초록 ▼

A variable speed drive (VSD) having a rectifier, an inverter, an inverter modulator, an inverter controller, and a control loop, for controlling a motor load, wherein the control loop reduces an amount of power transferred to the inverter during a voltage sag. The control loop may include a referenc

A variable speed drive (VSD) having a rectifier, an inverter, an inverter modulator, an inverter controller, and a control loop, for controlling a motor load, wherein the control loop reduces an amount of power transferred to the inverter during a voltage sag. The control loop may include a reference generator, a filter, a regulator, and a ride-through corrective algorithm. A method for controlling a VSD to improve voltage sag ride-through by monitoring a voltage applied to the VSD, generating a control signal representative of losses in a motor load when a voltage sag is detected in the voltage applied to the VSD and applying less power to the load of the inverter.

대표청구항 ▼

A variable speed drive (VSD) having a rectifier, an inverter, an inverter modulator, an inverter controller, and a control loop, for controlling a motor load, wherein the control loop reduces an amount of power transferred to the inverter during a voltage sag. The control loop may include a referenc

A variable speed drive (VSD) having a rectifier, an inverter, an inverter modulator, an inverter controller, and a control loop, for controlling a motor load, wherein the control loop reduces an amount of power transferred to the inverter during a voltage sag. The control loop may include a reference generator, a filter, a regulator, and a ride-through corrective algorithm. A method for controlling a VSD to improve voltage sag ride-through by monitoring a voltage applied to the VSD, generating a control signal representative of losses in a motor load when a voltage sag is detected in the voltage applied to the VSD and applying less power to the load of the inverter. e adapted to be biased. 9. The plural-beam tube of claim 8 wherein said resistance includes a high-resistivity coating on the interior surface of said tube envelope. 10. The plural-beam tube of claim 1 further comprising a shadow mask proximate said faceplate having a plurality of apertures therethrough, said shadow mask adapted to be biased at the screen potential, and wherein said phosphorescent material includes a pattern of different phosphorescent materials on said faceplate that emit different color light in response to the at least two beams of electrons impinging thereon through the apertures of said shadow mask. 11. The plural-beam tube of claim 1 wherein the source of at least two beams of electrons directs the at least two beams of electrons in directions toward said faceplate so that the at least two beams of electrons appear to emanate from a common point. 12. A bi-potential cathode ray tube comprising: a tube envelope having a generally flat faceplate and a screen electrode on the faceplate adapted to be biased at a screen potential, and having a tube neck opposite said faceplate; in said tube neck, a source of at least two beams of electrons directed toward said faceplate, wherein said source is adapted for magnetic deflection of said at least two beams of electrons; a deflection yoke around said tube neck for deflecting the at least two beams of electrons from said source over a predetermined range of deflection angles, whereby the deflected at least two beams of electrons impinge upon a given area of the screen electrode; phosphorescent material disposed on said faceplate fo