Distribution System Engineering
Advanced treatment of distributed-generation interconnection and electric power quality in modern distribution systems. The course examines rotating-machine and inverter-based resources, modeling and protection of low-inertia systems, interconnection and islanding concerns, and the causes, classification, measurement, and mitigation of common power-quality disturbances.
Objectives
- Compare synchronous, induction, and inverter-interfaced distributed-generation technologies.
- Develop appropriate steady-state, transient, and fault models for distributed energy resources.
- Explain interconnection, islanding, grounding, overvoltage, control, and protection requirements for distributed resources.
- Assess the challenges created by low-inertia and current-limited inverter-based systems.
- Define electric power quality in terms of equipment compatibility, supply characteristics, current, and system impedance.
- Classify transients, interruptions, sags, swells, unbalance, distortion, fluctuations, and frequency variations.
- Evaluate voltage-sag and momentary-interruption characteristics, equipment sensitivity, and mitigation options.
- Analyze harmonic sources, spectra, system response, resonance, and harmonic-control principles.
Modules
Description: Introduces the economic, reliability, resilience, and sustainability drivers for distributed energy resources. It surveys cogeneration, photovoltaics, wind, hydro, and storage, then compares synchronous, induction, and inverter-interfaced resources and their characteristic steady-state and fault models.
Description: Examines utility interconnection requirements and the behavior of distributed resources during normal and abnormal grid conditions. Topics include voltage and frequency response, grounding, fault current, relay coordination, ride-through, communications, and the operating impacts of increasing DER penetration.
Description: Focuses on islanding detection, temporary and transient overvoltage, protection and control of low-inertia and current-limited systems, inverter-dominated feeder behavior, modeling limitations, and future approaches to reliable DER integration.
Description: Defines power quality through equipment performance and electromagnetic compatibility, contrasts power quality with reliability, identifies current and system impedance as root causes of voltage distortion, and discusses distribution-system disturbances, customer impacts, and economic cost.
Description: Classifies power-quality disturbances by magnitude, duration, and spectral content. It covers impulsive and oscillatory transients, short- and long-duration voltage variations, interruptions, sags, swells, unbalance, waveform distortion, voltage fluctuations, and power-frequency variations.
Description: Examines sag and interruption magnitude, duration, and phase characteristics; faults and large-load starts as sources; equipment sensitivity; utility fault-clearing practices; and source, system, and end-use methods for reducing the frequency and impact of these events.
Description: Introduces linear and nonlinear loads, Fourier representation of distorted waveforms, characteristic harmonic orders, current flow through system impedance, voltage distortion, series and parallel resonance, harmonic indices, and principles for filtering and controlling harmonics.