A control device includes an electric motor, a battery, a capacitor, a power source selection portion, a determination unit configured to determine whether the battery is normal, and a control unit configured to select, as a control mode of the electric motor, one of a first mode and a second mode in which a power consumption amount of the electric motor is reduced as compared to when the electric motor is driven in the first mode, and drive the electric motor in the selected control mode. When the battery is transitioned from a state of being determined to be normal to a state of being determined to be not normal, the control unit switches the control mode from the first mode to the second mode and then makes the power source selection portion select the capacitor.

A drive apparatus includes a DC link; a rectifier to convert power of an external power supply into predetermined DC power to be supplied to the DC link; a motor to rotationally drive a compression mechanism; a supporter to magnetically support a rotating shaft of the compression mechanism; a first driver to drive the motor with power from the DC link, to cause the motor to execute regenerative operations of converting power from the rotating shaft into electric energy, and to output regenerative power to the DC link; and a second driver to drive the supporter with the power from the DC link, wherein the first driver causes the motor to execute the regenerative operations so that a voltage of the DC link becomes higher than a voltage of the DC link when the power of the external power supply is normally supplied.

UPS machine comprising a synchronous machine (9) coupled to an accumulator (10) of kinetic energy, which accumulator essentially comprises: a body (12) with a main shaft; a hollow drum (18) able to rotate about the axle; a pony motor, for starting the drum (18); a rotor (20) fastened to the main shaft coaxially with the drum (18), which is equipped with coils (24) in order to electromagnetically couple the drum (18) and the rotor (20); characterised in that: the rotor (22) comprises a core (21) made of iron with a certain number of poles (22) that are delineated by notches (23) parallel to the main shaft (11) and that are distributed around the circumference of the core (21) which, for each poll (22), is provided with a winding (24) wound in the notches (23) around the pole (22) in question; the cumulative width of all of the poles (22) in the narrowest portion thereof is at least equal to the cumulative width.

Embodiments of systems and methods disclosed provide a hydraulic fracturing unit that includes a reciprocating plunger pump configured to pump a fracturing fluid and a powertrain configured to power the reciprocating plunger pump. The powertrain includes a prime mover and a drivetrain, the prime mover including a gas turbine engine. The hydraulic fracturing unit also includes auxiliary equipment configured to support operation of the hydraulic fracturing unit including the reciprocating plunger pump and the powertrain. A power system is configured to power the auxiliary equipment. The power system includes a power source and a power network. The power source is configured to generate power for the auxiliary equipment. The power network is coupled to the power source and the auxiliary equipment, and configured to deliver the power generated by the power source to the auxiliary equipment. Associated systems including a plurality of hydraulic fracturing units are also provided.

A system for providing backup power to a facility includes a generator and a controller. The controller is configured to operate the generator until a condition is met, determine a load history that occurs while operating the generator until the condition is met, determine a cool-down time based on the determined load history, and run the generator to the point when the condition is met and in an unloaded condition for the cool-down time.

A power transforming apparatus for supplying power to a motor having a magnetic bearing includes: a converter configured to, in an initial operation, receive AC power, and an auxiliary circuit performing initial charging by rectifying the AC power to a second power and supplying the rectified second power to an inverter controller and a magnetic bearing controller. The inverter controller outputs a signal to an inverter using the second power and controls the inverter to supply a rectified DC voltage to the converter, and the converter is configured to, during a normal operation, stop supplying the second power to the inverter controller and control the rectified DC voltage to be supplied to the inverter controller and the magnetic bearing controller, and, based on a power failure being detected, outputs a control signal such that the second power is supplied to the inverter controller and the magnetic bearing controller.

An automatic switching interface box for generators in residential dwellings and small commercial applications provides a breaker box transfer switch for generators powering one or more electrical loads. In power blackout situations, the breaker box transfer switch uses a power control relay to keep the load power on, which eliminates the need for a hot generator plug, because the plug in box is not powered. The generator power output cord is plugged onto the male plug of the interface box, or hard wired thereto. If the auxiliary generator had been started and is at rated voltage, the load is immediately and automatically switched from the utility connection to the generator as electrical source. The relay keeps the prongs of the male plug safely unpowered until the generator is attached since the relay coil is powered by the generator output and the plug is connected to the normally open contacts.

A hybrid energy storage system is configured to control pulsed power. A first dynamo-electric machine is coupled to an inertial energy storage device and has multiple input stator windings configured to accept input power from a source. A polyphase output stator winding is configured to deliver electric power having a first response time to a DC bus. A secondary energy storage system is coupled to the DC bus and is configured to convert its stored energy to electric power in a bidirectional manner. A second dynamo-electric machine has an input stator winding and at least one polyphase output stator winding coupled to a converter, the converter coupled to a DC output. A polyphase boost exciter is configured to derive energy from the DC bus and excite the second machine input stator winding, wherein the second machine is configured to be excited at a faster rate than the first response time of the first machine.

A reserve power supply system for providing a supplemental source of electrical power to a main power source. The system includes a backup battery and a switch that can be controlled to couple the backup battery to the main power source when reserve power is needed. The system also includes a sensor to detect when the backup battery should be engaged and a system control unit.

A system and method for providing a backup power supply.