Power Distribution Systems
Electric power systems deliver the electric energy that drives modern society. Historically, these systems are represented by three distinct components: generation, transmission and distribution. The distribution network begins with primary circuits which leave the substation and ends as the secondary service enters the customer’s meter.
Advancements in communications and computer technologies have greatly improved power distribution system monitoring, control, and automation. These changes have significantly impacted system planning and operating schemes. At Drexel, a unique hands-on education and research laboratory has been developed to study these systems.
The RDAC lab consists of four identical distribution stations with a total of 36 buses, 16 three-phase lines, 16 three-phase normally closed switches, 16 three-phase normally open switches, and various types of loads. The total power handling capability of the lab is 43.2kW. Each station is composed of:
• 1:1 variable autotransformer
• 30 A three-phase circuit breaker
• 9-bus distribution system with two feeders
• dedicated multiphase resistive loads and capacitors
• remote terminal unit for data acquisition and digital control
A single-line diagram of RDAC is shown below for a typical setup.
Distribution Management System (DMS)
Using the power hardware and data acquisition system, voltages and currents can be captured at up to four buses at each station. To provide an interface between the students and the distribution system, a DMS has been developed which allows students to:
• visualize system setup using color-coded resistors and inductors to represent three-phase distribution lines and display specified number and connection types of loads
• calculating and displaying RMS voltages and currents, frequency, power, and power factor
• operating switches to reconfigure the system using LEDs to represent three-phase switches
• displaying oscillographic data
The RDAC Laboratory is used as part of the Drexel University undergraduate and graduate curriculum. Experiments have been designed to illustrate course topics and provide students with a tactile hands-on education experience. In addition, RDAC is utilized for senior design projects, outreach education activities, and scholarly research. The following is a list of experiments performed in the laboratory:
• Multi-phase radial power flow
• Network reconfiguration experiment for load balancing and loss reduction
• Service restoration experiment
• Capacitor placement and control
• Fault experiment
• K-12 and non-engineer outreach experiments in power flow and service restoration