Application of aaa battery alkalineonline monitoring technology in substations

　　1 Overview

　　The aaa battery alkalinein the substation plays an extremely important role as a backup power supply in the power system. Once there is a problem with the aaa battery alkalinepack during AC power loss or other accidents, the power supply system will be paralyzed, causing equipment outage and other major operating accidents. In recent years, with the widespread use of valve-regulated sealed lead-acid batteries (hereinafter referred to as valve-regulated batteries) in power systems, accidents caused by aaa battery alkalinefailures have occurred from time to time, even causing fires and station-wide power outages. Due to the special valve-controlled sealing structure of valve-regulated batteries, we cannot accurately grasp the health status of the batteries. Its "maintenance-free" advantage has become a shortcoming and difficulty in aaa battery alkalineoperation and management. While improving aaa battery alkalineperformance and reducing maintenance workload, how to quickly and effectively detect early aaa battery alkalinefailure and predict aaa battery alkalineperformance change trends has become a new topic in aaa battery alkalineoperation management. At present, in addition to conventional maintenance and detection methods such as verification discharge and terminal voltage measurement, some new detection methods have emerged with the development of technology. The new detection technology of aaa battery alkalineonline monitoring has begun to be gradually applied to power systems.

　　2Application of aaa battery alkalineonline monitoring technology

　　The most commonly used aaa battery alkalineonline monitoring device in power system substations is the aaa battery alkalineinspection instrument. The aaa battery alkalineinspection instrument is divided into two types. One is the inspection instrument that measures the voltage of the aaa battery alkalinecell. Its structure is composed of a main control module and It consists of several acquisition modules. The main module receives commands from the monitor and sends aaa battery alkalinedata to the monitor of the DC equipment; each module in the acquisition module collects the voltage, current and temperature of 10 to 20 batteries; through the monitor of the DC charging equipment It can display the voltage of each single battery, determine the number of the faulty aaa battery alkalineand give an alarm. This type of aaa battery alkalinepatrol monitor is generally provided by DC equipment manufacturers. It is an optional device when ordering DC equipment. Due to its single function, it cannot test capacity, and its measurement accuracy is poor and it is prone to false alarms, which limits its widespread use. The test diagram is shown in Figure 1:

　　The other is a smart inspection instrument. In addition to measuring the cell voltage of the battery, the intelligent inspection instrument also has the function of measuring and displaying the capacity of the entire aaa battery alkalinepack and performing intelligent data analysis. The structure is similar to the above one, consisting of a host computer and a aaa battery alkalineacquisition module. The host computer can be placed directly in the aaa battery alkalineroom, and the data display and alarm functions can be sent to the display unit installed in the control room through communication lines. This type of aaa battery alkalineinspection instrument is generally produced by professional aaa battery alkalineinspection instrument manufacturers. Its terminal voltage monitoring part also has large errors and is prone to false alarms; capacity monitoring measures changes in aaa battery alkalinecurrent and terminal voltage when the aaa battery alkalineis discharging and charging. , and use these data to draw curves to analyze the characteristics of the battery; analyze the aaa battery alkalinecapacity through the changes in internal resistance and terminal voltage during charging and discharging. When the aaa battery alkalinepack is discharging, the greater the internal resistance, the lower the terminal voltage, and when charging The greater the internal resistance, the higher the terminal voltage. Find the aaa battery alkalinewith the worst characteristics, calculate the internal resistance according to Ohm's law, and depict which batteries in the aaa battery alkalinepack have the smallest capacity. Use the characteristic curve to calculate the capacity of the aaa battery alkalinepack. Since the charge and discharge current changes during operation, the internal resistance is not a constant value, and the calculated and analyzed capacity is not very accurate.

　　The aaa battery alkalineinspection instrument can mainly detect aaa battery alkalineshort circuit, open circuit and aaa battery alkalineabnormality, but it is difficult to detect the decrease of aaa battery alkalinecapacity. It can monitor the capacity in real time, but there is a big gap with the real capacity. With the in-depth research on valve-regulated sealed lead-acid batteries, the internal resistance of the aaa battery alkalinehas become an important indicator to measure the quality of the battery, and internal resistance detection has become an important means of aaa battery alkalinemaintenance. There is no strict mathematical relationship between internal resistance and aaa battery alkalinecapacity. The life and capacity of the aaa battery alkalinecannot be predicted based on the internal resistance value of a single battery. If the internal resistance of the aaa battery alkalinesuddenly increases, the capacity of the aaa battery alkalinewill change. By continuously testing the internal resistance test data Cumulative and quantitative analysis can infer aaa battery alkalinecapacity change trends and lifespan. Manual internal resistance testing is time-consuming and requires little test data. It is generally required once a year. Test data cannot be stored in time and retained for many years, and the analysis function is poor. Therefore, on the basis of aaa battery alkalineinspection, online internal resistance detection is added, and modern communication and computer technologies are used to establish an online intelligent aaa battery alkalinemonitoring system. The system mainly consists of three parts: data acquisition module, discharge module and monitoring unit. It has the functions of real-time monitoring of aaa battery alkalineoperating parameters (voltage, current, temperature), scheduled automatic test of aaa battery alkalineinternal resistance, static discharge measurement of aaa battery alkalinecapacity, comprehensive measurement and judgment of aaa battery alkalineperformance and Change trends and display alarm functions, the system can also achieve networked and intelligent management. as shown in picture 2.

　　Different from the aaa battery alkalineinspection instrument, a discharge module is added to this system. The discharge module can withstand a large impact current. It receives the discharge command from the monitoring host, connects the discharge circuit, and the aaa battery alkalinedischarges through the load. At the same time, the acquisition module will collect every As for the change of aaa battery alkalinevoltage, the internal resistance characteristic curve of each aaa battery alkalineis obtained in the host computer. The discharge module can also be used as a long-term discharge load to achieve verification testing of aaa battery alkalinecapacity and activation of the entire aaa battery alkalinepack. This system realizes all aspects of aaa battery alkalinemonitoring and maintenance management.

　　3 Problems in the application

　　The aaa battery alkalineonline monitoring device is a new means of aaa battery alkalinedetection and maintenance, which is especially needed for unattended substations. It can detect aaa battery alkalineproblems in a timely manner to reduce the labor intensity of operators and maintenance personnel. However, no matter what type of aaa battery alkalineonline monitoring device, there are the following problems in use, which affect the role of online monitoring and increase some maintenance work.

　　3.1 Measurement error of aaa battery alkalineterminal voltage

　　According to the requirements of the regulations, a high-precision 4.5-digit digital multimeter is used for daily measurement of the aaa battery alkalineterminal voltage. Generally, the measurement accuracy of the aaa battery alkalineDC voltage range of a high-precision multimeter is above 0.7%. The measurement accuracy mentioned in the product manual of most online aaa battery alkalinedevices It has reached more than 0.5%; the measurement value displayed is that the measurement terminal voltage value of some aaa battery alkalineonline devices is 2 digits after the decimal point, which has a large error with the regulatory requirements; although the measurement value of some devices can be to 3 digits after the decimal point, it is not consistent with the actual measurement using a meter. The values are quite different. Judging from the operation situation, the error in the online monitoring of the terminal voltage is random, and each numerical deviation is inconsistent, and the deviation value changes with changes in ambient temperature, float voltage, etc. Table 1 shows the on-site random inspection of several aaa battery alkalinefloat voltages, and the error between on-site test values and online measurement values. The on-site test uses a FLUK111 numerical multimeter with a DC range measurement accuracy of 0.7%, and the online measurement is a WXJ-16 patrol meter from Xuji Power Supply Company. Tester, test environment temperature is 25℃.

　　Judging from the random inspection, there is a large error between the on-site test value and the measured value of the inspection instrument, which can no longer truly reflect the voltage of the aaa battery alkalinecells. Electric power industry regulations require that the aaa battery alkalinefloat charge voltage is 2.23V-2.28V at 25°C. If the measurement error exceeds 10mV, it will have a certain impact on aaa battery alkalinedetection, making it impossible to detect some batteries with abnormal voltage, while batteries with normal voltage will be detected. Abnormal battery. At present, the state and the power industry have not formulated relevant standards for devices such as aaa battery alkalineonline monitoring, and the quality of various products cannot be verified. During operation and use, due to the lack of authenticity of the data, manual terminal voltage testing is still used for daily maintenance of the substation, and the online detection effect of the aaa battery alkalineis greatly weakened.

　　3.2 False alarm

　　There are many false alarms in aaa battery alkalineinspection instruments in use. In addition to alarms caused by measurement errors, there are also more alarms caused by faults in the measurement circuit. The measurement loop wiring method is to connect a collection line to the positive and negative poles of each battery. One end with the insurance is connected to the aaa battery alkalinepole bolt, and the other end is connected to the collection unit. During operation, it is often found that due to damage to the fuse and poor contact between the fuse and the connecting part, abnormal voltage detection results in an alarm. Most of the aaa battery alkalinecollection parts use fragile glass tubes. Due to the difference in size of the glass tubes, poor contact is prone to occur. The maintenance workload caused by these false alarms greatly increases, which not only does not reduce the labor intensity, but also increases the cost. Work less.

　　3.3 Internal resistance monitoring issues

　　Online internal resistance monitoring of the aaa battery alkalineuses the aaa battery alkalineto instantaneously discharge to the discharge module, measure the voltage difference at the moment when the aaa battery alkalineis powered off, and calculate the aaa battery alkalineinternal resistance (R internal resistance = △V/I). The internal resistance test principle is shown in Figure 3. Due to problems such as terminal voltage monitoring errors, current fluctuations during discharge, voltage compensation measurement technology before and after power outage, and power failure detection of online connection lines, the accuracy of online internal resistance monitoring is not high. At present, the ABLER portable internal resistance tester in the United States is widely used in China. The test accuracy of its online internal resistance test system is slightly worse than that of the portable one, but it is still better than other products currently in use.

　　4 Development of aaa battery alkalineonline monitoring technology

　　At present, the monitoring of valve-regulated lead-acid batteries has gradually become a hot spot. In particular, power systems, telecommunications, and mobile communication systems have put forward higher requirements for aaa battery alkalineonline monitoring technology to meet the safety and reliability of important systems. Online aaa battery alkalinemonitoring should improve system reliability from three aspects. On the one hand, monitoring can ensure that the aaa battery alkalineis in the correct operating state. For example, it can give correct prompts or warnings for aaa battery alkalineovercharge and undercharge status. On the other hand, monitoring can detect batteries that are about to fail, that is, short circuits, open circuits, and batteries with reduced capacity can be detected to provide timely prompts for processing. The third aspect of monitoring can use the online monitoring function to perform on-site maintenance of batteries, such as timely activation of abnormal batteries and regular verification discharges. Related maintenance work can be carried out without carrying many tools, reducing the workload. The labor intensity of personnel.

　　Online aaa battery alkalinemonitoring can also use communication means for network management (as shown in Figure 4). The aaa battery alkalinemonitoring at several stations or a region can be networked through optical fibers to establish a real-time remote intelligent aaa battery alkalinemonitoring network management system to achieve information Centralized and remote control enables operation and maintenance personnel, relevant personnel and management decision-makers to grasp the operation status and performance change trends of the batteries in each substation in real time through any terminal in the LAN using IE browsing, so that the batteries can be timely updated Maintenance also provides a reliable basis for "equipment status maintenance" and transforms "regular maintenance and maintenance" into "condition maintenance" to achieve scientific management of batteries and ensure reliable and safe operation of the system.

　　Of course, the development of aaa battery alkalineonline monitoring technology still requires research on high-precision detection methods, so that the values of various monitored parameters (terminal voltage, internal resistance, etc.) can reach the same level as manual detection instruments such as high-precision multimeters and portable internal resistance tests. It is the basis for the survival of aaa battery alkalineonline monitoring technology and the basic condition for widespread application. In addition, the improvement of monitoring technology is also the direction of future development. For example, the aaa battery alkalinecollection wiring should be more reasonable to reduce line losses; the collection line wiring should be simple and convenient to reduce false alarms caused by insurance. In short, aaa battery alkalineonline monitoring has its own advantages, as well as more extended functions, and its widespread application will be the future development trend.

　　5Conclusion

　　There are many shortcomings in the current traditional detection and maintenance methods, such as: poor manual measurement accuracy, easy to be affected by human factors, poor real-time performance (especially during the discharge process) and poor continuity, etc. Although the verification discharge test lags behind the battery, it is generally completed every year Once, it was impossible to find out-of-date batteries before the test, and it was impossible to guarantee that failure would not occur within one year after the test, and the workload was heavy. Therefore, the traditional detection and maintenance methods not only lacked sources of information, but also lacked professional comprehensive analysis methods, resulting in Failure to detect faults and hidden dangers in time poses serious threats to production and safety. The development of aaa battery alkalineonline monitoring technology has made it possible to replace traditional testing methods. It not only has monitoring functions, but also can realize comprehensive analysis and intelligent management. If the testing accuracy can be improved, it can be more widely used in power systems.

Read recommendations:

801752 720MAH 3.7V

22000mAh High Muting Rate Drone Battery.lifepo10 battery for solar energy storage direct sales

home powerwall lithium ion battery.Precautions for using lithium batteries

solar energy storage battery pack

4LR44 battery