A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in the stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connects the single phase winding of the stator and the load and is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

A power generating apparatus is provided. The alternator includes a rotor, a stator, one or more sensors and an electrical circuit. The rotor includes a plurality of symmetric phase windings while the stator has a single phase winding. The excitation control device is configured to control the induced voltage generated in the stator by regulating the rotating magnetic field generated in the phase windings of the rotor. The excitation control device is also configured to regulate the engine speed responsive to calculated load power. The electrical circuit connects the single phase winding of the stator and the load and is configured in a way that the induced voltage generated in the single phase winding and the output voltage applied to the load are at the same frequency. This arrangement reduces costs of the apparatus.

An off-grid power generating apparatus is provided. The apparatus includes an engine, an alternator and an excitation control device. The alternator includes a rotor, a switch and a stator. The switch is movable between a first position and a second position. An output portion of the stator has first and second segments each of which has at least one coil. The first and second segments are operatively and separately connected with the switch. The first and second segments are connected in series at the first position and in parallel at the second position to provide a high voltage and a low voltage respectively. The excitation control device controls the output voltage to make it have a predetermined frequency, and to regulate the engine speed in response to the load power of the engine.

An off-grid power generating apparatus is provided. The apparatus includes an engine, an alternator and an excitation control device. The alternator includes a rotor, a switch and a stator. The switch is movable between a first position and a second position. An output portion of the stator has first and second segments each of which has at least one coil. The first and second segments are operatively and separately connected with the switch. The first and second segments are connected in series at the first position and in parallel at the second position to provide a high voltage and a low voltage respectively. The excitation control device controls the output voltage to make it have a predetermined frequency, and to regulate the engine speed in response to the load power of the engine.

An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

A voltage regulator for a generator having a dynamic voltage-to-frequency (V/F) ratio is disclosed. The voltage regulator may include a memory, a voltage calculator, and a selection module. The memory is configured to store a plurality of voltage-frequency curves for the generator. The voltage calculator is configured to receive data indicative of an output of the generator and configured to determine a resistance value from the output of the generator and a voltage value from the output of the generator. The selection module configured to select a voltage-frequency curve from the plurality of voltage-frequency curves in response to the resistance value and configured to select a voltage-frequency ratio from the selected voltage-frequency curve in response to the voltage value. An output adjustment for the generator is determined in response to the selected voltage-frequency ratio.

An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

An aircraft main power generation system includes a rotor shaft, a main power generator a permanent magnet, an exciter, an aircraft power bus, and a generator control unit. The generator control unit is configured to provide a control current to the exciter in response to a speed of the main power generator reaching a threshold speed and electrically couple the main power generator to the aircraft power bus in response to the speed of the main power generator reaching a minimum operating speed, the threshold speed being lower than the minimum operating speed; or provide a control current to the exciter in response to the speed of the main power generator reaching a predetermined speed and electrically coupling the main power generator to the aircraft power bus in response to a time period elapsing after the speed of the main power generator has reached the predetermined speed.

A power conversion apparatus capable of improving an EMI characteristic and an air conditioner including the same are disclosed. The power conversion apparatus includes an inverter including a plurality of switching elements corresponding to three phases, a gate driver configured to drive the switching elements of the inverter, and a noise reducer connected to the gate driver and configured to set switching noise occurrence times caused by the switching elements in the respective phases to be different.