WO2009030101A1

WO2009030101A1 - Online passive maintaining device for large capacity sealed lead-acid accumulator

Info

Publication number: WO2009030101A1
Application number: PCT/CN2008/001464
Authority: WO
Inventors: Yongchang Li; Tianshu Gao; Fengshan Xu; Jin Xu; Peihuan Lin; Haipeng Xie
Original assignee: Shenzhen Vdo Electronics Co. Ltd.
Priority date: 2007-08-28
Filing date: 2008-08-14
Publication date: 2009-03-12
Also published as: CN101114725A; CN100517859C

Abstract

An online passive maintaining device for large capacity sealed lead-acid accumulator. The device includes a single chip circuit (1), an under-voltage protection circuit (2), and a power output circuit (3), which are interconnected together. The single chip circuit (1) includes a single chip (U2), a clock circuit, a voltage reference circuit and a voltage detecting circuit. The voltage detecting circuit is connected to a positive pole of the accumulator, an input terminal of the under-voltage protection circuit (2) is connected to the positive pole of the accumulator, an output terminal of a power output circuit (3) is connected to the under-voltage protection circuit, and the circuits are separately connected to corresponding ports of the single chip (U2). The single chip circuit (1) also signal receiving and transmitting circuit connected to the corresponding port of the single chip.

Description

Online passive maintenance device for large-capacity sealed lead-acid battery

The invention relates to a passive maintenance device for suppressing the formation of lead sulfate crystals in a lead-acid battery plate and gradually recovering the battery capacity by using an electronic pulse method, in particular, an online passive maintenance device for a large-capacity sealed lead-acid battery. Background technique

At present, the equipment room of each communication and power system needs one or more sets of large-capacity sealed lead-acid batteries as backup power sources to prevent communication interruption and system failure during power failure. These backup batteries are in a floating state all the year round (the charging device should meet the DC load requirements first, and the small current should meet the internal self-discharge requirements of the battery). The theoretical life is more than 10 years. However, most of the large-capacity sealed lead-acid batteries of base stations or computer rooms need to be scrapped after being put into operation for 3-5 years because of the capacity drop or the imbalance of individual battery terminals. Existing online repair and protection products such as the online passive maintenance device disclosed in Chinese patents ZL 200520036931.3 and ZL 200520146861.7 can inhibit the growth of lead sulfate. However, the functions of these devices are relatively simple. The battery with too high or too low voltage can only be alarmed on-site, and the battery cell voltage cannot be balancedly managed, and the voltage detection accuracy is poor. Summary of the invention

The object of the present invention is to provide an in-line passive maintenance device for a large-capacity sealed lead-acid battery. In addition to suppressing the growth of lead sulfate, the device of the present invention can ensure the voltage balance of the battery during the floating charging process, and can gradually restore the battery capacity. , extend the life of the battery pack running online, and consume less energy.

The object of the present invention is achieved in accordance with the following technical solutions.

The invention relates to an online passive maintenance device for a large-capacity sealed lead-acid battery, which is characterized in that: it comprises a single-chip circuit, an undervoltage protection circuit, and a power output circuit connected, and the single-chip circuit comprises a single-chip microcomputer, a clock circuit, a voltage reference circuit, a voltage monitoring circuit; the voltage monitoring circuit is connected to a positive pole of the battery; an input end of the undervoltage protection circuit is connected to a positive pole of the battery; an output end of the power output circuit and the owed The voltage protection circuits are connected; the circuits are also respectively connected to corresponding ports of the single chip microcomputer.

The single chip circuit further includes a signal receiving and transmitting circuit connected to a corresponding port of the single chip microcomputer. The single-chip circuit further includes a status display circuit connected to a corresponding port of the single chip U2.

The clock circuit includes a capacitor and a quartz crystal oscillator;

The voltage reference circuit comprises a resistor, a capacitor C8 and a voltage regulator U1;

The voltage monitoring circuit includes resistors R1, R2, R3, RP2, and capacitor C7.

The undervoltage protection circuit 2 includes: a resistor R20, R7, an electrolytic capacitor C9, a transistor Q1, a relay K1 and a diode D1. The input end of the undervoltage protection circuit 2 is connected to the positive pole of the battery, and the control terminal and the single chip U2 The port RC7 is connected.

The power output circuit 3 includes capacitors C5, C6, resistors R4, R5, R6, R15, R16; inductors L1, L2; diode D2 _; the output of the power output circuit is connected to the undervoltage protection circuit The control terminal is connected to the port RC2 of the single chip microcomputer.

The signal receiving and transmitting circuit includes resistors R1, R14, a capacitor C10, a photocoupler U3, a start switch SW1, and output jacks JK1, JK2.

The status display circuit includes resistors R17, R18, R19, LEDs LED2, and LED3. In addition to the pulse maintenance function, the maintenance device of the invention also has a battery voltage monitoring function and a single floating charge voltage equalization function. When the connected battery terminal voltage is lower than the set voltage value, (for example, the utility power supply uses the battery pack to supply power. When a warning is issued, and the device is in a sleep state to reduce energy consumption. When the battery voltage returns to normal, it can automatically work normally. At present, the large-capacity sealed lead-acid battery packs used in base stations or computer rooms are all connected in series. In theory, the float currents of each battery are consistent, and the floating charge voltage of single cells is not much different. However, after the battery has been in operation for a certain period of time, the floating charge voltage of the single cell is inconsistent due to the difference of the internal resistance and the degree of water loss and the concentration of the electrolyte, and the floating charge voltage is biased when the single cell with the internal resistance and the electrolyte concentration flows through the same current. High, low internal resistance of the battery float voltage is low, the battery with high voltage is increased, resulting in reduced capacity, which will seriously affect the service life of the battery pack after the formation of a vicious cycle. When the invention detects that the connected battery terminal voltage is higher than the set voltage value, it also issues a warning, and simultaneously starts the discharge equalization circuit, so that the floating charge current is consumed by the equalization circuit without entering the battery, so that the terminal voltage of the battery is gradually decreased. Therefore, the battery voltage with low floating charge voltage will be gradually increased, which ensures the voltage balance and consistency of the whole battery in the series floating charging process. The invention can also have two modes of single machine operation and multi-machine rotation work. When the rotation work mode is adopted, the energy consumption of the maintenance device can be reduced to one-N, and the energy consumption is further reduced. (N is the total number of maintenance devices installed in the entire battery pack). In addition, the prior art undervoltage and overvoltage detection uses a Zener diode method, and the error is large. The voltage detection circuit of the present invention uses the 8-bit precision of the single chip microcomputer. A/D conversion circuit is realized, and the detection precision can be controlled within 100mV, which can fully satisfy the large-capacity lead-acid battery used in communication and power systems. Use the requirements to precisely control the float voltage.

The working process of the invention is: when the voltage of the protected battery is within the working voltage range set by the single chip circuit, the power is taken from the battery, and the port RC7 of the single chip outputs a high level, so that the control tube Q1 of the undervoltage protection circuit leads The relay coil is energized and the contacts are closed. At the same time, the oscillation pulse is output from the port RC2 of the single chip, and after being accelerated by the resistor R15 and the capacitor C5, it is sent to the control end of the electronic switch in the power output circuit, so that the switch with the fast rising edge during the on and off period of the electronic switch is enabled. The pulse is fed back to the battery to resonate with the coarse lead sulfate crystal inside the battery to dissolve and reduce the coarse lead sulfate crystal. When the connected battery terminal voltage is higher than the set voltage value, the port RC2 of the single chip outputs a high level, so that the electronic switch of the power output circuit is completely turned on, and the floating charge current is bypassed by the load resistors R4, R5, and R6. Discharge. When the battery terminal voltage is gradually reduced, it will automatically return to the pulse maintenance mode to equalize the voltage. If the battery voltage is too low, the port RC7 of the MCU outputs a low level, so that the contact of the relay of the undervoltage protection circuit is released, the power supply of the power output circuit is disconnected, and the port RC2 of the MCU outputs a low level, so that the power output is The electronic switch of the circuit is completely cut off, and no pulse is transmitted to the power output circuit, then the online passive maintenance device is in a standby state, and the protection battery is not over-discharged.

The invention adopts single machine work and multi-machine work in turn.

In summary, the invention not only has the function of preventing and eliminating the vulcanization, but also gradually restores the capacity of the battery, and has the function of equalizing the voltage of the cell, ensuring that the voltage balance of the battery during the floating charging process is uniform, and the energy consumption is low. Its combination of prevention and treatment extends battery life. DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a circuit block diagram of the present invention.

Figure 2 is a circuit schematic of the present invention.

Description of the code in the figure

1 single-chip circuit 2 undervoltage protection circuit 3 power output circuit 4 battery being maintained

C1~C11 Capacitor D2 Fast Recovery Diode DK D3, Diode F1 Thermistor

1 Relay SW1, SW2 tact switch JK1, JK2 output socket XL1 quartz crystal

LK L2 core inductor L2 color ring inductor LED1 LED diode LED2 red and green two-color LED

R1 -20 Resistor U1 Regulator U2 Microcontroller (PIC16F73) U3 Optocoupler

VT1 switch tube (field effect tube) Z1 regulator tube Q1 triode 1 is a circuit block diagram of the present invention, comprising a single chip circuit 1, an undervoltage protection circuit 2, and a power output circuit 3 connected. The single chip circuit 1 includes a single chip U2, a clock circuit, a voltage reference circuit, a voltage monitoring circuit; the voltage monitoring circuit is connected to the positive pole of the battery; the input end of the undervoltage protection circuit 2 is connected to the positive pole of the battery 4; the output end of the power output circuit 3 and the undervoltage The protection circuit 2 is connected; the circuits are also respectively connected to corresponding ports of the single chip U2.

The single chip circuit 1 further includes a signal receiving and transmitting circuit connected to a corresponding port of the single chip U2. The single chip circuit 1 further includes a status display circuit connected to a corresponding port of the single chip U2.

2 is a circuit schematic diagram of the present invention, and the figure has:

Clock circuit, including capacitor Cl, C2, quartz crystal oscillator XL1;

Voltage reference circuit, including resistors R10, R13, RP1, capacitor C8 and regulator Ul;

Voltage monitoring circuit, including resistors Rl, R2, R3, RP2, capacitor C7. The voltage monitoring circuit is connected to the RAO port of the U2 of the single-chip microcomputer to monitor the terminal voltage of the connected battery in real time. The single-chip microcomputer U2 automatically switches between the under-voltage protection, the over-voltage discharge equalization, and the normal pulse maintenance according to the battery voltage.

The undervoltage protection circuit 2 includes: a resistor R20, R7, an electrolytic capacitor C9, a transistor Q1, a relay K1 and a diode D1. The input of the undervoltage protection circuit 2 is connected to the anode of the battery, and the control terminal is connected to the RC7 port of the microcontroller.

The power output circuit 3 includes capacitors C5 and C6, resistors R4, R5, R6, R15, and R16; and inductors L1 and L2: diode D2; the output end of the power output circuit is connected to the undervoltage protection circuit 2, and is controlled. The terminal is connected to the port RC2 of the microcontroller.

The signal receiving and transmitting circuit comprises a resistor Rl l, R14, a capacitor C10, a photoelectric coupler U3, a start switch SW1 and an output socket JK1, JK2; a trigger signal receiving and transmitting state display circuit for controlling the rotation operation of the device includes a resistor R17 , R18, R19, LED LED2, LED3.

The working process is as follows: Connect the terminal of the maintenance device to the two ends of the battery 4 according to the polarity, the battery voltage is filtered by the inductor L4, L3, the current limit of the resistor R8, the Zener diode Z1 voltage regulator, the capacitor C4 filter, The power supply pin Vdd of the single chip U2 and the reset terminal MCLR of the single chip microcomputer are obtained; the single chip microcomputer U2 starts working after self-test, at this time, the power indicator LED1 is lit, indicating that the power supply is normal; the other circuit is via the resistors R10, R13, RP1, capacitor C8 and voltage regulator. The voltage reference circuit composed of U1; gives the precision reference voltage of port RA3 of the single chip U2; the other circuit reaches the control port RA4 of the single chip U2 via the resistor R11, the high level is the single working mode, when the SW1 is pressed or the other is received The trigger signal sent by an online passive maintenance device When the port goes low, the unit changes to the turn-on startup mode. Battery voltage is another resistor

The voltage monitoring circuit composed of Rl, R2, R3, RP2 and capacitor C7 is sent to the A/D conversion input port RA0 of the single chip U2 to monitor the terminal voltage of the battery 4 in real time, when the battery terminal voltage is in the normal range (this case is set 6.00V~7.05V) The output port RC5 of the MCU U2 outputs a high level, so that the green LED in the LED2 is lit; at the same time, the port RC7 of the MCU U2 outputs a high level, reaches the base of Q1 via R20, and saturates the Q1. The relay K1 coil is energized, the contacts are attracted, and the voltage of the battery 4 passes through the contacts, the resistors R4, R5, and R6, the inductors L1 and L2, and reaches the drain of the switch tube VT1. The output of the port RC2 of the single chip U2 is 120uS. The oscillation pulse of amplitude 5V is accelerated by R15 and C5 shaping, and then sent to the control end of the electronic switch VT1 in the controlled power output circuit 3 to control the on/off of the electronic switch. During the conduction of the electronic switch, the power supply charges the storage capacitor C6 via the inductor L2. The current passes through the K1 contact, the resistors R4, R5, and R6, L2 and L1, and then goes to the negative pole to give the battery a rapid discharge. Due to the large current, the inductor L1 is quickly magnetically saturated. During the off period of the switching tube VT1, the storage capacitor C6 Discharge; When the switching tube VT1 is turned off, due to the self-inductance of the inductor L1, a self-induced electromotive force is generated on the inductor L1. Because the inductance of the inductor L3 is large, the self-inductance electromotive force is unidirectionally rectified by the diode D2. A high-voltage pulsed direct current having a frequency of 8.33 KHz, a width of less than 5 μ ≤, a leading edge of less than 800 nS, and a thickness of about 3 Α (depending on the battery capacity) is applied to both ends of the battery 4 via F1. Under constant pulse perturbation, the conditions for the formation of lead sulfate crystals are destroyed, and the formed lead sulfate crystals are gradually removed. When the terminal voltage of the battery 4 is higher than the voltage 7.05V set by the single chip U2, the port RC5 of the single chip U2 outputs a low level, so that the green light emitting diode in the LED2 is extinguished; at the same time, the port RC4 of the single chip U2 outputs a high level and a low level, so that the LED2 The red LED in the flashing light flashes, the alarm indicates that the battery voltage is too high; at the same time, the port RC2 of the single chip U2 turns off the oscillation pulse output, and the high level output makes the electronic switch VT1 of the controlled power output circuit 3 fully guided. In the on state, the floating current flowing through the protected battery is bypassed by the load resistors R4, R5, and R6. The gradual decrease of the elevated terminal voltage ensures the voltage balance and uniformity of the entire battery during the floating process. When the terminal voltage of the battery 4 is lowered to 6.75V, the automatic discharge discharge state is changed to the normal pulse maintenance operation state. When the battery 4 supplies power to the system load and the terminal voltage is lower than 6.00V, the RC4 port of the single chip U2 outputs a low level, so that the red LED of the LED2 is lit; the alarm indicates that the battery voltage is too low, and the output of the RC7 port of the single chip U2 is low. The level causes the contact of the relay K1 of the undervoltage protection circuit 2 to be released, the power supply of the power output circuit 3 is turned off, and the port RC2 of the single chip U2 outputs a low level, so that the electronic switch of the controlled power output circuit 3 is completely turned off. When no pulse is transmitted to the power output circuit 3, the online passive maintenance device is in a standby state, and the power of the battery 4 is no longer consumed. When the installed online passive maintenance device needs to be set to work in the turn-on mode, after installing the output line, connect the signal cable from the JK1 jack of the first maintenance device to the JK2 jack of the second maintenance device. The JK1 jack of the second maintenance unit is connected to the JK2 jack of the third maintenance unit... Connect the JK1 jack of the last maintenance unit to the JK2 jack of the first maintenance unit. After the signal cable is connected correctly, press the SW1 button of any maintenance device. The maintenance device is in standby state after working for a period of time. At the same time, the port RA5 of the MCU U2 sends a trigger signal, which is transmitted to the next through the resistor R14, the socket JK2 and the signal line. The JK1 of the maintenance device lights the LEDs 4 in the photocoupler U3, and the phototransistor Q3 in the photocoupler U3 receives the optical signal and turns on, and pulls the RA4 port of the U2 of the maintenance device to a low level. Switch to work in turn. And so on, and repeat.

Claims

right

1. An online passive maintenance device for a large-capacity sealed lead-acid battery, characterized in that: it comprises a single-chip circuit (1), an undervoltage protection circuit (2), and a power output circuit (3) are connected to each other; The single chip circuit (1) comprises a single chip (U2), a clock circuit, a voltage reference circuit, and a voltage monitoring circuit; the voltage monitoring circuit is connected to the positive pole of the battery; the input end of the undervoltage protection circuit (2) and the battery The positive terminals of the power output circuit (3) are connected to the undervoltage protection circuit (2); the circuits are also respectively connected to corresponding ports of the single chip (U2).

2 . The online passive maintenance device for a large-capacity sealed lead-acid battery according to claim 1 , wherein: the single-chip circuit (1 ) further comprises a signal receiving and transmitting circuit connected to a corresponding port of the single chip (U2). .

3. The in-line passive maintenance device for a large-capacity sealed lead-acid battery according to claim 1, wherein: the single-chip microcomputer circuit (1) further comprises a status display circuit connected to a corresponding port of the single-chip microcomputer (U2).

4. The in-line passive maintenance device for a large-capacity sealed lead-acid battery according to any one of claims 1 to 3, wherein the clock circuit comprises a capacitor (Cl, C2) and a quartz crystal oscillator (XL1);

The voltage reference circuit includes a resistor (R10, R13, RP1), a capacitor (C8), and a voltage regulator (U1); the voltage monitoring circuit includes a resistor (R1, R2, R3, RP2) and a capacitor (C7) .

5. An in-line passive maintenance device for a large-capacity sealed lead-acid battery according to any one of claims 1 to 3, characterized in that:

The undervoltage protection circuit (2) comprises: a resistor (R20, R7), an electrolytic capacitor (C9), a triode (Q1), a relay (K1) and a diode (D1), the undervoltage protection circuit (2) The input is connected to the positive terminal of the battery, and the control terminal is connected to the port (RC7) of the microcontroller.

6. An in-line passive maintenance apparatus for a large-capacity sealed lead-acid battery according to any one of claims 1 to 3, characterized in that:

The power output circuit (3) includes capacitors (C5, C6) and resistors (R4, R5, R6, R15, R16); Inductor (L1, L2); Diode (D2); The output of the power output circuit is connected to the undervoltage protection circuit (2), and the control terminal is connected to the port (RC2) of the microcontroller.

7. The in-line passive maintenance device for a large-capacity sealed lead-acid battery according to claim 2, wherein said signal receiving and transmitting circuit comprises a resistor (R1, R14), a capacitor (C10), and an optocoupler. Device

(U3), start switch (SW1) and output socket (JK1, JK2) o

8. The in-line passive maintenance device for a large-capacity sealed lead-acid battery according to claim 3, wherein the state display circuit comprises a resistor (1 17 , 1 18 , 1 19 ) and a light emitting diode (1^). 02, 1^03).