Storage battery pack real-time detection and active equalization device

Abstract

The invention discloses a real-time detection and active equalization device for a storage battery pack, which comprises a battery pack data acquisition system, an active equalization system, a display system, a temperature control system, an alarm indication system, a power supply system and a communication monitoring system, and if the data is abnormal, the alarm indication system is started to give an alarm. Based on battery state data fed back by the battery pack data acquisition system, the active equalization system utilizes small current to charge part of batteries with low voltage and discharge part of batteries with high voltage after the large current of the system stably charges the battery pack, so that the purpose of equalization management of the voltage of the battery pack is achieved. The device provided by the invention can solve the overcharge and discharge phenomena of the battery pack and ensure the normal and efficient operation of the battery pack.

Description

Technical Field

[0001] The present invention relates to the technical field of battery management, and in particular to a real-time detection and active equalization device for a battery pack. Background Art

[0002] The voltage of a single battery is very low, and usually it needs to be connected in series to form a battery pack to meet the voltage requirements. When the battery is used in a group, it is more likely to be overcharged and over-discharged, and the root cause is the consistency error of the battery. The single battery in the battery pack has different usage characteristics due to the different manufacturing and use conditions of the battery, that is, the battery voltage, capacity, internal resistance and self-discharge rate are different under different temperatures, different charge and discharge rates, different charge states, different use history and other conditions. If these differences are not properly controlled during the charging and discharging process, they will be further increased, causing some batteries to be overcharged and discharged, resulting in a sharp decline in battery capacity and life, and ultimately leading to accidents. Therefore, battery management is required during use.

[0003] Battery management systems generally have battery voltage, current and temperature detection, and include high and low voltage, high and low temperature and overcurrent alarm functions. Basically, they only monitor the operating status of the battery pack. With the rapid development of new energy and electric vehicles, in recent years, the new generation of battery management systems have included battery balancing functions, but most solutions are for the balancing management of the entire battery pack and do not involve the control of the single cells. Another solution is to transfer energy from the single cells in the battery pack and achieve balancing management of high voltage to low voltage energy transfer through capacitors, inductors or transformers. This solution has been in the experimental stage. In terms of its implementation principle, it is redundant and complex, and the effect is not ideal. Summary of the invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a real-time detection and active balancing device for a battery pack, which can solve the problem of overcharging and discharging of the battery pack and ensure the normal and efficient operation of the battery pack.

[0005] Technical solution: To achieve the above-mentioned purpose, the real-time detection and active balancing device of a battery pack described in the present invention is characterized in that it includes an active balancing system composed of a plurality of parallel battery balancing subsystems, each battery balancing subsystem includes a supplementary discharge unit and a supplementary charging unit for supplementary discharge or supplementary charging of the battery.

[0006] Wherein, the supplementary discharge unit is composed of a relay selection circuit and a resistance network.

[0007] Wherein, the supplementary charging unit is composed of a relay selection circuit and a charging power supply.

[0008] It also includes a battery pack data acquisition system, a display system, and an alarm indication system. The battery pack data acquisition system is used to collect battery pack data and feed it back to the display system for display. If the data is abnormal, the alarm indication system will be activated to sound an alarm.

[0009] The battery pack data acquisition system includes a single cell voltage acquisition unit, a terminal voltage acquisition unit, a battery pack charge and discharge current acquisition unit, a temperature acquisition unit and a single chip microcomputer control unit.

[0010] Wherein, the voltage acquisition unit adopts a differential operational amplifier linear direct sampling circuit.

[0011] Wherein, the current acquisition unit adopts a differential operational amplifier circuit which can self-identify the current direction.

[0012] Wherein, the single chip control unit adopts a 32-bit microcontroller based on the ARM core.

[0013] The display system includes a data display unit, a status indication unit and a parameter setting unit, and the alarm indication system includes a sound alarm unit, an indicator light alarm unit and an alarm transmission unit.

[0014] It also includes a temperature control system, a power supply system and a communication monitoring system. The temperature control system includes a multi-stage temperature detection unit and a fan control unit. The power supply system includes a communication isolation power supply unit, a control power supply unit, a working power supply unit and a supplementary charging power supply unit. The communication monitoring system includes an isolation communication unit, a human-machine interface unit and a DCS background monitoring unit.

[0015] Beneficial effects: The present invention has the following advantages: 1. The present invention is used to solve the balancing problem of battery packs. After the system is charged with a large current and stabilized, a small current is used to supplement the charging of some batteries with low voltages and to supplement the discharge of some batteries with high voltages, so that the battery pack voltage can be balanced. 2. The device of the present invention includes multiple data acquisition and multiple control modes, which can detect battery packs with up to 42 batteries in series, and can be expanded in a cascade manner to meet the requirements of complex systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a structural block diagram of the device;

[0017] Figure 2 It is the schematic diagram of device data monitoring;

[0018] Figure 3 This is the schematic diagram of the active equalization circuit. DETAILED DESCRIPTION

[0019] The technical solution of the present invention is described in detail below in conjunction with the embodiments and drawings.

[0020] like Figure 1 As shown, the battery pack real-time detection and active balancing device described in the present invention includes a battery pack data acquisition system, an active balancing system, a display system, a temperature control system, an alarm indication system, a power supply system and a communication monitoring system.

[0021] The battery pack data acquisition system collects the battery pack voltage, current and ambient temperature, processes them and transmits them to the display system for display. If the data is abnormal, the alarm indication system starts to alarm. The active balancing system is based on the battery status data fed back by the battery pack data acquisition system. After the system charges the battery pack with a large current and stabilizes it, it uses a small current to supplement the charging of some low-voltage batteries and discharge some high-voltage batteries, so as to achieve the purpose of balanced management of the battery pack voltage.

[0022] The battery pack data acquisition system includes a single cell voltage acquisition unit, a terminal voltage acquisition unit, a battery pack charge and discharge current acquisition unit, a temperature acquisition unit and a single chip microcomputer control unit.

[0023] The voltage acquisition unit adopts a differential op amp linear direct sampling circuit. This sampling method uses a differential operational linear circuit with adjustable gain and excellent performance. It can quickly track and measure the voltage of a single battery cell and effectively suppress the common-mode voltage in the measurement. It has the characteristics of good real-time performance, high precision, easy expansion, good anti-interference and strong adaptability. The current acquisition unit adopts a differential op amp circuit that self-identifies the direction of current. The single-chip control unit adopts a 32-bit microcontroller based on the ARM core, a 32-bit microcontroller system based on the ARM core, and a successive approximation analog-to-digital converter with 18 channels and 12-bit ADC. The powerful computing power can easily realize various control and management of the system.

[0024] The active balancing system is composed of several parallel battery balancing subsystems, each of which includes a supplementary discharge unit and a supplementary charging unit. The supplementary discharge unit is composed of a relay gating circuit and a resistor network, and the supplementary charging unit is composed of a relay gating circuit and a charging power supply.

[0025] The display system includes a data display unit, a status indication unit and a parameter setting unit.

[0026] The temperature control system includes a multi-stage temperature detection unit and a fan control unit.

[0027] The alarm indication system includes a sound alarm unit, an indicator light alarm unit and an alarm transmission unit.

[0028] The power supply system includes a communication isolation power supply unit, a control power supply unit, a working power supply unit and a supplementary charging power supply unit.

[0029] The communication monitoring system includes an isolation communication unit, a human-machine interface unit and a DCS background monitoring unit.

[0030] The above display system can conveniently and quickly display the operating parameters of the battery pack. The communication monitoring system based on the RS485 bus is convenient for setting system parameters and clearly understanding the status of the battery pack, thereby achieving the purpose of remote background monitoring.

[0031] Based on the above device, the principle of real-time detection is as follows Figure 2 As shown, the communication monitoring system specifically sends out a measurement command, and the battery pack data acquisition system measures the battery voltage, battery internal resistance, and battery temperature respectively, and further processes the collected data. If the data is less than the set threshold, it is considered normal and the corresponding data is recorded. If it is abnormal, an alarm information is issued through the alarm indication system, and the data is displayed through the temperature control system.

[0032] Based on the above device, the principle diagram of active charge and discharge balance management is as follows Figure 3 The specific implementation process is as follows:

[0033] 1. When charging, use a main charger to charge the battery pack in series, and its charging current accounts for about 90% of the total charging current.

[0034] 2. At the same time or when the battery capacity is charged to 80% to 90%, the supplementary charging unit is started (switch Ka is closed), and the voltage of each single battery is tracked in real time through the detection circuit. When a single battery Ui with a relatively low battery voltage is detected, the switch Ki is closed to perform supplementary charging on this battery alone. When the battery charging voltage reaches the set value, the supplementary charging of the battery is reduced or stopped (switch Ki is opened).

[0035] 3. In this way, some batteries in the battery pack are supplemented and charged cyclically until the charging voltage of all batteries reaches the set value and the total charging current is reduced to the set minimum charging current. Then the charging of the main charger and the supplementary charging unit is stopped (switch Ka is disconnected).

[0036] 4. After the main charge and discharge of the system, some batteries Ui with relatively high voltage may appear. Start the supplementary discharge unit (close the switch Kb) and close the switch Ki to discharge this battery separately. When the discharge voltage reaches the set value, reduce or stop (open the switch Ki) the supplementary discharge of the battery.

[0037] In this way, some batteries in the battery pack are supplemented and discharged cyclically until the voltage of all batteries reaches the set value, and then the supplementary discharge unit is stopped (the switch Kb is turned off).

[0038] The above-mentioned device is mainly used as energy storage equipment in DC power supply cabinets. It can solve the problem of overcharging and discharging of battery packs and ensure the normal and efficient operation of battery packs. It has a wide range of applications in communications, electricity, transportation and new energy, and is of great significance for maintaining the normal operation of battery packs.

Claims

1. A real-time detection and active balancing device for a battery pack, characterized in that: The invention comprises an active balancing system composed of a plurality of battery balancing subsystems connected in parallel, each of which comprises a supplementary discharge unit and a supplementary charge unit for supplementary discharge or supplementary charge of the battery.

2. The battery pack real-time detection and active equalization device according to claim 1, characterized in that: The supplementary discharge unit is composed of a relay gating circuit and a resistor network.

3. The real-time detection and active equalization device for a battery pack according to claim 1, characterized in that: The supplementary charging unit is composed of a relay gating circuit and a charging power supply.

4. The battery pack real-time detection and active balancing device according to claim 1, characterized in that: It also includes a battery pack data acquisition system, a display system, and an alarm indication system. The battery pack data acquisition system is used to collect battery pack data and feed it back to the display system for display. If the data is abnormal, the alarm indication system is activated to sound an alarm.

5. The real-time detection and active equalization device for a battery pack according to claim 4, characterized in that: The battery pack data acquisition system comprises a single cell voltage acquisition unit, a terminal voltage acquisition unit, a battery pack charge and discharge current acquisition unit, a temperature acquisition unit and a single chip microcomputer control unit.

6. The battery pack real-time detection and active equalization device according to claim 5, characterized in that: The voltage acquisition unit adopts a differential operational amplifier linear direct sampling circuit.

7. The battery pack real-time detection and active equalization device according to claim 5, characterized in that: The current acquisition unit adopts a differential operational amplifier circuit which can self-identify the current direction.

8. The battery pack real-time detection and active equalization device according to claim 5, characterized in that: The single chip control unit adopts a 32-bit microcontroller based on the ARM core.

9. The real-time detection and active equalization device for a battery pack according to claim 4, characterized in that: The display system comprises a data display unit, a state indication unit and a parameter setting unit, and the alarm indication system comprises a sound alarm unit, an indicator light alarm unit and an alarm transmission unit.

10. The battery pack real-time detection and active equalization device according to claim 1, characterized in that: It also includes a temperature control system, a power supply system and a communication monitoring system. The temperature control system includes a multi-stage temperature detection unit and a fan control unit. The power supply system includes a communication isolation power supply unit, a control power supply unit, a working power supply unit and a supplementary charging power supply unit. The communication monitoring system includes an isolation communication unit, a human-machine interface unit and a DCS background monitoring unit.

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