Abstract: A phase-shifted full-bridge converter, and a method and a device for controlling the phase-shifted full-bridge converter are provided. The method includes: acquiring a current currently inputted to the phase-shifted full-bridge converter; determining, based on a correspondence between inputted currents and operation modes, an operation mode corresponding to the current currently inputted to the phase-shifted full-bridge converter; and acquiring, from maximum power point tracking in the determined operation mode, a phase angle for the phase-shifted full-bridge converter and a switching frequency of a switch transistor in the phase-shifted full-bridge converter, to control the switch transistor to operate based on the phase angle and the switching frequency.

Abstract: Provided is a detection apparatus for a photovoltaic component, including a detection device and a control device. An input terminal of the detection device is connected to an output terminal of the breaking device. The detection device is configured to detect, based on at least one of a voltage and a current outputted from the photovoltaic component, whether the photovoltaic component and a connection circuit for the photovoltaic component operate normally. The control device is connected with the breaking device and the detection device. The control device is configured to control to switch on the breaking device, to transmit the at least one of a voltage and a current outputted from the photovoltaic component to the detection device.

Abstract: A circuit protection method, system, and apparatus are provided. The method includes: receiving a current between an output terminal of the inverter circuit and a power grid; determining, based on the current, whether a current abnormality occurs; and controlling to switch off switch transistors in the inverter circuit, on determining that a current abnormality occurs.

Abstract: A power supply system and a solar photovoltaic inverter, a DC/DC module and a rectification module. Since a power supply outputted from a solar panel is low-voltage power, the power supply at an output end of the solar panel can be directly supplied to a DC driving module and a DC side circuit. Since a power supply outputted from a main transformer is high-voltage power, the AC outputted from the main transformer can be directly supplied to an inverter driving module, a rectification driving module, and an AC side circuit, without additionally providing an auxiliary power supply for high-voltage isolation, namely, without additionally providing a switching circuit, a transformer, a second rectifier module, and a third rectifier module, thereby avoiding the noise and power consumption caused by frequent ON or OFF of the switching circuit, and reducing the cost.

Abstract: A module switchoff device and a security protection system of a photovoltaic power generation system.

Abstract: A three-phase inverter and a control method therefor are provided. Resonant capacitors are provided between the midpoints of three bridge arms and the positive and negative poles of a DC bus to constitute resonant units with output inductors, so as to establish a resonant network for the implementation of soft switching, without adding a switching transistor. Compared with the soft-switching of the three-phase inverter in the conventional technology, circuit devices are saved, the control process is simplified, and system hardware and software overheads are reduced. By controlling the three-phase inverter to operate in a continuous mode, the switching loss of the switching transistor and the conduction loss of a flyback diode in the switching transistor are reduced, the conversion efficiency is improved, the electromagnetic noise caused by the switching transistor is reduced, and high-quality grid currents are output.

Abstract: A three-phase grid-connected inverter, a control system thereof and a control method therefor. The inverter is a three-phase three-leg grid-connected inverter, and a filter capacitor is connected to a negative electrode of a DC input bus to form a filter loop, so as to filter harmonic wave in the circuit, realizing high-quality grid-connected current at small power, without increasing an inductance value, so that the parallel inverter device in the system operates stably and thus is applicable to photovoltaic microinverters. Moreover, the three-phase three-leg grid-connected inverter operates in a discontinuous conduction mode, that is, in a switching cycle, the inductive current is reduced to 0, so that the switching loss of the three-phase three-leg grid-connected inverter is reduced.

Abstract: A three-phase grid-connected inverter, and a method and a device for controlling the three-phase grid-connected inverter are provided. The method is applied to a three-phase three-leg grid-connected inverter. A structure of the three-phase three-leg grid-connected inverter is improved, so that a filter capacitor (C1, C2, and C3) is connected to a negative electrode of a direct current input bus to form a harmonic bypass circuit. Inverter devices connected in parallel in the system operate stably without increase of inductance of an inductor (L1, L2, L3). In addition, the three-phase three-leg grid-connected inverter according to the present disclosure operates in a discontinuous mode of inductor current (iL1, iL2, and iL3). That is, in the process that a power switch transistor (Q1, Q2, Q3, Q4, Q5 and Q6) on bridge legs is turned on, the inductor current (iL1, iL2, and iL3) drops to zero.

Abstract: A module switchoff device and a security protection system of a photovoltaic power generation system.

Abstract: A three-phase grid-connected inverter, a control system thereof and a control method therefor. The inverter is a three-phase three-leg grid-connected inverter, and a filter capacitor is connected to a negative electrode of a DC input bus to form a filter loop, so as to filter harmonic wave in the circuit, realizing high-quality grid-connected current at small power, without increasing an inductance value, so that the parallel inverter device in the system operates stably and thus is applicable to photovoltaic microinverters. Moreover, the three-phase three-leg grid-connected inverter operates in a discontinuous conduction mode, that is, in a switching cycle, the inductive current is reduced to 0, so that the switching loss of the three-phase three-leg grid-connected inverter is reduced.

Abstract: A three-phase grid-connected inverter, and a method and a device for controlling the three-phase grid-connected inverter are provided. The method is applied to a three-phase three-leg grid-connected inverter. A structure of the three-phase three-leg grid-connected inverter is improved, so that a filter capacitor (C1, C2, and C3) is connected to a negative electrode of a direct current input bus to form a harmonic bypass circuit. Inverter devices connected in parallel in the system operate stably without increase of inductance of an inductor (L1, L2, L3). In addition, the three-phase three-leg grid-connected inverter according to the present disclosure operates in a discontinuous mode of inductor current (iL1, iL2, and iL3). That is, in the process that a power switch transistor (Q1, Q2, Q3, Q4, Q5 and Q6) on bridge legs is turned on, the inductor current (iL1, iL2, and iL3) drops to zero.

Abstract: This invention provides a solar photovoltaic system, comprising: a plurality of photovoltaic assemblies, for harvesting solar energy to generate DC currents; a plurality of micro-optimizers having input terminals coupled to the photovoltaic assemblies and having output terminals connected in series with each other, for optimizing output currents and/or output voltages of the photovoltaic assemblies, to generate maximum power; a manager configured to communicate with the plurality of micro-optimizers, for managing operating states of the micro-optimizers; and an inverter coupled to one or more strings of the micro-optimizers, for converting the optimized DC currents into AC currents and outputting the AC currents to a power grid. This invention further provides a method for energy harvest optimization and a method for fault detection of a solar photovoltaic system.

Abstract: The invention provides a solar photovoltaic three-phase micro-inverter, comprising DC terminals, connected with three DC photovoltaic assemblies for receiving DC; three single-phase inverter circuits, having DC input terminals connected with the DC photovoltaic assemblies via the terminals, for converting the DC to AC; AC terminals, connected with the AC output terminals of the inverter circuits and a three-phase AC power grid, for outputting the AC generated by the inverter circuits; wherein DC input terminals of each inverter circuit are connected in parallel with each other, and AC output terminals are connected with one phase of the three-phase AC power grid and a neutral wire via the AC terminals. The invention further provides a solar photovoltaic generation system. The invention connects DC sides of three single-phase inverter circuits in parallel, which can simply eliminate ripple power at DC side input terminals in a three-phase micro-inverter.

Abstract: The invention provides a solar photovoltaic three-phase micro-inverter system comprising a plurality of three-phase micro-inverters. Every three of the three-phase micro-inverters form a group and are coupled to a three-phase AC power grid. Each of the three-phase micro-inverters comprises 3 single-phase inverter circuits, each of the single-phase inverter circuits comprises 2 conversion circuits, and each of the conversion circuits corresponds to one phase of the three-phase AC power grid. AC outputs of the same conversion circuits of the three micro-inverters in one group are coupled to three-phase live wires of the three-phase AC power grid respectively. Accordingly, the invention provides a method for improving conversion efficiency of the solar photovoltaic three-phase micro-inverter system.

Abstract: A solar photovoltaic three-phase micro-inverter comprises: DC terminals, coupled with three DC photovoltaic assemblies adjacent to each other; three single-phase inverter circuits having input terminals coupled respectively with the three DC photovoltaic assemblies via the DC terminals, for converting the DC currents generated by the three DC photovoltaic assemblies to AC currents, respectively; AC terminals coupled with a three-phase AC power grid; wherein output terminals of each single-phase inverter circuit are coupled respectively with a neutral wire and one of the three phases of the three-phase AC power grid. A solar photovoltaic power generation system is also provided. The three single-phase inverter circuits can be integrated as above Because the three DC photovoltaic assemblies on one three-phase micro-inverter are disposed adjacently and have similar environment conditions, such as illumination, temperature, etc., the three-phase AC current can be well balanced.

Abstract: This invention provides a solar photovoltaic system, comprising: a plurality of photovoltaic assemblies, for harvesting solar energy to generate DC currents; a plurality of micro-optimizers having input terminals coupled to the photovoltaic assemblies and having output terminals connected in series with each other, for optimizing output currents and/or output voltages of the photovoltaic assemblies, to generate maximum power; a manager configured to communicate with the plurality of micro-optimizers, for managing operating states of the micro-optimizers; and an inverter coupled to one or more strings of the micro-optimizers, for converting the optimized DC currents into AC currents and outputting the AC currents to a power grid. This invention further provides a method for energy harvest optimization and a method for fault detection of a solar photovoltaic system.

Abstract: The invention provides a solar photovoltaic three-phase micro-inverter system comprising a plurality of three-phase micro-inverters. Every three of the three-phase micro-inverters form a group and are coupled to a three-phase AC power grid. Each of the three-phase micro-inverters comprises 3 single-phase inverter circuits, each of the single-phase inverter circuits comprises 2 conversion circuits, and each of the conversion circuits corresponds to one phase of the three-phase AC power grid. AC outputs of the same conversion circuits of the three micro-inverters in one group are coupled to three-phase live wires of the three-phase AC power grid respectively. Accordingly, the invention provides a method for improving conversion efficiency of the solar photovoltaic three-phase micro-inverter system.

Abstract: The invention provides a solar photovoltaic three-phase micro-inverter, comprising DC terminals, connected with three DC photovoltaic assemblies for receiving DC; three single-phase inverter circuits, having DC input terminals connected with the DC photovoltaic assemblies via the terminals, for converting the DC to AC; AC terminals, connected with the AC output terminals of the inverter circuits and a three-phase AC power grid, for outputting the AC generated by the inverter circuits; wherein DC input terminals of each inverter circuit are connected in parallel with each other, and AC output terminals are connected with one phase of the three-phase AC power grid and a neutral wire via the AC terminals. The invention further provides a solar photovoltaic generation system. The invention connects DC sides of three single-phase inverter circuits in parallel, which can simply eliminate ripple power at DC side input terminals in a three-phase micro-inverter.

Abstract: A solar photovoltaic three-phase micro-inverter comprises: DC terminals, coupled with three DC photovoltaic assemblies adjacent to each other; three single-phase inverter circuits having input terminals coupled respectively with the three DC photovoltaic assemblies via the DC terminals, for converting the DC currents generated by the three DC photovoltaic assemblies to AC currents, respectively; AC terminals coupled with a three-phase AC power grid; wherein output terminals of each single-phase inverter circuit are coupled respectively with a neutral wire and one of the three phases of the three-phase AC power grid. A solar photovoltaic power generation system is also provided. The three single-phase inverter circuits can be integrated as above Because the three DC photovoltaic assemblies on one three-phase micro-inverter are disposed adjacently and have similar environment conditions, such as illumination, temperature, etc., the three-phase AC current can be well balanced.

Abstract: An alternating parallel flyback converter with alternated master and slave circuit branches is provided. The flyback converter includes a master flyback circuit branch, a slave flyback circuit branch connected with the master flyback circuit branch in parallel, and a controller. The controller controls the operation of each of the flyback circuit branches based on the current and the voltage at the output terminal of the flyback converter. The master flyback circuit branch operates continuously while the slave flyback circuit branch only operates when the output power of the flyback converter is higher than a threshold. The master flyback circuit branch and the slave flyback circuit branch are periodically alternated, and in particular, through zero crossing of the power. With the flyback converter of the present invention, the reliability and the service life of the converter can be improved.