Features of sinusoidal and resistive current loads in harmonic distorted networks

Growing numbers of consumers distort AC networks with harmonics. Therefore suppression of the network pollution should be considered. This problem can be solved by using "network-friendly" converters. In this article some consumers are presented that pollute the single-phase AC networks with harmonics. Therefore the network voltage waveform will be distorted. In our study we examine the features of sinusoidal and resistive current loads that connect to the distorted single phase AC network. If adequate current control strategies are used for network-friendly converters then these behave like sinusoidal or resistive current loads of the network. In this article we are dealing with two current control strategies of single phase four quadrant converters (4QS). The examined sinusoidal and the resistive current control strategies are known, but the differences between the two methods have not been studied before. This paper deals with the comparison of these two strategies. First, the analytical examination is presented. By comparing their consumed RMS currents we defined a coefficient (k[%]), which depends only on the total harmonic distortion of the network voltage (THD_u). We demonstrated that at high THD_u resistive current control method is more favorable. Then simulation examination is discussed, by presenting our model of the 4QS. Finally simulation results are represented and compared with the analytical results.