CN105223517A - The online balanced monitoring method of a kind of battery pack - Google Patents

Abstract

An on-line equalization monitoring method for storage battery packs relates to the field of electric power. The invention aims to solve the problem that some accumulators are overcharged and other accumulators are undercharged in the existing accumulators, and the existing capacity of the accumulators needs to be manually checked, the workload is large, and the efficiency is low. The present invention uses N battery modules in series to form a storage battery pack, uses N reverse discharge units to enable each battery module to discharge normally under open circuit conditions, and uses N battery activation units to monitor the internal resistance of each battery module. Use N equalization modules to monitor the voltage of each battery module in real time, use the acquisition control unit to collect the open circuit signal, internal resistance value, capacitance value and voltage value of each battery module in real time, and process them, and send the processing results to the main control box , the main control box exchanges data with the server through Ethernet, and uses the current Hall sensor to collect the charging and discharging current of the entire battery pack. It is used for battery pack balancing monitoring.

Description

A method for on-line equalization monitoring of battery packs

technical field

The invention relates to an on-line equalization monitoring method for a battery pack. belongs to the field of electricity.

Background technique

In the electric power industry, the role of the battery pack in the electric operating power supply is particularly important. Various units usually compare the battery to the last lifeline of safe operation. The equipment maintenance and management departments of each unit should pay attention to the maintenance of the battery from the perspective of ensuring operation quality, production safety and property safety. Other important loads provide power supply. Due to factors such as battery design, tooling equipment, and quality control before leaving the factory, the internal resistance, capacity, and self-discharge degree of each battery are different, but the floating charge current for each battery is exactly the same during use. In the operating power supply, there is no quality control management system for battery packs running. As a result, some batteries are overcharged while others are undercharged, leading to the phenomenon of falling off and deterioration of the active material of the battery, corrosion and vulcanization of the positive grid, which will make the whole battery The capacity of the battery pack is lost, the voltage is uneven, and the single battery is behind. This will bring great hidden dangers to safe production. When the power grid fails, battery power supply is needed, and the vicious accident that the battery fails to discharge electricity.

But at present, it is impossible to eliminate the phenomenon that some accumulators are overcharged while others are undercharged, and the capacity of the accumulators is allowed to decline and there is nothing to do. At the same time, due to the lack of necessary professional instruments and meters, the capacity test of the battery pack is still at the level of manual detection. Test maintenance. It is very common that the battery packs currently in use have not done a thorough capacity test since the project was completed and delivered. As the last pass of the electric power supply, if the battery is allowed to operate in an unknown state for a long time, there will be countless hidden dangers. With the passage of time, the service life of the battery increases, and the interruption accident caused by the battery will be hard to prevent.

Contents of the invention

The invention aims to solve the problem that some accumulators are overcharged and other accumulators are undercharged in the existing accumulators, and the capacity of the existing accumulators needs to be detected manually, resulting in heavy workload and low efficiency. An online equalization monitoring method for a battery pack is now provided.

An on-line balance monitoring method for a storage battery pack, which is implemented based on the following system, the system comprising N battery modules, N reverse discharge units, N battery activation units, N discharge capacity measuring units, and N balance module, N acquisition control units, main control box and current Hall sensor, N is a positive integer,

N battery modules are connected in series, and the two open-circuit signal input/output terminals of each reverse discharge unit are simultaneously connected to both ends of a battery module and two open-circuit signal output/input terminals of an acquisition control unit,

The two internal resistance detection signal input/output terminals of each battery activation unit are simultaneously connected to the two ends of a battery module and the two internal resistance detection signal output/input terminals of an acquisition control unit,

The two capacity detection signal input/output terminals of each discharge capacity measuring unit are simultaneously connected to the two ends of a battery module and the two capacity detection signal output/input terminals of an acquisition control unit,

The two voltage signal input/output terminals of each equalization module are simultaneously connected to the two ends of a battery module and the two voltage signal output/input terminals of an acquisition control unit,

The N acquisition control units are all connected to the main control box through the communication bus,

The current signal output terminal of the main control box is connected to the current signal input terminal of the current Hall sensor,

The voltage signal output terminal of the main control box is connected to the voltage signal input terminal of the voltage Hall sensor;

An online equalization monitoring method for battery packs based on the above system is as follows:

Step 1, using N collection and control units to collect the open circuit signal of each reverse discharge unit in real time, and control each reverse discharge unit so that each battery module can discharge normally under the condition of open circuit;

At the same time, N collection and control units collect the internal resistance of each battery activation unit in real time. When the internal resistance of the battery module is greater than the set value, the battery activation unit is controlled to activate the battery module.

At the same time, N collection and control units collect and control the capacity of each discharge capacity measurement unit in real time,

At the same time, N collection and control units collect the voltage of each equalization module in real time, and when the voltage of the battery module is greater than the set value, control the equalization module to discharge the battery module;

Step 2. All acquisition control units exchange information with the main control box through the communication bus,

Step 3: The main control box performs data interaction with the server through the Ethernet, and at the same time uses the current Hall sensor to collect the charging and discharging current of the entire battery pack, and uses the voltage Hall sensor to collect the voltage of the entire battery pack. The balanced voltage of each battery module realizes the online balanced monitoring of the battery pack.

The beneficial effects of the present invention are: each battery module is equipped with a detection and maintenance module, which includes a reverse discharge unit, a battery activation unit, a discharge capacity measurement unit, an equalization module and an acquisition control unit,

When the reverse discharge unit is used to open the battery, the battery pack can be discharged normally. When the battery module is in the open circuit state, the battery can be automatically bypassed to maintain the charge of the whole set of batteries when the whole set of batteries is in the state of charging or discharging. Discharge state; the battery activation unit is used to monitor the internal resistance of each battery module. When an increase in the internal resistance of the battery is detected, the battery will be activated for diagnosis and treatment, so as to detect problems in advance and solve the problem; the discharge capacity measurement unit does not need Perform deep discharge on each battery module without any manual wiring operation. It only takes a few minutes to detect the battery capacity. A balance module is used to monitor the voltage of each battery module. When the voltage of the battery module is greater than the expected value, the battery module Discharge is carried out to stabilize the voltage, thereby improving the service conditions of the battery and prolonging the life of the battery. Finally, the voltage signal of each equalization module, the internal resistance detection signal of each battery activation unit and each discharge signal are collected by the control unit. The capacity detection signal of the capacity measurement unit is collected, and transmitted to the main control box through the communication bus to realize control. The main control box adopts the standard of intelligent power equipment. Through the modeling of each single battery monitoring module, the IED node formed by the modeling is It is provided to upstream systems such as smart substation systems for unified operation of substations. The main control box sends the signal to the server through the Ethernet, and maintains each battery in the heart according to the command issued by the server. The current Hall sensor is used to monitor the charging and discharging current of the entire battery pack in real time, and the voltage Hall sensor is used to collect the data of the entire battery pack. According to the voltage of the entire battery pack, the equalization voltage of each battery module is set to realize online equalization monitoring of the battery pack. The system uses a balance module to implement one-to-one voltage adjustment for each single battery, ensuring that the voltage of each battery terminal in the battery pack is consistent, avoiding overcharging and undercharging, and actively responding to possible abnormalities and failures of the single battery. Deal with it, and prevent and reduce losses in advance before failures such as battery pack function failure occur.

Description of drawings

FIG. 1 is a schematic diagram of a method for on-line equalization monitoring of a battery pack described in the first embodiment.

detailed description

Specific Embodiment 1: This embodiment will be described in detail with reference to FIG. 1. The online balance monitoring method for battery packs described in this embodiment is implemented based on the following system. The system includes N battery modules 1 and N Reverse discharge unit 2, N battery activation units 3, N discharge capacity measurement units 4, N equalization modules 5, N acquisition control units 6, main control box 7 and current Hall sensor 8, N is a positive integer,

N battery modules 1 are connected in series, and the two open-circuit signal input/output terminals of each reverse discharge unit 2 are simultaneously connected to two ends of a battery module 1 and two open-circuit signal output/input terminals of an acquisition control unit 6,

The two internal resistance detection signal input/output terminals of each battery activation unit 3 are simultaneously connected to two ends of a battery module 1 and two internal resistance detection signal output/input terminals of an acquisition control unit 6,

The two capacity detection signal input/output terminals of each discharge capacity measuring unit 4 are simultaneously connected to the two ends of a battery module 1 and the two capacity detection signal output/input terminals of an acquisition control unit 6,

The two voltage signal input/output ends of each equalization module 5 are simultaneously connected to two ends of a battery module 1 and two voltage signal output/input ends of an acquisition control unit 6,

N collection control units 6 are all connected with the main control box 7 through the communication bus,

The current signal output terminal of the main control box 7 is connected to the current signal input terminal of the current Hall sensor 8,

The voltage signal output end of the main control box 7 is connected to the voltage signal input end of the voltage Hall sensor 9;

An online equalization monitoring method for battery packs based on the above system is as follows:

Step 1, using N collection and control units 6 to collect the open-circuit signal of each reverse discharge unit 2 in real time, and control each reverse discharge unit 2 so that each battery module 1 can discharge normally in the case of an open circuit;

At the same time, N acquisition control units 6 collect the internal resistance of each battery activation unit 3 in real time, and when the internal resistance of the battery module 1 is greater than the set value, control the battery activation unit 3 to activate the battery module 1,

At the same time, N collection control units 6 collect and control the capacity of each discharge capacity measuring unit 4 in real time,

At the same time, N collection control units 6 collect the voltage of each equalization module 5 in real time, and when the voltage of the battery module 1 is greater than the set value, control the equalization module 5 to discharge the battery module 1;

Step 2, all acquisition control units 6 perform information interaction with the main control box 7 through the communication bus,

Step 3: The main control box 7 performs data interaction with the server through Ethernet, and at the same time uses the current Hall sensor 8 to collect the charging and discharging current of the entire battery pack, and uses the voltage Hall sensor 9 to collect the voltage of the entire battery pack. The voltage sets the balanced voltage of each battery module to realize online balanced monitoring of the battery pack.

In this embodiment, the main functions and characteristics of the system:

1. Battery online detection

The content of battery online detection includes battery pack voltage real-time detection, battery pack current real-time detection, single cell voltage detection, single cell internal resistance detection, single cell capacity detection, intelligent module temperature monitoring, and ambient temperature monitoring. It can detect the internal resistance of each battery online, judge the quality of the battery, and predict the capacity and life of the battery. Online real-time monitoring of single battery voltage, total voltage, current, and ambient temperature; internal resistance can be measured automatically on a regular basis, and the measurement process does not require manual intervention.

2. Battery online protection

The content of battery online protection includes single battery electronic backup and busbar voltage loss protection.

The digital protection and equalization module implements one-to-one electronic backup for each single battery. When the internal resistance of the battery increases abnormally and approaches an open circuit, the module can automatically bypass the faulty battery to avoid DC bus voltage loss. The bypass current of each protection module allows 100A for one hour and 200A for one minute without damage. During the discharge process of AC power outage, at most 5 batteries are allowed to be opened successively or at the same time without affecting the discharge of the battery pack.

3. Battery online balance

The content of battery online equalization includes the voltage limiting function of single battery and the automatic voltage equalization function of batteries in the same group. The digital protection and equalization module implements one-to-one voltage regulation for each single battery to ensure that the terminal voltage of each battery in the battery pack is consistent and avoid overcharging and undercharging.

4. Battery online maintenance

The content of battery online equalization includes single battery online activation, single battery online checking discharge, program-controlled automatic activation, and battery discharge cycle counting.

On-line activation of individual batteries refers to remote or local control of individual batteries to be activated online in sequence. Programmable automatic activation of individual batteries can be set. During the activation process, the battery pack can maintain more than 99.4% of its working capacity at any time. DC bus voltage loss.

On-line checking discharge of single battery refers to the online checking discharge of single battery controlled by remote or local in sequence, during the discharge process, the battery pack maintains more than 99.4% of its working capacity at any time, and the AC power failure at any time will not cause the DC bus to lose voltage.

5. Battery online fault tolerance

The online fault tolerance of the storage battery refers to allowing mixed use of new and old batteries, and allowing mixed use of batteries from different manufacturers.

The server includes user management, user information setting, adding users, group management, etc., mainly used for authority setting, dry contact alarm output to facilitate access to other centralized monitoring systems, client expert data analysis, client database server, and log service records during operation Historical events, including device control events, user setting events, alarm records, etc., report service output daily report, monthly report.

Embodiment 2: This embodiment is a further description of the online balance monitoring method for battery packs described in Embodiment 1. In this embodiment, the communication bus is realized by RS458 or CAN bus.

Specific embodiment 3: This embodiment is a further description of a battery pack online equalization monitoring method described in specific embodiment 1. In this embodiment, the N equalization modules 5 are all realized by the equalization module of the model PJH-2 .

Embodiment 4: This embodiment is a further description of the battery pack online balance monitoring system described in Embodiment 1. In this embodiment, the number of battery modules is 108.

Embodiment 5: This embodiment is a further description of the on-line balance monitoring system for battery packs described in Embodiment 1. In this embodiment, in step 3, each battery pack is set according to the voltage of the entire battery pack. The process of equalizing the voltage of the module is:

Under the charging condition, the voltage Hall sensor is used to collect the actual voltage value of the battery pack, and the voltage value is divided by the number of battery modules in the battery pack, plus the voltage difference allowed to float upward, so as to obtain the balance of each battery module Voltage.

In this embodiment, the voltage Hall sensor is used to monitor the voltage of the entire battery pack, avoiding the cumulative error caused by only summing the individual voltages of the batteries in the pack

Because the requirements for setting the equalization voltage of each battery are relatively precise, it is necessary to calculate the equalization target value of each battery. The calculation method is to collect the actual voltage value of the battery pack under charging conditions, and divide the voltage value by the The number of batteries, plus the voltage difference allowed to float upward.

For example, the charging voltage of the whole group of batteries is 235V, and there are 108 fast batteries in the group, then the real-time charging equalization target value is 235/108+0.05=2.22V, where 0.05 is the allowed upward floating voltage value, which can be obtained by querying the empirical value table.

Claims (5)

1. the online balanced monitoring method of battery pack, the method realizes based on following system, described system comprises N number of battery module (1), N number of back discharge unit (2), N number of cell activation unit (3), N number of electric discharge survey appearance unit (4), N number of balance module (5), N number of collection control module (6), Main Control Tank (7), current Hall sensor (8) and voltage hall sensor (9), N is positive integer

N number of battery module (1) is connected, two open circuit signaling input/output terminals of each back discharge unit (2) connect the two ends of a battery module (1) and two open circuit signaling input/output ends of collection control module (6) simultaneously

Two internal resistance detection signal input/output terminals of each cell activation unit (3) connect the two ends of a battery module (1) and two internal resistance detection signal input/output ends of collection control module (6) simultaneously,

Each electric discharge is surveyed two the capacity check signal input/output terminals holding unit (4) and is connected the two ends of a battery module (1) and two capacity check signal input/output ends of collection control module (6) simultaneously,

Two voltage signal input/output terminals of each balance module (5) connect the two ends of a battery module (1) and two voltage signal input/output ends of collection control module (6) simultaneously,

N number of collection control module (6) is all connected with Main Control Tank (7) by communication bus,

The current signal output end of Main Control Tank (7) connects the current signal input end of current Hall sensor (8),

The voltage signal output end of Main Control Tank (7) connects the voltage signal inputs of voltage hall sensor (9);

It is characterized in that, the online balanced monitoring method of a kind of battery pack based on said system is:

Step one, adopt the open circuit signaling of each back discharge unit (2) of N number of collection control module (6) Real-time Collection, and control each back discharge unit (2) and make each battery module (1) in the case of an open circuit, can regular picture;

Simultaneously, the internal resistance of each cell activation unit (3) of N number of collection control module (6) Real-time Collection, when the internal resistance of battery module (1) is greater than setting value, controls cell activation unit (3) and activation process is carried out to battery module (1)

Meanwhile, N number of collection control module (6) Real-time Collection also controls the capacity that appearance unit (4) is surveyed in each electric discharge,

Simultaneously, the voltage of each balance module of N number of collection control module (6) Real-time Collection (5), when the voltage of battery module (1) is greater than setting value, controls balance module (5) and battery module (1) is discharged;

Step 2, all collection control modules (6) carry out information interaction by communication bus and Main Control Tank (7),

Step 3, Main Control Tank (7) carry out data interaction by Ethernet and server, adopt current Hall sensor (8) to gather the charging and discharging currents of whole battery pack simultaneously, voltage hall sensor (9) is adopted to gather the voltage of whole battery pack, the equalizing voltage of each every block battery module is set according to this whole accumulator battery voltage, realizes the online balanced monitoring of battery pack.

2. the online balanced monitoring system of a kind of battery pack according to claim 1, is characterized in that, communication bus adopts RS458 or CAN to realize.

3. the online balanced monitoring system of a kind of battery pack according to claim 1, is characterized in that, N number of balance module (5) all adopt model be PJH-2 balance module realize.

4. the online balanced monitoring system of a kind of battery pack according to claim 1, is characterized in that, the number of battery module is 108.

5. the online balanced monitoring system of a kind of battery pack according to claim 1, is characterized in that, in step 3, the process arranging the equalizing voltage of each every block battery module according to this whole accumulator battery voltage is:

Under charging operating mode, adopt voltage hall sensor to gather battery pack actual voltage value, this magnitude of voltage, divided by battery module number in electric battery, adds the voltage difference allowing upwards to float, thus obtains the equalizing voltage of every block battery module.