Implementation principle of prepayment function for smart meters

The prepayment function of smart metering meters is implemented through four core mechanisms: balance control, real-time monitoring, remote communication, and secure encryption to achieve "payment before use". The specific implementation principle is as follows:

1、 Balance Control: The Core Logic of Prepaid Payment

Recharge and Storage

Users recharge their electricity bills through channels such as IC cards, mobile apps, and web pages, and the fund information is synchronized to the power company's cloud platform. The platform generates recharge instructions and sends them to the electricity meter through communication methods such as 4G/NB IoT. The security chip (such as encryption storage module) built into the electricity meter receives instructions, converts the recharge amount into electricity value, and stores it. The data is not lost after power failure.

Dynamic deduction of fees

The built-in microprocessor (MCU) in the electricity meter calculates the user's electricity consumption per second and dynamically deducts the balance based on "real-time electricity consumption x unit price". If tiered pricing is supported, the MCU will automatically switch gears based on electricity consumption (such as low first gear and high third gear) for segmented billing.

Threshold alarm and power outage

When the balance is lower than the preset value (such as 20 yuan), the electricity meter triggers an audible and visual alarm or reminds the user to recharge through APP/SMS. After the balance is reset to zero, the MCU sends instructions to the relay module to cut off the user circuit and stop power supply. After the user recharges, the platform issues a command to restore power supply, the relay closes, and electricity is restored.

2、 Real time monitoring: precise measurement and abnormal handling

Electronic Metrology Technology

The electric meter collects electrical energy signals through current transformers and voltage transformers, and obtains the electrical energy value after processing by high-precision metering chips. Compared to traditional induction meters, electronic meters have higher measurement accuracy (error ≤ ± 1%) and no mechanical wear issues.

Power quality monitoring

The electric meter monitors parameters such as voltage, current, and power factor in real-time to ensure measurement accuracy. If abnormalities are detected (such as voltage drops or sudden changes in current), the electricity meter will record the event and upload it to the platform for analysis by operation and maintenance personnel.

Exception handling mechanism

When communication is interrupted or balance data is abnormal, the meter automatically switches to "emergency mode" to provide temporary power supply (such as 1 hour) to avoid sudden power outages for users. Meanwhile, the electricity meter continues to attempt to reconnect with the platform and restore data synchronization.

3、 Remote Communication: Data Transmission and Instruction Issuance

communication module

The electricity meter integrates communication modules such as 4G/NB IoT/RS485, supporting real-time or timed uploading of electricity consumption data to the cloud platform. After receiving the data, the platform stores and analyzes it, and generates user bills, electricity usage reports, etc.

Remote command issuance

Users initiate recharge, query and other operations through the APP/web platform, and the platform generates corresponding instructions and issues them to the electricity meter. For example, after the user recharges, the platform converts the recharge amount into electricity value and sends it to the meter security chip through an encrypted channel to update the remaining balance.

Batch operation and compatibility

The platform supports batch setting of electricity prices, control of electricity meters, instrument configuration, and other operations to improve management efficiency. At the same time, the electricity meter is compatible with multiple communication protocols (such as DL/T 645, Modbus), making it easy to integrate with smart homes and energy management systems.

4、 Secure Encryption: Data Protection and Anti tampering

security chip

The electricity meter is equipped with an encrypted storage module that uses national encryption algorithms (such as SM4) to encrypt sensitive information such as balance and electricity consumption data, preventing data leakage or tampering.

Communication encryption

The data transmission between the electricity meter and the platform is encrypted using SSL/TLS protocol to ensure communication security. At the same time, the platform conducts multi factor authentication of user identity (such as password+SMS verification code) to prevent illegal operations.

Relay control safety

When the relay module receives MCU instructions, it will verify the legality of the instructions (such as checksum, digital signature) to prevent malicious attacks from causing false power outages.

5、 Application scenarios and advantages

residential electricity

Users can check their balance and electricity consumption at any time to avoid power outages due to overdue payments. For example, household users can set a balance threshold (such as 50 yuan) through the app, and automatically remind to recharge when the balance is below this value.

commercial electricity

Shopping malls, office buildings, and other scenarios can monitor the electricity usage of each merchant through the platform to achieve accurate billing. For example, a certain shopping mall managed merchants' electricity usage through prepaid meters, resulting in an 80% decrease in overdue rates.

industrial electricity

Factories can monitor equipment electricity usage in real-time through electricity meters to optimize production plans. For example, a steel plant used prepaid electricity meters to analyze high energy consuming equipment, saving an annual electricity fee of 2 million yuan.

Summary of Advantages

Convenience: Users can recharge and check anytime and anywhere, without the need for on-site operations.

Real time: Electricity consumption data and balance information are updated in real-time, and consumption is transparent.

Security: Multiple encryption and tamper proof design ensure data security.

Management efficiency: Reduce manual meter reading and fee collection costs, and improve service quality.