Abstract:
A transformer enclosure has a hood and sill attached to a tank. The hood is retractable upon hinges connected to the top face of the tank. The sill is attached to the front face of the tank near the base and has a gate that drops down to an expanded position. When the enclosure is in a closed position, the hood and sill meet with the sill gate fully retracted along a tamperproof interface. A tamperproof interface is formed at the side of the enclosure by a flange on the side panels of the sill and a baffle on the bottom edges of the hood. A tamperproof interface is formed at the front of the enclosure by a bend and lip formed in the front panel of the hood in cooperation with a recessed portion formed in the gate.
Abstract:
A transformer enclosure has a hood and sill attached to a tank. The hood is retractable upon hinges connected to the top face of the tank. The sill is attached to the front face of the tank near the base and has a gate that drops down to an expanded position. When the enclosure is in a closed position, the hood and sill meet with the sill gate fully retracted along a tamperproof interface. A tamperproof interface is formed at the side of the enclosure by a flange on the side panels of the sill and a baffle on the bottom edges of the hood. A tamperproof interface is formed at the front of the enclosure by a bend and lip formed in the front panel of the hood in cooperation with a recessed portion formed in the gate.
Abstract:
Arc resistant enclosures for dry-type transformers. More particularly, transformer enclosures having one or more arc-resistant features, including arc channels, arc fault dampers, and arc fault plenums, and methods for providing same.
Abstract:
In a neutral-point-clamped power inverter, gate drive circuit comprises four drive blocks providing bipolar DC signals to control switch gates. The first and third drive blocks are bootstrapped to the second and fourth. Inverter's neutral bus is commonly connected to the positive and negative DC buses through clamping capacitors. An arm of four serially-stacked-switches bridges DC buses. The switch arm midpoint is an output of the inverter. A first clamping diode connects the neutral bus to the first switch emitter; a second clamping diode connects the neutral bus to the third switch emitter. In one embodiment, a second switch arm mirrors the first, providing a second output; a second gate drive circuit mirrors the first. A bias circuit provides two reference voltages for the gate drive circuits. Three isolated DC sources provide signals that, when used by the gate drive circuit, result in seven isolated bipolar DC signals.
Abstract:
Arc resistant enclosures for dry-type transformers. More particularly, transformer enclosures having one or more arc-resistant features, including arc channels, arc fault dampers, and arc fault plenums, and methods for providing same.
Abstract:
A motor box is used to rack withdrawable devices into or out of the associated cell in a switchgear cabinet. A hand held control is used to operate the motor box from a remote location. The motor box is attached to a mounting assembly on the switchgear cabinet door. The assembly can be part of the door or separately attached to the door. The mounting assembly allows for easy alignment of the motor box to the door and prevents rotation of the motor box when the box is latched to the mounting assembly. A cart is used to transport the motor box, remote control and associated peripherals to and from the switchgear cabinet.
Abstract:
A voltage converter includes a transformer with a pair of primary coils and a secondary coil. The converter has a DC input and a capacitor bank, having a pair of capacitors, is connected across the DC input. A switch is associated with each primary coil. A gate drive feedback module outputs a pulse width modulated signal to drive either the first or second primary coil. A gate drive switch has as an input the pulse width modulated signal and outputs to the first second switch. A pulse steering logic module determines which of the first or second capacitors has a higher voltage and controls the gate drive switch to direct the pulse width modulated signal in response thereto.
Abstract:
A method and apparatus for improving power generation in a thermal power plant. A dynamic reactive compensation system is provided and is connected to a high voltage bus or a generator bus of the power plant. The dynamic reactive compensation system comprises power electronic devices and is operable to provide most of the reactive power that is required from the power plant.
Abstract:
The system and method make transformer core assemblies from core segments output from a segment forming machine. The system includes a rack assembly and a transfer mechanism for moving the segments from the segment forming machine to the rack assembly. A work table is positioned adjacent to the rack assembly. The rack assembly is rotatable and holds a pair of racks, wherein one rack receives segments and the other may be lowered at the same time to perform finishing steps. The system further increases efficiency by including a second segment forming machine, transfer mechanism, and rack assembly.