ELECTRICAL CONTROL EQUIPMENT FOR DRILLING INSTALLATIONS WITH AC ELECTRICAL MOTORS WHICH IS SUPPLIED FROM LOW AND MEDIUM VOLTAGE POWER SOURCES

The invention relates to an electrical control equipment for drilling installations with AC electrical motors. According to the invention, the equipment is supplied with three-phase alternating current from a medium voltage supply network (12) by means of medium voltage station (1) which comprises a medium voltage input cell (14) which has the output terminals connected to a medium voltage alternating three-phase current bar system (A), whereto there are connected some input terminals of a medium voltage measuring cell (16) and some medium voltage cells (17, 18 and 19) for transformers, by means of which there are power supplied some primary windings of some transformers (22, 23 and 24) for supplying the rectifiers in a transformer station (8) and whose secondary windings are connected by some circuit breakers (26, 27, 28 and 29) to a low voltage alternating three-phase current bar system (B) in a station (11) for controlling the motor speed, wherefrom there are supplied with alternating current some power rectifiers (30 and 31) coupled to a direct current bar system (C) in a station (11) which supplies some inverters (32, 33, 34, 35 and 36) used for controlling the speed of alternating current motors (37 and 38) used for driving the mud pumps (39), of some alternating current electrical motors (40 and 41) used for driving a hoist (42) and an alternating current electric motor (43) for a rotary table (44). Invenţia se referă la un echipament electric de comandă şi reglare, pentru instalaţiile de foraj cu motoare electrice de curent alternativ. Echipamentul conform invenţiei este alimentat cu curent alternativ trifazat, de la o reţea de alimentare (12) de medie tensiune, prin intermediul unei staţii (1) de medie tensiune, care conţine o celulă (14) de intrare de medie tensiune, care are conectate bornele de ieşire la un sistem (A) trifazat de bare de curent alternativ de medie tensiune, la care sunt conectate nişte borne de intrare ale unei celule (16) de măsură de medie tensiune şi nişte borne de intrare ale unor celule (17, 18 şi 19) de medie tensiune, pentru transformatoare prin care sunt alimentate nişte înfăşurări primare ale unor transformatoare (22, 23 şi 24) de alimentare redresoare, dintr-o staţie de transformatoare (8), şi ale căror înfăşurări secundare sunt conectate prin nişte întrerupătoare (26, 27, 28 şi 29), la un sistem (B) trifazat de bare de curent alternativ de joasă tensiune, dintr-o staţie (11) de comandă şi reglare a turaţiei motoarelo