An electromagnetic induction device includes: a main tank, a magnetic core arranged in the main tank, an On-Load Tap Changer, OLTC, comprising: an OLTC tank mounted to the main tank, a fine selector, a diverter switch, a change-over selector, and a customer interface; and a barrier separating the main tank from the OLTC tank, wherein the diverter switch and the change-over selector are arranged in the OLTC tank, and the fine selector and customer interface are arranged in the main tank, and wherein the barrier comprises a plurality of electrical connections configured to connect the diverter switch and the change-over selector to the fine selector.

A resistor assembly can be used in a tap changer. The resistor assembly may include: a resistor element, which is held by at least two resistor holders; a base plate with at least one opening and on which the at least two resistor holders holding the resistor element are arranged; a plurality of guides, respectively formed in each of the resistor holders and being configured to position a first end and a second end of the resistor element with respect to a longitudinal direction between the two resistor holders; and contact points of the resistor element, the contact points being electrically contacted by contacts of the tap changer in a condition where the resistor element is inserted into the resistor holder.

The present disclosure provides an exemplary three-phase multi-tap balancing distribution transformer capable of operation with both balanced and unbalanced loads and that provides a wide range of incremental voltages to compensate for the varying voltage drops and imbalances as the attached conductor length increases and allows users the ability to incrementally and independently adjust the voltage specifically feeding a specific phase. Incremental adjustment is achieved via the transformer and without any fragile or other external devices or components between the power source and load-side equipment terminals. The transformer, through the use of at least one phase-specific tap-change switch is capable of directly controlling the secondary voltage of the applicable phase independently from the other phases and, thus, does not affect the voltage on the other phases.

The present disclosure provides an exemplary three-phase multi-tap balancing distribution transformer capable of operation with both balanced and unbalanced loads and that provides a wide range of incremental voltages to compensate for the varying voltage drops and imbalances as the attached conductor length increases and allows users the ability to incrementally and independently adjust the voltage specifically feeding a specific phase. Incremental adjustment is achieved via the transformer and without any fragile or other external devices or components between the power source and load-side equipment terminals. The transformer, through the use of at least one phase-specific tap-change switch is capable of directly controlling the secondary voltage of the applicable phase independently from the other phases and, thus, does not affect the voltage on the other phases.

An on-load tap changer has: a first selector rod and a second selector rod; a load changeover-switch rod; a switch; and a transmission. The first selector rod, the second selector rod and the load changeover-switch rod are arranged collinearly. The transmission is configured to: move the first selector rod and the second selector rod during changeover from one selector contact to an adjacent selector contact in a first direction; and move the load changeover-switch rod during the changeover in the first direction and a second direction, which is opposite to the first direction, so as to actuate the switch.

An on-load tap-changer for switching, without interruption, between winding taps of a tap-changing transformer, including a diverter switch for performing a switch-over from a first to a second fixed contact, a selector for preselecting, without power, the first and second fixed contact, and a first controller, wherein the diverter switch has a plurality of semiconductor and mechanical switching elements, the selector has a first and second selector arm, which are actuatable independently of one another and can contact each of the fixed contacts, and the first controller is configured to trigger a switch command and to actuate the first and second selector arm and the plurality of mechanical switching elements by a motor drive, wherein the on-load tap changer includes a second controller to actuate the plurality of semiconductor switching elements, and wherein during the switch-over the first controller actuates the motor drive depending on the second controller.

A method of operating a power generating system for a wind turbine connected to an electrical grid, the power generating system comprising a power generator, a converter, a transformer and a tap changer, the method comprising; when operating the power generating system in a grid-forming configuration, monitoring a signal for detecting a voltage of the electrical grid which requires an increase in output voltage from the power generating system in order to maintain the grid voltage within a predetermined voltage range; and operating the tap changer to tap-up the transformer to provide at least part of the voltage increase required to maintain the grid voltage within the predetermined voltage range.

A method of operating a power generating system for a wind turbine connected to an electrical grid, the power generating system comprising a power generator, a converter, a transformer and a tap changer, the method comprising; when operating the power generating system in a grid-forming configuration, monitoring a signal for detecting a voltage of the electrical grid which requires an increase in output voltage from the power generating system in order to maintain the grid voltage within a predetermined voltage range; and operating the tap changer to tap-up the transformer to provide at least part of the voltage increase required to maintain the grid voltage within the predetermined voltage range.

Transformer assembly has an input terminal, principal housing with main chamber for high voltage coil(s) having plurality of taps, low voltage coil(s) and retaining oil. An auxiliary housing extends outwardly from principal housing and is fluidly connected to main chamber so that auxiliary housing contains oil. A potential transformer; load tap changer having a controller, a motor and a plurality of switches; electrical wiring connected to taps, switches within auxiliary housing chamber are submerged by oil within auxiliary chamber; load tap change controller can adjust taps while the switches and electrical connections are submerged in oil of auxiliary housing chamber. The upper level of oil in the main housing chamber is at a level equal to or above the switches of the load tap changer. The auxiliary housing has an access opening and cover. System apparatus with frames, having beams, lattices and cable guides for routing cables for assembly.

Transformer assembly has an input terminal, principal housing with main chamber for high voltage coil(s) having plurality of taps, low voltage coil(s) and retaining oil. An auxiliary housing extends outwardly from principal housing and is fluidly connected to main chamber so that auxiliary housing contains oil. A potential transformer; load tap changer having a controller, a motor and a plurality of switches; electrical wiring connected to taps, switches within auxiliary housing chamber are submerged by oil within auxiliary chamber; load tap change controller can adjust taps while the switches and electrical connections are submerged in oil of auxiliary housing chamber. The upper level of oil in the main housing chamber is at a level equal to or above the switches of the load tap changer. The auxiliary housing has an access opening and cover. System apparatus with frames, having beams, lattices and cable guides for routing cables for assembly.