A power system includes at least one generator driven by at least one of a number (N) of prime movers, at least one energy storage device, and at least one control device, wherein the generator and the energy storage device provide electrical energy to a power grid having an external load. The power system includes at least one first measuring device for determining at least one first signal for a computer to determine what amount of electrical power (ΣP.sub.G,i) has to be generated by the at least one generator to meet a power requirement (P.sub.load) of the external load. The at least one control device is configured to receive the at least one first signal and to influence the control of the speed (n.sub.i) of the at least one of the number (N) of prime movers or the frequency (f) of the power grid taking into account the at least one signal to change the mechanical power generated by the at least one of the number (N) of prime movers such that the electrical power provided by the at least one generator approaches the power requirement (P.sub.load) of the external load in situations where the power requirement (P.sub.load) of the external load is at least partially provided for by the at least one energy storage device.

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.

In some embodiments, apparatuses and methods are provided herein useful to operating uninterruptible power supplies (UPS). The embodiments may include a plurality of capacitor banks, a UPS control circuit, and a central control circuit. The UPS control circuit is configured to cause an output of a clean electrical power, sample the clean electrical power, calculate control algorithm outputs based on the sampled clean electrical power, and output control algorithm results to the central control circuit. The central control circuit configured to detect a degradation of the plurality of capacitor banks, and transmit a service alert in response to the detection of the degradation of the plurality of capacitor banks.

A contactless battery system includes a sealable dustproof and waterproof case that houses a battery unit and at least one wireless power transmission coupler connected to the battery unit. The at least one wireless power transmission coupler is disposed with respect to at least one face of the sealable case to enable magnetic inductive signaling for charging, discharging, and communication with the battery.

Without physical contacts, the battery is inherently safe since voltage and current are not available to the touch. The lack of physical contacts also means that contact wear is eliminated and the battery modules have the benefit of inherent galvanic isolation. Since the battery system is sealed, internal intrusion detection systems may be used to detect improper attempts at battery changes or attacks on the electronics containing the usage and charging records in an attempt to increase the battery unit's value on the secondary battery market.

A power supply assembly including a primary source connection, a secondary source connection, a load connection, a primary current supply route, a supply switch system, and a converter system. The supply switch system is electrically located in the primary current supply route, and adapted for disconnecting the primary source connection from the load connection, the supply switch system including a plurality of supply switch units connected in parallel, each of the supply switch units including a controllable semiconductor switch. The power supply assembly includes a series impedance system having at least one series impedance member, and adapted to provide a balancing voltage drop for each of the parallel connected supply switch units of the supply switch system, wherein the balancing voltage drop is in series with a corresponding supply switch unit.

Disclosed is an electrical unit with a first port configured to be operatively connected to an AC-grid, a second port configured to be operatively connected to an AC-load, and a third port to be operatively connected to an AC-side of a first inverter. The electrical unit includes a first choke arranged between the third port and the second port. The electrical unit is configured to transfer electrical power provided by the first inverter from the third port via the first choke to the second port. The electrical unit is configured to provide grid-forming electrical power to the second port in case of disconnection from the AC-grid at the first port. Further disclosed is a backup power system and a method for operating a backup power system.

The present invention provides a method for detecting a ground fault in a battery of a uninterrupted power supply, the battery includes at least one string with multiple battery cells, the method including the steps of defining multiple individual battery blocks of battery cells along the at least one string, performing an reference impedance measurement for the multiple individual battery blocks at a first point of time, performing a verification impedance measurement for the multiple individual battery blocks at a second point of time, evaluating a change of measured impedance between the reference impedance and the verification impedance for the multiple individual battery blocks of the at least one string, and identifying a ground fault based on a correlated change of measured impedance of the multiple individual battery blocks along the at least one string. The present invention also provides a battery management system for managing a battery of a uninterrupted power supply, which is adapted to perform the above method. The present invention further provides a UPS device and a UPS system, each of which including an above battery management system.

A power supply assembly including a source connection system including a primary source connection, a load connection, a converter system including at least one converter controllable for reactive power compensation, an energy saving transfer route connecting the primary source connection electrically to the load connection, and bypassing the converter system, and a control system. The control system is adapted to provide an efficiency optimization operation including transferring energy through the energy saving transfer route, and controlling the converter system according to an optimal operating scheme that optimizes efficiency of the power supply assembly while keeping reactive power drawn from the source connection system within a required range, wherein the optimal operating scheme defines an optimal combination for the converters used for reactive power compensation such that each of the converters operates in a predetermined optimal efficiency range thereof.

Operating electric power is preferably supplied to a battery assembly control circuit from both a power converting device and a battery module. An electricity storage device includes a battery module including battery cells and a battery assembly control circuit, and a power converting device configured to charge the battery module with a commercial power supply and to supply electric power to a load. The power converting device supplies electric power to the battery assembly control circuit while an output voltage of the power converting device is higher than a predetermined voltage. The battery module starts to supply operating electric power to the battery assembly control circuit upon detecting that the electric power from the power converting device starts to be supplied to the battery assembly control circuit. The battery module stops supplying the electric power to the battery assembly control circuit when the battery module stops being discharged.

Examples of the disclosure include an uninterruptible power supply comprising an input configured to be coupled to a power source, an output configured to output power to a load, a main controller, a main logic power supply, an auxiliary logic power supply, and an auxiliary controller configured to receive power from the auxiliary logic power supply, the auxiliary controller being configured to receive a signal indicating that the load is not powered by the uninterruptible power supply, output a first signal to initiate shutdown of the main controller and the main logic power supply, and output a second signal to power-up the main controller and the main logic power supply after a predetermined period of time elapses after outputting the first signal.