The invention provides an electrical generating system comprising an AC electrical generator (G) having an output, and a capacitor arrangement (Ca) provided at the output of the generator and arranged so as to offset a drop of voltage from no-load to full-load occurring at the output of the generator. As described, the generator (G) is a permanent-magnet generator having a plurality of terminals and associated output lines, and the capacitor arrangement comprises a respective capacitor (Ca) conn...

A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a minimal number of current sensors and controlling at least one of a machine flux, an output voltage and generator torque, based on the stator or rotor flux magnitude and position. This method comprises measuring a plurality of current amounts; transforming them into a two phase reference system; measuring a DC voltage; measuring voltage amounts in the g...

A method of controlling an induction generator such as an automotive starter-alternator or a windmill is disclosed. The method comprises using a plurality of flux sensing coils and controlling at least one of a machine flux and an output voltage based on the stator or rotor flux magnitude and position. One embodiment of the invention only uses flux sensing coils without requiring current sensors or position sensors. This method comprises the steps of measuring a stator flux in the generator usin...

An induction system of the invention is adapted to apply coordinate transformation to the excitation current reference vector corresponding to the primary interlinkage magnetic flux vector reference value and the primary current vector so that they exist in the same coordinate system, thereafter to control the secondary current vector so that the primary interlinkage magnetic flux vector is in correspondence with the primary interlinkage magnetic flux vector, thereby allowing the primary side of...

An induction machine driven as a generator has its output connections coupled to the output connections of a static inverter circuit, connected to operate not as an inverter but as a switching system. A capacitor is coupled to the bus conductors of the switching system. D-c excitation is furnished to the induction generator system only for starting, and is then disconnected. At rated speed the static inverter circuit operates as a switching system to regulate connection of the capacitor to the i...

A method for enhancing the operation of an electrical power supply includes selecting a prime mover having a chosen power rating. An induction motor having a first power rating at a rated speed and a second power rating at an overspeed is chosen. The overspeed may be at least about 10%, or at least about 25%, 50%, 75%, 10 to 300%, 25 to 300%, or 50 to 100%, greater than the rated speed. The induction motor may be chosen so that the second power rating is substantially the same as the chosen powe...

The disclosed voltage generating system includes certain known components, such as an induction machine driven as a generator, the output connections of which are coupled to the normal load connections of a switching system, which can be a bridge-type inverter. The system switching frequency f.sub.1 is regulated by firing pulses from a logic circuit in turn controlled by an oscillator. By controlling operation of the inverter switches with respect to the synchronous frequency (mechanical rotatio...

A method and apparatus for operating a variable speed power generation system in which the generated output of an induction generator is adjusted by controlling current in the secondary side of the induction generator. Rotation speeds of the induction generator coupled to a prime mover are detected, a secondary current command for controlling a difference between a detected rotation speed and a speed command to be zero is generated, and current in the secondary side of the induction generator is...

An induction machine is driven to operate as a generator, and has its electrical output conductors coupled to a switching system, which can be an inverter circuit. An oscillator and logic circuit are connected to regulate the switching of the power switches, such as thyristors, in the inverter circuit which operates as a switching system. The thyristors in the switching system are regulated to switch at a frequency sufficiently below the synchronous frequency of the induction machine to enable t...

A background discussion of induction machine equivalent circuits, including operation as an induction generator, is provided. Selective shorting of the machine terminals is described, to convert at least some of the mechanical input energy into electrical field energy for the machine. Systems are described for accomplishing the selective shorting with a single-phase machine, including sensing of the zero-crossing of the output voltage to insure that the shorting is effected at the appropriate ti...