Abstract: A shutdown control system and a shutdown control method are provided. A main circuit is a series circuit formed by connecting output ends of multiple shutdown circuits in series or a series-parallel circuit formed by connecting output ends of multiple such series circuits in parallel. Each of the multiple shutdown circuits is connected to at least one of direct current power supplies in a distributed power generation system. A control circuit includes a SCU, one or more ACUs, and multiple PCUs corresponding to the multiple shutdown circuits. The SCU and the ACU are configured to transmit respective mode control instructions when respective condition is satisfied. Each of the multiple PCUs is configured to obtain multiple criteria based on the mode control instructions, determine a target operation mode of a corresponding shutdown circuit, and control the shutdown circuit to operate in the target operation mode.

Abstract: A shutdown control system and a shutdown control method are provided. A main circuit is a series circuit formed by connecting multiple shutdown circuits in series or a series-parallel circuit formed by connecting multiple such series circuits in parallel. Each shutdown circuit is connected to at least one direct current power supply. A control circuit includes a SCU and multiple PCUs corresponding to the multiple shutdown circuits. The SCU and the PCUs are configured to transmit respective mode control instructions when respective condition is satisfied. Each PCU is configured to obtain multiple criteria based on the mode control instructions from the SCU and other PCUs, determine a target operation mode of the shutdown circuit corresponding to the PCU based on the multiple criteria, and control the shutdown circuit corresponding to the PCU to operate in the target operation mode.

Abstract: A shutdown control system and a shutdown control method are provided. A shutdown unit is a series circuit of multiple shutdown circuits connected in series or a series-parallel circuit of multiple such series circuits connected in parallel. Each shutdown circuit is connected to at least one direct current power supply. A SCU periodically transmits a first communication signal until receiving a first user command. A TCU controls states of a electrical energy transforming unit to control the operation state of a power generation system. Each PCU determines whether the first communication signal is received during a preset time period and whether the distributed power generation system operates in a power generation state, and controls a corresponding shutdown circuit to operate in a normal operation mode if at least one of the conditions is met; and otherwise operate in a security mode.

Abstract: A shutdown apparatus for a photovoltaic module is provided. Only one first switch is connected in series in an output circuit of the photovoltaic module, and a controller controls the first switch to be switched on in a normal power generation state and controls the first switch to be switched off in a shutdown state. If a short circuit fault occurs in the first switch, the controller controls a second switch connected in parallel with the photovoltaic module to be switched on, thereby causing the output of the photovoltaic module short-circuited and ensuring a reliable shutdown. In addition, the second switch is in the shutdown state when the photovoltaic module normally provides output, and the second switch does not cause losses to the output of the photovoltaic module, such that it is not necessary to select a device with a low impedance.

Abstract: An active bypass control device and an active bypass control method for a photovoltaic module are provided. The device includes a power source, a sampling unit, a controller, N first driving circuits, and N first controllable switches. Each first controllable switch is connected between one pair of bypass ports and includes a first switch and a first diode that are antiparallel. The first diode is reversely connected between the pair of bypass ports, and a control end of the first switch is connected to the controller via the corresponding first driving circuit. Based on a sampling signal provided by the sampling unit, the controller determines whether analog quantity information of the first controllable switch meets a predetermined bypass condition. If the predetermined bypass condition is met, the first switch is controlled to be turned on by using the first driving circuit.

Abstract: A voltage compensation apparatus for a photovoltaic system and a photovoltaic system are provided. The voltage compensation apparatus includes a current direction limiting circuit and a compensation power supply connected in series; or only includes a current direction limiting circuit. The current direction limiting circuit includes at least one limiting device configured to conduct a current in a unidirectional manner. The voltage compensation apparatus is connected between the output terminal of the converter and the ground. The photovoltaic system includes: a photovoltaic array, a converter, a transformer and the voltage compensation apparatus. An output terminal of the converter is connected with a primary side of the transformer, and an input terminal of the converter is connected with the photovoltaic array. The voltage compensation apparatus is configured to raise or lower a voltage at the output terminal of the converter.

Abstract: The application provides an access control method of parallel direct current power supplies and a device thereof. Direct current power supplies with single insulation resistances to ground failing to meet a first preset condition or causing a total insulation resistances to fail to meet a second preset condition are disconnected from a grid-connected inverter, and direct current power supplies with single insulation resistance to ground meeting the first preset condition and enabling the total insulation resistance to meet the second preset condition are connected with the grid-connected inverter for grid-connected inverting. Unlike in conventional technology, not all the direct current power supplies connected to a direct current bus are made stop outputting, thereby avoiding the loss of inverter power generation.

Abstract: A communication host and a photovoltaic power generation system are provided. The communication host includes an acquiring module, a determining module and a control module. The acquiring module is configured to acquire an operating state parameter of the system. The determining module is configured to determine whether the optimizer meets a first preset triggering condition based on the operating state parameter. In a case where the optimizer meets the first preset triggering condition, a first triggering instruction is transmitted, to instruct the system to decrease, in response to the first triggering instruction, the direct current bus voltage of the grid-connected inverter, and/or a second triggering instruction is transmitted, to instruct the system to increase, in response to the second triggering instruction, an output voltage limiting value of at least one of the optimizers meeting the first preset triggering condition.

Abstract: A communication host and a photovoltaic power generation system are provided. The communication host includes an acquiring module, a determining module and a control module. The acquiring module is configured to acquire an operating state parameter of the system. The determining module is configured to determine whether the optimizer meets a first preset triggering condition based on the operating state parameter. In a case where the optimizer meets the first preset triggering condition, a first triggering instruction is transmitted, to instruct the system to decrease, in response to the first triggering instruction, the direct current bus voltage of the grid-connected inverter, and/or a second triggering instruction is transmitted, to instruct the system to increase, in response to the second triggering instruction, an output voltage limiting value of at least one of the optimizers meeting the first preset triggering condition.

Abstract: A method for regulating output characteristics of a photovoltaic module and a DC/DC converter are provided. The DC/DC converter connected with the photovoltaic module determines whether an output voltage of the DC/DC converter detected in a real-time manner is greater than a first preset voltage threshold, and controls an output current of the DC/DC converter to be greater than a first preset current threshold and less than zero or control an output power of the DC/DC converter to be greater than a first preset power threshold and less than zero, in a case that the output voltage is greater than a first preset voltage threshold.

Abstract: An electrical energy control method and an electrical energy control apparatus for a photovoltaic system are provided. With the electrical energy control apparatus, a photovoltaic module meeting a preset electrical energy reverse flow condition is controlled to receive electrical energy stored on a direct current capacitor of the electrical energy control apparatus. That is, the photovoltaic modules are separately controlled to be heated by corresponding electrical energy control apparatuses, so as to avoid the issue in conventional technologies that, due to unified heating, excessive reverse power is received by some modules and causes performance degradation or damage of the modules, thereby ensuring that each of the photovoltaic modules is safely and reliably controlled to be heated for snow melting and deicing.

Abstract: A photovoltaic rapid shutdown device and a photovoltaic system are provided. The device includes a first switch, a second switch, a bypass diode, an auxiliary power supply, a control circuit and a communication circuit. One of multiple photovoltaic modules serves as a power supplying photovoltaic module, and an output terminal of the power supplying photovoltaic module is connected to an input terminal of the auxiliary power supply. The first switch is connected in series between the power supplying photovoltaic module and an adjacent photovoltaic module. Two terminals of the second switch are connected to positive and negative output terminals of a branch formed by the multiple photovoltaic modules connected in series, respectively. A cathode of the bypass diode is connected to a low voltage terminal of the adjacent photovoltaic module.

Abstract: A photovoltaic rapid shutdown device and a photovoltaic system are provided. The device includes a first switch, a second switch, a bypass diode, an auxiliary power supply, a control circuit and a communication circuit. One of multiple photovoltaic modules serves as a power supplying photovoltaic module, and an output terminal of the power supplying photovoltaic module is connected to an input terminal of the auxiliary power supply. The first switch is connected in series between the power supplying photovoltaic module and an adjacent photovoltaic module. Two terminals of the second switch are connected to positive and negative output terminals of a branch formed by the multiple photovoltaic modules connected in series, respectively. A cathode of the bypass diode is connected to a low voltage terminal of the adjacent photovoltaic module.

Abstract: An IV curve scan method for a photovoltaic module and an optimizer are provided. The optimizer receives an IV curve scan signal and controls an output voltage of the photovoltaic module corresponding to the IV curve scan signal to change from an open-circuit voltage to a preset minimum voltage according to a preset rule, while photovoltaic module connected to another optimizer can still operate normally, so that the system can operate normally. Then the optimizer uploads IV curve data of the photovoltaic module corresponding to the IV curve scan signal, to complete an IV curve scan on a single photovoltaic module.

Abstract: Provided are a photovoltaic system and a method for controlling a photovoltaic system. The photovoltaic system includes a photovoltaic output device, an inverter device, an AC interface device, a control device and an AC load, where a supply terminal of the AC load is connected to an AC output side of the inverter device, and a control terminal of the AC load is connected to the control device, and the method for controlling the photovoltaic system is applied to the control device. The method for controlling the photovoltaic system includes: controlling the AC interface device to maintain the inverter device being disconnected from an electrical grid; starting the inverter device and then starting the AC load; and controlling the AC interface device to connect the inverter device to the electrical grid, in a case that it is determined that a grid connection condition is met for the photovoltaic system.

Abstract: Provided is a pre-charge circuit and a photovoltaic inverter. The pre-charge circuit includes an alternating current power source, a half-bridge rectifier, an auxiliary charging capacitor, a current limiting device and a controllable switch. The pre-charge circuit is connected to a target charging capacitor to form a voltage doubling rectifier circuit. A direct current side of the half-bridge rectifier is connected in parallel to the target charging capacitor, and an alternating current side of the half-bridge rectifier is connected to one end of the alternating current power source. One end of the auxiliary charging capacitor is connected to any one end of the target charging capacitor, and the other end of the auxiliary charging capacitor is connected to the other end of the alternating current power source.

Abstract: The application provides an access control method of parallel direct current power supplies and a device thereof. Direct current power supplies with single insulation resistances to ground failing to meet a first preset condition or causing a total insulation resistances to fail to meet a second preset condition are disconnected from a grid-connected inverter, and direct current power supplies with single insulation resistance to ground meeting the first preset condition and enabling the total insulation resistance to meet the second preset condition are connected with the grid-connected inverter for grid-connected inverting. Unlike in conventional technology, not all the direct current power supplies connected to a direct current bus are made stop outputting, thereby avoiding the loss of inverter power generation.

Abstract: Provided are a device for suppressing potential induced degradation and a system. The device includes a rectification module, a non-isolated voltage conversion module and at least one capacitor. An input terminal of the rectification module is connected to an output terminal of a converter, the rectification module is configured to rectify an alternating current outputted by the converter into a direct current, the non-isolated voltage conversion module is configured to perform voltage conversion on the direct current outputted by the rectification module, and the voltage conversion is boost conversion or voltage reverse conversion. The capacitor is connected in parallel with an output terminal of the direct current, and either a positive electrode or a negative electrode of the capacitor is grounded.

Abstract: A voltage compensation apparatus for a photovoltaic system and a photovoltaic system are provided. The voltage compensation apparatus includes a current direction limiting circuit and a compensation power supply connected in series; or only includes a current direction limiting circuit. The current direction limiting circuit includes at least one limiting device configured to conduct a current in a unidirectional manner. The voltage compensation apparatus is connected between the output terminal of the converter and the ground. The photovoltaic system includes: a photovoltaic array, a converter, a transformer and the voltage compensation apparatus. An output terminal of the converter is connected with a primary side of the transformer, and an input terminal of the converter is connected with the photovoltaic array. The voltage compensation apparatus is configured to raise or lower a voltage at the output terminal of the converter.

Abstract: Provided is a pre-charge circuit and a photovoltaic inverter. The pre-charge circuit includes an alternating current power source, a half-bridge rectifier, an auxiliary charging capacitor, a current limiting device and a controllable switch. The pre-charge circuit is connected to a target charging capacitor to form a voltage doubling rectifier circuit. A direct current side of the half-bridge rectifier is connected in parallel to the target charging capacitor, and an alternating current side of the half-bridge rectifier is connected to one end of the alternating current power source. One end of the auxiliary charging capacitor is connected to any one end of the target charging capacitor, and the other end of the auxiliary charging capacitor is connected to the other end of the alternating current power source.