The invention relates to a method and a photovoltaic inverter (2) for determining the insulation resistance (R.sub.iso) of a photovoltaic system (1) relative to ground (PE). According to the invention, the voltage required for the measurement can be provided by the intermediate circuit (6) in the form of the intermediate circuit voltage (U.sub.Zk), and the measuring device (13) is designed to actuate an input short-circuit switch (S.sub.Boost) for short-circuiting the DC input (3) with the AC disconnector (8) open, as a result of which the intermediate circuit voltage (U.sub.Zk) can be applied to the DC input (3) in the reverse direction, and the measuring device (13) is configured to record measured voltages (U.sub.M1, U.sub.M2) with the switch (S.sub.iso) of the voltage divider (14) open and closed, and to determine the insulation resistance (R.sub.iso) from the measured values of the two measured voltages (U.sub.M1, U.sub.M2) recorded with the switch (S.sub.iso) of the voltage divider (14) open and closed.

The invention relates to a method and a photovoltaic inverter (2) for determining the insulation resistance (R.sub.iso) of a photovoltaic system (1) relative to ground (PE). According to the invention, the voltage required for the measurement can be provided by the intermediate circuit (6) in the form of the intermediate circuit voltage (U.sub.Zk), and the measuring device (13) is designed to actuate an input short-circuit switch (S.sub.Boost) for short-circuiting the DC input (3) with the AC disconnector (8) open, as a result of which the intermediate circuit voltage (U.sub.Zk) can be applied to the DC input (3) in the reverse direction, and the measuring device (13) is configured to record measured voltages (U.sub.M1, U.sub.M2) with the switch (S.sub.iso) of the voltage divider (14) open and closed, and to determine the insulation resistance (R.sub.iso) from the measured values of the two measured voltages (U.sub.M1, U.sub.M2) recorded with the switch (S.sub.iso) of the voltage divider (14) open and closed.

Systems and methods are provided for protecting solar panels from damage due to overheating. A system comprises a solar panel and a control system. The solar panel comprises a plurality of solar cells, and a plurality of thermochromic temperature sensors thermally coupled to different areas of the solar panel. The thermochromic temperature sensors are configured to change color in response to heat generated by the solar cells in the different areas of the solar panel. The control system is configured to detect colors of the thermochromic temperature sensors, determine a temperature of each area of the solar panel based on the detected colors of the thermochromic temperature sensors, and cause the solar panel to shut down in response to determining that the temperature of at least one area of the solar panel exceeds a predetermined temperature threshold.

Systems and methods are provided for protecting solar panels from damage due to overheating. A system comprises a solar panel and a control system. The solar panel comprises a plurality of solar cells, and a plurality of thermochromic temperature sensors thermally coupled to different areas of the solar panel. The thermochromic temperature sensors are configured to change color in response to heat generated by the solar cells in the different areas of the solar panel. The control system is configured to detect colors of the thermochromic temperature sensors, determine a temperature of each area of the solar panel based on the detected colors of the thermochromic temperature sensors, and cause the solar panel to shut down in response to determining that the temperature of at least one area of the solar panel exceeds a predetermined temperature threshold.

A mobile, electricity generating carport appliance with removable caster wheels and optional ground anchors has a framework with corner posts and a rectangular top, a base plate lying flat on a support surface with the corner posts joined securely to the baseplate, solar panels mounted to the top of the framework, a plurality of solar panels hinged along sides of the framework, one solar panel hinged along a top edge of each end of the framework, support apparatus hinged to posts on each side of the framework, adapted to support the plurality of solar panels hinged on each side of the framework, support apparatus hinged to posts on each end of the framework, adapted to support the one solar panel hinged on each end of the framework, and circuitry and wiring connecting the solar panels to a cable ending in a connector compatible with and connected to an inverter.

A mobile, electricity generating carport appliance with removable caster wheels and optional ground anchors has a framework with corner posts and a rectangular top, a base plate lying flat on a support surface with the corner posts joined securely to the baseplate, solar panels mounted to the top of the framework, a plurality of solar panels hinged along sides of the framework, one solar panel hinged along a top edge of each end of the framework, support apparatus hinged to posts on each side of the framework, adapted to support the plurality of solar panels hinged on each side of the framework, support apparatus hinged to posts on each end of the framework, adapted to support the one solar panel hinged on each end of the framework, and circuitry and wiring connecting the solar panels to a cable ending in a connector compatible with and connected to an inverter.

The application provides a photovoltaic inverter system, an automatic locating method of RSDs and a fault control method thereof. The automatic locating method comprises turning off all RSDs and sampling a voltage of an output end of each RSD as a first voltage before an inverter operates; turning on any one of the RSDs and sampling a voltage of the output end of each RSD as a second voltage, determining all RSDs in a photovoltaic module string to which the RSD in a turned-on state belongs according to the first voltage and the second voltage, and repeating the above control method for any one of the RSDs outside the photovoltaic module string to which the determined RSDs belong until corresponding connection relations between all RSDs and all photovoltaic module strings are determined.

The application provides a photovoltaic inverter system, an automatic locating method of RSDs and a fault control method thereof. The automatic locating method comprises turning off all RSDs and sampling a voltage of an output end of each RSD as a first voltage before an inverter operates; turning on any one of the RSDs and sampling a voltage of the output end of each RSD as a second voltage, determining all RSDs in a photovoltaic module string to which the RSD in a turned-on state belongs according to the first voltage and the second voltage, and repeating the above control method for any one of the RSDs outside the photovoltaic module string to which the determined RSDs belong until corresponding connection relations between all RSDs and all photovoltaic module strings are determined.

A solar tracker apparatus includes an adjustable hanger assembly that has a clam shell hanger assembly. The clam shell hanger assembly may hold a torque tube comprising a plurality of torque tubes configured together in a continuous length from a first end to a second end. A center of mass of the solar tracker apparatus may be aligned with a center of rotation of the torque tubes, in order to reduce a load of a drive device operably coupled to the torque tube. Solar modules may be coupled to the torque tubes. The solar tracker includes an energy system that includes solar panel, a DC to DC converter, a battery, and a micro-controller. The energy system may facilitate full operation movement of the tracker apparatus without any external power lines.

The disclosure describes a method for detecting an arc in a direct-current (DC) circuit comprising a DC load, a DC source supplying the DC load, and a circuit arrangement arranged between the DC source and the DC load. A power flow P between an input and an output of the circuit arrangement is suppressed by means of a switching circuit through cyclical interruption such that the power flow P is enabled in an active time window with the first period Δt.sub.1 and the power flow P is suppressed in an inactive time window with the second period Δt.sub.2. Via detection of an input current I.sub.in flowing at the input and/or an input voltage U.sub.in applied to the input and comparison of values of the input current I.sub.in and/or input voltage U.sub.in detected in the inactive time window with a current threshold value I.sub.TH or a voltage threshold value U.sub.TH an arc presence criterion is signaled if the input current I.sub.in detected in the inactive time window falls below the current threshold value I.sub.TH and/or the input voltage U.sub.in detected in the inactive time window does not exceed the voltage threshold value U.sub.TH. The application also describes a circuit arrangement for detecting an arc and a photovoltaic (PV) inverter including such a circuit arrangement.