A safety shut-down system for a solar energy installation includes a DC to AC inverter converting DC power from a photovoltaic solar array to AC power and generating remote control signals to enable or disable the flow of DC power from each individual photovoltaic panel or string of panels to a photovoltaic output circuit. One or more manual switches, one of which may be at a service entrance for electrical power to the installation, are operative to cause the DC to AC inverter to disable all DC power from the photovoltaic solar array; this also occurs when the DC to AC inverter is shut off. A storage battery may selectively receive DC power from one or more photovoltaic panels or strings of panels for charging. The DC to AC inverter may generate AC power from the battery when the photovoltaic solar array is disabled.

A safety shut-down system for a solar energy installation includes a DC to AC inverter converting DC power from a photovoltaic solar array to AC power and generating remote control signals to enable or disable the flow of DC power from each individual photovoltaic panel or string of panels to a photovoltaic output circuit. One or more manual switches, one of which may be at a service entrance for electrical power to the installation, are operative to cause the DC to AC inverter to disable all DC power from the photovoltaic solar array; this also occurs when the DC to AC inverter is shut off. A storage battery may selectively receive DC power from one or more photovoltaic panels or strings of panels for charging. The DC to AC inverter may generate AC power from the battery when the photovoltaic solar array is disabled.

A single- or multi-phase DC to AC converter system suited for solar energy installations achieves cost reduction by eliminating low-frequency power transformers. One DC input polarity is selectively switched to an output terminal when the instantaneous AC output from a second output terminal is desired to be of the opposite polarity, while the other DC input polarity is used to form an approximation to a segment of a sine wave of the desired polarity at the second output terminal. The approximation for each phase is built in a multilevel fashion by outputting, at different times, voltage levels that differ by an integer multiple of a predetermined voltage step size, to the respective live AC output terminal through an associated low pass filter. A common-mode AC signal is thereby created on the balanced DC input lines at a frequency which is the AC output frequency times the number of phases, and which is useful for detecting ground faults in the DC circuit.

An aggregation control system for adjusting electric power between a plurality of facilities via a mobile storage battery apparatus, wherein each of the plurality of facilities includes a control apparatus that controls charging and discharging of the mobile storage battery apparatus, and the aggregation control system includes a server apparatus coupled to each control apparatus; and wherein the server apparatus: creates a charge-discharge condition for the mobile storage battery apparatus on the basis of management information for electric power demand and supply at a specified facility among the plurality of facilities; compares a charge-discharge request to a control apparatus of the specified facility with the charge-discharge conditions; and issues a command to the control apparatus to charge or discharge the mobile storage battery apparatus according to a result of the comparison.

An adaptive electrical power distribution panel receives electrical power from at least an alternative power source other than a utility electric grid, and selectively outputs power to a plurality of branch circuits, appliances, or devices. An internal or remote controller monitors conditions. In response to the monitored conditions, the controller algorithmically divides the plurality of branch circuits, appliances, or devices into a first group to receive power from the alternative power source and a second group to not receive power from the alternative power source, and breaks electrical connections between the alternative power source and the second group. The monitored conditions may include operating parameters the grid; an instantaneous or average individual current flow; and a charge state of storage batteries. The division into groups may also be in response to stored information, such as a priority of, or history of current usage by, each branch circuit, appliance, or device.

A DC to AC inverter for solar energy installations is configured to convert DC input power at a first voltage to a desired AC output power waveform. The inverter includes multilevel circuitry configured to define a plurality of different levels, wherein each level is defined by lower and upper voltage values; a jittering controller configured to jitter between the lower and upper voltage values in each level in order to generate a preliminary AC waveform by producing waveform values between the lower and upper voltage values within each level; and a low pass filter configured to filter the preliminary AC waveform to remove the jittering in order to provide a smooth output AC waveform.

Apparatus and methods for recovering energy in a petroleum, petrochemical, or chemical plant as described. The apparatus includes a fluid process stream flowing through a petroleum, petrochemical, or chemical process zone. There are at least one variable-resistance power-recovery turbine, a portion of the first process stream flowing through the first power-recovery turbine to generate electric power as direct current therefrom. There is a single DC to AC inverter electrically connected to at least one power-recovery turbine, and the output of the DC to AC inverter electrically connected to a first substation.

An adaptive electrical power distribution panel receives electrical power from at least an alternative power source other than a utility electric grid, and selectively outputs power to a plurality of branch circuits, appliances, or devices. An internal or remote controller monitors conditions. In response to the monitored conditions, the controller algorithmically divides the plurality of branch circuits, appliances, or devices into a first group to receive power from the alternative power source and a second group to not receive power from the alternative power source, and breaks electrical connections between the alternative power source and the second group. The monitored conditions may include operating parameters the grid; an instantaneous or average individual current flow; and a charge state of storage batteries. The division into groups may also be in response to stored information, such as a priority of, or history of current usage by, each branch circuit, appliance, or device.

The invention relates to a system and method for supplying AC output power to at least one desired AC load. Values of electrical currents and/or voltages are measured by an energy measurement device within the system and an AC output power demand of the AC load is determined. An inverter unit inverts DC power received via the internal DC bus to AC power to supply AC output power to the connected AC load. The invention further comprises that the controller controls the electrical energy consumption of the inverter unit based on the AC output power demand.

A power management method includes a step A of transmitting a power command message for controlling a distributed power supply from a power management server to a local control apparatus, the power management server managing a plurality of facilities, the distributed power supply being individually provided in each facility, and the local control apparatus being individually provided in each facility, wherein the step A includes a step of transmitting the power command message based on a specifying result or an estimating result of a local operation plan of the distributed power supply in each facility.