The present application discloses a method for optimized design of an independent micro-grid system, the independent micro-grid system comprising diesel generators, wind powered generators, a photovoltaic array, and an energy storage battery, the optimization method referring specifically to a multi-objective optimization design model based on the independent micro-grid system. In terms of the optimization planning design model, the method takes into account a combined start-up mode for a plurality of diesel generators and a control strategy for coordinating between the energy storage battery and the diesel generators, such that the usage rate of renewable energy in the independent micro-grid is higher, and operations more economical and environmentally friendly. Regarding the stability of the system optimization planning design model, the method takes into account the reserve capacity needed for stability of the independent micro-grid. In terms of the solving algorithm of the optimization planning design model, the method employs a multi-objective genetic algorithm based on NSGA-II to implement multi-objective problem-solving, thereby allowing a multi-objective optimization of the three major objectives of economy, reliability, and environmental friendliness of an independent micro-grid system.

Techniques for power sharing in DC networks using virtual impedance frequency droop control are provided. In one aspect, a method for power sharing in a DC network having multiple electrical energy generation sources connected to at least one load includes the steps of, at each of the electrical energy generation sources: generating a controllable DC voltage; superimposing a controllable AC signal on top of the DC voltage; regulating the AC signal using virtual impedance frequency droop control; and determining a desired DC voltage output using the regulated AC signal. The DC voltage can then be regulated to match the desired DC voltage output. A system for power sharing in a DC network is also provided.

A distributed predictive control based voltage restoration scheme for microgrids, comprising: step 10) adopting a distributed finite time observer to acquire the global reference voltage for restoring the voltage of each local controller; step 20) each local controller adopts a droop control to acquire the local voltage value of each generation, and adds a secondary voltage compensation term into the droop characteristic formula to form the voltage reference value of a distributed generation; step 30) establishing a trended prediction model; step 40) acquiring a predictive control term at a current time as the secondary voltage compensation command, and acting on the local controllers; and step 50) determining, whether the local voltage of each distributed generation of the microgrid reaches the voltage reference value under the secondary voltage compensation command.

The present invention relates to a voltage source converter based DC connection method and a control method for implementing a system for maintaining respective different frequencies (multi-frequencies) by reflecting load quality levels of respective microgrids when multiple stand-alone microgrids are connected to each other in which voltage source converters (VSCs) installed at connection points of the microgrids for effectively controlling respective microgrids having different frequency control ranges present an effective control method based on a concept using normalizing frequencies of unit microgrids to be similarly applied in an islanded operation mode of multiple grid-connected microgrids as well as multiple stand-alone microgrids to avoid the same frequency criterion and enable an economic operation to which the load power quality level of the microgrid is reflected, thereby minimizing a transient to stably operate a microgrid system.

A power system and method for performing a blackstart on a microgrid. The power system includes at least a first power converter and a second power converter. The first power converter comprises a first controller having a plurality of startup sequences for performing the blackstart. The second power converter is electrically coupled to the first power converter at a point of common coupling. During the blackstart, the first controller is configured to select and perform one of the plurality of startup sequences according to a point at which the second power converter is within the second power converter's startup sequence during the blackstart. The first controller selects the one of the plurality of startup sequences according to a microgrid voltage at the point of common coupling.

The present invention relates to a trigeneration energy supply system having improved cooling and system use efficiency. The trigeneration energy supply system according to one embodiment of the present invention can comprise: a vacuum pump; a vacuum chamber inside which a vacuum is created by the vacuum pump; a condensed water storage tank positioned higher than the vacuum chamber, and prepared so as to store condensed water formed when steam generated by evaporating water brought inside the vacuum chamber is transferred to the inside of the tank by the vacuum pump; a cooling pipeline arranged to pass through the inside of the vacuum chamber cooled during the water evaporation and prepared to deliver cool air to a cooling load; and a small hydroelectric power generation system for generating electrical power by allowing the condensed water stored in the condensed water storage tank to be poured from at least the height of the condensed water storage tank.

A process/method is provided, which facilitates resource optimization considering all dispatchable resources as well as user rate charges, which are rate charges comprised of a base rate plus an incremental excess fee associated with designated usage parameters. The proposed system and method may utilize inputs to construct a periodic load profile over varied periods of time. The disclosure relates to forming a periodic load profile over varied periods of time based upon considerations of short-term and long-term cost for uses within microgrids to create microgrid resource schedules that optimize usage of loads and generation resources within a microgrid for minimizing both short-term energy charges and long-term demand charges while increasing microgrid resource efficiencies.

A power system and method for performing a blackstart on a microgrid. The power system includes at least a first power converter and a second power converter. The first power converter comprises a first controller having a plurality of startup sequences for performing the blackstart. The second power converter is electrically coupled to the first power converter at a point of common coupling. During the blackstart, the first controller is configured to select and perform one of the plurality of startup sequences according to a point at which the second power converter is within the second power converter's startup sequence during the blackstart. The first controller selects the one of the plurality of startup sequences according to a microgrid voltage at the point of common coupling.

Starter system for an electric motor (M) supplied by an electrical network (1), the starter system comprising an electronic control circuit (7) and an electronic switch (10) for controlling one phase of the motor (M), the electronic switch (10) being controlled by the control circuit (7). The starter system comprises a sensor (3) intended to deliver an analog signal (4) that is representative of the derivative of a current flowing through the phase of the motor (M), a detection board (5) comprising means for transforming said analog signal (4) into a binary signal (6) that is representative of the changes in sign of said analog signal, and comprising means for transmitting said binary signal to the control circuit (7), so as to optimize the control of the electronic switch (10).

An improvement to a utility (U) meter's (M) meter reading schema. The improvement includes a device (D) responsive to a native language with which a meter is programmed to convert communications to and from the meter from that native language into a neutral language. The neutral language is convertible by other meters programmed with different native languages into the native language of a particular meter for meters programmed with different native languages can communicate with each other. This allows facilities within a localized area of a utility's power grid (G) to form into a micro-grid (MG) in which meters programmed with the same or different native languages can communicate with each other without having communications between them routed through a central location of the utility.