Evaluation of a Trapezoidal Predictive Controller for a Four-Wire Active Power Filter for Utility Equipment of Metro Railway, Power-Land Substations

Figure 6

Experimental verification of the APF prototype with the 1.6 kW balanced load of (a). (a) Measured waveforms (yellow), (green), (red), and (blue) before and after the activation of the APF. (b) Measured response of (yellow), (red), (green), and (yellow) to a filter inductance step from 50 mH to 100 mH. (c) Measured response of (blue) and (green) to a predictive current controller step from Euler to the trapezoidal approximation, which is contrasted against the reference (red) and load current . (d) Time amplification of (c) at the instant of the predictive controller step. 127 V, 60 Hz supply, 400 V APF DC link, and a 21.6 kHz APF sampling frequency.

(a)

(b)

(c)

(d)