A cascading tap changing regulator has a set of input taps to power multiple stages of the cascade. Each tap in the set of taps is selectively engagable in respective on-off modes to effect a number of regulation steps, and a ratio of the number of steps to the number of taps in the set is greater than 1:1.

A method for controlling a transformer includes specifying, in one or more control devices, an initial operating limit (e.g. an initial current limit or an initial temperature limit) for one or more windings of the transformer. Further, the method includes monitoring, via one or more sensors, at least one electrical condition of the one or more windings of the transformer (e.g. current or voltage). The method also includes receiving, by the one or more control devices, a signal indicative of the at least one electrical condition of the one or more windings of the transformer. As such, the method further includes adjusting, by the one or more control devices, the initial operating limit based at least in part on the at least one electrical condition of the one or more windings of the transformer.

A circuit comprises an output connector connectable to a load. A relay selectively connects the output connector to an AC power source. The relay is responsive to a disabling signal to disconnect the output connector from the AC power source. A sensor senses a level of power delivered to the load via the output connector. A detector emits a first fault signal when the sensed power level exceeds a fixed power limit. A latch maintains the first fault signal until it receives a rearm signal. A controller emits a second fault signal when the sensed power level exceeds a configurable power threshold, receives a user command to rearm the circuit, and in response to receiving the user command, emits the rearm signal and ceases the emission of the second fault signal. A logic combiner generates the disabling signal when it receives one of the first and second fault signals.

System for controlling voltage supply to a portion of a distribution grid. The portion of the grid includes a substation providing one or more transformers operable to increase or decrease the voltage supplied to consumers within the portion of the grid. The voltage control system providing a data set can include a previously measured power consumption associated with previously measured values of (a) property(ies) for a portion of the grid, the property(ies) being one of voltage, current, frequency or load, or a combination thereof. The voltage control system can provide a measurement device to measure the property(ies) supplied within the portion of the grid. The voltage control system can provide a processing device to determine from the previously measured values of the property(ies) in the data set a most likely effect of altering the value of the property(ies) from a first value to a second value, on the power consumption.

System for controlling voltage supply to a portion of a distribution grid. The portion of the grid including a substation providing one or more transformers operable to increase or decrease the voltage supplied to consumers within the portion of the grid. The voltage control system includes: a data set including a previously measured power consumption associated with previously measured values of a property(ies) being one of voltage, current, frequency or load, or a combination thereof, a measuring device to measure the property(ies) within the portion of the grid, a processing device to determine a most likely effect of altering the value(s) of the property(ies) from a first value to a second value, a storage device for storing one or more rules associating a trigger event with a response action associated with the substation, and a control device to receive a measurement of the property(ies) within the portion of the grid.

This disclosure describes techniques to evaluate power usage and characteristics on a power distribution system. The power distribution system may include local distribution systems as well as transmission systems. Additionally, this disclosure describes techniques to evaluate the effectiveness of Conservation Voltage Reduction (CVR), for example, by using two variable characteristics to model a power load as a sum of a constant impedance load and a constant power load.

A device having a step-up transformer that includes a magnetic core, a primary winding for connecting to an AC network, and an output secondary winding; and a step-down transformer that includes a magnetic core, a primary winding identical to and connected opposite to the secondary winding of the step-up transformer, and a secondary winding identical to the primary winding of the step-up transformer. The opposite connected secondary winding of the step-up transformer and primary winding of the step-down transformer form a second voltage harmonic generation circuit that generates, when voltage is supplied to the step-up transformer from the AC network, a second voltage harmonic in the windings and magnetic cores of said transformers so that frequency of external voltage oscillations of the AC network is doubled in said second voltage harmonic generation circuit, thereby generating an autoparametric resonance therein.

A method of preventing disjunctions in a power distribution unit having a plurality of output connectors is disclosed. A power level of each of the output connectors is sensed. It is detected that the power level of a given output connector exceeds a fixed power limit. In response to the detection, a delivery of power by the given output connector is stopped while maintaining a delivery of power by a remainder of the output connectors. Power delivery may be resumed in response to receiving a user command to rearm the given output connector. A power distribution unit adapted to prevent disjunctions is also disclosed.

A phase shifting transformer for poly-phase alternating current includes source side terminals, load side terminals, an exciting unit, and a series unit. The exciting unit includes further coils that are magnetically coupled to primary coils and to the secondary coils of the exciting unit to provide further voltages. The further coils are connected in series between the source side terminals and the series unit, so that the voltages at the load terminals are combinations of the quadrature voltages and the further voltages with the source voltages, thus modifying the voltage phase displacement between the source side terminals and the load side terminals.

A method for voltage regulation, control, protection and monitoring of state of on-load tap changers of power transformers, voltage regulators, and capacitor banks comprising: uses a voltage regulation system that has sets of voltage regulation parameters available for programming by a user. Each of these sets is adjustable in an independent manner for a given prevailing load condition. The parameters include a desired rated voltage at a load: a voltage variance percentage allowed over and below rated voltage; time delay adjustments for CDC (15) actuation in order to correct voltage; choice of linear or reverse time delay type; and parameters referring to voltage drop in the line.