This power supply device includes: a power interconnection path connecting a power interconnection port to a power conversion unit via a first switch; a stand-alone power supply path leading from an auxiliary input port via a second switch to an output port to which a load is connected; a storage-battery-side power supply path leading from a storage battery via the power conversion unit to the output port; and a control unit, the control unit causing the power conversion unit to charge/discharge the storage battery when interconnected with a commercial power grid, the control unit supplying power to the load via one of the stand-alone power supply path and the storage-battery-side power supply path when disconnected from the commercial power grid, the control unit switching the power supply path from the one to the other within an extremely short time period such as not to influence the load.

Embodiments herein described provide systems and techniques for performing black start operations. For example, one embodiment provides a method for performing black start operations. The method generally includes operating a wind turbine in a wind park in a first mode to provide power to an alternating-current (AC) grid using a control system. The control system may include a reactive power control leg and an active power control leg. The method also includes switching operation of the wind turbine from the first mode to a second mode based on an indication to perform a black start of an electrical grid and by activating a controller with an integral action to thereby increase output power of the wind turbine, the controller being coupled between the reactive power control leg and the active power control leg, and providing power to the electrical grid while operating in the second mode.

A method for controlling a wind power installation, comprising the following steps: measuring a grid voltage of an electrical power supply grid, setting a DC-link voltage at a converter of the wind power installation depending on the measured grid voltage and using a first time constant and a second time constant, wherein the first time constant is different than the second time constant.

A cascaded H-bridge (CHB) inverter for higher rated power conditioning systems which operates at medium voltages while providing high power quality and low dv/dt. By incorporating battery energy storage, the power conditioning system operates at night to provide power to a load or grid and stabilizes the system during sudden changes in climatic conditions. Various energy storage system (ESS) configurations such as AC side coupled ESS, dual active bridge based ESS, and chopper based ESS configurations for cascaded H-bridge inverters are described. A comparison of these configurations on the basis of cost, control complexity, controller hardware requirements was performed and the advantages of chopper based ESS configurations over other ESS configurations was demonstrated. A control algorithm for the chopper based configurations was developed to operate the system in standalone and grid-connected modes of operation.

An electrical distribution grid energy management and router device, or GER device, may be installed in a distribution grid, and route power from power supply to one or more power consumers. The GER devices described herein may provide platforms to add one or more features to a distribution transformer, provide additional features and benefits to both the utility company and end consumer, and may serve as a platform for providing other features, such as communications services, local and remote management, and intelligence to components of the distribution grid. A GER device may include sensors to measure electrical properties of incoming and outgoing power, and may include an electrical circuit layer having a central DC power stage. A GER device may also include a communications platform for one or more communication devices to communicate with a utility, power consumers, other electrical devices/parties, and/or other GER devices to form a micro-grid.

An electrical distribution grid energy management and router device, or GER device, may be installed in a distribution grid, and route power from power supply to one or more power consumers. The GER devices described herein may provide platforms to add one or more features to a distribution transformer, provide additional features and benefits to both the utility company and end consumer, and may serve as a platform for providing other features, such as communications services, local and remote management, and intelligence to components of the distribution grid. A GER device may include sensors to measure electrical properties of incoming and outgoing power, and may include an electrical circuit layer having a central DC power stage. A GER device may include a physical layer providing a communications platform for one or more communication devices that may communicate with other GER devices to form a micro-grid, a utility, power consumers, third parties, and other electrical devices.

A converter controller is provided, by which the current valves are controlled by means of a switching frequency. It is provided to alter the switching frequency in a step-wise manner between a first and at least one second integral multiple of the grid frequency. According to the invention, this is effected in that the switching frequency is switched over cyclically, and a frequency spacing between the switching frequencies is at least double the grid frequency, specifically in such a manner that none of the switching frequencies is an integral multiple of another of the switching frequencies. In this way, harmonics can be selectively reduced, no intermediate frequencies being produced, owing to the integrality in relation to the grid frequency.

A converter controller is provided, by which the current valves are controlled by means of a switching frequency. It is provided to alter the switching frequency in a step-wise manner between a first and at least one second integral multiple of the grid frequency. According to the invention, this is effected in that the switching frequency is switched over cyclically, and a frequency spacing between the switching frequencies is at least double the grid frequency, specifically in such a manner that none of the switching frequencies is an integral multiple of another of the switching frequencies. In this way, harmonics can be selectively reduced, no intermediate frequencies being produced, owing to the integrality in relation to the grid frequency.

The present disclosure relates to a recloser control that provides autosynchronization of a microgrid to an area electric power system (EPS). For example, a recloser control may include an output connector that is communicatively coupled to a recloser at a point of common coupling (PCC) between the area EPS and the microgrid. The recloser control may include a processor that acquires a first set of measurements indicating electrical characteristics of the area EPS and acquires a second set of measurements indicating electrical characteristics of the microgrid. The recloser control may send synchronization signals to a microgrid controller to synchronize the microgrid controller based on the first set of measurements and the second set of measurements.

The present disclosure relates to a recloser control that provides autosynchronization of a microgrid to an area electric power system (EPS). For example, a recloser control may include an output connector that is communicatively coupled to a recloser at a point of common coupling (PCC) between the area EPS and the microgrid. The recloser control may include a processor that acquires a first set of measurements indicating electrical characteristics of the area EPS and acquires a second set of measurements indicating electrical characteristics of the microgrid. The recloser control may send synchronization signals to a microgrid controller to synchronize the microgrid controller based on the first set of measurements and the second set of measurements.