In modern power systems, complex electromagnetic environments are everywhere, which poses a huge challenge to the precise measurement of electronic transformer calibrators. To ensure measurement accuracy, the calibrator first uses shielding technology. Its shell is usually made of metal materials with high magnetic permeability to form a closed Faraday cage, which effectively blocks the intrusion of external electric and magnetic fields, isolates the internal circuit from the complex electromagnetic environment, and reduces the interference effect from a physical level.
Filtering technology is also a key link. The calibrator has built-in multiple filters, such as low-pass, high-pass, and band-pass filters, which accurately filter electromagnetic interference of different frequencies. For the common 50Hz power frequency interference and its harmonics, the specially designed power frequency filter can greatly attenuate the signal in this frequency band, so that the useful signal can be clearly extracted, and the interference signal can be avoided from mixing into the measurement data to cause errors.
It is also important to use differential signal transmission. In the signal acquisition and transmission line, the calibrator uses a differential amplifier to convert the signal from the sensor into a differential signal. In this way, common-mode interference (such as the in-phase interference voltage generated by electromagnetic induction) is offset by each other during the differential amplification process, and only the differential-mode signal representing the measured value is retained, which greatly improves the anti-interference ability of signal transmission.
Anti-interference measures at the software algorithm level are indispensable. The calibrator has a built-in intelligent digital signal processing algorithm, which analyzes and judges the collected signals in real time, identifies and removes abnormal fluctuation data, which are often caused by sudden interference such as electromagnetic pulses. The algorithm can also smooth the signal, restore the true measurement value, and ensure that the data is stable and reliable.
The calibrator is also very particular about grounding design. Reasonable single-point grounding or multi-point grounding strategies are flexibly used according to different working conditions to provide a low-impedance path for interference current to flow into the earth, avoid the formation of interference voltage in the ground loop, and thus affect the measurement accuracy.
In addition, for some areas with strong electromagnetic radiation, the calibrator is also equipped with an adaptive adjustment function. When the environmental electromagnetic intensity is detected to exceed a certain threshold, the internal circuit parameters such as gain and sampling frequency are automatically adjusted to optimize the measurement performance to adapt to the harsh electromagnetic environment and always ensure measurement accuracy.
Through the comprehensive application of multiple anti-interference technologies, the electronic transformer calibrator can accurately measure in complex electromagnetic environments, providing reliable data support for the safe and stable operation of the power system.
