Electricity meters are used to measure the amount of electricity that is consumed by consumers. They are essential for the accurate billing of energy amounts and thus for the quality and reliability of power supplies to users. Various tests are required in order to ensure that the electricity meters are able to accurately and reliably record energy consumption. This is why it is important that the energy meters are tested and verified thoroughly.
The Single-phase Energy Meter Test Bench can be used to verify the accuracy of a smart meter and its corresponding operating values in accordance with relevant regulations and standards.
This testing equipment combines a meter tester, a reference source and a control computer.
During the test the following values are recorded in the smart meter: voltage and current levels, voltage and current angle, frequency, active power, reactive power and apparent power. The maximum absolute deviations and standard deviations of the measured values vary in a wide range. However, they are always below the maximum tolerances of the smart meter.
In addition, a curve display is available to show the actual values of all voltage and current channels. It also offers the possibility to determine whether the electrical signals have been distorted by harmonics. The display of these harmonics can be set according to the requirements of the customer.
It is also possible to set the measuring intervals for a load profile and operational value acquisition. The measurement intervals (MI) can be varied between one and 60 minutes. The device has a memory that stores positive reactive and active power.
There are many different kinds of meter test equipment. From the smallest devices that are the size of a single-phase meter, to customised semi-automatic devices with over 40 measuring stations. They are designed for use in design, diagnostics, quality control and monitoring.
They include oscilloscopes, multimeters and test bench power supplies, thermocouple probes and test leads with function generators as well as barometers, data loggers and sound level meters.
The test bench can be used to determine errors in the averaging of the smart meter and its operating values as a basis for further research. This consists of three steps:
In the first step, operational values are recorded by precise measurement units under real conditions for different scenarios. Then the fluctuations of these values are analyzed with regard to their change rate in amount and time intervals. The results of these calculations are then compared to the values of a real meter, which was previously calibrated to a reference standard.
In this way, a comprehensive test bench concept has been created which is based on the legal regulations, industry standards and occupational health and safety rules.
It is a valid and practical solution for the verification of the accuracy of a smart meter and therefore represents equally high standards for an official calibration inspection.