A multi-power distributed storage system including a first power source; a second power source electrically connected to a common bus with the first power source; a single input port inverter electrically connected to the common bus. The system including a controller configured to communicate with at least the second power source, and the single input port inverter. The second power source including a plurality of battery banks and a plurality of bi-directional DC/DC converters configured to charge and discharge the plurality of battery banks and provide DC to the single input port inverter.

Disclosed is a method for controlling battery charging/discharging current in an off-grid mode of a hybrid energy storage inverter that is based on photovoltaic and a lithium battery. If photovoltaic energy is sufficient and a battery is not fully charged, the photovoltaic energy is supplied to a load and excess energy is supplied to the battery, to achieve maximum power point tracking of an output power of a photovoltaic component achieves maximum power point tracking; if photovoltaic energy is sufficient and a battery has been fully charged, the photovoltaic energy is supplied to a load, the excess photovoltaic energy is prohibited from charging the battery to prevent overcharging of the lithium battery; if photovoltaic energy is insufficient, the photovoltaic energy and battery energy are jointly supplied to a load, to achieve maximum power point tracking of an output power of a photovoltaic component.

An embodiment solar cell system includes a first photovoltaic (PV) module and a second PV module connected in series with each other, a differential power processing (DPP) converter configured to convert electricity generated by the first PV module and the second PV module, using a magnetic material having a multi-winding structure, and to provide the converted electricity to a battery, and a control signal generator configured to generate a control signal that controls a main switch for controlling an input-side current path and an output-side current path of the DPP converter, and to adjust a pulse width of the control signal such that a magnetizing current of the DPP converter becomes substantially zero.

Systems and methods relating to control systems for DC/AC inverters that receive power from photovoltaic based renewable energy resources. When the DC/AC inverters are operated in on-grid mode, the DC/AC inverters and the DC/DC control system operate to provide on-grid functions such as maximum power point tracking (MPPT) and DC-bus voltage regulation. When in off-grid mode, the DC/AC inverter and the off-grid control system regulates the resulting AC voltage from the DC/AC inverter to be within a pre-set range. The off-grid control system is based on differential geometry and uses a Lie Group controller for setting a frequency reference signal. The frequency and current amplitude reference are used to generate a sinusoidal current reference signal which is then tracked by a current controller. The current controller controls the switches in the DC/AC inverter to regulate the AC voltage.

An electric device is configured to be powered by direct-current power or alternating-current power supplied from a power converter. The power converter is configured to convert generation power of a photovoltaic cell into direct-current power or alternating-current power. The electric device includes a power detector configured to directly detect the generation power of the photovoltaic cell, or direct-current power or alternating-current power that is converted from the generation power of the photovoltaic cell.

A grid-forming photovoltaic (PV) system and method for both islanded connection and grid-connected mode is provided. An inverter converts PV array voltage to a voltage usable as a power source to an electric power system load. Active power-frequency droop controller regulates a modulator that generates drive signals to drive the inverter. Proportional integral controller generates a frequency shift value that adjusts output of the active power-frequency droop controller to yield a phase angle control for modulation of the inverter drive signals. A control mode switch selects among a plurality of control modes for operation of the proportional integral controller. A model-free control algorithm controls the control mode switch, including a control mode (221b) for synchronizing the PV system with the grid in which proportional integral controller (a) detects offset between inverter output voltage and grid output voltage and (b) generates the frequency shift value.

Methods for supplying a power from a photovoltaic panel to an electric motor; a computer-readable storage medium, a computer program product, a processor and a control circuit including instructions allowing carrying out the methods; and a variable speed drive adapted to implement the methods.

A photovoltaic inverter and a control method thereof, and a photovoltaic system. The photovoltaic inverter system includes a voltage conversion circuit, an inverter circuit, and a controller. The controller is configured to increase, based on an output power of the inverter circuit in a current time period and an output power of the inverter circuit in a first time period, an output power of the inverter circuit when the voltage conversion circuit does not work in a maximum power state. An increase of the output power of the inverter circuit is an estimated power increment value of the inverter circuit so as to stably increase an output power of the inverter while ensuring stable operation of the inverter and safe use of a power component, and improve power supply efficiency of the photovoltaic system.

An energy production system with energy store and method for operating an energy production system, solar cells, particularly a module including solar cells, being connected to an inverter, especially at its DC-side terminal, the inverter being connected at its terminal on the alternating-voltage side to a power consumer and/or an AC system, a DC/DC converter being connected, especially with its first DC-side terminal, in parallel to the solar cells, particularly to the module including solar cells, the DC/DC converter being connected to an energy store, particularly which is connected to the second DC-side terminal of the DC/DC converter.

An electrodialysis system controller is configured to be coupled to a power supply, and powered devices that include a pump, and an electrodialysis unit. The controller receives inputs including an input indicative of a flow rate through the electrodialysis unit, an input indicative of a concentration level of fluid in the electrodialysis unit, and an input indicative of a power differential (e.g., indicating a degree to which a power usage by the powered devices differs from available power of the power source), and provides outputs for controlling the powered devices, including an output for causing a variable current level to be applied in the electrodialysis unit, and an output for causing a variable fluid flow rate through the electrodialysis unit. The controller is configured to match the power usage to the available power, for example, to keep the power differential as small as possible, while maximizing the theoretical desalination rate of the electrodialysis system.