Methods for starting a combustion turbine and combustion turbine generator configured to implement same methods

A method for starting a combustion turbine power generator comprising a shaft, a combustion turbine for driving the shaft when operating add having a starting rotational speed, a rotor connected to the shaft, a stator surrounding the rotor, a DC-field exciter comprising an armature connected to the shaft and a field surrounding the armature so that the rotor is connected to receive all DC electrical power from the armature of the DC-field exciter, and

• a turning gear for rotating the shaft between a nominal rotational speed and an upper rotational speed, the method comprising:
• rotating the shaft with the turning gear to the upper rotational speed thereof to cause the DC-field exciter to provide all of the DC electrical power to the rotor upon reaching the upper rotational speed,
• supplying electrical power to the stator as the shaft is rotating so that the stator cooperates with the rotor to operate as a motor to increase a rotational speed of the shaft up to the starting rotational speed of the combustion turbine;
• and
• disengaging the turning gear after supplying electrical power to the stator.

A combustion turbine power generator comprising:

• a shaft;
• a combustion turbine for driving said shaft when operating and having a staring rotational speed;
• a rotor connected to said shaft;
• a stator surrounding said rotor;
• a DC-field exciter comprising an armature connected to said shaft and a field surrounding said armature, supplying a rotating rectifier, said rectifier connected to said rotor to supply all DC electrical power thereto;
• a turning gear for rotating said shaft;
• a stator power supply for supplying variable frequency and magnitude electrical power to said stator;
• and
• a starting controller connected to said turning gear and said stator power supply for controlling said turning gear to rotate said shaft so that said Dc-field exciter provides all of the DC electrical power to said rotor, and
• controlling said stator power supply to supply electrical power to said stator as said shaft is rotating so that said stator cooperates with said rotor to operate as a motor to increase a rotational speed of said shaft up to the starting rotational speed of said combustion turbine;
• wherein the turning gear has a nominal rotational speed and an upper rotational speed;
• and wherein starting controller causes the shaft to be rotated with the turning gear and the rotational speed of the shaft to be increased from the nominal rotational speed to the upper rotational speed;
• wherein the stator power supply supplies electrical power to the stator upon the shaft reaching the upper rotational speed;
• and
• wherein the turning gear disengages the shaft substantially concurrently with the stator power supply starting to supply electrical power to the stator.