| 摘要 |
There is described a method for regulating the height of the electrodes in a three-phase melting furnace operating with freely burning electric arcs in dependence on the arc voltages, and with each electrode having an associated arc voltage regulator which receives the arc voltage as the actual value and a desired arc voltage value and which produces a regulating value therefrom. The method includes determining the respective arc voltages from the phase voltages and the active and reactive voltage drops across the respective high current lines. The respectively determined arc voltage values and the associated desired arc voltage values are fed to the associated regulators. The respective desired arc voltage values are formed by: providing a voltage which is proportional to the actual arc current; providing a limit value corresponding to the desired arc length; and, during each half wave of the arc current proportional voltage, utilizing the smaller momentary value, with respect to magnitude, of the arc current proportional voltage and the limit value as the desired arc voltage value which is fed to the associated arc voltage regulator. |
