| 摘要 |
A resistance annealing furnace for annealing a metal wire, strand, string, wire rod or strap having at least two electric axes, which are provided with respective pulleys for conveying the metal wire, and DC voltage generator means suppliable by an AC voltage source to generate an annealing voltage applied between the two electric axes. The DC voltage generator means has a first voltage rectifier stage connectable to the AC voltage source to generate an intermediate DC voltage, an active power filter, connected so as to compensate the current harmonics at the input of the first voltage rectifier stage, a pulse width modulator to transform the intermediate voltage into a first PWM voltage, a voltage transformer to transform the first PWM voltage into a corresponding second PWM voltage, and second voltage rectifier means to transform the second modulated PWM voltage into the annealing voltage. |
