Method and arrangement for detecting and damping transcient oscillations at or near a natural resonant frequency in a power transmission system
US5677852A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 8, 1995 |
| Grant date | Oct 14, 1997 |
| Priority date | — |
| Expiry date | Mar 8, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/60
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Apparatus for damping oscillations at or near a natural resonant frequency in a power transmission system, in which an oscillator emits a reference signal oscillating at the natural resonant frequency; a multiplication circuit for multiplying an operating signal corresponding to the prevailing operating condition of the HVDC-system with the reference signal; a memory and a clock-pulse generator for serially sampling the output signal from the multiplication circuit by clock-pulses; the memory has the capacity to store sampling values up to a number which at least corresponds to the period of the reference signal; a summation circuit which, via a parallel output from the memory, for summing a number of the latest sampling values which corresponds to at least one period of the reference signal; a diagnostic and determination circuit provided with the output signal from the summation circuit, in which circuit the size, sign, variability and presence of an output signal from the summation circuit is tested according to determined criteria; means for generating a regulating signal provided with an output signal from the summation circuit, and a circuit closer activated by the output sig…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.