Today, I will introduce a national invention authorized patent-a method and system for compensating non-full-period sampling errors of digital electric energy meters. The patent was applied for by the State Grid Corporation of China, and the authorization was announced on March 8, 2017.

Content description

The invention relates to the technical field of electric energy meters, and more specifically, to a method and system for compensating non-full-period sampling errors of digital electric energy meters.

Background of the invention

The calculation of the electric quantity of the digital electric energy meter needs to be based on the full cycle sampling of the voltage and current signals, and the full cycle sampling needs to ensure that the sampling frequency is an integer multiple of the signal frequency, because the sampling frequency is the product of the power frequency (50HZ) and the number of sampling points Therefore, only need to ensure that the signal frequency is the power frequency.

However, due to the change of the grid load and the limited speed of the generator set, the signal frequency is generally higher or lower than 50HZ, so that the sampling frequency is no longer an integer multiple of the signal frequency, and the two are no longer synchronized, resulting in active power The calculation error, which in turn leads to the measurement error of the active electricity.

It can be seen that the sampling is non-periodic sampling is the main cause of measurement error. At present, in order to reduce the non-periodic sampling measurement error, the common solution is to use a frequency synchronization device (such as a digital phase locker, etc.) to achieve the sampling frequency Synchronize with the signal frequency to reduce measurement errors. However, the frequency synchronization device increases the hardware complexity of the digital electric energy meter. In addition, since the digital electric energy meter calculates electric energy based on the digital voltage and current signals provided by the electronic transformer, it is impossible to directly obtain frequency information. Therefore, how to provide a non-full-period sampling error compensation method for a digital electric energy meter to reduce the measurement error without increasing the hardware complexity of the digital electric energy meter is a technical problem to be solved urgently in this field.

Summary of the invention

In view of this, the present invention provides a method and system for compensating non-full-period sampling errors of a digital electric energy meter to solve the problem of increasing the complexity of the digital electric energy meter caused by the use of a frequency synchronization device.

How to compensate the non-full-period sampling error of the electric energy meter

A method for compensating non-full-period sampling errors of a digital electric energy meter, comprising: receiving a sampling value of one cycle transmitted by an electronic transformer, where the sampling value is the condition of the electronic transformer at a power frequency and a preset number of sampling points Next, the voltage signal and current signal of the power grid are sampled to obtain, and the sampled value includes the instantaneous voltage value and the instantaneous current value corresponding to each sampling point.

It can be seen from the above technical solution that the present invention provides a method and system for compensating the non-full-period sampling error of a digital electric energy meter, which uses the instantaneous voltage and current values ​​of one cycle measured by an electronic transformer, and uses zero-crossing. The detection algorithm calculates the current frequency of the current cycle. The compensation value of active power is calculated by substituting the current frequency, instantaneous value of voltage and instantaneous value of current into the mathematical analytic formula of non-periodic sampling error, which is based on the compensation value of active power and The active power of the current cycle obtained in advance can obtain the compensated active power, which achieves the purpose of reducing the measurement error. It can be seen that the present invention realizes the non-full-period sampling error compensation of the digital electric energy meter by adopting the technical means of calculating the compensation value of the active power. Since the sampling frequency and the signal frequency need not be synchronized during the compensation process, there is no need to use The frequency synchronization device achieves the purpose of reducing measurement errors without increasing the hardware complexity of the digital electric energy meter.

Portable radios

Portable radios,Motorola Two Way Radios,Motorola Talkabout Radios,Motorola Handheld Radio

Guangzhou Etmy Technology Co., Ltd. , https://www.gzdigitaltalkie.com

Posted on