Abstract: The subject specification comprises enhanced power system balance control for a multi-tier hierarchical electrical distribution network (EDN). The EDN comprises a specified number of distribution network node controller (DNNC) components employed to desirably control power system balance, data communications, and power distribution between respective tiers of the EDN to facilitate efficient power distribution. In each tier, a power system balance component (PSBC), associated with a DNNC component, can monitor power system balance, such as load phase balance, associated with multi-phase power distribution for its tier, and detect power system imbalances in that tier. A power balance correction action can be identified and executed (e.g., automatically) in response to the detected power system imbalance to rectify the imbalance, wherein the correction action can include dynamic switching of loads between phases and/or filtering of the power signal.

Abstract: An output circuit providing isolation between inputs and the output employs first and second opto-couplers for isolation. Pulse activation of the first opto-coupler turns on an output transistor and pulse activation of the second opto-coupler turns off the output transistor. An input stage of the output circuit is and light emitting devices of the first and second opto-couplers are powered by a first power source and an output stage of the output circuit is powered from an external power source. Power consumption by the input stage of output circuit occurs only during pulse activation of the first and second opto-couplers.

Abstract: Three coils, each having several serial windings, have selected windings connected in a delta. Input AC power is applied through outrigger windings at the delta apices. At least two strategically located, direct tap, natural output points are provided at each side of the delta. For 6-phase output, only the six natural output points are required. For 9-phase output, an additional central output terminal connects to each side of the delta through a stub winding. The 6-phase or 9-phase output is passed to a rectifier circuit.

Abstract: The invention includes a transformer for converting three-phase AC power to nine-phase AC power. An autotransformer includes three coils, each coil including a plurality of serial windings that together form a polygon. Nine output nodes are provided between adjacent winding pairs, the windings sized and arranged such that adjacent output voltages are separated by 40 degree phase shift and such that output voltage magnitudes are essentially identical. Both step-up and unity gain input node sets are provided wherein, when three phase AC supply lines are linked to the step-up input set the output voltage is stepped up and when the three phase AC supply lines are linked to the unity gain input set the transformer gain is unity. An isolation transformer includes a secondary arranged like the autotransformer configuration described above.

Abstract: Electrical power monitoring apparatus comprises a loop and a first conductor. A current sensor coupled to the first conductor provides a current signal that is representative of the current in the first conductor. A voltage sensor coupled at least to the first conductor provides a voltage signal that is representative of the voltage on the first conductor relative to that on a reference terminal. A multiplier coupled to the current sensor and voltage sensor has a power output which provides a power signal that is proportional to the instantaneous value of electrical power carried by the first conductor. A calibration circuit in the loop has an input coupled to the power output and has an adjustable output. A current regulator in the loop has an input coupled to the adjustable output to maintain the current in the loop between predetermined minimum and maximum loop current values.

Abstract: The invention provides for an autotransformer for converting three-phase AC power to nine-phase AC power. The autotransformer includes three coils each having a plurality of serial windings and a plurality of stub windings. The serial windings form a delta and the stub windings are magnetically coupled with the serial windings from the same coil. Three terminals are provided at the apices of the delta and the three-phase AC source may be directly connected to the respective apex terminals. A plurality of direct outputs are interposed between respective serial windings and a plurality of indirect outputs are electrically connected with the second ends of the stub windings. The voltage magnitude of each of the direct outputs is preferably equal to the voltage magnitude of each of the indirect outputs. The voltages of the direct outputs and indirect outputs are out of phase with the voltages at the apex terminals.

Abstract: An arrangement for transforming electrical power is disclosed. An embodiment of the arrangement includes conductors for electrically connecting to an input source of three phase electrical power. This embodiment of the arrangement also includes a transforming device electrically connected to the conductors. The transforming device includes circuitry for transforming the input source of three phase power into at least two output phases separated from one another by approximately 180 electrical degrees. The transforming device also includes circuitry for reducing the level of instantaneous power drawn from the input source by shifting each output phase a predetermined number of electrical degrees from one of the three phases of the input source.

Abstract: A method and apparatus for providing a source of alternating current electrical power to a plurality of loads in an office environment, including a plurality of non-linear loads which draw power for only a portion of the alternating current cycle, includes an input source of electrical power to a primary side of a power transforming device which provides an output at its secondary side which comprises at least two phases and a shared neutral. The plurality of loads are evenly distributed between each phase of the output power source and the shared neutral so as to reduce by current cancellation the current which would otherwise flow in the shared neutral conductor due to the presence of the non-linear loads. In one embodiment, each of six output phase is separated from the other by 120 electrical degrees, and the fourth, fifth and sixth phases are separated from the first, second and third phases, respectively, by 180 electrical degrees.

Abstract: A rotary phase converter for connection to a single AC power source intended to supply triphase current to a triphase electrical load with minimum current and voltage imbalances. Furthermore, it is not necessary to adjust the equipment as the load changes on the overall range.The phase converter embodies an induction machine acting as rotary phase-shifter and a compensation circuit containing passive elements only. Another version with additional features for improved efficiency is also shown.Moreover, because of the current symmetry available, this phase converter can also be connected to a triphase power source to supply a single-phase load.

Abstract: A method and apparatus for providing a source of alternating current electrical power to a plurality of loads in an office environment, including a plurality of non-linear loads which draw power for only a portion of the alternating current cycle, includes an input source of three-phase electrical power to a primary side of a power transforming device which provides an output at its secondary side which comprises at least six phases and a shared neutral. The plurality of loads are evenly distributed between each phase of the output power source and the shared neutral so as to reduce by current cancellation the current which would otherwise flow in the shared neutral conductor due to the presence of the non-linear loads. Each of the six phases is separated from the other by 120 electrical degrees, and the fourth, fifth and sixth phases are separated from the first, second and third phases, respectively, by 180 electrical degrees.

Abstract: A traction power supply system in which one, two or three single-phase traction loads are supplied from a 3-phase high voltage system. Balancing of the load in each phase of the high voltage system and reduction of reactive currents in that high voltage system is achieved by simulating any further single-phase load or loads necessary to make the number up to three and providing individual controllable balancing circuits for all of the single phase circuits together with individual harmonic filters designed to include accommodation of the harmonic currents generated by the balancing circuits.

Abstract: Circuit for providing low ripple DC power supply from a single-phase AC source without the use of a filter capacitor. The circuit comprises a high leakage reactance transformer with a primary winding and two secondary windings arranged with the secondary windings on opposite sides of the primary winding, a leading current circuit connected to one secondary winding and a lagging current circuit connected to the other secondary winding, and a three-phase full wave rectifier bridge connected to the leading and lagging current circuits to provide a low ripple DC power output. The DC power supply circuit is used with a pulse generating circuit to provide pulsed operation of a gaseous discharge lamp such as a high pressure sodium vapor lamp, and produces desirable relationship of lamp watts to lamp volts for improved lamp life and uniformity of illumination.