A method for operating an electric island power network having a renewable energy generation plant, a conventional energy generation plant, an energy store, and an energy consumer, includes: defining first operating parameters for the network for when a frequency and/or voltage of the network is outside defined limits; operating the network using the first operating parameters causing the frequency and voltage of the network to both be within the defined limits; defining second operating parameters for the network after the expiration of a defined time span over which the frequency and voltage have remained within the defined limits, the second operating parameters being defined such that operating the network using the second operating parameters causes the network to operate cost-optimally. If verified that the second operating parameters ensure that the frequency and voltage remain within the defined limits, operation using the second operating parameters is maintained. Otherwise, it is discontinued.

Provided is a server (10) having an attribute information receiving unit (15) which receives attribute information of an electric power output apparatus (30) having a function of outputting electric power from the electric power output apparatus (30); an output condition transmitting unit (18) which transmits an output condition determined in accordance with the attribute information to the electric power output apparatus (30); an analysis result receiving unit (16) which receives a processing result obtained by performing predetermined processing on output waveform data at the time when the electric power output apparatus (30) outputs electric power according to the output condition; and an evaluating unit (17) which calculates an electric power output performance of the electric power output apparatus (30) on the basis of the processing result and the output condition.

A method for determining a sequence of operation of at least one set of generator units of an electrical network includes assigning a rank to each generator unit; from a projected load curve, determining a minimum number of generator units; for each generator unit having a rank less than or equal to the minimum number of generator units, allocating in the sequence of operation the on state to the generator unit for each time interval; for each generator unit having a rank greater than the minimum number of generator units, allocating, by increasing rank, for each time interval of the sequence of operation the on state or the off state to the generator unit, and for each generator unit to which is assigned the on state at a given time interval of the sequence of operation, allocating an operating power, by optimisation of a cost function over a period.

A power source apparatus includes a plurality of first power sources, each connected to a load through a power supply line, and at least one second power source, which is a sub power source to be used when the first power source is unable to output a predetermined voltage. The second power source is connected in parallel to the power supply line of at least one of the first power source through a diode. The second power source is provided on an anode side of the diode, the load is configured to operate at a voltage equal to or more than a first voltage, the first power source outputs a second voltage higher than the first voltage, the second power source outputs a third voltage, which is higher than the first voltage, the voltage output through the diode from the second power source being lower than the second voltage.

Electrical power distribution system for supplying a set of fixed-frequency loads and a set of variable-frequency loads, includes a set of at least one fixed-frequency AC voltage generator and a set of at least one variable-frequency AC voltage generator, a DC distribution network supplying the variable-frequency loads by means of inverter stages, a first set of rectifier stages connected between the fixed-frequency generators and the distribution network, and a second set of rectifier stages connected between the variable-frequency generators and the DC distribution network. The first set of rectifier stages includes bidirectional rectifiers capable of providing a bidirectional transfer of power and protection means against fault currents connected between the bidirectional rectifiers and the distribution network.

An aircraft propulsion system (10) comprises at least first and second electrical generators (15a, 15b), each being configured to provide electrical power to a respective first and second AC electrical network (16a, 16b). The system (10) further comprises at least first and second AC electrical motors (19a, 19b) directly electrically coupled to a respective AC network (16a, 16b) and coupled to a respective propulsor (4), and a DC electrical network electrically coupled to the first and second AC networks (16a, 16b) via respective first and second AC to DC converters (17a, 17b), and to a further electrical motor 19c), the further electrical motor (19c) being coupled to a propulsor (4).

A system for monitoring and optimizing fuel consumption by a genset at an oil rig is described. Gensets require large amounts of fuel to initiate and to maintain in a standby, idling position. The system accesses data in a drill plan to determine the present and future power requirements and initiates gensets if needed; otherwise gensets can be shut down. Excess power can be stored in a power storage unit such as a capacitor, battery, or a liquid air energy storage unit.

The present disclosure discloses a method and apparatus for detecting a short-circuit capacity at a grid connection point of a wind turbine. The method includes: modulating, when a converter is in a grid-side no-load modulation state and a power grid is in a short-circuited state with respect to the converter, a reactive power reference value and a braking power reference value of the converter; collecting a modulated three-phase voltage signal and a modulated three-phase current signal at the grid connection point of the wind turbine; and obtaining, according to the modulated three-phase voltage signal and the modulated three-phase current signal at the grid connection point of the wind turbine as well as a rated line voltage at the grid connection point of the wind turbine, the short-circuit capacity at the grid connection point of the wind turbine.

A power generation system includes a plurality of photovoltaic cell panels for outputting DC power, a plurality of inverters for converting DC power into AC power, and a high-order device for communicating with the plurality of inverters. The high-order device is configured to acquire a predetermined power factor, and transmit a command value to each of the plurality of inverters so that the power factor corresponding to the predetermined power factor is achieved by a total output of the plurality of inverters. The high-order device is configured so as to determine a specific inverter that has room to increase the amount of reactive power output from among the plurality of inverters, to transmit a reactive power increasing command value for increasing reactive power to the specific inverter.

A method for determining parameters for controlling N electric generators at an instant t, the method including, for a required power P.sub.tot(t)=Σ.sub.i=1.sup.NP.sub.i(t) at an instant t with P.sub.i(t) the electric power supplied by the electric generator i at the instant t and a reserve power P.sub.reserve(t)≤Σ.sub.i=1.sup.N(P.sub.i.sup.max−P.sub.i(t)×δ.sub.i(t) at an instant t with P.sub.i.sup.max the maximum power that the electric generator i can develop and δ.sub.i(t) the coefficient of activation of the electric generator i which is equal to 1 when the electric generator is on and 0 when the electric generator is off, a step of determining the optimal power P.sub.i.sup.opt(t) at the instant t associated with each electric generator i so as to minimise the fuel consumption per unit of electrical energy produced $\mathrm{sfc}\left(t\right)=\frac{1}{P_{\mathrm{tot}}\left(t\right)}\underset{i=1}{\overset{N}{.Math.}}{f}_i\left(P_i\left(t\right)\right)\times P_i\left(t\right)$
with f.sub.i(x) the function giving the fuel consumption of the electric generator i for the electric power x.