A converter and an operation method thereof are provided. A converter interconnected with a wind power generation farm includes a power monitor unit configured to detect a direct-current voltage of an entire system interconnected with the converter, a control unit configured to compare the detected direct-current voltage of the entire system with a reference voltage and adjust an alternating-current voltage that is supplied to the wind power generation farm to a preset value, and a switching unit configured to perform a switching operation based on the adjusted preset value to convert alternating-current power into direct-current power.

The gas turbine power generation system of the present invention repeats either the supply or absorption of power, in addition to generating power. The gas turbine power generation system is provided with a first rotation shaft, a compressor, a combustor, a first turbine upon which combustion gasses impinge, thereby causing the first turbine to rotate, and driving the first rotation shaft, a rotating electrical machine connected to the first rotation shaft, a speed adjustment mechanism for controlling the speed of the compressor by adjusting an air volume, a frequency converter for converting a frequency of power, the frequency converter being connected between the rotating electrical machine and a power system via a power line, and a controller for obtaining a request for an output from the gas turbine power generation system and controlling the combustor on the basis of the request. With respect to the frequency converter, the controller performs frequency converter control for changing the rotational speed of the rotating electrical machine on the basis of the request. The rotating electrical machine supplies or absorbs power in accordance with the change in the rotational speed. With respect to the speed adjustment mechanism, the controller performs speed adjustment mechanism control for setting the rotational speed to a reference value.

A multiple uninterruptible power supply system includes at least two uninterruptible power supply modules. Each uninterruptible power supply module has a control unit with the control unit coupled to a synchronization bus. The uninterruptible power supply module are synchronized to each other with one of the uninterruptible power supply modules being operated as a sync master UPS and its control unit sending synchronization signals on the synchronization bus that are received on the synchronization bus by control units of each of the other uninterruptible power supply module which are each operated as a slave UPS synchronized to the sync master UPS. When a bypass power source for the uninterruptible power supply module that is being operated as the sync master becomes unqualified, another one of the UPS modules is operated as the sync master and its control unit then sends out the synchronization signals.

A multiple uninterruptible power supply system includes at least two uninterruptible power supply modules. Each uninterruptible power supply module has a control unit with the control unit coupled to a synchronization bus. The uninterruptible power supply module are synchronized to each other with one of the uninterruptible power supply modules being operated as a sync master UPS and its control unit sending synchronization signals on the synchronization bus that are received on the synchronization bus by control units of each of the other uninterruptible power supply module which are each operated as a slave UPS synchronized to the sync master UPS. When a bypass power source for the uninterruptible power supply module that is being operated as the sync master becomes unqualified, another one of the UPS modules is operated as the sync master and its control unit then sends out the synchronization signals.

An energy storage system for a building includes a battery asset configured to store electricity and discharge the stored electricity for use in satisfying a building electric load. The system includes a planning tool configured to identify one or more selected functionalities of the energy storage system and generate a cost function defining a cost of operating the energy storage system over an optimization period. The cost function includes a term for each of the selected functionalities. The planning tool is configured to generate optimization constraints based on the selected functionalities, attributes of the battery asset, and the electric energy load to be satisfied. The planning tool is configured to optimize the cost function to determine optimal power setpoints for the battery asset at each of a plurality of time steps of the optimization period.

Control of supplying power to a storage device is performed based on carbon emission strength or a power rate. A battery center 13 that constitutes a storage device 11 performs radio communication with a gateway 4 and is controlled by the gateway 4. The gateway 4 collects a measured value of power consumed by electric appliances in a home and obtains the carbon emission strength in real time. A solar panel 9 is provided and a battery of the storage device 11 is charged with an output of the solar panel. The battery is also charged with direct current power obtained from power from outside. The power is stored in the storage device 11 based on the carbon emission strength by charging control.

A grid connection power conversion device having isolated operation function for connecting a distributed power supply to a commercial power system is provided which comprises an inverter for converting DC power to AC power, a capacitor connected between the inverter and the commercial power system, a commercial voltage amplitude detection circuitry, an amplitude adjustment circuitry to increase an amplitude of an output voltage from the inverter stepwise from a given value to match the amplitude of the commercial system voltage, and a start-up control circuitry to control the grid connection power conversion device so that after the amplitude adjustment circuitry adjusts the amplitude of the output voltage from the inverter, after the start-up, to match the amplitude of the commercial system voltage detected by the commercial voltage amplitude detection circuitry, the start-up control circuitry connects the inverter to the commercial power system to start grid-connected operation.

Apparatus comprise control circuitry configured to control a line frequency of a microgrid by directing a first set of one or more electrical devices coupled to the microgrid to produce a change in the line frequency through a change in operation of the first set, such that a second set of one or more electrical devices coupled to the microgrid adjusts operation in response to a detected line frequency changeably produced by the first set. Related methods and additional apparatus and methods are disclosed. Apparatus and methods are disclosed that use line frequency and/or line voltage. Apparatus and methods are also disclosed that use control history.

An integrated multi-mode, large-scale electric power support system supplies on demand at least 2,500 kW to an electrical grid with low harmonic distortion either from co-located solar or wind renewable energy DC power sources or in combination with, or alternatively, from system stored energy DC power sources via a plurality of DC-to-AC inverters with phase-shifted outputs. The power support system can also inject on demand grid power factor correcting reactive power. An alternative high voltage power support system can supply on demand at least 50 megawatts to the grid.

A wind turbine converter system with a rectifier and an inverter and a converter controller has at least first and second converter strings. The converter system is controlled by a master-converter controller and a slave-converter controller. The master-converter controller controls the first converter string and the slave-converter controller controls the second converter string. The master-converter controller receives commands from a superordinate wind turbine controller, provides the slave-converter controller with string-control commands on the basis of the superordinate control commands, and controls the conversion operation of the first converter string on the basis of the superordinate control command. The slave-converter controller receives the string-control commands from the master-converter controller and controls the conversion operation of the second converter string on the basis of the string-control commands received. The first and the second converter strings can be arranged in a bipolar configuration giving access to a neutral point. Fault detection can be performed based on current through the neutral. The system is capable of fault ride-through. Also, in case of failure of the master-converter controller, a redundant unit takes its place.