Identification of unbalanced power in a three-phase three-wire power system under linear loading

In the paper, two orthogonal components of unbalanced power in the three-phase three-wire power supply system were introduced to simplify the distributed filtration control. Integral formulas are obtained to determine the applied unbalanced power components, making it possible to record their contribution to the deterioration of electrical energy quality. The relationship between power unbalance components and the linear unbalanced load parameters was established to verify the above-mentioned integral formulas by computer experiment. Experimental studies show complete coincidence of the measured power points with the curves of the calculated dependences. It has been found that with given source symmetric voltages, the three-phase sinusoidal process of the unbalanced load is fully identified by four scalar values: active and reactive powers and applied orthogonal components of the unbalance power. These scalar variables can be used to synthesize control signals for distributed active filters of intelligent local power grids.