Electric synchronous machine which is excited via rotating rectifiers

• US 4,591,775 A
• Filed: 02/12/1985
• Issued: 05/27/1986
• Est. Priority Date: 02/17/1984
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Radmer, Alfred, Nussel, Lothar
• Primary Examiner(s): Smith, Jr., David
• Application Number:
  US06/700,979
• Time in Patent Office: 469 Days
• Field of Search: 318/711-719, 322/59
• US Class Current: 318/711
• CPC Class Codes: H02P 25/03 with brushless excitation
• CPC Class Codes: H02P 9/12 for demagnetising; for reducing effects of remanence; for preventing pole reversal

Abstract

An electric synchronous machine is excited via rotating rectifiers by an exciter machine. To this end, the three-phase winding of the exciter machine is connected to two Y-connected rectifiers having different current conduction directions. One end of the field winding of the synchronous machine is connected to the central point of the three-phase winding. In addition, there is provided between the Y-point of the rectifiers and the other end of the field winding one thyristor each, to the control electrodes of which a parallel-connected voltage sensitive firing device is coupled. Furthermore, stationary electrical elements are connected to the exciter device via switches and auxiliary slip rings and liftable brushes. These elements contain a d-c current source which can be connected between the control electrodes and the cathodes of each thyristor in the forward direction in order to fire the former, as well as a capacitor which can be connected, for quenching, parallel to each thyristor, and also a de-energizing resistor which can be connected via antiparallel diodes in parallel with the field winding. In this manner, the direction of the field current of the synchronous machine can be reversed in order to obtain a given pole wheel position.

Claims

1. An exciter arrangement for an electric synchronous machine, the synchronous machine having an exciter winding excited via rotating rectifier means from a rotating, Y-connected three-phase winding of an exciter machine, three outputs of the three-phase winding being coupled to the rectifier means, the rectifier means being Y-connected and having a Y-point, the Y-point being coupled to one end of the exciter winding, the other end of the exciter winding being coupled to a central point of the three-phase winding of the exciter machine, auxiliary slip ring means being provided on a rotating shaft of the exciter machine, said auxiliary slip ring means being coupled to said central point of the three-phase winding and being coupled to stationary electrical means by liftable brush means contacting said slip ring means and further including switch means coupled to said brush means, said rectifier means comprising first and second rectifier means for conducting current from said three-phase winding having different current conduction directions, each rectifier means having a Y-point, and further comprising first and second thyristor means coupled between respective Y-points of said first and second rectifier means and one end of said exciter winding, the control electrodes of each of said thyristor means being coupled to voltage sensitive firing means, the auxiliary slip ring means comprising first auxiliary slip ring means coupled to one end of the exciter winding, second auxiliary slip ring means coupled to the other end of the exciter winding, third and fourth auxiliary slip ring means respectively coupled to the Y-points of the first and second rectifier means, fifth and sixth auxiliary slip ring means coupled to the respective control electrodes of the first and second thyristor means,

the stationary electrical means comprising d-c voltage source means selectively coupled between the control electrode and the cathode of respective ones of the thyristor means so as to fire the respective thyristor means, capacitor means selectively coupled in parallel across the cathode and anode of each thyristor means, and de-energizing means selectively coupled in parallel with the exciter winding by selected ones of anti-parallel connected diode means.

2. The exciter arrangement for an electric synchronous machine recited in claim 1, wherein the capacitor means is coupled to charging means via switch means.