Synchronous machine with switching element in the excitation circuit
A separately excited synchronous machine ( 1 b 1 k ) with an excitation circuit on the side of the rotor includes an excitation winding ( 3 ) and a power supply for the excitation winding ( 3 ) as well as a switching element ( 8 a, 8 e ) for connecting the power supply to the excitation winding ( 3 ). Further, the synchronous machine ( 1 b 1 k ) comprises a first stator-side primary winding ( 5 a 5 f ) and a first rotor-side secondary winding ( 6 a 6 f ). Moreover, the synchronous machine ( 1 b 1 k ) may comprise a) a tap of the first rotor-side secondary winding ( 6 d ) connected to a control element ( 9 a, 9 e ) of the switching element ( 8 a, 8 e ) or b) a second rotor-side secondary winding ( 14 d ), which is coupled to the first stator-side primary winding ( 5 a 5 f ) and connected to a control element ( 9 a, 9 e ) of the switching element ( 8 a, 8 e ).
1. A separately-excited synchronous machine comprising:
a rotor-side circuit arrangement;
an excitation circuit in said rotor-side circuit arrangement;
said excitation circuit having an excitation winding;
a power supply for said excitation winding;
a rotor-side secondary winding at least partially forming said power supply;
a switch configured to connect said power supply to said excitation winding;
said rotor-side secondary winding being electrically coupled to a first stator-side primary winding;
said rotor side secondary winding having a tap, said tap being connected to a control of said switch.
2. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control to open said switch with a delay after termination of voltage at said primary winding.
3. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
a field effect transistor drain-source path forming said switch;
a field effect transistor gate electrode forming said control; and,
a field effect transistor containing said drain-source path and said gate electrode.
4. A separately-excited synchronous machine as claimed in claim 3 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control, said capacitor being arranged between said gate electrode and a source electrode of said field effect transistor.
5. A separately-excited synchronous machine as claimed in claim 3 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control, said capacitor being arranged between said gate electrode and a drain electrode of said field effect transistor.
6. The separately-excited synchronous machine as claimed in claim 3 , wherein:
said field effect transistor has an avalanche effect sufficient to dissipate stored inductive energy of said excitation winding subsequent to transistor cut-off.
7. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
an insulated gate bipolar transistor emitter-collector path forming said switch;
an insulated gate bipolar transistor gate electrode forming said control;
an insulated gate bipolar transistor containing said emitter-collector path and said gate electrode; and,
said capacitor being arranged between said gate electrode and a collector electrode of said insulated gate bipolar transistor.
8. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
an insulated gate bipolar transistor emitter-collector path forming said switch;
an insulated gate bipolar transistor gate electrode forming said control;
an insulated gate bipolar transistor containing said emitter-collector path and said gate electrode; and,
said capacitor being arranged between said gate electrode and an emitter electrode of said insulated gate bipolar transistor.
9. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
a zener diode arranged in parallel to said switch.
10. A separately-excited synchronous machine as claimed in claim 1 , further comprising:
a varistor arranged in parallel to said switch.
11. A separately-excited synchronous machine comprising:
a rotor-side circuit arrangement;
an excitation circuit in said rotor-side circuit arrangement;
said excitation circuit having an excitation winding;
a power supply for said excitation winding;
a first rotor-side secondary winding at least partially forming said power supply;
a switch configured to connect said power supply to said excitation winding;
said first rotor-side secondary winding being electrically coupled to a first stator-side primary winding; and,
a second rotor-side secondary winding which is electrically coupled to said first stator-side primary winding, said second rotor-side secondary winding being connected to a control of said switch.
12. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
a common core, said first rotor-side secondary winding and said second rotor-side secondary winding being arranged on said common core.
13. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control to open said switch with a delay after termination of voltage at said primary winding.
14. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
a field effect transistor drain-source path forming said switch;
a field effect transistor gate electrode forming said control; and,
a field effect transistor containing said drain-source path and said gate electrode.
15. A separately-excited synchronous machine as claimed in claim 14 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control, said capacitor being arranged between said gate electrode and a source electrode of said field effect transistor.
16. A separately-excited synchronous machine as claimed in claim 14 , further comprising:
a capacitor connected between said rotor-side secondary winding and said control, said capacitor being arranged between said gate electrode and a drain electrode of said field effect transistor.
17. The separately-excited synchronous machine as claimed in claim 14 , wherein:
said field effect transistor has an avalanche effect sufficient to dissipate stored inductive energy of said excitation winding subsequent to transistor cut-off.
18. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
an insulated gate bipolar transistor emitter-collector path forming said switch;
an insulated gate bipolar transistor gate electrode forming said control;
an insulated gate bipolar transistor containing said emitter-collector path and said gate electrode; and,
said capacitor being arranged between said gate electrode and a collector electrode of said insulated gate bipolar transistor.
19. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
an insulated gate bipolar transistor emitter-collector path forming said switch;
an insulated gate bipolar transistor gate electrode forming said control;
an insulated gate bipolar transistor containing said emitter-collector path and said gate electrode; and,
said capacitor being arranged between said gate electrode and an emitter electrode of said insulated gate bipolar transistor.
20. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
a zener diode arranged in parallel to said switch.
21. A separately-excited synchronous machine as claimed in claim 11 , further comprising:
a varistor arranged in parallel to said switch.
22. A separately-excited synchronous machine comprising:
a rotor-side circuit arrangement;
an excitation circuit in said rotor-side circuit arrangement;
said excitation circuit having an excitation winding;
a power supply for said excitation winding;
a rotor-side secondary winding at least partially forming said power supply;
said rotor-side secondary winding being electrically coupled to a first stator-side primary winding;
a switch configured to connect said power supply to said excitation winding;
a resistive load connected in parallel to said switch;
a control configured to controllably selectively open and close said switch;
a control circuit containing said control, said control circuit including a rotor-side voltage source configured to power said control;
an opto-coupler configured to controllably connect said rotor-side voltage source to said control so as to operate said switch, said opto coupler having a photo-sensitive element in said control circuit, and said opto-coupler having a controllable light source configured to provide a control signal to said photo-sensitive element.