A drive device for operating an electrical machine has a regulator for driving a rotor winding, which has a highside switch and a de-energization switch. A first terminal of the rotor winding can be connected to a positive supply terminal via the high-side switch, the first terminal of the rotor winding can be connected to a negative supply terminal via a semiconductor component, and a second terminal of the rotor winding can be connected to the negative supply terminal via the de-energization switch. The drive device is arranged to enter a safe state in the presence of at least one fault by disconnecting and/or de-energizing the rotor winding from the positive supply terminal. At least one of the switches is designed to be redundant; and/or the regulator has a plurality of measuring points.

The method of control according to the invention slaves a DC voltage generated by the alternator to a predetermined setpoint value by controlling an excitation current flowing in an excitation circuit comprising an excitation winding of a rotor of the alternator. The excitation current is controlled by means of a semiconductor switch, in turn controlled by a control signal having a predetermined period. The method comprises a detection of a failure of the excitation circuit. At least one short-circuit of the excitation winding is detected. According to another characteristic of the method, the control signal is generated on the basis of a combination of a setpoint signal formed by pulses of the predetermined period exhibiting a duty ratio representative of the setpoint value and of a detection signal indicative of the short-circuit.

A rotary electrical machine includes a switch for supplying power to a field winding and a controller. A ratio of an on-time to a switching cycle of the switch, i.e., a duty ratio which is larger than the duty ratio corresponding to the field current that gives the maximum reduction amount of the inductance of the field winding with respect to an increasing amount of the field current in a range that the field current can take and which has a predetermined value less than 100%. The controller calculates the duty ratio on the condition that an upper limit of the duty ratio is set as the predetermined value and turns on/off the switch based on the calculated duty ratio, and sets the predetermined value to be larger as a rotation speed of a rotor is higher, or as a d-axis current flowing through an armature winding is larger.

A synchronous machine and related systems include a stator and rotor separated by an air gap. The rotor includes a rotating DC power supply coupled to exciter windings disposed adjacent the air gap. Power from air gap harmonics, including air gap slot harmonics induce current in the exciter windings, which is rectified and supplied to the rotor field windings. In operation, a desired current level in the rotor field windings can be achieved through control of the DC power supply or superposition of harmonics into the stator winding current which induces the prescribed current in exciter windings.

A master generator is configured to use a duty upper limit value and a duty lower limit value to perform duty restriction processing on a PWM signal in continuous Y cycles out of generated X cycles, and transmit the PWM signal after the restriction processing to a slave generator. The slave generator is configured to receive the PWM signal after the restriction processing transmitted from the master generator as a received PWM signal, and determine that a reception abnormality exists when the received PWM signal is received as a signal representing a duty less than the duty lower limit value or a duty more than the duty upper limit value in continuous (X−Y+1) cycles.

A system for variable speed drives using generators adjusting the motor frequency having a plurality of main generators 1, 2, 3 and 4 as the means of adjusting a plurality of AC motors frequency, a processor is provided that opens a main bus tie breaker in a power system to create two separate power systems, power source A and power source B, wherein power source a is powered by a generator 1 and a generator 2. and power source b is powered by a generator 3 and a generator 4, wherein the generators 1-4 are configured to operate on a droop curve wherein the output frequency of the generator is slightly reduced as the load increases.

A vehicle charging apparatus includes: an electric generator 3 that is driven by an internal combustion engine 1 and outputs an adjustable alternating-current voltage; a rectifier 4 that converts the outputted alternating-current voltage to a direct-current voltage; an electric storage device 5 that is charged with the converted direct-current voltage; and a voltage sensor 6 that measures an output voltage of the rectifier 4. The vehicle charging apparatus is provided with a control device 7 that controls the electric generator 3 for a charging voltage to be a target charging voltage calculated from the output voltage in order to suppress a charging current to be lower than a charging current upper limit value when the electric storage device 5 is charged. It thus becomes possible to achieve efficiency higher than that of a charging apparatus in the related art while preventing deterioration or damage of the electric storage device.

A rotary transformer for an electrical machine includes a rotary printed circuit board and a stator printed circuit board. The rotary printed circuit board is operatively connected to the stator printed circuit board for relative rotation with respect to the stator printed circuit board. A conductor is fixed to the one of the printed circuit boards and includes a spiral coil for transferring electrical energy between the rotary printed circuit board and stator printed circuit board.

A control device for rotating electric machine, which controls a rotating electric machine as a charging electric generator, using an inverter circuit, the control device including: an energization amount generating unit for generating a first electric generation mode in which an energization amount for a field winding and an energization amount for an armature winding of the rotating electric machine are controlled and the inverter circuit is driven to perform electric generation, and a second electric generation mode in which an energization amount for the field winding is controlled to perform electric generation; and an energization signal generating unit for, on the basis of variation-related information relevant to variation in one of electric generation torque and electric generation current of the rotating electric machine, performing switching between the first electric generation mode and the second electric generation mode, and generating energization signals for the field winding and the armature winding.

A control device for rotating electric machine, which controls a rotating electric machine as a charging electric generator, using an inverter circuit, the control device including: an energization amount generating unit for generating a first electric generation mode in which an energization amount for a field winding and an energization amount for an armature winding of the rotating electric machine are controlled and the inverter circuit is driven to perform electric generation, and a second electric generation mode in which an energization amount for the field winding is controlled to perform electric generation; and an energization signal generating unit for, on the basis of variation-related information relevant to variation in one of electric generation torque and electric generation current of the rotating electric machine, performing switching between the first electric generation mode and the second electric generation mode, and generating energization signals for the field winding and the armature winding.