THE UNBALANCE POWER IDENTIFICATION IN THE THREE-PHASE FOUR-WIRE POWER SUPPLY SYSTEM FOR THE NEEDS OF ITS DISTRIBUTED COMPENSATION

The idea of distributed active filtration is to compensate the currents of higher harmonics and undesirable power components of the main network with renewable energy converters of the connected microgrid, which have reserves of apparent power. For the convenience of distributed compensation, it is proposed to identify the sinusoidal mode of the three-phase four-wire power system, provided from the symmetric source by six mutually orthogonal components of the three-coordinate load current vector. The unbalance power is shown to be due to four mutually orthogonal components of load current vector with defined reference voltage vectors, each of which is proportional to a separate orthogonal component of the unbalance power. Integral formulas for determining the scalar values of the four specified orthogonal components of unbalance powers have been obtained, which open the possibility to account for their contribution to the deterioration of the power quality and synthesize the control signals for distributed active filtration. The connection between the four specified orthogonal components of the unbalance power and the linear asymmetric load parameters was established, making it possible to verify these integral formulas using a computer experiment. It is analytically established and experimentally confirmed that the squares of the two orthogonal components of the unbalance powers associated with the current of the neutral wire are included in the decompositions of the square of apparent power and power losses with the multiplier, depending on the ratio of the resistances of the transmission line of the three-phase four-wire power system. References 17, figures 3. © 2022. Artemenko M.Yu., Chopik V.V., Mikhalsky V.M., Shapoval I.A., Polishchuk S.Y. All Rights Reserved.