Geomagnetic effects modelling for the PJM interconnection system.II. Geomagnetically induced current study results

The development of a computer program far calculation of geomagnetically induced current (GIC) and a GIC power system model for the Pennsylvania-New Jersey-Maryland Interconnection (PJM) is described. Results of GIC for three different ionospheric source configurations are shown. A new method is presented for estimating GIC in unmetered parts of the system based on a few measurements and precalculated geomagnetic disturbance conditions. The use of an interactive, menu driven GIC program to study mitigation concepts including the effects of line outages, line series capacitors, transformer neutral blocking resistors and transformer neutral blocking capacitors is also presented     

Requirements for composite system reliability evaluation models

The requirements of composite generation and transmission system reliability evaluation methods for use in power system planning are described. The focus of this report, which is based on inputs obtained for utility system planners, is on the philosophy and purpose of composite system reliability evaluation rather than on the modeling details     

Pressure surge reflector for pipe type cable system

The development and testing of a pressure surge reflector designed to reduce the pressure seen at potheads during an electrical failure in a pipe-type cable system are described. The reflector is designed to protect the potheads from failing because of a pressure surge that may be large enough to fracture the porcelain, particularly when the electrical failure is physically close to the pothead. Tests indicate that the gaskets in the pothead-base-riser pipe flanges will rupture and leak dielectric fluid at a pressure surge of 900-1200 psi when the bolts are torqued to specified values. Destruction of the high-strength pothead design may first occur in the range of 1600-1800 psi. Therefore, it is possible that an electrical failure in the cable pipe in close proximity to the cable end will initiate leaks of dielectric fluid at the gaskets rather than destroy the pothead. The prototype reflector lowers the pressure significantly, bringing the pressure surge below the factory pressure test level for standard potheads     

Bounds for convex variational programming problems arising in power system scheduling and control

The convex variational programming problem has been found of practical importance to power system scheduling and control. Convex variational programming problems are closely related to the convex programming problems treated by Kuhn and Tucker [8]. Among their positive attributes are the absence of difficulties with weak relative minima and with saddle-point or conjugate-point conditions. As a result it is feasible to develop dual-variational problems and to provide estimates for bracketing the extreme value of the functional of the variational problem when gradient or successive approximations methods are employed for determination of near optimal control schedules. This paper develops necessary and sufficient conditions for the optimal control schedule and a means for numerically determining bounds to the extreme value of the functional. Applications are given to the problem of hydrothermal power system coordination.