Schweitzer Engineering Laboratories, Inc. will present three technical papers at the IEEE PES T&D Conference. They include:
Fault Location for Power Lines With Multiple Sections
Yanfeng Gong, Mangapathirao Mynam, and Armando Guzmán
Abstract—Fault location information is critical for operating and maintaining transmission and subtransmission networks. Some of the challenges in calculating accurate fault location include fault resistance, zero-sequence impedance variations, zero-sequence mutual coupling, load, system nonhomogeneity, and power lines composed of multiple sections with considerably different characteristics. This paper presents a fault location method that provides accurate fault location information for power lines with multiple sections. These sections can have different impedance characteristics.
The proposed method is suitable for different types of power lines, including overhead lines, underground cables, and composite lines that include both overhead line and underground cable sections. Fault resistance, parallel-line mutual coupling, system nonhomogeneity, and load variations have minimal effect on the accuracy of the proposed fault location method.
This paper compares fault location results calculated from event reports that were obtained from the field and from models of real power systems.
Modernizing Protection, Control, and Monitoring Systems With IEC 61850
Héctor J. Altuve and David J. Dolezilek
Abstract—During the past few years, a worldwide acceptance of IEC 61850 has been demonstrated as more and more substation devices are being integrated based on Ethernet technology. This trend represents new challenges for integrators, manufacturers, and end users. However, the field-proven benefits and lessons learned are truly valuable to managers, supervisors, and executives curious about bringing the benefits of IEC 61850 to their utilities. Utilities from around the world have deployed innovative projects based on the IEC 61850 communications standard, including Elektro in Brazil, NamPower in Namibia, NTPC Limited in India, and Comisión Federal de Electricidad (CFE) in Mexico.
This paper summarizes these successful deployment projects and presents network architectures and lessons learned during these projects.
Volt/VAR Control for Wind Generation
Michael Thompson, Tony Martini, and Nicholas Seeley
Abstract—Wind generating facilities often require significant reactive power support to maintain voltage and power factor within operating limits prescribed by the transmission grid entity. Many installations include multiple stages of switched capacitor and reactor banks for this purpose. Coordinated control of these capacitor and reactor banks, which are often connected to the point of interconnection via multiple step-up transformers, requires a centralized control system.
This paper discusses a reactive power control system that utilizes a central automation controller to regulate both power factor and voltage at the point of utility interconnection. This controller includes the capabilities of a complete communications processor to exchange voltage, power flow, and status information along with control commands to microprocessor-based relays throughout the system. It also includes a powerful IEC 61131-3-compliant soft programmable logic controller (PLC) logic engine to execute the control algorithms. The system is easily adaptable and scalable to nearly any configuration.
The challenge when controlling both power factor and voltage is to prevent hunting due to conflicts between the two control requirements. An adaptive algorithm is utilized to deal with this challenge. The controller also includes a sophisticated sequencing algorithm to ensure that both reactors and capacitors are not in service at the same time, to optimize power factor through multiple step-up transformers to reduce losses, and to even out switching operations between reactive banks.