Abstract: A regulator is provided for establishing asymmetrical voltage increase/decrease capability between an input node and an output node for enhanced regulation of either a voltage sag or a voltage swell within a utility system. The regulator includes an autotransformer having an input tap coupled to the input node of the regulator and an output tap coupled to the output node. The regulator further includes an electronic tap changer system coupled to the winding of the autotransformer. Together, the autotransformer and the electronic tap changer system provide the regulator with its asymmetrical voltage increase/decrease capability between the input node and the output node thereof. The regulator can be configured for voltage increase only, voltage decrease only, or both, provided an asymmetrical voltage increase/decrease capability is defined.

Abstract: A device/method for actively interrupting fault current in an ac or dc power system before the fault current is capable of growing to peak magnitude or steady state condition, respectively, is presented. In an ac implementation, a commutating capacitance of desired polarity from one of two commutating circuits is coupled across a circuit interrupter comprising a pair of separable contacts. The circuit interrupter operates to open circuit the power system upon reaching zero current therethrough. The commutating capacitance of appropriate polarity actively drives the fault current to zero before the fault current reach peak magnitude, thereby allowing the circuit interrupter to open circuit the power system before the fault current's natural current zero. In dc implementation, the commutating capacitance is connected to dissipate a fault current while the system is in transient state, thereby protecting the power system from full steady state fault current condition.

Abstract: A method for generating a computer model for use in system component design as well as overall system evaluation is disclosed. The method includes the steps of generating an equation model of the system component, modifying the equation model by integrating according to the trapezoidal rule, wherein an integrated model is formed having a plurality of parameter values. Certain of such parameter values define historical parameter values accounting for historical parameter information. the parameter values are arranged in matrix form and reordered. The reorder matrix equation is reduced by eliminating certain of the parameter values, thereby forming a reduced model. When the reduced model is incorporated is a system model it is necessary to modify the system model to account to the component model current parameter information. Such information is used by the component model to update the historical information.

Abstract: A method for generating a computer model for use in system component design as well as overall system evaluation is disclosed. The method includes the steps of generating an equation model of the system component, modifying the equation model by integrating according to the trapezoidal rule, wherein an integrated model is formed having a plurality of parameter values. Certain of such parameter values define historical parameter values accounting for historical parameter information. the parameter values are arranged in matrix form and reordered. The reorder matrix equation is reduced by eliminating certain of the parameter values, thereby forming a reduced model. When the reduced model is incorporated is a system model it is necessary to modify the system model to account to the component model current parameter information. Such information is used by the component model to update the historical information.

Abstract: A tap changing system for operation with a transformer and featuring a special group of gate-controlled electronic devices that operate as a circuit breaker and recloser such that, after half-cycle of short-circuit current, said special group is transferred to the OFF-state, whereby the tap changer winding is open circuited; the advantage being that only the special group of devices need be rated to sustain short-circuit conditions; a further feature is the concept of Discrete-Cycle Modulation (DCM) whereby tap voltage magnitudes are obtainable in increments intermediate the physical tap winding voltage magnitudes.

Abstract: A disk wound transformer winding employing at least two external electrostatic shields extending axially along the outside of the disk winding for grading the impulse voltage within the winding. The inner external shield closest to the winding is connected to the line terminal and the outer external shield is connected to ground. A substantially linear voltage gradient under impulse conditions is attained by the combination of a disk winding arrangement and a specifically tailored assembly of external shields extending along the outside of the winding.

Abstract: Transformer coils wound with disk winding sections nonsequentially arranged are provided with shields between the turns of mechanically adjacent sections to increase the series capacitance of the winding. The increased series capacitance of the winding allows a reduction in insulation between the individual winding turns and between the winding discs.

Abstract: Transformer coils wound with disk winding sections nonsequentially arranged are provided with shields between the turns of mechanically adjacent sections to increase the series capacitance of the winding. The increased series capacitance of the winding allows a reduction in insulation between the individual winding turns and between the winding discs.