A method for controlling a switching circuit including an input port electrically coupled to a photovoltaic device and an output port electrically coupled to a load includes (1) entering a voltage limiting operating mode and (2) in the voltage limiting operating mode (i) causing a control switching device of the switching circuit to repeatedly switch between its conductive and non-conductive states in a manner which limits magnitude of an output voltage to a maximum voltage value, the output voltage being a voltage across the output port, and (ii) varying the maximum voltage value as a function of magnitude of an output current, the output current being a current flowing through the output port.

A PV-optimiser power system for a photovoltaic installation for supply of power from a photovoltaic installation. The system includes a first DC/DC converter connected to a PV panel and to one or more energy storage modules, and a second DC/DC converter, connected in parallel to the PV panel in a string of PV panels of a PV installation, wherein the second DC/DC converter is configured to operate as an optimiser and execute a maximum power point tracking algorithm (MPPT) to determine the maximum power output of the PV panel of the plurality of the PV panels in the string.

A distributed energy conversion system may include one or more DC power sources and two or more inverters to convert DC power from the power sources to AC power. The AC power from the two or more inverters may be combined to provide a single AC output. A module may include one or more photovoltaic cells and two or more inverters. An integrated circuit may include power electronics to convert DC input power to AC output power and processing circuitry to control the power electronics. The AC output power may be synchronized with an AC power distribution system.

Embodiments of this application disclose a control method for a photovoltaic power generation system and a photovoltaic power generation system, to reduce a photovoltaic energy loss. The method includes: presetting, by the photovoltaic power generation system, an upper limit value for each converter in the photovoltaic power generation system, where the upper limit value is a maximum voltage value of an output voltage to ground of the converter, and the output voltage to ground is a voltage difference between a positive output end of the converter and a ground point of the photovoltaic power generation system; and limiting, by the photovoltaic power generation system, an output voltage to ground of a target converter based on an upper limit value corresponding to the target converter, where the target converter may be any converter in the photovoltaic power generation system.

A plurality of photovoltaic (PV) modules are configured into a PV string to generate a PV string voltage in a solar power system. The number of PV modules per PV string is based on operating conditions at the solar power system site and cause the PV string voltage to exceed a maximum voltage specification when operating at the lowest expected ambient temperature at the site, but only exceeds the maximum voltage specification for a limited number of occurrences for which the operating conditions at the site cause the PV string voltage to exceed the maximum voltage specification. Under control of a string voltage control circuit, voltage bypass circuits selectively bypass the bypass photovoltaic module so as to eliminate the PV module from the PV string voltage when the operating conditions at the site cause the PV string voltage to exceed the maximum voltage specification.

Device for controlling solar driven water pumps with three selectable modes on the control panel being: I) speed mode with 100% use of the available solar DC power at all times; II) solar mode using available solar DC power only, and III) eco mode combining the use of the available solar DC power with the use of the AC power from a grid or a generator and/or batteries, by automatic switching between two stages, being (i) solar stage running on solar DC power only, and (ii) hybrid stage running with solar DC power and AC power from grid or generator and/or batteries like in speed mode. The purpose of the present disclosure is to preferentially use solar energy from solar panels over AC current from the electric grid or from a generator and/or batteries while ensuring sufficient pumping capacity.

A solar charging system for the vehicle includes a first photovoltaic (PV) module, a second PV module serially connected to the first PV module, and a differential power processing (DPP) transformer that converts power generated from the first PV module and the second PV module by using a magnetic body having a multi-winding structure.

Various examples are directed to a solar power electrolyzer system comprising a first electrolyzer stack, a second electrolyzer stack, a first converter and a first converter controller. The first electrolyzer stack may be electrically coupled in series with a photovoltaic array. The first converter may be electrically coupled in series with the first electrolyzer stack and electrically coupled in series with the photovoltaic array. The second electrolyzer stack electrically may be coupled at an output of the first converter. The first converter controller may be configured to control a current gain of the first converter.

A DC power feeding device includes a power feed line connected to a DC load, a first DC/DC converter provided between a solar battery and the power feed line, and a second DC/DC converter provided between a battery and the power feed line. A first controller controls the first DC/DC converter such that maximum power tracking control of the solar battery is performed in a normal state of a commercial AC power source. The first controller controls the first DC/DC converter such that the solar battery outputs a power smaller than a load power in a power failure. A second controller controls the second DC/DC converter such that the battery is charged in the normal state of the commercial AC power source. The second controller controls the second DC/DC converter such that DC voltage on the power feed line attains a reference voltage in the power failure.

System, device and method for exporting power are provided including at least one AC optimizer with plurality of DC inputs each connecting with respective one of plurality of DC sources, and independent maximum power point tracking (MPPT) performed for each respective DC source to extract power from each DC source for output and coupling to AC grid. When multiple AC optimizers are employed, with each AC optimizer having multiple DC inputs, each DC input can be connected to PV module with independent MPPT function. Since, each AC optimizer can serve multiple PV modules, significant cost saving and efficiencies can be achieved. Optionally, on PV sub-module level, each of the multiple DC inputs can be used as an independent MPPT channel for a PV sub-module cell string.