Measurement chip and measurement accuracy of electric energy meter
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1、 The working principle of metrology chips: the cornerstone of high-precision measurement
The measuring chip samples current and voltage signals, amplifies and filters them through analog circuits, converts them into digital signals, and then integrates them through digital circuits to finally calculate the energy consumption. This process involves the following key technologies:
High precision sampling: using current transformers (CT) or Hall sensors to convert high currents into low voltage signals, and voltage dividers to obtain low voltage signals, ensuring good linearity of the signals within the measurement range.
Anti interference design: By using digital filtering algorithms to eliminate harmonic and noise interference in the power grid, especially in environments with large fluctuations in rural power grids, measurement stability can be significantly improved.
Dynamic calibration: Some chips have built-in temperature compensation and self calibration functions, which can automatically correct the impact of environmental temperature and humidity changes on the sensor and reduce error drift.
2、 The core function of metrology chips: upgrading from accuracy to intelligence
Basic measurement function:
Multi parameter measurement: not only calculates active energy, but also measures reactive power, power factor, voltage/current effective value, etc., providing comprehensive data for rural electricity analysis.
Wide range design: Supports a current range from a few amps to one hundred amps, adapting to changes in electricity load in rural households and small workshops, and avoiding measurement distortion caused by overload.
Security protection function:
Data encryption: Adopting encryption algorithms such as AES128 to prevent remote meter reading data from being tampered with and protect the electricity rights of rural users.
Lightning protection design: By optimizing circuit layout and adding protective components, the risk of chip damage from lightning strikes is reduced, and the service life of the electricity meter is extended.
Intelligent expansion:
Communication interface: Integrated with RS485, LoRa and other modules, supporting real-time interaction with intelligent distribution boxes or cloud platforms, realizing remote cost control, abnormal power consumption alarm and other functions.
Edge computing capability: some chips can process power consumption data locally, identify abnormal modes such as no-load and leakage, and reduce the cost of manual inspection.
3、 Key factors affecting measurement accuracy: chip selection and matching design
Chip performance selection:
Accuracy level: Priority should be given to selecting chips with 0.5S or higher accuracy to meet the measurement requirements of rural trade settlement meters.
Starting current: Low starting current (such as ≤ 0.4% Ib) can ensure accurate measurement of small load electricity (such as LED lights) and avoid the phenomenon of "power theft".
Peripheral circuit design:
Transformer matching: The current transformer ratio needs to be matched with the chip range to avoid nonlinear errors caused by excessive secondary load.
Power stability: Adopting a wide voltage input power module to prevent voltage fluctuations in rural power grids from affecting the working status of chips.
Environmental adaptability:
Temperature range: Select chips with a working temperature of -40 ℃~+85 ℃ to adapt to the large temperature difference between day and night in rural areas.
Moisture proof treatment: Apply three proof paint outside the chip package to prevent short circuits or corrosion caused by moisture.
4、 Future trend: Chip technology drives rural electricity meter upgrade
SoC integration: Integrating functions such as metering, communication, and control into a single chip, reducing the size and cost of electricity meters, and facilitating large-scale deployment in rural areas.
AI algorithm application: By analyzing electricity consumption patterns through machine learning, predicting peak loads, and providing data support for rural power grid planning.
Integration of blockchain technology: Utilizing the tamper proof nature of blockchain to achieve transparent measurement of distributed energy transactions (such as photovoltaic power generation connected to the grid).
