Research and compensation of voltage transformer errors considering DC bias and interference sources

Voltage transformers contain highly nonlinear components, which are affected by various interference sources, and rapid transient overvoltage leads to DC bias phenomenon, resulting in low accuracy and efficiency. Therefore, a research and compensation method for voltage transformer errors considering DC bias and interference sources has been proposed. Based on the equivalent circuit of the voltage transformer, the excitation error and load error are calculated, taking into account DC bias and interference sources. Then, the primary and secondary voltage waveforms of the voltage transformer under different DC bias voltages and interference sources are calculated. Combined with the phase diagram relationship, the voltage transformer error compensation function is designed, and the ratio/phase error compensation amount is solved to achieve voltage transformer error calculation and compensation. The experimental results show that the variation of power sampling error in voltage transformers is small, very close to the actual power sampling error, fluctuating between -0.03 and 0.03, and the error compensation time is only 42ms, effectively improving the accuracy and efficiency of voltage transformer error compensation.