IC card electric meter management system

Hu Guannan

Ankerui Electric Co., Ltd. Cable Company Shanghai Jiading

summaryThis article elaborates on the traditionalICThe main functions of card type prepaid energy meters are analyzed, including their application advantages and disadvantages; A detailed introduction is given to a prepaid energy meter, which expands its functions and promotes practical value after integrating communication technology and intelligent control technology, thus describing the possible technological development trends of prepaid energy meters.

keywords: Prepaid fees;electricity meter;application;analyze

Electricity bills are the main source of funding for power supply enterprises to maintain production and development, and timely recovery plays an important role in the capital circulation of power supply enterprises. Due to years ofThe electricity consumption model of "use electricity first, pay later", the wide range of electricity customers and the technical means of on-site power rationing, as well as the mismatch between supporting regulations and market economy, directly lead to huge risks for power supply enterprises in electricity fee recovery. Over the years, they have also invested manpower, financial resources, and operational pressure. In this context, prepaid energy meters have been widely used to better adapt to the reform of the power system.

Due to the immature application of early core associated communication technology, system compatibility has become an important obstacle to the promotion and application of remote automatic meter reading systems for energy metering management, especially the inconsistency between communication protocol compatibility and manufacturing standards.ICCard type prepaid energy meters, in the current environment, helplessly avoided the application bottleneck of communication technology.

one IC card electric meter management system

（1） Main Function Implementation

1Measurement function: single-phase time-sharing measurement of active energy; Save historical battery levels and have a battery freeze function.

2Multiple rate function: programmable time slot and multiple rate settings. The timing clock has temperature compensation function.

3 Communication function: equipped withRS485Interface and an infrared communication interface.RS485The interface is generally isolated from the inside of the electricity meter and has anti AC capabilities220VAccess protection design.

4Display function: LCD display, buttons can automatically cycle to display remaining amount, total electricity consumption, current electricity price and other information.

5Information retrieval for purchasing electricity function: One meter, one card, that is, one meter can only correspond to one purchasing card. When inserting a card for power transmission, the electricity consumption information in the meter is automatically copied back to the power purchase card; When purchasing electricity again,The information in the card is automatically written to the computer for archiving and data verification.

6Meter recharge prompt function: generally equipped with display alarm and power outage alarm, and added with load cut-off function.

7Overload control function: By setting a power threshold, it can achieve power-off control for load overload. The power-off time can be set in two ways: immediate power-off and delayed power-off. Pressing buttons or inserting cards can restore power.

8Prepaid control function: The electricity meter implements a management method of purchasing electricity first and then using it. When there is no electricity bill in the meter, the load switch inside the meter will automatically cut off the load power supply. After recharging the meter, it will be reconnected to restore the load power supply function. With continuous improvement, the overdraft function has been added, which allows for moderate overdraft according to actual conditions. Overdraft can be set, and after the overdraft is completed, the electricity meter will be powered off. The overdraft part will be automatically charged or reduced during the next electricity meter recharge.

9Anti hoarding electricity function: Due to the macroeconomic regulation of electricity pricing policies, in order to prevent excessive electricity (amount) from being charged into the meter, a hoarding electricity threshold is set in the meter to limit customers from charging too much electricity (amount) at once.

10Security protection function: generally usedCPUCard technology is used for system security design.CPUCard energy meter andCPUThe security authentication of the card is through the energy meterESAMThe module has been completed,CPUThe card energy meterMCUDuring the authentication process, it only plays a role in data transmission and does not participate in data encryption or decryption work. When selling electricity, a series of key authentication tests can be conducted to confirm the purchase of electricity cards, allow the writing of information on the purchase card, and allow the erasure of binary files.

（2） Its main application advantages

1Improve meter reading efficiency and accuracy. can be passed throughRS485Interface and infrared communication interface, using corresponding handheld meter readers for on-site batch recording. This plays a very important role in the current situation of a sharp increase in the number of energy meters managed by power supply enterprises.

2Effectively solve the problem of arrears. Significantly reduced the operating costs of electricity fee recovery work and enhanced the security of electricity fee fund recovery.

3Relieve the contradiction of difficult payment. The significantly increased number of customers and relatively concentrated payment periods make the traditional charging model prone to payment congestion. The application of prepaid energy meters effectively reduces the pressure of counter charges and service risks.

（3） Problems in the application

1Poor resistance to attacks.ICThe loss or damage of cards, especially their open onesICThe card read/write port is vulnerable to external attacks. After being attacked, it is difficult to obtain evidence and determine the failure of the control system in the table, which can easily lead to power disputes.

2 Difficulties in management. due toICThe suddenness and randomness of card purchase of electricity have increased the selling pressure on the power supply department. At the same time, in order to ensure the security of data, intelligent technology is widely usedCPUCard, itsCOSThe system and dynamic key authentication ensure data security while also increasing the management workload of the electricity management department. Moreover, multiple stages of argumentation increase the occurrence of unexpected failures.

3The adaptability of policy adjustments to electricity prices is not strong. The electricity price is determined at the time of purchase and written into the prepaid energy meterICThe electricity price stored in the card prepaid energy meter cannot be adjusted in real time, and each adjustment adds a lot of workload to the power supply enterprise, and customers are also prone to raise objections.

4Data collection is not timely. Unable to reflect customers' electricity usage status in real time, unable to effectively monitor electricity theft behavior, and unable to meet the real-time management needs of electricity management automation.

5 The expandability of the power purchase method is not high. withICThe prepaid system that uses cards as a data transmission medium is not easily linked to electricity purchasing methods such as telephone banking and online banking. Often, customers use their cards to purchase electricity at sales outlets, which reduces the quality of electricity marketing services and increases the workload of power supply companies. Therefore, in order to solveICThe problems and drawbacks of card prepaid energy meters in practical applications, coupled with the adoption of open communication protocols, are equivalent toIEC62056ofGB/T19882TheGB/ T19897National standards for "Automatic Meter Reading System" series; The compatibility issue of the communication system has been resolved. The breakthrough of the bottleneck of core related technologies has provided a vast and possibly unimaginable space for the remote application of prepaid energy meters.

two Integration of Prepaid Energy Meters and Remote Meter Reading Systems

（1） The basic communication methods in remote meter reading systems mainly include fiber optic communication, telephone line communicationRS485Bus, cable TV cable, Internet, power line carrier communication, instrument bus, satellite communicationGPRSandCDMAWait. All types of communication methods have their own advantages, disadvantages, and applicable areas. Based on the industry characteristics of power supply enterprises and the practical application of technologies such as low-voltage power line carrier spread spectrum, frequency hopping, forwarding relay (carrier meters can be dynamically set as routers or repeaters by local concentrators through power lines) and dedicated chips, the remote automatic meter reading system in low-voltage substation areas currently mostly adopts the centralized meter reading method of power line carrier+GPRSremote transmission+A comprehensive technical solution for prepaid energy meters.

(two)The system structure of the power line carrier centralized meter reading system consists of a centralized meter reading master station, a collector, a concentrator, an electricity meter, and other equipment. A dedicated network is established according to the on-site situation, and meter reading, control, and management of electricity consumption are carried out through software. The system consists of three physical layers and two link layers. The data collection of the main station adopts a star structure, which means that one power management center is responsible for multiple concentrators and serves as the management layer; From the main station to the data concentratorGPRSNetwork connectivity; Install concentrators in the substation area as the control layer; The concentrator is connected to each collector through low-voltage power lines, and the collector is installed in the meter box. The collector is connected to the customer's energy meter throughRS485The interface is connected in parallel to form the client layer.

（3） System features

1AdoptingPLC(Power line carrier) communication method: effectively utilizing the topology structure of the power grid, easy to construct.

2Basic data group: All customers included in the centralized reading system can be selected for reading (point reading, full reading), multi-point reading to form a basic data group, and various analyses (line loss, compound rate, load, etc.) can be conducted to meet customers' various intelligent management needs.

3Integration of software and hardware: The system design fully considers the needs and convenience of users. On the basis of fixed hardware, all system functions, management modifications, and operation additions (remote power control) are completed by backend software.

4It has the advantages of easy installation, high reliability, good safety, and strong maintainability. At the same time, the project cost is low, the system maintenance is simple, and the operating cost is low.

（4） Main functional applications

The remote prepaid electricity meter, in conjunction with the electricity management system, can achieve functions such as remote meter reading, remote prepayment, electricity theft prevention, and load management.

1 Remote meter reading

The main station can perform random meter reading and determine whether the on-site energy meter has malfunctioned and whether the customer's electricity consumption is abnormal based on the data collected. The main station can also read meters on a daily basis and transmit the retrieved data to the power marketing management information system for electricity bill calculation. At the same time, the main station can also remotely set the energy meter to report on-site data information on a regular basis.

2 Remote prepaid fee

Customers can purchase electricity in various forms, effectively avoiding payment peaks. When the remaining amount in the customer's table is0At this time, the meter outputs a trip signal to cause the internal relay or external load control switch to operate and cut off power, avoiding overdue behavior. The remote prepaid method is secure and reliable, avoiding the risk of being affected byICMalfunctions such as failure to read the card and information errors during card transmission. At the same time, when the electricity price is adjusted, the on-site electricity price parameters in bulk can be modified in a timely manner through the main station, ensuring that the on-site electricity price parameters are synchronized with the price adjustment.

3 Preventing electricity theft

When the parameters of the on-site electricity meter change or there are faults such as voltage loss, current loss, or incorrect wiring, the electricity meter can automatically report to the main station. The electricity inspection personnel can determine whether the customer is suspected of electricity theft based on the information uploaded by the electricity meter and promptly go to the site for inspection. This function can effectively prevent electricity theft and prevent it before it happens.

4Load management

The main station can collect voltage, current Perform load analysis and management on power, electricity, and other data. Based on current data, a load curve can be drawn to monitor changes in electrical load. The voltage qualification rate can be calculated based on voltage data. By setting active power limits in the table, customers can control their overloaded electricity consumption.

（5） Gain analysis

1Due to the use of remote meter reading, a significant amount of manpower costs for meter readers can be saved. At the same time, it can avoid errors in manual meter reading and timely detect meter faults, thereby improving service levels.

2Due to the implementation of prepaid fees, there has been a significant reduction in overdue behavior, an increase in electricity fee recovery rates, and a decrease in operational costs for on-site power restoration in electricity fee recovery management.

3Due to the ability to monitor the operation status of on-site electricity meters online, it can effectively prevent electricity theft and reduce unknown losses in electricity consumption.

4Due to automatic load control, the occurrence of overloading and meter burning is eliminated, while avoiding the phenomenon of customers failing to implement time of use electricity pricing and power rate assessment due to underreporting of electricity capacity.

three Application scenarios of Ankerui prepaid products

IC card electric meter management systemfunction

Pre paid electricity meter and electricity fee collection, control, and overdue trip; Provide a postpaid management module; Energy consumption analysis module;

Prepaid water fee collection for water meters, control measures, and close valves for overdue payments;

Rent and property management fees are collected, and overdue fees are blocked;

Sharing and collecting electricity bills in public areas;

Meter reading and measurement in public areas and substations;

prepaid+Integrated system for measuring building energy consumption and classified sub items of energy;

property management/Centralized financial control of real estate groups, with separate authority for subsidiary properties;

Wireless solution modification is convenient and easy to debug

four Product Selection

five Conclusion

Although the many drawbacks of traditional prepaid energy meters are becoming increasingly prominent and cannot meet the needs of modern electricity management, they still have a certain applicability in the short term, especially in regions with relatively dispersed customer groups. On the other hand, with the continuous development of society, prepaid energy meters will inevitably be more closely integrated with communication technology and intelligent control technology (such as remote prepaid energy meters based on mobile communication technology may completely replace traditional ones)ICScope of application for card type prepaid energy meters. For prepaid energy meters, it is an inevitable technological development trend to expand their horizons and have the function of "remote real-time intelligent control". For power supply enterprises, the promotion and application of the "remote real-time intelligent control" function will definitely continuously improve the level of daily electricity management and service quality.

References:

[1]Peng Lei, Application Analysis of Prepaid Energy Meters, Science Garden Forum

[2]Design and Implementation of Solemn Power Remote Meter Reading System[J] .Microcomputer information,2006

[3]Design and Application Manual for Enterprise Microgrid.2022.05edition