Fault Location Using Sparse Wide Area Measurements
Transmission line fault location allows quick repair of the damage caused by the fault and timely restoration of the line affected by the fault. Accuracy of the fault location is quite important since it affects repair crew’s ability to physically locate the damage part quickly. Typically, the desirable accuracy is to be able to locate a fault within a span of the transmission line towers. This paper presents a new fault location scheme which uses synchronized phasor measurements from different substations sparsely located near the region where the fault has occurred. When fault occurs different Intelligent Electronic Devices (IEDs) such as Phasor Measurement Units (PMUs) and Digital Fault Recorders (DFRs) connected to Global Positioning System (GPS) receivers and installed in some of the substations in the region will be automatically triggered by the change in monitored signals and will record corresponding current, voltage and status signals. Apart from these sparse measurements, the proposed method also uses SCADA PI Historian data which is utilized for tuning the power system model data with the pre-fault condition in real time information. The paper presents how the technique is implemented and shows test results using actual power system model as well as actual field data from a utility company that supported demonstration of the technique. The results are quite encouraging since the sparse measurement problem for such unique transmission line configurations does not allow any other known techniques to produce accurate and reliable results while the proposed technique produces satisfactory results.
Fault resistance sensitivity of sparse measurement based transmission line fault location
Traditional transmission line fault location methods require measurements from at least one end of the faulted line. Measurements from all the ends of the faulted line are desirable but not always available. Sparse measurement based fault location scheme using phasor measurements from different substations located in the vicinity where the fault has occurred can be applied if the measurements are not available from any of the line ends. Fault resistance is one of the major sources of uncertainty in transmission line fault location estimation. This paper presents a correction scheme to reduce impact of fault resistance on sparse measurement method.
Physical Principles of Wind Energy Conversion
The primary component of a wind turbine is the energy converter which transforms the kinetic energy contained in the moving air, into mechanical energy. For the initial discussions of principles, the exact nature of the energy converter is irrelevant. The extraction of mechanical energy from a stream of moving air with the help of a diskshaped, rotating wind energy converter follows its own basic rules.