Abstract: A system and method provide Time-of-Use (TOU) rate schedules that are bound by windows of time, i.e., a type of fuzzy switch time, which is bounded on both sides, rather than instantaneous switch times. The fuzzy TOU schedule defines the time of a tier switch as the end time of the first completed interval recorded after the start of some window of time. A monitoring system may be included that implements configurable usage filters that allow for the classification of usage in terms of interval data. Usage filters can be defined so that they are applied against individual interval readings, various aggregations of interval readings, and/or the statistical products of interval readings, etc. A filtering algorithm allows for the comparison of incoming and/or historical interval data against defined usage and schedule filters to determine if usage is abnormal and should be investigated further.

Abstract: A trigger control system for a thyristor-controlled series capacitor (TCSC) is disclosed. In one application, a power system 10 is coupled to a load 12 by a series capacitor 14 connected in parallel to a thyristor unit 16 and inductor 17. The thyristors are triggered by the control system 18, which includes a first circuit 20 that generates signals proportional to the peak of the line currents, a stabilizer circuit 22, an adder 24, a look-up table 26, a conversion circuit 28, a pulse generator 30, a phase-locked loop (PLL) 32, a ramp generator 34, a trigger window circuit 36, and a three input AND gate 38 the output of which is a grid pulse signal 40 that triggers the thyristor unit 16. The control system diminishes power swing oscillations and subsynchronous resonance oscillations.

Abstract: A dynamic mechanically-switched damping (DMSD) system is described which utilizes one or more mechanical switches and appropriate controls to switch series or shunt reactive impedances in order to provide power oscillation damping in power systems. The DMSD system provides a controller which can be configured based on the number of mechanical switches in the DMSD system, the type of reactive impedances interfaced to the power system by each switch and the magnitude of each of the reactive impedance. The DMSD system monitors parameters of the power system and the controller generates a modulation signal based on the monitored parameters. The modulation signal is processed to identify a reactive impedance of the available DMSD system reactive impedances required to damp power oscillations. Appropriate switches are selected for supplying the required reactive impedance.