Q:

Consider the IEEE 23 kV, 30-bus distribution system [9, 10] shown in Fig. E9.1.1. System transmission-line data, bus data, and capacitor data are provided in Tables E9.1.1 to E9.1.3, respectively. To investigate the impact of large AC drive systems on the power quality of the distribution system, a PWM adjustable-speed drive (675 kW, 439 kVAr) and a variable-frequency drive (350 kW, 175 kVAr) are connected to buses 15 and 18, respectively. Table E9.1.4 depicts the spectra of the current harmonics injected by typical AC drives into the system. Use harmonic current sources to model the two nonlinear loads and utilize the decoupled harmonic power flow algorithm (Chapter 7, Section 7.5.1) to simulate the system. Determine the total harmonic voltage distortion ( THD _v) of the system and at the individual buses before and after the installation of the hybrid passive filter banks listed below. Plot the voltage and current waveforms at bus 15 before and after filtering.

1. Two filter banks are placed at the terminals of nonlinear loads (buses 15 and 18). Each bank consists of a number of shunt-connected series resonance passive filters tuned at the respective dominant harmonic frequencies. Assume R _f = 100 ? and L _f = 100 mH for all filters and compute the corresponding...