摘要:
The invention relates to an induction heating method implemented in a device for heating a metal part, the device including magnetically coupled inductors (Ind1, Ind2, ..., Indp), each inductor being powered by a dedicated inverter (O1, O2, ..., Op) combined with a capacitor (C1, C2, ..., Cp) such as to form an oscillating circuit (OC1, OC2, ..., OCp). The oscillating circuits have at least approximately the same resonance frequency, each inverter is controlled by a control unit (M1, M2, ..., Mp) such as to vary the amplitude and the phase of the current passing through the corresponding inductor, the device also including a means for determining said current as well as a means for determining an actual temperature profile (θ 1 mes , θ 2 mes , ..., θ n mes ) of said part. The method includes the following steps: a) comparing said actual temperature profile with a reference temperature profile (θ 1 ref , θ 2 ref , ..., θ n ref ) and calculating a profile of the reference power density (Dp ref 1 , Dp ref 2 , ..., Dp ref n ) which the heating device must inject into said part; b) calculating the target currents which the inverters must produce in order for the currents of the inductors to reach target values (I 1 ref , I 2 ref , ..., I P ref ) that are suitable for injecting said reference power density profile into said part; c) determining the currents passing through the inductors in order to compare said currents with said target values and determine current deviations (δI 1 corr , δl 2 corr , ..., δl p corr ) to be corrected, and sending correction instructions to said control units (M1, M2, ..., Mp) in accordance with said current deviations.
摘要:
The invention concerns a device for supplying direct charging current (CHj) to an arc furnace. The device comprises at least a transformer (28, 29) powered at its primary coil with a three-phase alternating current, a rectifier (RDi) for delivering a rectified voltage and a rectified current and dc-to-dc converter means controlled by a current setpoint (Irefj) and placed between the output of at least a rectifier and the charge (CHj). The direct current Ichj supplying the charge is represented by the formula Ichj = Pref/Vchj, wherein: Pref is a substantially constant physical quantity and Vchj is the value of the voltage measured at the terminal of the charge (CHj). The invention is applicable in the field of steel production.