In the power system, accurate measurement of transformer short-circuit impedance is of great significance for evaluating transformer performance and ensuring stable operation of the power grid. Electronic transformer calibrator plays a key role in this measurement process.
First of all, the measurement principle of electronic transformer calibrator is based on high-precision signal acquisition and processing technology. It synchronously samples the voltage and current signals of the primary and secondary sides of the transformer, and then calculates the short-circuit impedance using a specific algorithm. Its advantage is that it can achieve high-speed and high-precision data acquisition, effectively avoiding the errors caused by insufficient instrument accuracy and sampling frequency in traditional measurement methods.
However, in actual measurement, there are still many factors that affect accuracy. First, signal interference is a major challenge. The power grid environment is complex and electromagnetic interference is everywhere. The anti-interference ability of the calibrator is directly related to the reliability of the measurement results. To address this problem, modern electronic transformer calibrators usually use shielding technology, filtering circuits, and anti-interference algorithms in digital signal processing to reduce the impact of interference signals on the measurement signal.
Second, the connection method and contact resistance of the measurement loop cannot be ignored. Poor connection will introduce additional resistance, thereby affecting the short-circuit impedance measurement value. Operators must strictly follow the operating procedures to ensure reliable connections and good contact, and regularly check the integrity of the measurement loop.
The calibration link is crucial to improving measurement accuracy. The calibrator needs to be calibrated regularly using a standard impedance source to correct errors caused by aging and drift of the instrument's own components. At the same time, ambient temperature, humidity and other conditions during the calibration process should also be recorded and their potential impact on the measurement results should be considered.
When measuring transformers of different types and capacities, the parameter settings of the calibrator need to be flexibly adjusted. For example, for large-capacity transformers, a higher sampling frequency and a larger measurement range may be required to ensure that the voltage and current changes during short circuits can be accurately captured.
In addition, the optimization of the calibrator software algorithm is also the key to improving accuracy. Continuously improved algorithms can process the collected data more accurately, such as using more advanced Fourier transform algorithms to separate fundamental and harmonic components, thereby obtaining more accurate short-circuit impedance calculation results.
Electronic transformer calibrator has many advantages in measuring transformer short-circuit impedance. However, to ensure measurement accuracy, it is necessary to comprehensively consider and take effective measures from multiple aspects such as anti-interference, connection circuit, calibration, parameter setting and software algorithm to meet the power system's requirements for accurate transformer measurement.
