CN107728079A - A kind of photovoltaic energy storage battery rapid detection system - Google Patents

Abstract

The invention discloses a photovoltaic energy storage battery rapid detection system, which includes a microcomputer device and a signal acquisition circuit, the signal acquisition circuit includes a voltage detection circuit and an internal resistance detection circuit, and a single-chip microcomputer in the microcomputer device is electrically connected to the voltage detection circuit and the internal resistance detection circuit And transmit the collected information to the computer in the microcomputer device. The photovoltaic energy storage battery rapid detection system in the present invention can detect the failure of the photovoltaic energy storage battery, judge whether the battery is invalid, and can perform strict judgment and quantitative analysis of the repairable and irreparable failures, and the energy storage The repair of the battery provides a basis for repair. It enables the staff to troubleshoot the different failure types of the battery in time, so as to ensure the normal energy storage and operation of the entire photovoltaic energy storage battery.

Description

A rapid detection system for photovoltaic energy storage batteries

technical field

The invention relates to the technical field of battery detection, in particular to a rapid detection system for photovoltaic energy storage batteries.

Background technique

The development and utilization of new energy sources have attracted widespread attention, especially the rapid development of photovoltaic power generation. Most of the energy storage batteries used in photovoltaic power generation are lead-acid batteries, and the management of batteries is too simple. Most of the rapid detection and evaluation of photovoltaic energy storage systems are judged by perceptual knowledge, and there is no repairable failure of energy storage. Strict determination and quantitative analysis of irreparable failures will virtually increase the cost of the energy storage system.

Contents of the invention

The purpose of the present invention is to provide a rapid detection system for photovoltaic energy storage batteries to solve the problems in the above-mentioned prior art. While performing rapid detection of photovoltaic energy storage systems, it can also detect repairable failures and irreparable failures of energy storage batteries. Carry out strict judgment and quantitative analysis of type failures, and provide repair basis for the repair of energy storage batteries.

In order to achieve the above object, the present invention provides the following solution: the present invention provides a photovoltaic energy storage battery rapid detection system, including a microcomputer device and a signal acquisition circuit, the signal acquisition circuit includes a voltage detection circuit and an internal resistance detection circuit, the The single-chip microcomputer in the microcomputer device is electrically connected with the voltage detection circuit and the internal resistance detection circuit and transmits the collected information to the computer in the microcomputer device.

Optionally, the internal resistance detection circuit uses a battery internal resistance measuring instrument.

Optionally, the voltage detection circuit adopts a differential amplifier circuit, and the differential amplifier circuit includes an operational amplifier and four resistors.

Optionally, the detection system further includes a voltage follower, and the voltage follower is connected to the differential amplifier circuit.

Optionally, the voltage follower is also connected with a limiter circuit.

Optionally, the signal acquisition circuit also includes a current detection circuit, the current detection circuit uses a Hall current sensor, the voltage signal output by the Hall current sensor enters the voltage follower, and finally passes through the conversion circuit and the The above MCU connection.

Optionally, the signal acquisition circuit further includes a temperature detection circuit, the temperature detection circuit adopts a digital temperature sensor, and the temperature detection circuit is signal-connected to the single-chip microcomputer.

Optionally, the detection system further includes a single load detection circuit, and the load detection circuit includes a multimeter and a load electrical appliance.

Compared with the prior art, the present invention has achieved the following technical effects:

The photovoltaic energy storage battery rapid detection system in the present invention can detect the failure of the photovoltaic energy storage battery, judge whether the battery is invalid, and can perform strict judgment and quantitative analysis of the repairable and irreparable failures, and the energy storage The repair of the battery provides a basis for repair. It enables the staff to troubleshoot the different failure types of the battery in time, so as to ensure the normal energy storage and operation of the entire photovoltaic energy storage battery.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without paying creative labor.

Fig. 1 is a processing flowchart of the rapid detection system for photovoltaic energy storage batteries in the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The purpose of the present invention is to provide a rapid detection system for photovoltaic energy storage batteries to solve the problems in the above-mentioned prior art. While performing rapid detection of photovoltaic energy storage systems, it can also detect repairable failures and irreparable failures of energy storage batteries. Carry out strict judgment and quantitative analysis of type failures, and provide repair basis for the repair of energy storage batteries.

The photovoltaic energy storage battery rapid detection system provided by the present invention includes a microcomputer device and a signal acquisition circuit, the signal acquisition circuit includes a voltage detection circuit and an internal resistance detection circuit, and the single-chip microcomputer in the microcomputer device is electrically connected to the voltage detection circuit and the internal resistance detection circuit. The collected information is transmitted to the computer in the microcomputer device.

Detect the energy storage battery through the voltage detection circuit and internal resistance detection circuit in the signal acquisition circuit, judge whether the voltage and internal resistance of the energy storage battery are in a failure state, and judge the failure of the battery according to the displayed voltage value and internal resistance value The degree, so that the information is fed back to the computer through the single-chip microcomputer, which is convenient for the staff to monitor and judge.

In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Please refer to FIG. 1 , wherein FIG. 1 is a processing flow chart of the rapid detection system for photovoltaic energy storage batteries in the present invention.

There are many failure forms of photovoltaic energy storage batteries. This invention takes the commonly used energy storage lead-acid batteries as the research object. The failure forms of lead-acid batteries mainly include dehydration, sulfation, softening of plates, grid corrosion, short circuit, and open circuit. , thermal runaway, non-antimony effect, appearance expansion and damage, and normal use reaching the service life of the battery. Some cases are repairable while others are not. The present invention detects and analyzes the realization of the above-mentioned centralized battery, can find out the cause of failure of the battery in time, and make corresponding countermeasures, repair and use the repairable battery in time, and replace the irreparable battery in time , does not affect the normal operation of the entire set of energy storage batteries.

In the photovoltaic energy storage battery rapid detection system of the present invention, the signal acquisition circuit includes a voltage detection circuit, an internal resistance detection circuit, and a temperature detection circuit, and the failure degree of the battery is detected by setting the above circuit and combining the needs of the battery detection process .

First, the voltage at both ends of the energy storage battery is detected by the voltage detection circuit, and the differential amplifier circuit is a circuit that amplifies the difference between the signals applied to the two input terminals and then serves as an output circuit. The basic differential amplifier circuit consists of an operational amplifier and four resistors. The first stage of the circuit is a differential amplifier circuit, and the second stage is a voltage follower. In order to prevent the surge voltage from damaging the A/D port of the microcontroller before output, a The limiter circuit, according to the requirements of the microcontroller for collecting voltage, can realize the voltage detection of the energy storage battery by selecting a suitable resistor. Whether the voltage of the energy storage battery reaches the failure voltage is detected by a voltage detection circuit.

Then, the internal resistance detection is performed on the energy storage battery whose detected voltage reaches the failure voltage after detection by the overvoltage detection circuit.

Faults of valve-regulated sealed batteries, such as grid corrosion and growth, poor contact, and reduced active material availability, are mainly manifested in the increase in battery resistance and the decrease in conductance. Therefore, the level of resistance or conductance can provide a reflection of battery failure and Available information on degree of use.

The measurement method of the battery internal resistance measuring instrument is to use an AC generator to inject a low-frequency 20-30 Hz or 60 Hz AC signal into the battery cell or battery pack, measure the AC current passing through the battery and the AC voltage at both ends of each battery, and then Calculate the I/U or Vac/lac ratio, then get the conductance or resistance value of the battery, and display this value. That is, the battery internal resistance measuring instrument injects an AC signal into the battery to measure the AC voltage at both ends of the battery and the current passing through the battery. If there is a certain amount of ripple voltage on the battery pack, in many cases offline testing must be done or steps must be taken to eliminate the ripple.

An internal resistance detection circuit is used to detect the internal resistance of the energy storage battery to determine whether the resistance of the energy storage battery has reached a failure value.

When the detected voltage and resistance of the energy storage battery are all failure values, the failure cause is further judged, and whether the failure cause is a repairable failure or an irreparable failure.

Judgment of short circuit of energy storage battery

The energy storage battery is composed of several batteries connected in series. The short circuit fault of the energy storage battery refers to the short circuit of the positive and negative electrodes in a single battery. Between the positive and negative plates that are superimposed on each other, under normal circumstances, it must be kept in an inactive state, so that a potential difference can be generated in the electrolyte to form the positive and negative electrodes of the electrochemical reaction. In order to reduce the volume of the battery during manufacture and improve the anti-vibration ability of the battery during movement, the positive and negative plates in the casing must be kept in a compressed state. If the surface of the plate is uneven during manufacturing, if there are raised bumps, or if a large sharp conductive substance is clamped during assembly, the insulating separator will bear a relatively large extrusion force. Under the dual effects of vibration and extended service time, a certain point of the positive and negative plates inside the battery is directly connected (equivalent to short-circuiting the positive and negative electrodes outside the battery), causing the parallel positive and negative active materials to produce electrochemical discharge reactions, and finally become into lead sulfate, which cannot be restored during charging.

According to the state of the battery, once it is found that the terminal voltage value of the battery is always 2V or its multiple smaller than that of other batteries, it can be confirmed that a single battery in the battery has a short-circuit fault.

There are other reasons for the single failure of the battery, such as large charge and discharge currents that lead to plate bending and deformation, resulting in short circuit damage to the separator (large charge and discharge currents lead to plate bending and deformation, active material expansion, shedding and accumulation short circuit, or poor manufacturing quality of the plates. , The active material falls off early, and the accumulation short circuit), the conductive material falling into the battery makes the internal short circuit of the battery, etc.

The method of confirming the fault cell: use the pole terminal and liquid injection port outside the battery, and use a voltmeter to measure the voltage value of the pole terminal and the bus bar in the liquid injection port to find the fault cell. When operating, pay attention to distinguish whether it is in contact with the positive bus bar or the negative bus bar. The surface of the positive busbar generally has poor contact with the stylus during _PbO2 measurement. The surface of the negative busbar is Pb, and the work of stylus contact measurement is relatively easy. Therefore, try to choose the pole terminal and negative bus bar outside the battery.

If it is determined that conductive substances have fallen into the battery, the battery can be turned upside down, and the conductive substances can be poured out from the liquid injection port. For batteries with early-stage shedding and accumulation of short-circuit faults, it can be eliminated by adding electrolyte to rinse and eliminate the deposits, but because the capacity of the single-cell battery becomes smaller after the active material falls off, the performance parameters of each monomer are inconsistent. So it doesn't make much sense to fix it.

Judgment of failure of open circuit (open circuit) of energy storage battery

The internal open circuit fault of the energy storage battery means that the circuit that can conduct current is disconnected, so that the normal active material participates in the electrochemical reaction of charging and discharging, and the current cannot pass through.

Use a light bulb and a multimeter to check the terminal voltage of a single battery when it is loaded. If there is no voltage when loaded, it is judged that the internal battery is open. If the open circuit fault occurs at the pole terminal of the bus bar and the battery, it can be repaired. First check whether there is an open circuit at the resin potting of the pole terminal, dig out the epoxy resin on the surface of the open circuit, replace the pole or re-weld the lead wire to restore the performance of the battery. If it is confirmed that the open circuit fault is caused by cross-welding of busbars or through-wall welding inside the battery, the battery must be replaced.

Judgment of plate sulfation

The failure of sulfation is characterized by the reduction of active material on the plate, high resistance, and a decrease in the relative density of the electrolyte. By checking the terminal voltage of the fully charged battery, it can be checked whether the energy storage battery is sulfated. If the terminal voltage of the fully charged energy storage battery drops significantly, it can be judged that sulfation of the plate has occurred inside the battery.

Once the battery is sulphated, the situation is not too serious, and hydrotherapy can be used to try to repair it.

Judgment of thermal runaway

During the charging process, the recombination reaction in the battery will generate a large amount of heat energy. Due to the sealed structure of the battery, the heat is not easy to dissipate, resulting in the failure of the battery due to excessive temperature rise.

Through the digital temperature sensor in the temperature detection circuit, in order to reduce interference, the connection adopts twisted pair, and through the access to the single bus, the temperature is transmitted back to the single chip microcomputer for judgment and further display.

It should be noted that for different failure types of energy storage batteries, targeted detection devices can be used, which will not be described one by one in the embodiments of the present invention. It is easy to think of setting on the basis of the present invention, therefore, also within the scope of protection of the present invention; In addition, in the present invention, the selection of specific measuring instruments in the voltage detection circuit, internal resistance detection circuit and temperature detection circuit can also be based on The model or type can be replaced according to actual needs, as long as the corresponding detection requirements can be met, and it also falls within the scope of protection of the present invention.

In the present invention, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method and core idea of the present invention; meanwhile, for those of ordinary skill in the art, according to the present invention The idea of the invention will have changes in the specific implementation and scope of application. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (8)

1. A kind of 1. photovoltaic energy storage battery rapid detection system, it is characterised in that：Including microcomputer apparatus and signal acquisition circuit, institute Stating signal acquisition circuit includes voltage detecting circuit and internal resistance detection circuit, the single-chip microcomputer in the microcomputer apparatus and the electricity Pressure detection circuit and the electrical connection of internal resistance detection circuit and the computer for giving the information transmission being collected into the microcomputer apparatus.
2. 2. photovoltaic energy storage battery rapid detection system according to claim 1, it is characterised in that：The internal resistance detection circuit Using internal resistance of cell measuring instrument.
3. 3. photovoltaic energy storage battery rapid detection system according to claim 1, it is characterised in that：The voltage detecting circuit Using differential amplifier circuit, the differential amplifier circuit includes an operational amplifier and four resistance.
4. 4. photovoltaic energy storage battery rapid detection system according to claim 3, it is characterised in that：In the detecting system also Include voltage follower, the voltage follower is connected with the differential amplifier circuit.
5. 5. photovoltaic energy storage battery rapid detection system according to claim 4, it is characterised in that：The voltage follower is also It is connected with an amplitude limiter circuit.
6. 6. photovoltaic energy storage battery rapid detection system according to claim 5, it is characterised in that：The signal acquisition circuit Also include current detection circuit, the current detection circuit uses Hall current sensor, and the Hall current sensor is defeated The voltage signal gone out enters the voltage follower, and last converted circuit is connected with the single-chip microcomputer.
7. 7. photovoltaic energy storage battery rapid detection system according to claim 1, it is characterised in that：The signal acquisition circuit Also include temperature sensing circuit, the temperature sensing circuit uses digital temperature sensor, the temperature sensing circuit with it is described Single-chip microcomputer signal connects.
8. 8. photovoltaic energy storage battery rapid detection system according to claim 1, it is characterised in that：In the detecting system also Including single band load detection circuit, the band, which carries detection circuit, includes universal meter and with load electrical equipment.