Abstract: A power supply system, a converter, and a circulating current suppression method of the converter. The power supply system includes at least two converters that are coupled between a direct current power supply and an alternating current grid. Each converter obtains target output reactive power when an output current of the converter starts to increase from an initial current, obtains a reactive power compensation parameter based on the three-phase output voltages. Further, each converter obtains compensated output reactive power of the converter based on the reactive power compensation parameter and adjusts actual output reactive power of the converter based on the target output reactive power and the compensated output reactive power, so that an absolute value of a difference between common-mode output voltages of any two of the at least two adjusted converters is less than a difference threshold.

Abstract: A converter and a power backfeed control method applied to a photovoltaic power generation system are provided. The power backfeed control method includes: controlling, according to a backfeed instruction, the converter to enter a backfeed mode, where in the backfeed mode, the converter can transmit energy of the power grid to a selected photovoltaic string with a corresponding number; determining a backfeed control voltage according to the backfeed instruction, and determining a voltage limit in a process of determining the backfeed control voltage; determining an actual backfeed voltage based on the backfeed control voltage and the voltage limit, where the actual backfeed voltage is a smaller one of the backfeed control voltage and the voltage limit; and controlling the converter to output the actual backfeed voltage to the selected photovoltaic string, to enable the selected photovoltaic string to generate an electroluminescent effect.

Abstract: A control method of a three-phase multi-level inverter includes: determining a modulation ratio based on output of the three-phase multi-level inverter, where the modulation ratio indicates a ratio of an amplitude value of a sinusoidal modulation wave in pulse width modulation to an amplitude value of a carrier; generating, based on the modulation ratio and a modulation ratio threshold, a common-mode voltage regulation signal for regulating a common-mode voltage in phase voltages of the three-phase multi-level inverter; adding the common-mode voltage regulation signal and a differential-mode voltage regulation signal for regulating a differential-mode voltage in the phase voltages of the three-phase multi-level inverter to obtain a composite regulation signal, where the composite regulation signal is presented as a modulation wave for discontinuous pulse width modulation (DPWM); and generating, based on the composite regulation signal, drive signals for controlling switches of phases of the three-phase multi-

Abstract: An energy storage system includes at least two power conversion systems PCSs, output terminals of the at least two PCSs are connected in parallel to connect to an alternating current power grid, and input terminals of the at least two PCSs are connected to an energy storage power supply. The first PCS is any one of the at least two PCSs. The voltage detection circuit detects a power grid voltage at a parallel connection point of the output terminals of the at least two PCSs. When determining, based on the power grid voltage at the parallel connection point, that islanding occurs in the alternating current power grid, the controller adjusts an angle of an output voltage of the first PCS to a reference angle, so that angles of output voltages of the at least two PCSs are the same.

Abstract: One example method includes obtaining output powers at initial scanning points of photovoltaic strings in a first group and a second group. The output powers at the initial scan points of the photovoltaic strings in the first group can then be controlled to sequentially decrease, and the output powers at the initial scan points of the photovoltaic strings in the second group can then be controlled to sequentially increase. Scanning can then be performed in the initial scanning direction starting from output voltages corresponding to the output powers at the initial scan points of the first group. Scanning can then be performed in the initial scanning direction starting from output voltages corresponding to the output powers at the initial scan points of the second group, where output powers of the first group and the second group are kept to compensate each other during IV curve scanning.

Abstract: This application provides a solar cell, a method for preparing the solar cell, smart glasses, and an electronic device. The solar cell includes a first conductive layer, a second conductive layer, a first conductive lattice, a second conductive layer, and a functional layer. The functional layer is disposed between the first conductive layer and the second conductive layer, the functional layer is configured to absorb light and generate a photocurrent, and both the first conductive layer and the second conductive layer are configured to receive the photocurrent. The first conductive lattice is in contact with a surface that is of the first conductive layer. The second conductive lattice is in contact with the second conductive layer, and the first conductive lattice and the second conductive lattice are configured to output the photocurrent to the target device. This application can mitigate impact of a sheet resistance on cell efficiency.

Abstract: This application provides a solar cell, including a front electrode, a functional layer, and a back electrode. The front electrode is an electrode on a side of an illuminated surface. The front electrode includes a high-conductivity region and a low-conductivity region that are adjacent to each other, or the back electrode includes a high-conductivity region and a low-conductivity region that are adjacent to each other. The front electrode and/or the back electrode may be designed to be separated by region, and conductivity of one conductive region is designed to be higher than conductivity of the other conductive region. This can effectively avoid a film rectangular resistance loss caused by large-scale non-uniform lateral transfer of a photocurrent, and improve photoelectric conversion efficiency of the cell. In addition, cell comprehensive performance can be improved by flexibly selecting materials based on different requirements of different regions in different application scenarios.

Abstract: A power supply system and a method for controlling the power supply system includes a direct current voltage conversion apparatus, an inverter, and a diode. The direct current voltage conversion apparatus includes a controller and a direct current voltage conversion circuit. The controller is configured to: control the output voltage of the direct current voltage conversion circuit, so that the diode is in a conducted state; detect a voltage on the direct current bus; and determine, based on the voltage on the direct current bus, whether high voltage ride-through occurs in the power supply system. According to the power supply system and the method for controlling the power supply system provided in this application, high voltage ride-through can be quickly detected while fault isolation is implemented, thereby improving efficiency of detecting high voltage ride-through.

Abstract: A photovoltaic power system includes a DC/AC inverter circuit, N DC/DC converter circuits that are located at a previous stage of the DC/AC inverter circuit and that are respectively connected to photovoltaic strings, and a controller connected to the DC/AC inverter circuit and the N DC/DC converter circuits. The controller is configured to: perform MPPT control on n DC/DC converter circuits, and perform CPG control on (N?n) DC/DC converter circuits. In the two control manners, a fast and accurate power reserve or limit of a photovoltaic string inverter with any illumination intensity and ambient temperature can be implemented, and fluctuation of a DC bus voltage and AC output power of the photovoltaic string inverter can be eliminated. Control on a virtual synchronous generator of the photovoltaic string inverter is implemented, and a lifespan of the photovoltaic string inverter is prolonged, without a need to add an energy storage element.

Abstract: This application provides a vehicle and a control method for a vehicle suspension. The vehicle includes a first component, a second component, and a vehicle suspension. The vehicle suspension is located between the first component and the second component. The first component is a component that the vehicle suspension bears, the second component is configured to bear the vehicle suspension and the first component, and the vehicle suspension includes a variable damper connected between the first component and the second component. The variable damper is configured to provide a first force to the first component based on a first acceleration of the first component, to control a displacement of the first component relative to the second component in a height direction of the vehicle. In the embodiments of this application, bumps in a driving process of the vehicle can be effectively reduced, so that vehicle ride comfort is improved.

Abstract: An islanding detection method and apparatus, and a computer-readable storage medium. The detection method includes: determining a harmonic amplitude growth rate and a frequency growth rate of alternating current electricity output by an alternating current port of a grid-tied inverter; determining an islanding disturbance coefficient corresponding to the harmonic amplitude growth rate, where the harmonic amplitude growth rate and the islanding disturbance coefficient are in a monotonically increasing relationship; determining an islanding injection amount based on the frequency growth rate and the islanding disturbance coefficient corresponding to the harmonic amplitude growth rate; controlling, based on the islanding injection amount, the grid-tied inverter to output a reactive power or a reactive current over the alternating current port; and performing islanding detection based on a frequency of the alternating current electricity output by the alternating current port.

Abstract: An inverter includes an inverter circuit; an alternating current filter, where an input port of the alternating current filter is connected to an output port of the inverter circuit; an alternating current electromagnetic interference (EMI) filter; and a first alternating current switch, connected between an output port of the alternating current filter and an input port of the alternating current EMI filter. The first split capacitor is disposed between the first alternating current switch and the input port of the alternating current EMI filter; and when the first alternating current switch is turned off, the first split capacitor is disconnected from the output port of the alternating current filter, and the first split capacitor is connected to a circuit in which an alternating current system connected to the output port of the alternating current EMI filter is located, to suppress harmonic distortion of the alternating current system.

Abstract: A photovoltaic power system includes a DC/AC inverter circuit, N DC/DC converter circuits that are located at a previous stage of the DC/AC inverter circuit and that are respectively connected to photovoltaic strings, and a controller connected to the DC/AC inverter circuit and the N DC/DC converter circuits. The controller is configured to: perform MPPT control on n DC/DC converter circuits, and perform CPG control on (N?n) DC/DC converter circuits. In the two control manners, a fast and accurate power reserve or limit of a photovoltaic string inverter with any illumination intensity and ambient temperature can be implemented, and fluctuation of a DC bus voltage and AC output power of the photovoltaic string inverter can be eliminated. Control on a virtual synchronous generator of the photovoltaic string inverter is implemented, and a lifespan of the photovoltaic string inverter is prolonged, without a need to add an energy storage element.

Abstract: Embodiments of this application disclose a heat dissipating element control method, including: obtaining a status parameter set and a detected temperature of a first device, where the status parameter set is associated with a running temperature of the first device; determining values of a first temperature parameter and a second temperature parameter in a target adjustment function based on the status parameter set; and determining the heat dissipating efficiency of the heat dissipating element based on the values of the first temperature parameter and the second temperature parameter and the detected temperature, and controlling running of the heat dissipating element. This resolves a problem that the heat dissipating efficiency is not adjusted in time because the detected temperature is unable to reflect an actual temperature in real time.

Abstract: A string inverter control method includes: in a process of performing IV curve scanning on one or more first direct current/direct current step-up circuits, controlling a change of an output voltage of one or more second direct current/direct current step-up circuits on which the IV curve scanning does not need to be performed, where a change trend of the output voltage and a change trend of an input voltage of the one or more first direct current/direct current step-up circuits on which the IV curve scanning is performed present a non-strictly monotonically increasing relationship. Therefore, for the direct current/direct current step-up circuit on which the IV curve scanning is performed, a voltage difference between two ends of the direct current/direct current step-up circuit is not always in a relatively high state, so that a ripple current on an input inductor in the direct current/direct current step-up circuit can be reduced.

Abstract: This application provides a converter and a power backfeed control method that are applied to a photovoltaic power generation system. One end of the converter is connected to at least one photovoltaic string, and another end of the converter is connected to a power grid. Each photovoltaic string corresponds to one string number.

Abstract: A photovoltaic inverter is provided, including an inverter circuit, a data sampling module, and a control module. The inverter circuit includes a switch component and an alternating current output terminal. The data sampling module is configured to collect, from the alternating current output terminal, an instantaneous current value at each sampling point moment in target sampling duration and an instantaneous value of each-phase current at a target moment. The control module is configured to: determine a valid current value of the target sampling duration based on the instantaneous current value at each sampling point moment, determine an upper switching frequency limit and a lower switching frequency limit of an Nth switching period based on the valid current value, and determine a target instantaneous current value IN based on the instantaneous value of each-phase current at the target moment.

Abstract: An islanding detection method and apparatus, and a computer-readable storage medium. The detection method includes: determining a harmonic amplitude growth rate and a frequency growth rate of alternating current electricity output by an alternating current port of a grid-tied inverter; determining an islanding disturbance coefficient corresponding to the harmonic amplitude growth rate, where the harmonic amplitude growth rate and the islanding disturbance coefficient are in a monotonically increasing relationship; determining an islanding injection amount based on the frequency growth rate and the islanding disturbance coefficient corresponding to the harmonic amplitude growth rate; controlling, based on the islanding injection amount, the grid-tied inverter to output a reactive power or a reactive current over the alternating current port; and performing islanding detection based on a frequency of the alternating current electricity output by the alternating current port.

Abstract: A control method for a string inverter, comprising: in a current/voltage (IV) curve scanning process, controlling an output power of an inverter circuit to be a specified power reference value, and controlling an output voltage of each non-IV curve scanning direct current (DC) to DC (DC-DC) circuit to be a specified voltage reference value, where the specified power reference value is less than or equal to a sum of input powers of all non-IV curve scanning DC-DC circuits the before IV curve scanning process, and where the specified voltage reference value is greater than or equal to a preset percentage of a maximum value in open-circuit voltages, before the IV curve scanning process, of photovoltaic strings connected to all IV curve scanning DC-DC circuits.

Abstract: A control method and apparatus for a single-phase five-level converter are provided. The method includes: obtaining a first-phase initial modulated wave and a second-phase initial modulated wave of the single-phase five-level converter; obtaining a first-level modulated wave, a second-level modulated wave, a third-level modulated wave, a fourth-level modulated wave, and a fifth-level modulated wave that are output by the single-phase five-level converter; calculating the first-level modulated wave, the second-level modulated wave, the third-level modulated wave, the fourth-level modulated wave, the fifth-level modulated wave, the first-phase initial modulated wave, and the second-phase initial modulated wave, to obtain a common-mode modulated wave of the single-phase five-level converter; and calculating the first-phase initial modulated wave, the second-phase initial modulated wave, and the common-mode modulated wave, to obtain a pulse-width modulated wave of the single-phase five-level converter.