process of manufacture and use. The resulting inconsistency improves the overall performance of the series battery pack and the safety and reliability of charging.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall include Within the protection scope of the present utility model.

Claims (5)

1. a kind of series battery intelligent equalization charging device, it is characterized in that：Including Power Entry Module, charge control and detection Protection module, equalizaing charge detection control module, CPU module, charge power supply through Power Entry Module, CPU module control under By charge control charging current, CPU module and equalizaing charge detection are automatically provided with detection protection module for battery pack to be charged Control module treats the intelligence of rechargeable battery set by detecting each monomer battery voltage of battery pack to be charged in real time to realize Equalizaing charge.

2. series battery intelligent equalization charging device according to claim 1, it is characterized in that：Described power input mould Block includes the access electric power polarity decision circuitry that resistance R7, R8 and metal-oxide-semiconductor VT1 are formed, for reducing the noise on access power supply To bypass filter capacitor C2, C3, C4 of charging device interference, noise is produced to external power supply disturbance for reducing charging device Decoupling filter capacitor C1, resistance R9 ~ R13, electric capacity C10 and amplifier IC1A compositions access voltage detection circuit simultaneously export ADin0 forms a voltage-dropping type to CPU module, resistance R1 ~ R6, electric capacity C6 ~ C9, diode D1, inductance L1 and IC 2 Mu balanced circuit is exporting the vdd voltage of subsequent logic control circuit.

3. series battery intelligent equalization charging device according to claim 1, it is characterized in that：Described charge control with Detecting protection module is included by metal-oxide-semiconductor VT2 ~ VT3, diode D2 ~ D3, resistance R27 ~ R30, electric capacity C11 ~ C12 and inductance L2 groups Into Buck-Boost main circuits, the Buck- being made up of triode pipe VT5 ~ VT11, resistance R14 ~ R26, amplifier IC1C and IC1D Boost control circuits, the charging voltage being made up of resistance R31 ~ R33, electric capacity C13 ~ C14 and amplifier IC3C detects circuit, by electricity Hinder R42 ~ R47, the charging current detecting circuit of electric capacity C19 ~ C20 and amplifier IC3A composition, by resistance R34 ~ R41, electric capacity C15 ~ C18, triode pipe VT12, the battery pack access detection of metal-oxide-semiconductor VT4 and amplifier IC3D compositions and protection circuit；Buck-Boost Control circuit is to treat by Buck-Boost main circuits under CPU module output control signal PWM1, PWM2, KZXH1 control Rechargeable battery set automatically provides charging current, and from charging voltage detection circuit, charging current detecting circuit in real time to CPU module Feed back charging voltage signal Adin1, charging current signal Adin2, battery pack charge circuit only access in battery pack to be charged and Turned on when polarity is correct and its conducting and shut-off can be controlled by CPU module control signal KZXH2.

4. series battery intelligent equalization charging device according to claim 1, it is characterized in that：Described equalizaing charge inspection The four-way cell terminal voltage that surveying control module includes being made up of resistance R48 ~ R67, electric capacity C21 ~ C24 and amplifier IC4 is examined Slowdown monitoring circuit, cut by resistance R68 ~ R75, metal-oxide-semiconductor VTA1 ~ 4 and metal-oxide-semiconductor VTB1 ~ 4, electric capacity C25 the monomer battery voltage equilibrium formed Circuit is changed, the balanced control switching circuit being made up of resistance R76 ~ R83, photoelectric isolated driver IC5 ~ IC6 and decoder IC7； Each equalizaing charge detection control module can realize the electric voltage equalization of 4 cells, and multiple equalizaing charges detect control module Between can cascade to realize the application of more cells；The charge power supply positive pole PWRin+ of equalizaing charge detection control module, Logic circuit operating voltage VDD, reference ground GND are connected with Power Entry Module, 4 cell connection terminal BAT0, BAT1, BAT2, BAT3, BAT4 are connected to the end points of group each cell in pond to be charged, the both ends detection voltage of 4 cells BATin1, BATin2, BATin3, BATin4 are connected to the A/D converter input of CPU module, 3 balanced switch-over control signals KZM0, KZM1, KZM2 are connected to the logic output terminal of CPU module；During cascade, the charging of each equalizaing charge detection control module Positive source PWRin+, logic circuit operating voltage VDD, reference ground GND are in parallel, the cell connection terminal BAT0 of the latter circuit It is in parallel with the cell connection terminal BAT4 of previous circuit, the two of 4 cells of each equalizaing charge detection control module End detection voltage BATin1, BATin2, BATin3, BATin4 and 3 balanced switch-over control signal KZM0, KZM1, KZM2 difference It is connected to the A/D converter input and logic output terminal of CPU module；Equalizaing charge detection control module is treated by detecting in real time Multiple cell both end voltage BATin0~BATin of rechargeable battery setnThe A/D converter input of CPU module is connected to, CPU module carries out intelligent decision according to the real-time terminal voltage of each cell and exports multiple control code KZM0 through logic output terminal ~KZMkThe intelligent equalization charging of rechargeable battery set is treated in the work of control equalizaing charge detection control module to realize.

5. series battery intelligent equalization charging device according to claim 1, it is characterized in that：Described CPU module bag CPU, clock and reset circuit, adc circuit, output latch circuit, pwm circuit, LCD or LED display circuit, key circuit are included, Adc circuit gathers detection of the charge control with detecting protection module, equalizaing charge detection control module under the control of cpu to be believed Number, by after CPU intelligent decisions through output latch circuit, pwm circuit output a control signal to charge control with detection protection module, Equalizaing charge detects control module to realize the intellectuality of whole charging process, when clock is used to provide to CPU with reset circuit Zhong Yuan and reset signal, LCD or LED display circuit are used to show charged state, parameter or curve, key circuit is used to setting, Consult or change the parameter of pond group to be charged.