Abstract: A cascading tap changing regulator has a set of input taps to power both stages of the cascade, each stage having its own series injection transformer to regulate the output. A set of switches are 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 switches in the set is greater than 1:1.

Abstract: A reactive power control device includes a limit value deriver configured to derive a limit value of reactive power, which is output by one or a plurality of power conversion devices determined for system stabilization and control of a system voltage, on the basis of a voltage of a point other than a voltage control target, and a command value adjuster configured to adjust a reactive power command value for the one or plurality of power conversion devices on the basis of the limit value derived by the limit value deriver.

Abstract: A switch apparatus (10) for a measuring device (30) for a transformer includes controllable switch device (14) which are configured to short-circuit respectively assigned terminals (11) of one of a plurality of windings of the transformer. A test apparatus (40) including the switch apparatus (10) and a method (50) for operating the switch apparatus (10) are also disclosed. With apparatuses (10, 40) and methods (50) according to the exemplary embodiments, the work effort, time expenditure and errors and inaccuracies can be reduced through an automated testing of transformers.

Abstract: A system for controlling voltage comprising a transformer having a terminal, a plurality of windings and a plurality of winding taps. A voltage monitor coupled to the terminal of the transformer and configured to generate voltage data representing a voltage appearing at the terminal of the transformer. A non-bridging tap changer controller coupled to the voltage monitor and configured to generate tap changer control data for changing a configuration of a tap changer in response to the voltage data. A tap changer motor coupled to the non-bridging tap changer controller and configured to move the tap changer in response to the tap changer control data.

Abstract: A circuit (15) for an electrical plant (10) with a first and a second control winding (11, 13) comprises a first on-load tap changer (16) with a first diverter terminal (161) and three first switch terminals (162), of which at least two can be connected with associated first taps (12) of the first control winding (11); and a second on-load tap changer (17) with a second diverter terminal (171) and three second switch terminals (172) of which at least two can be connected with associated second taps (14) of the second control winding (13); wherein the second diverter terminal (171) is connected with the first diverter terminal (161) or with a first switch terminal (162?) not associated with the first tap (12).

Abstract: A tapping arrangement for a transformer, the arrangement comprising a plurality of fixed contacts, a movable rotary contact, a transition rotor with pairs of transition contacts, an interrupter coupling assembly and driving motor(s) are compacted into a single vacuum chamber.

Abstract: The invention relates to a step switch, comprising a pre-selector and a fine selector. The invention is characterized in that the step switch has a connection (36) between the pre-selector and the fine selector (18), at least one coupling switch (38) being arranged in said connection. A pre-selector can be switched in a largely gas-free manner by means of said switchable connection with the aid of the fine selector.

Abstract: A transformer arrangement and transformer for mitigating transient voltage oscillations. The transformer included a transformer core enclosing at least one core leg. A winding is wound around one of the at least one core leg. The winding extends from a first winding terminal to a second winding terminal and includes a first winding section along a first conductor extending from the first winding terminal to a first intermediate end point, and a second winding section along a second conductor extending from a second intermediate end point to the second winding terminal. The transformer arrangement further includes an external passive electric component connected between the first intermediate end point and either the second intermediate end point or the second winding terminal arranged to decrease an effective difference between capacitive and inductive voltage distributions between the intermediate end points such that transient voltage oscillations in the winding are mitigated.

Abstract: The invention relates to an on-load tap changer for switching among different winding taps of a step transformer without interruption. According to the invention, the selector contact unit (7) and the switching means (16, 17) for switching the load without interruption are jointly actuated without using an intermediate energy accumulator, by means of a threaded spindle (5) which is rotated by a drive motor (2) during a switching operation.

Abstract: A system for controlling voltage including a transformer having a terminal, a plurality of windings and a plurality of winding taps. A voltage monitor coupled to the terminal of the transformer and configured to generate voltage data representing a voltage appearing at the terminal of the transformer. A non-bridging tap changer controller coupled to the voltage monitor and configured to generate tap changer control data for changing a configuration of a tap changer in response to the voltage data. A tap changer motor coupled to the non-bridging tap changer controller and configured to move the tap changer in response to the tap changer control data.

Abstract: The invention relates to a distribution transformer having a tap-changing device for no-break switching between different winding taps of a distribution transformer. The general inventive concept consists in actuating both the selector contact unit and the switching means for no-break load switching by means of a common motor drive without interposition of an energy store.

Abstract: An electric power system includes an on-load tap changing (OLTC) transformer. The transformer includes a plurality of primary windings and a plurality of secondary windings. At least a portion of one of the primary windings and the secondary windings are inductively coupled to each other. The system also includes at least one on-load tap changer coupled to at least one of the primary windings and the secondary windings. The on-load tap changer is selectively configurable to regulate the portion of at least one of the primary windings and the secondary windings inductively coupled to each other. The system further includes at least one processor coupled to the on-load tap changer. The processor is configured to adaptively regulate a voltage set-point of the on-load tap changer as a function of an adaptive OLTC transformer power flow dependent voltage set-point characteristic.

Abstract: The invention relates to an on-load tap changer for step transformers, which has one main current branch and one auxiliary current branch for each of the two winding taps to be switched. In each main current branch and auxiliary current branch, switching is accomplished by means of a vacuum switching tube. According to the invention, an additional mechanical contact is provided in each of the main current branches and in each of the auxiliary current branches between the respective winding tap to which said branch is electrically connected and the respective vacuum switching tube in said branch. Said mechanical contacts are switched in such a way that the vacuum switching tubes in the main current branch and the auxiliary current branch of the unconnected winding tap can be galvanically isolated from the unconnected winding tap.

Abstract: A change-over structure disposed between a moving contact and a static contact of a tap selector includes an insulation changer base plate, static contacts which are fixed on the insulation changer base plate in at least one column at intervals, the inner ends of the static contacts are electrically connected to respective tap windings of a transformer, rotation shafts, each comprising moving contacts that are evenly distributed on each of the rotation shafts and are electrically connected to each other, and arc-shaped conductors corresponding to the static contacts in at least one column. Each of the arc-shaped conductors and outer ends of the static contacts are disposed at the same circumference with a center of one of the rotation shafts as a circle center. When one of the moving contacts is changed over between the two static contacts, another moving contact is electrically connected to the arc-shaped conductor.

Abstract: The invention relates to a transformer with a tap changer, wherein optionally the primary or secondary side can be regulated by the tap changer, and wherein, on the side of the transformer to be regulated, a main winding and at least one regulating winding, which is connectable by the tap changer, are provided. According to the invention, the main winding is divided into two main winding parts, and the at least one regulating winding and the tap changer (3) connecting the regulating winding are arranged electrically between the two main winding parts (1, 2).

Abstract: A load tap changer includes a mechanical switch, a semiconductor switch and an impedance branch or an uncontrolled semiconductor switch. The mechanical switch is connected to a power terminal of a voltage conversion device to carry an electric current and is activated to switch from a first tap to a second tap of the voltage conversion device when a tap change signal is received. The semiconductor switch is then connected between the first tap and the power terminal of the voltage conversion device and is disconnected before the mechanical switch is connected to the second tap. The impedance branch or the uncontrolled semiconductor switch is connected between the second tap and the power terminal of the voltage conversion device before the mechanical switch is connected to the second tap. The impedance or the uncontrolled semiconductor switch is disconnected after the mechanical switch is connected to the second tap.

Abstract: A transformer tap-changing circuit comprises an apparatus that includes a transformer comprising a secondary winding configured to inductively couple to a primary winding when a current is passed through the primary winding from an energy source, a first rectifier coupled to the secondary winding and configured to rectify a first AC voltage from the secondary winding into a first DC voltage, and a second rectifier coupled to the secondary winding and configured to rectify a second AC voltage from the secondary winding into a second DC voltage. The apparatus also includes a DC bus coupled to the first and second rectifiers and configured to receive the first and second DC voltages therefrom, wherein the first AC voltage is higher than the second AC voltage, and wherein the first DC voltage is higher than the second DC voltage.

Abstract: The invention relates to the arrangement of a stepping switch on a control transformer, wherein either only the mechanical contact system (8) of the stepping switch or also its load changeover switch (7) is or are arranged within the tank (1) of the transformer, under the transformer cover (4) and above the iron yoke (3).

Abstract: Disclosed herein are systems and methods for regulating a voltage profile of an electric power delivery system. According to some embodiments, a system may include a remote voltage regulating device configured to regulate voltage profile by selecting among a plurality of taps on a remote transformer and an associated a remote voltage regulator controller in communication. The remote voltage regulator controller may calculate remote voltage regulation information and may transmit the remote voltage regulation information to a local voltage regulator controller. The local voltage regulator controller may be in communication with a local voltage regulating device configured to regulate the voltage profile of a local portion of the electric power delivery system by selecting among a plurality of taps on a local transformer. The local voltage regulator controller may be configured to receive the remote voltage regulation information and generate a tap change command for the local voltage regulating device.

Abstract: A method of operating a tap changer of a transformer or a voltage regulator in a power grid includes obtaining a load forecast for a time period. An average voltage profile is determined for the time period based on the load forecast. The method further includes estimating tap positions of the tap changer for leveling the average voltage profile during the time period. Switching signal commands are provided to the tap changer based on the estimated tap positions.

Abstract: Regulation of a remote load center voltage from a local location of a voltage regulator and a voltage regulator control using voltage measurements from the remote load center obtained using a metering device at the load center in communication with the voltage regulator control. The metering device may obtain remote voltage information at the load center and communicate such to the voltage regulator control using a direct communications line, a wide area network, or the like. The communications may include electrical (e.g. copper cable), light (e.g. infrared over fiber optics), radio frequency, or the like. The voltage regulator control may be configured to use local measurements and a line drop compensation algorithm in the event that the remote voltage information becomes unavailable.

Abstract: The invention relates to a manual drive for step-by-step operation, without any power, of a tap changer (1) on a tap-changing transformer. The manual drive has a position indication wheel (4) which is used not only, in conjunction with a pointer (15), for actual position indication, but at the same time as a component of mechanical final-position limiting (10, 11, 12). It can also furthermore be used (18) in a particularly advantageous manner as a component of electrical switching monitoring.

Abstract: The invention relates to an on-load tap changer for step transformers, which has one main current branch and one auxiliary current branch for each of the two winding taps to be switched. In each main current branch and auxiliary current branch, switching is accomplished by means of a vacuum switching tube. According to the invention, an additional mechanical contact is provided in each of the main current branches and in each of the auxiliary current branches between the respective winding tap to which said branch is electrically connected and the respective vacuum switching tube in said branch. Said mechanical contacts are switched in such a way that the vacuum switching tubes in the main current branch and the auxiliary current branch of the unconnected winding tap can be galvanically isolated from the unconnected winding tap.

Abstract: The method determines the optimal settings for the controllable taps ut of voltage regulating transformers and the capacitor bank switches uc in a distribution network. Var optimization is calculated with the controllable tap settings ut fixed at an initial value, or the best value found so far, to output an optimized set of control settings uc. Voltage optimization is calculated with the control settings uc fixed at the best solution found so far, to output an optimal set of control settings ut. Using an objective function, system performance is evaluated using the optimal set of control settings ut and uc and repeating the steps until either the control values ut and uc do not change from one iteration to the next, the objective function value does not change or if the new objective function value is greater than the last. The control values ut and uc are then output to a distribution control system.

Abstract: An on-load tap changer (OLTC) for a transformer winding is disclosed. The OLTC includes a first MEMS switch coupled in series with a first tap on the transformer winding and a neutral terminal. The OLTC also includes a second MEMS switch coupled in series with a second tap on the transformer winding and the neutral terminal. The OLTC further includes a controller coupled to the first MEMS switch and the second MEMS switch, the controller configured to coordinate the switching operations of the first MEMS switch module and the second MEMS switch module to obtain a first predetermined turns ratio or a second predetermined turns ratio for the transformer winding.

Abstract: A smart link in a power delivery system includes an insulator, which electrically isolates a power line, and a switchable conductance placed in parallel with the insulator. The switchable conductance includes switchgear for sourcing, sinking, and/or dispatching real and/or reactive power on the power line to dynamically in response to dynamic loading, transient voltages and/or currents, and phase conditions or other conditions on the power line.

Abstract: A method for voltage stabilization of an electrical power network system including a producing power network system side, a consuming power network side including a power load, a power transmission line with an impedance ZLN, a transformer and an on-line tap changer added to the transformer. The impedance of the line is measured in case of dynamic instabilities. A transformer ratio n is controlled by changing a voltage reference Vref of the on-line tap changer. The voltage reference is changed according to a feed forward compensation from the impedance of the line.

Abstract: An apparatus for controlling a power flow in a high voltage network. A phase shifting transformer includes a tap changer.

Abstract: An inverter capable of supplying power to utility grids of varying line voltages is described. In some examples, the inverter contains multiple output taps that are selected to output power to the utility grid based on the voltage of the utility grid. In some examples, the inverter includes a multi-pin connector that connects with one of multiple receptacles associated with a desired voltage configuration. In some examples, the inverter is capable of adapting to a defined line voltage in two steps.

Abstract: A device for control of power flow in a three-phase ac transmission line. The device includes a series transformer unit, a shunt transformer unit, and a reactance unit.

Abstract: An apparatus for controlling power flow in a high voltage network. A phase shifting transformer includes a tap changer.

Abstract: An apparatus for controlling the power flow in a high voltage network. A phase shifting transformer includes a tap changer.

Abstract: A method for controlling the power flow in an ac transmission line including prompt handling of voltage recovery and only thereafter thermal constraints.

Abstract: Provided are methods for controlling operation of a voltage regulator of a single-phase of a three-phase power system to regulate a measured voltage. One of the methods includes recording a first elapsed time between detecting a first excursion of the measured voltage from an in-band area to an out-of-band area, and a first return of the measured voltage to the in-band area. The method also includes recording a second elapsed time period (dip period) between detecting the first return and a second excursion of the measured voltage from the in-band area to an out-of-band area. If the second elapsed time period is less than a predetermined dip time period, causing a tap position change of the voltage regulator upon expiration of a countdown period initiated upon detecting the first excursion, thereby adjusting the measured voltage to the in-band area while allowing a voltage drop of limited length.

Abstract: The present invention provides an apparatus for enhancing Q factor of an inductor. The apparatus includes a negative resistance generator coupled to the inductor for providing a negative resistance, and a bias circuit coupled to the negative resistance generator for biasing the negative resistance generator.

Abstract: Provided are methods for controlling operation of a voltage regulator of a single-phase of a three-phase power system to regulate a measured voltage. One of the methods includes recording a first elapsed time between detecting a first excursion of the measured voltage from an in-band area to an out-of-band area, and a first return of the measured voltage to the in-band area. The method also includes recording a second elapsed time period (dip period) between detecting the first return and a second excursion of the measured voltage from the in-band area to an out-of-band area. If the second elapsed time period is less than a predetermined dip time period, causing a tap position change of the voltage regulator upon expiration of a countdown period initiated upon detecting the first excursion, thereby adjusting the measured voltage to the in-band area while allowing a voltage drop of limited length.

Abstract: Embodiments according to the present invention can enhance an efficiency of an apparatus or method capable of converting power of a system. An apparatus for converting power includes a load state variation detector that detects a load characteristic state of the load unit; and an adjusting unit that adjusts a preset value of the circuit device of the load unit in accordance with the value detected by the load state variation detector. A method for controlling a power includes checking a load characteristic with respect to one or more than one element of system elements; and adjusting one or more than one circuit device value of a power block of the one or more than one element with respect to the load characteristic. In embodiments, it is possible to increase an efficiency of a DC/DC converter by varying a turn ratio of an inductor among the circuit devices of a converter and adjusting an inductance L.

Abstract: An on-load transformer tap changing system, for example for a power transformer, wherein the secondary or primary of a transformer includes at least one first tap and one second tap. A main connection circuit is used for permanent connection of the first tap or the second tap to an output terminal of the secondary or primary of the transformer. Secondary connection circuits are each used to connect a tap temporarily and directly to the output terminal of the secondary or primary of the transformer. Each of the connection circuits includes one or more insulated gate bipolar transistors. The system can be controlled without zero current value transition detection in the secondary winding.

Abstract: A voltage converter includes a transformer circuit, a filter, and a controller. The transformer circuit is coupled to the filter, and the controller is coupled to the transformer circuit and the filter. The transformer circuit includes an input port and an autotransformer coupled to the input port. The voltage converter receives an input signal at the input port and generates a transformer output signal from a transformer output port. The filter receives the transformer output signal on a filter input port and the filter generates an output signal at an output port. The controller receives the output signal from the filter and provides one or more control signals to the transformer circuit to control the output signal.

Abstract: Apparatus for regulating an electric voltage in at least one of electric supply networks and consumer units. The apparatus includes a regulating transformer arranged between a network node and at least one end consumer. The regulating transformer utilizes a primary winding and a regulating winding which includes switchable partial windings and a high leakage impedance. The transformer conducts a nominal current. A transfer switch switches the partial windings of the regulating transformer. Adjacent tappings of the partial windings are adapted to short circuit such that, in an event of the short circuit, the high leakage impedance limits a ring current which results from the short circuit to an order of magnitude of the nominal current. The regulating transformer produces both an increase in voltage and a decrease in voltage at the end consumer. This abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.

Abstract: The invention relates to a method for regulating the electrical voltage in electrical supply networks and/or consumer units and a device for carrying out said method. A regulating transformer (3) is inserted between a network node (1) in the supply network and/or consumer unit and at least one end user (2). The regulating transformer (3) comprises a high leakage impedance, which limits the ring current to the order of magnitude of the nominal current, in the case of a short-circuit between adjacent tappings (5) of the partial windings (4). The regulating transformer further comprises a transfer switch (7), to switch the partial windings (4).

Abstract: A series-compensating power flow transformer implements power flow control in a transmission line of an n-phase power transmission system, where each phase of the power transmission system has a transmission voltage. The transformer has n primary windings, where each primary winding is on a core and receives the transmission voltage of a respective one of the phases of the power transmission system. The transformer also has n secondary windings on the core of each primary winding for a total of n2 secondary windings. Each secondary winding has a voltage induced thereon by the corresponding primary winding, and one secondary winding from each core is assigned to each phase. For each phase, the secondary windings assigned to the phase are coupled in series for summing the induced voltages formed thereon, where the summed voltage is a compensating voltage for the phase.

Abstract: An actuator using an electromechanical transducer capable of maintaining stable driving function even under a severe environment of high temperature and/or high humidity, or the like, and an apparatus mounted with the actuator. The actuator are disclosed is constituted to move a slider block frictionally coupled to a drive shaft in a predetermined direction by reciprocating oscillation having different speeds of the drive shaft driven by elongation and contraction displacements of a piezoelectric element and the piezoelectric element, a portion where the piezoelectric element is coupled to the drive shaft and a portion where the piezoelectric element is coupled to a frame is sealed by silicone resin, fluorinated resin or the like to thereby protect them from the high temperature and/or high humidity environment.

Abstract: A voltage control apparatus (10) selectively boosts or bucks an input voltage in order to provide a selected output voltage. In the preferred embodiment, the apparatus includes a transformer (T1) having a plurality of secondary voltages presented at respective output connections (A-E), a connection circuit (12) having actuatable connection elements (R1-R6) to interconnect selected ones of the output connections, and a control circuit (14) operable to sense the input voltage at the primary of the transformer (T1) and to activate selected ones of the connection elements to produce a selected output voltage for delivery to a load. The preferred connection elements include electro-mechanical relays.

Abstract: A system for indicating the position of a tap of a voltage regulator system. An electrical signal representing the tap position is converted to a digital format and provided to a processor which controls an electronic display. The display provides a graphical representation of the tap position. As the tap position changes, the processor samples the tap position data and upon determining that the tap has settled at a position, updates the display accordingly. The processor also keeps track of the minimum and maximum tap positions and displays those as "drag-hand" positions on the tap position display. The displayed "drag-hand" positions are reset in accordance with a signal received from a user-operated reset switch. The tap position indication system can also communicate tap position information via a data port and provide variable-amperage control. The data port can also be used to reset the "drag-hand" positions and to communicate variable-amperage information and settings (e.g.

Abstract: Autoranging power supply apparatus may comprise a power output section having a plurality of pairs of output terminals, each of which has a maximum voltage and current rating. A switching network associated with the power output section connects and disconnects the plurality of pairs of output terminals to the external load. A control system connected to the switching network operates the switching network in response to changes in the impedance of the external load to connect and disconnect to the external load selected ones of the plurality of pairs of output terminals of the power output section to compensate for impedance variations in the external load and to prevent from being exceeded the maximum voltage and current ratings for each of the plurality of pairs of output terminals.

Abstract: An alternating current power control device including a phase comparison controller for comparing a phase of an input voltage with that of a first reference voltage, a single-winding transformer for varying the input voltage, a mutual induction reactor for lowering the input voltage by a desired level in response to an output voltage from the single-winding transformer, an output voltage comparator for comparing an output voltage with a second reference voltage, an output current comparator for comparing an output current with a reference current, an OR logic controller for performing an OR operation with respect to output signals from the phase comparison controller and output current comparator, and a switch array for selectively transferring the output voltage from the single-winding transformer to the mutual induction reactor in response to output signals from the output voltage comparator and OR logic controller.

Abstract: The invention concerns a switching arrangement for load change-over switches of step switches and for selector switches, wherein two switching contacts movable in two directions are present. The first switching contact is in the form of a main switching contact and is connected to the load derivation by means of a first vacuum switchgear cell. The second switching contact is in the form of a resistance switching contact which is likewise connected to the load derivation by means of a series connection comprising a second vacuum switchgear cell and a transition resistor. Both the main and the resistance switching contacts can be moved independently of one another and without mutual coupling or influence. The main switching contact always reaches the new fixed contact abruptly and independently of the switching direction before the resistance switching contact leaves the previous fixed contact.

Abstract: A tap changing circuit has each tap of a power transformer connected with a selector vacuum switching cell. The odd numbered cells and the even numbered cells are connected to respective sides of a load switch each including a further vacuum switching cell. The sides are bridged by a transition inductor or resistor.

Abstract: An electrical apparatus (100) line actuator (102), such as a voltage regulator or circuit breaker, has resident therein a personality module, electronically reconfigurable memory device (126) which stores actuator operational information, such as specifications (132), historical and maintenance information. An apparatus controller (106) communicates with the personality module (126) and can change the operational information stored therein. If either or both of the controller (106) and actuator (102) is replaced at a site, the controller (106) of the replacement apparatus configuration (100) can read the operational information stored in the personality module (126) and adapt its operational interaction with the actuator (102) in conformance with the information.