Wound field synchronous machine control system and method

A wound field synchronous machine control system comprising:

• (a) alternating current (AC) voltage sensors for sensing AC phase voltage signals from the machine;
• (b) a phase controlled rectifier for rectifying the AC phase voltages and supplying rectified DC voltage;
• (c) a direct current (DC) voltage sensor for sensing a DC voltage signal from the rectifier;
• and
• (d) a controller for selectively using the AC phase voltage signals and the DC voltage signal to estimate a DC load voltage signal, obtaining a difference between a load voltage command and the estimated DC load voltage signal, and using the difference for controlling operation of the synchronous machine.

A wound field synchronous machine control method comprising:

• (a) obtaining auxiliary AC voltage of the wound field synchronous machine from terminals of an auxiliary windings;
• (b) rectifying the auxiliary AC voltage and supplying rectified DC voltage to a field winding of the wound field synchronous machine;
• and
• (c) using a voltage signal across the terminals of the auxiliary winding to obtain volt-second values of the auxiliary winding,
• wherein rectifying comprises using the volt-second values, wherein using the voltage signal across the auxiliary winding to obtain volt-second values of the auxiliary winding comprises using the voltage signal to measure voltage integrals, and using the voltage integrals to detect zero crossings and obtain the volt-second values.

A control method comprising:

• (a) obtaining a voltage signal across a winding;
• (b) using the voltage signal to measure voltage integrals;
• and
• (c) using the voltage integrals to detect zero crossings, obtain volt-second values, and synchronize firing angle control of switches of a phase controlled rectifier.

A wound field synchronous machine control method comprising:

• (a) obtaining auxiliary AC voltage of the wound field synchronous machine from terminals of an auxiliary winding;
• (b) rectifying the auxiliary AC voltage and supplying rectified DC voltage to a field winding the wound field synchronous machine;
• and
• (c) obtaining airgap flux values of the wound field synchronous machine,
• wherein rectifying comprises using the airgap flux values.

A wound field synchronous machine control method comprising:

• (a) obtaining a voltage signal from the wound field synchronous machine;
• (b) rectifying AC voltage and supplying rectified DC voltage to the wound field synchronous machine;
• (c) using the voltage signal to obtain volt-second values;
• and
• (d) obtaining airgap flux values of the wound field synchronous machine,
• wherein rectifying comprises using the volt-second values and airgap flux values.

A wound field synchronous machine control method comprising:

• (a) sensing AC phase voltage signals from the machine;
• (b) rectifying the AC phase voltages and supplying rectified DC voltage;
• (c) sensing a DC voltage signal from the supplied rectified DC voltage;
• (d) selectively using the AC phase voltage signals and the DC voltage signal to estimate a DC load voltage signal;
• (e) obtaining a difference between a load voltage command and the estimated DC load voltage signal;
• and
• (f) using the difference for controlling operation of the synchronous machine.

A traction vehicle comprising:

• (a) a wound field synchronous machine;
• and
• (b) a wound filed synchronous machine control system comprising:
• (i) an auxiliary winding for obtaining auxiliary AC voltage from the wound field synchronous machine,
• (ii) a phase controlled rectifier for rectifying the auxiliary AC voltage and supplying rectified DC voltage to the wound field synchronous machine, and
• (iii) a controller for using a voltage signal across the auxiliary winding to obtain volt-second values of the auxiliary winding and using the volt-second values for firing angle control of switches of the phase controlled rectifier.

A traction vehicle comprising:

• (a) a wound field synchronous machine;
• and
• (b) a wound field synchronous machine control system comprising
• (i) an auxiliary winding for obtaining auxiliary AC voltage from the wound field synchronous machine,
• (ii) a phase controlled rectifier for rectifying the auxiliary AC voltage and supplying rectified DC voltage to the wound field synchronous machine, and
• (iii) a controller for obtaining airgap flux values of the wound field synchronous machine and using the airgap flux values for firing angle control of switches of the phase controlled rectifier.

A traction vehicle comprising:

• (a) a wound field synchronous machine;
• and
• (b) a wound field synchronous machine control system comprising
• (i) alternating current (AC) voltage sensors for sensing AC phase voltage signals from the machine,
• (ii) a rectifier for rectifying the AC phase voltages and supplying rectifier DC voltage,
• (iii) a direct current (DC) voltage sensor for sensing a DC voltage signal from the rectifier;
• and
• (iv) a controller for selectively using the AC phase voltage signals and the DC voltage signal to estimate a DC load voltage signal , obtaining a difference between a load voltage command and the estimated DC load voltage signal, and using the difference for controlling operation of the synchronous machine, wherein the controller is configured to obtain an AC derived voltage estimate for comparison with the DC voltage signal and, when the DC voltage signal exceeds the AC derived voltage estimate, use the AC derived voltage estimate as the DC load voltage signal.