New approach to the optimisation of three-phase three-wire systems with sinusoidal voltage sources and nonlinear loads

摘要

The problems presented in the paper deal with the three-phase three-wire system with sinusoidal voltage sources and nonlinear loads. In the model of the three-phase voltage source the inner impedance has been included. In contrast to earlier proposed methods, the solution of this problem is based in the frequency domain. This method can be used for systems with some classes of nonlinear loads, i.e. for inertialess elements, which consume the active power of the basic harmonic of the voltage source and where the currents of the system are periodic. The above-mentioned power is an additional condition of the presented minimisation. The solution (the active currents) is obtained by means of Lagrange factors and a suitable measurement experiment. The last stage of this method is the determination of the parameters of the compensator, which connected to the system under research evoke the active currents of the voltage sources. This working point for the three-phase three-wire system can be obtained by means of LC, RLC or (RLC,-R) compensators.