A method and a photovoltaic inverter determines the system capacitance of a photovoltaic system relative to ground. The voltage required for the measurement can be provided by the intermediate circuit in the form of the intermediate circuit voltage, and the measuring device is designed to actuate an input short-circuit switch for short-circuiting the DC input with the AC disconnector open, as a result of which the intermediate circuit voltage can be applied to the DC input in the reverse direction, and the measuring device is configured to determine the system capacitance from the temporal waveform of the measured voltage after the switch of the voltage divider is closed.

A photovoltaic system, an inverter, and a direct current electric arc detection method. The system includes an inverter, a controller, and at least two converters. When detecting an electric arc, the controller controls an input current of the inverter to decrease to extinguish the arc. After the arc is extinguished, the controller controls an output voltage of at least one photovoltaic string to decrease to a first preset voltage, where the first preset voltage is less than an input voltage of the inverter when the electric arc is detected, or controls a maximum value of an output current of the at least one photovoltaic string to be a second preset current, where the second preset current is less than the input current of the inverter when the electric arc is detected. In the foregoing two recovery manners, no electric arc recurs.

A photovoltaic system, an inverter, and a direct current electric arc detection method. The system includes an inverter, a controller, and at least two converters. When detecting an electric arc, the controller controls an input current of the inverter to decrease to extinguish the arc. After the arc is extinguished, the controller controls an output voltage of at least one photovoltaic string to decrease to a first preset voltage, where the first preset voltage is less than an input voltage of the inverter when the electric arc is detected, or controls a maximum value of an output current of the at least one photovoltaic string to be a second preset current, where the second preset current is less than the input current of the inverter when the electric arc is detected. In the foregoing two recovery manners, no electric arc recurs.

Disclosed are a transformer, and a power conversion apparatus or a photovoltaic module including the same. The transformer includes a first core including a base, a first protrusion member to protrude from the base, and a first external wall spaced apart from the first protrusion member and to surround the first protrusion member, a first winding wound in the first core, a second core including a second base, a second protrusion member to protrude from the second base, and a second external wall spaced apart from the second protrusion member and to surround the second protrusion member, a second winding wound in the second core, and a barrier rib configured to separate the first winding and the second winding from each other. Thus, ease of processing is achieved and radiation of electromagnetic noise is reduced.

Disclosed are a transformer, and a power conversion apparatus or a photovoltaic module including the same. The transformer includes a first core including a base, a first protrusion member to protrude from the base, and a first external wall spaced apart from the first protrusion member and to surround the first protrusion member, a first winding wound in the first core, a second core including a second base, a second protrusion member to protrude from the second base, and a second external wall spaced apart from the second protrusion member and to surround the second protrusion member, a second winding wound in the second core, and a barrier rib configured to separate the first winding and the second winding from each other. Thus, ease of processing is achieved and radiation of electromagnetic noise is reduced.

It is disclosed an insulation impedance detection circuit and detection method of a photovoltaic inverter system. The photovoltaic inverter system includes one or more input circuits and an inverter circuit, each of the input circuit electrically coupled to the inverter circuit through a positive bus and a negative bus, with a first equivalent impedance R.sub.p between the positive bus and a protective earth point and a second equivalent impedance R.sub.n between the negative bus and the protective earth point. The detection circuit includes: a bus voltage sampling circuit coupled to the positive bus and the negative bus for generating a first bus voltage and a second bus voltage; a protective earth voltage sampling circuit coupled to the protective earth point for generating a first protective earth voltage and a second protective earth voltage; and a controller for calculating an equivalent insulation impedance.

It is disclosed an insulation impedance detection circuit and detection method of a photovoltaic inverter system. The photovoltaic inverter system includes one or more input circuits and an inverter circuit, each of the input circuit electrically coupled to the inverter circuit through a positive bus and a negative bus, with a first equivalent impedance R.sub.p between the positive bus and a protective earth point and a second equivalent impedance R.sub.n between the negative bus and the protective earth point. The detection circuit includes: a bus voltage sampling circuit coupled to the positive bus and the negative bus for generating a first bus voltage and a second bus voltage; a protective earth voltage sampling circuit coupled to the protective earth point for generating a first protective earth voltage and a second protective earth voltage; and a controller for calculating an equivalent insulation impedance.

An inline DC feeder DC/DC voltage step-up harness for photovoltaic solar facilities includes a housing, a plurality of PV input connectors, an at least one PV output connector. The housing incorporates a DC/DC converter, and has an input and an output. The plurality of PV input connectors are operatively connected to the housing at the input. The PV output connector is operatively connected to the housing at the output.

An inline DC feeder DC/DC voltage step-up harness for photovoltaic solar facilities includes a housing, a plurality of PV input connectors, an at least one PV output connector. The housing incorporates a DC/DC converter, and has an input and an output. The plurality of PV input connectors are operatively connected to the housing at the input. The PV output connector is operatively connected to the housing at the output.

Disclosed is a photovoltaic air conditioning system, which includes a photovoltaic cell array; an air conditioning unit, comprising a first cabinet, a first inverter module and a variable frequency compressor, wherein the first inverter module and the variable frequency compressor are installed in the first cabinet, and the first inverter module is configured to supply power to the variable frequency compressor; a current conversion unit, comprising a second cabinet, a rectifier module and a second inverter module, wherein the second cabinet resides outside of the first cabinet, the rectifier module and the second inverter module are installed in the second cabinet.