METHOD FOR CONTROLLING A MULTI-PHASE AC INVERTER-FED ELECTRIC MOTOR

The invention relates to a method for controlling a multi-phase ac inverter-fed electric motor. The phases of the motor are divided into three-phase groups each of which is star-connected and is switched to a three-phase valve bridge, to the output of which an auxiliary three-phase valve bridge is switched via commutating capacitors, valves are embodied in the form of thyristors which are divided into the cathode and anode groups, the poles of the two bridges are connected in parallel and are switched to the output of a DC power supply via a smoothing reactor, wherein the control electrodes of all the thyristors are connected to a control unit which is used for transmitting and deleting control signals from each thyristor. The inventive method consists in forming a reference signal in each star, in counting, with respect to said reference signal, two specified time intervals, values of which are constant within a full range of the motor speeds of rotation from the values closed to zero to the maximum values, upon the expiration of the first time interval, in deleting the control signal of the thyristor of a phase to be switched off in the main bridge, in simultaneously transmitting the control signal of the thyristor of a phase to be switched off in the auxiliary bridge, upon the expiration of the second time interval, in deleting the control signal of the thyristor of a phase to be switched off in the auxiliary bridge and in simultaneously transmitting the control signal of the thyristor of a phase to be switched off in the main bridge. L'invention concerne un procédé de commande d'un moteur multiphasé commandé par redresseur. Les phases du moteurs sont réparties en groupes triphasés dont chacun est relié en étoile et connecté à un pont redresseur principal triphasé, à la sortie duquel on a connecté via des condensateurs de commutation un pont redresseur auxiliaire triphasé; les redresseurs se présentent comme des thyristors, les thyristors sont réparties en thyristors du groupe de cathodes et en thyristors du groupe d'anodes, les pôles de ces ponts sont connectés en parallèle et branchés via une bobine de lissage à la sortie d'une source de courant continu; les électrodes de commande de tous les thyristors sont branchées à l'unité de commande qui effectue l'envoi et la suppression des signaux de commande de chaque thyristor. L'invention se distingue en ce que dans chaque étoile on forme un signal de référence par rapport auquel on calcule des intervalles