A method for determining when a connection of a power system to a grid has been disconnected. The method includes the power system supplying a first amount of reactive power to the grid to which the power system is connected, and the power system determining if there is a frequency change within the grid. This includes if the frequency change does not exceed a predetermined threshold, the power system supplying a second amount of reactive power to the grid, and if the frequency exceeds a predetermined threshold, the power system supplying a first amount of reactive power to the grid.

A method and apparatus is described for conveying the amount of loading of a power source to a load control device by controlling the frequency of the AC power output from that power source in a manner that controlled frequency represents the loading. At a different location in the power system, the frequency is measured and the corresponding loading of the power source is used to prevent or alleviate a power source overload.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

A method and system for controlling voltage and reactive power for electrical grids includes monitoring the output of the energy generation facilities at the point of interconnection (POI) of each energy generation facility to the power transmission system of the electrical grid. In addition, the voltage at a point of utilization (POU) is monitored to determine when the output voltage of the energy generation facilities must be adjusted to maintain voltage at the POU. In addition, when it is determined that energy generation facilities are exchanging reactive power, the voltage set points of the energy generation facilities are adjusted to reduce the exchanged power.

A method and system of controlling the time dependent transfer of electrical power between a first electrical network and a second electrical network is disclosed. The first electrical network is operable to provide instantaneous electrical power to the second electrical network located at a location, the second electrical network includes electrical generating capacity at the location based on stored energy accessible at the location. The method and system involves receiving at the second electrical network pricing information from the first electrical network, the pricing information associated with the future supply of electrical power by the first electrical network to the second electrical network and then modifying substantially in real time the transfer of electrical power between the first and second electrical networks in accordance with the pricing information and the electricity demand characteristics of the location.

The present invention relates to a method and plant of operating a grid forming power supply plant based on both a renewable energy, such as based on wind energy, solar energy, hydro energy, wave energy, and a carbon based energy, such as carbon based fuel. The grid includes a power input connection from a renewable power supply system and a power input connection from an carbon fuel engine based generator set. The generator set includes an engine for converting the carbon-based energy into motion energy, a generator, such as an alternator, for converting the motion energy into electrical energy, and a clutch for coupling and uncoupling of the engine with the generator. The system also includes a power buffer, such as a battery, subsystem for providing short term grid forming capacity and a plant grid forming controller for controlling grid parameters by means of controlling steps of a method. The plant grid forming controller includes interaction means for interacting with a control unit of the renewable power supply system, interaction means for interacting with a power buffer control unit, and interaction means for interaction with a control unit of the generator set.

A system, module, and method for generating reliable, high quality power on demand and off-grid includes a photovoltaic array for delivering DC power; a generator having a size ranging from about 5 kW to about 30 kW, and comprising an engine powered by hydrocarbon gas filtered through a coalescing filter and comprising an extended lubrication system; an uninterruptible power supply (UPS) comprising a storage battery, the UPS being coupled to the photovoltaic array for receiving the DC power, and to the generator by a bi-directional inverter for receiving, transmitting, and qualifying DC or AC power; and an intelligent controller coupled to the UPS for controlling output of the DC or AC power to at least one air compressor capable of providing compressed air to one or more pneumatic devices.

The application is directed to a power system that may be provided in a portable form and operationally configured for use at a work site as a single source of electric power, hydraulic power and pneumatic power for work site operations. In regard to hydraulic fracturing stimulation of a wellbore, the power system is operationally configured as the source of hydraulic power for transportable pumping units of a fracturing operation and for hydraulic power tools, as the source of pneumatic power for pneumatic power tools and as the source of electric power for electric power tools and electronic equipment at a well site.

The present disclosure is directed to systems and methods for economically optimal control of an electrical system. Some embodiments employ generalized multivariable constrained continuous optimization techniques to determine an optimal control sequence over a future time domain in the presence of any number of costs, savings opportunities (value streams), and constraints. Some embodiments also include control methods that enable infrequent recalculation of the optimal setpoints. Some embodiments may include a battery degradation model that, working in conjunction with the economic optimizer, enables the most economical use of any type of battery. Some embodiments include techniques for load and generation learning and prediction. Some embodiments include consideration of external data, such as weather.

Electrical power systems and methods of controlling electrical power systems are described. One such electrical power system comprises: a first ac bus and a first generator set configured to supply the first ac bus with ac electrical power; a second ac bus and a second generator set, configured to supply the second ac bus with ac electrical power; an interconnecting transformer connected between the first and second ac busses; a primary electrical load connected to both the first and second ac busses via a converter arrangement; an auxiliary load connected to the first ac bus; and a controller configured to control the first generator set according to a first droop control profile and to control the second generator set according to a second droop control profile, the first and second droop control profiles relating respective generator operating frequencies of the first and second generator sets to respective output powers of the first and second generator sets.