Showing papers on "Power optimizer published in 1967"

Evaluation of harmonic levels on an hvdc transmission line

Abstract: ehv dc has come into prominence in recent years as a possible economical means of bulk power transmission. Present systems, such as the proposed Pacific Northwest Southwest Intertie, consist of two converter terminals interconnected by a dc transmission line. The source terminal rectifies power from the ac system to dc while the load terminal inverts incoming dc power to ac. Either converter terminal may be used as a rectifier or inverter, depending upon the power system needs. Direct current power interties have the inherent advantages of being a non-synchronous tie between ac sources, controlling power flow for stability, and not adding to the short circuit capacity of either system.

High power thyristor-battery drive for high peak, low average power pulser

Abstract: High power thyristors are employed with a battery to provide constant voltage to a quarter-megawatt dc load for 1/2 second, in order to operate a sonar transducer at a pulse repetition period of 10 seconds. Despite the heavy pulse power and the low duty cycle, the power drawn from the mains is maintained almost constant at approximately 12.5 kilowatts, with less than 5 percent variation over a power pulse cycle. The system utilizes a battery for energy storage, in conjunction with a phase-controled ac line to charge the battery at essentially constant current. The availability of high power thyristors for a high frequency inverter-type dc to dc converter makes the entire concept feasible, as the battery voltage drops substantially during the pulse. The inverter is pulse-width-controlled during the output power pulse, to maintain the dc output voltage constant within 3 percent during the power pulse. Basic circuits are described for providing the high peak power to the load, and maintaining virtually constant average power drain from the source over the entire cycle.

D-C transmission in power systems

Abstract: This text on DC power transmission includes information on the development and use of DC systems, operation of equipment such as converters and capacitors in transmission circuits, the stability of DC systems and the influence of such systems on the stability of associated AC systems, and methods for increasing the capacity and reliability of DC systems. A bibliography of 166 items is provided. (LCL)