Abstract: A power unit includes: a plurality of power converters, a first output terminal of one of two adjacent power converters among the plurality of power converters is connected successively to a second output terminal of the other one of the two adjacent power converters; a local controller configured to output a plurality of control signals; and a plurality of driving circuits configured to output driving signals according to the plurality of control signals, to drive the plurality of power semiconductor switches to be turned on and off, wherein the control signals corresponding to the power semiconductor switches in the same position of the plurality of power converters are the same, the power semiconductor switches in the same position of the plurality of power converters are simultaneously turned on and off.

Abstract: The disclosure provides a system of providing power to a chip on a mainboard, including: a preceding-stage power supply, located on a mainboard, and configured to receive a first DC voltage and to provide a second DC voltage, wherein the first DC voltage is greater than the second DC voltage; and a first post-stage power supply and a second post-stage power supply, located on the mainboard, to receive the second DC voltage, the first post-stage power supply is disposed at a first side of the chip, the second post-stage power supply is disposed at a second side of the chip, the first post-stage power supply provides a third DC voltage to the chip, the second DC voltage is greater than the third DC voltage, the second post-stage power supply provides a fourth DC voltage to the chip, and the second DC voltage is greater than the fourth DC voltage.

Abstract: The present disclosure discloses a gate voltage control circuit of an IGBT and a control method thereof. The gate voltage control circuit of the IGBT comprises a voltage control circuit, an active clamping circuit and a power amplifier circuit. A control voltage outputted by the voltage control circuit indirectly controls a gate voltage of the IGBT, so as to achieve a better control of the gate voltage of the IGBT with a smaller loss. It may prevent the active clamping circuit from a too-early response and may increase the active clamping circuit response speed; and may avoid the voltage oscillation of the collector-emitter voltage Vce and the gate voltage Vge, and may improve the reliability of the IGBTs connected in series.

Abstract: A power module and a method for manufacturing the same are provided. The power module comprises: a substrate, at least one power device, and an organic heat dissipating structure. The substrate has an upper surface and a lower surface. The organic heat dissipating structure comprises a plane layer and a plurality of organic heat dissipating protrusions formed on a lower surface of the plane layer, wherein an upper surface of the plane layer is attached on the lower surface side of the substrate and configured to transfer heat generated by the power device outwardly.

Abstract: The power distribution device includes a power regulating device and a first auxiliary power distribution component. The power regulating device has a first output end connected to an AC power grid and a second output end. The first auxiliary power distribution component has a first movable end electrically connected to a load, a first fixed end electrically connected to the AC power grid and a second fixed end electrically connected to the second output end, and a ground line of the second fixed end is grounded. When the AC power grid is normal, the first movable end is connected to the first fixed end, such that the AC power grid supplies power to the load. And when the AC power grid is abnormal, the first movable end is connected to the second fixed end, such that the power regulating device supplies power to the load through the second output end.

Abstract: A ventilation fan comprises a fan, a cover module and a filter. The fan includes an inlet and an outlet. The cover module is disposed at the inlet and includes a main body and a cover. The main body includes an opening and fixing portions. The opening is disposed corresponding to the inlet. The periphery of the opening is configured with two opposite slideways. The fixing portions are disposed on the main body. The cover and the main body are disposed separately to form a gap and the cover includes connecting portions correspondingly connected to the fixing portions. The filter detachably slides on the slideways to be disposed at the opening. The size of the cover is larger than that of the opening. The air flows to the filter and inlet through the gap and flows out of the outlet through the fan.

Abstract: The present disclosure discloses a method and a device for loading a webpage. The method for loading a webpage includes: sending a webpage request message to a server; receiving an initial webpage of the webpage returned from the server, the initial webpage including an agent; sending a WebSocket connection request message to the server through the agent, to establish a WebSocket connection with the server; sending a page component request message of the webpage to the server based on the WebSocket connection, to load page component of the webpage; receiving the page components of the webpage returned from the server based on the WebSocket connection; and creating the page components at corresponding positions in the initial webpage.

Abstract: A method for estimating a property of a signal (1) sensed in an electrical system, comprises the steps of sensing the signal (1) and estimating a fundamental period of a fundamental of the signal (1) by comparing the sensed signal (1) with at least one threshold (2) to detect threshold crossings and estimating the fundamental period from the threshold crossings. The signal property is then estimated from the fundamental period and/or from the sensed signal (1) during an interval of a length of the fundamental period. An electronic device according to the invention comprises a micro controller and/or an analogue circuitry which performs the method for estimating a property of a signal. Preferably, the micro controller and/or analogue circuitry controls other parts of the electronic device depending on the results obtained by the method for estimating a property of a signal.

Abstract: The present disclosure provides a gradient amplifier driver stage circuit, a gradient amplifier system and a control method thereof. The gradient amplifier driver stage circuit includes: a gradient coil and a plurality of gradient driver modules electrically cascaded with each other and forming an output end, the output end being electrically connected to the gradient coil, wherein each gradient driver module includes a pre-stage power supply and a bridge amplifier connected in parallel, output voltage of the pre-stage power supplies of the plurality of gradient driver modules are the same, and each gradient driver module is configured to provide an inductive voltage drop and a resistive voltage drop on the gradient coil.

Abstract: The embodiments of the present disclosure relate to a power package module of multiple power chips and a method of manufacturing a power chip unit. The power package module of multiple power chips includes: a power chip unit including at least two power chips placed in parallel and a bonding part bonding the two power chips; a substrate supporting the power chip unit and including a metal layer electronically connecting with the power chip unit; and a sealing layer isolating the power chip unit on the substrate from surroundings to seal the power chip unit; the bonding part and the sealing layer are made from different insulated material, the distance of a gap between the two power chips placed in parallel is smaller than or equal to a preset width, and the bonding part is filled in the gap, insulatedly bonding the two power chips placed in parallel.

Abstract: A method of upgrading inverter software comprises: embedding a software upgrade package for software to be upgraded into an application package and uploading the application package to a server; obtaining the application package from the server through a terminal; obtaining version information of the software from an inverter to be upgraded through the terminal, wherein the terminal and the inverter are connected through a wireless communication; comparing the version information of the software from the inverter to be upgraded with version information of the software upgrade package in the application upgrade package through the terminal; if the comparison result is that the version information of the software to be upgraded is lower than the version information of the software upgrade package in the application upgrade package, sending the software upgrade package to the inverter through the terminal for the inverter to perform an upgrade operation.

Abstract: A motor control system includes an electric motor and inverter. The electric motor includes a stator, rotor, and winding structure. The stator includes an iron core with a plurality of slots formed therein along a radial direction of the stator. The winding structure has a plurality of hairpin wires with pins disposed in the slots. The winding structure is configured to provide a plurality of phase windings and each phase winding includes a plurality of motor windings. The inverter includes a switching controller configured to control the turning-on and turning-off of the motor windings of each phase winding of the winding structure. When the electric motor operates in a high-speed mode, the switching controller controls the turning-on and turning-off of the motor windings of each phase winding such that a number of the phase windings turned-on is ? less than a number of all the phase windings.

Abstract: Disclosed is a stack structure and its manufacturing method. The stack structure includes at least two stacked modules, wherein at least one of the modules is a power module; at least one metal connection component which is in integrated structure and comprises a first end, a second end and a connection portion with the first end being electrically connected to one of the modules and the second end being electrically connected to the other module; at least one molding compound packaging the at least one module and the end of the metal connection component which is electrically connected to the module, respectively.

Abstract: A converter module includes: a system board; and an isolated rectifier unit connected with the system board via at least one pin, the isolated rectifier unit including: a system board; a circuit module; and an isolated rectifier unit arranged adjacent to the circuit module and connected with the system board; wherein the isolated rectifier unit includes: a magnetic core comprising at least one core column parallel to the system board and two cover plates provided at both ends of the core column; and multiple carrier board units provided between the two cover plates and perpendicular to the system board, wherein each of the carrier board units comprises at least one via hole, at least one primary winding, at least one secondary winding and at least one switch connected with the at least one secondary winding.

Abstract: A control device applied to a flyback converter including an auxiliary switch includes: an output voltage integrator, configured to integrate an output voltage of the flyback converter to obtain an amplitude of a negative magnetizing current of the flyback converter; and a comparator controller, configured to compare the obtained amplitude of the negative magnetizing current with a reference value, and turn off the auxiliary switch according to a comparison result. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A control device, which is applied to a flyback converter including an auxiliary switch, includes: an on-time setter, configured to set an on-time threshold according to a reference value and an output voltage of the flyback converter; and an on-time controller, configured to output a control signal to turn on the auxiliary switch, and turn off the auxiliary switch when on-time of the auxiliary switch reaches the on-time threshold. According to the present disclosure, it is able to achieve zero voltage switching of a primary-side switch of the flyback converter with variable outputs.

Abstract: A method for distributing unbalanced and harmonic power among a plurality of inverters connected in parallel and operating in an islanded state, by respectively injecting an small-AC-signal in each inverter, including: sampling an output voltage and an output current of each inverter, extracting a fundamental positive sequence component, a fundamental negative sequence component, at least one major order of harmonic component from the current, and current components of the small-AC-signal; calculating an active power and a reactive power of the inverter, calculating the unbalanced and harmonic power; calculating a frequency and an amplitude of a fundamental positive sequence reference voltage, calculating a frequency reference value of the small-AC-signal; calculating a virtual impedance; calculating a voltage drop of the virtual impedance; generating a total reference voltage; and regulating the output voltage of the inverter to follow the total reference voltage.

Abstract: A regulator converting an input voltage into a supply voltage includes a first differential amplifier, a second differential amplifier, a pass element, and a feedback voltage divider. The first differential amplifier includes a reference voltage with a feedback voltage to generate a first output voltage and a first inverse output voltage. The second differential amplifier compares the first output voltage and the first inverse output voltage to generate a second output voltage. The pass element passes an output current from the input voltage to the supply voltage according to the second output voltage. The feedback voltage divider divides the supply voltage by a feedback factor to generate the feedback voltage.

Abstract: Disclosed are a photovoltaic system and its rapid shutdown method. The photovoltaic system includes a photovoltaic array including a photovoltaic array panel and a shutdown device, a junction box and an inverter, the shutdown device is electrically connected to the photovoltaic array panel and is connected to the inverter; the photovoltaic system further includes a shutdown device controller, which is coupled to the high voltage wires, and is configured for receiving a first detection signal reflecting a state of the AC side of the inverter, determining whether the AC side of the inverter is in a power-off state, outputting a first power-off signal when the AC side of the inverter is in the power-off state, and transferring the first power-off signal to the shutdown device; and the shutdown device receives the first power-off signal and prohibits the electric energy from transferring to the inverter.

Abstract: Method, apparatus and system for crosstalk suppression of power line communication are provided. The method includes: receiving a joining request message; judging a matching state of the communication terminal based on a history matching record and communication terminal identifier, if matching state of the communication terminal is unmatched: sending a joining response message to the communication terminal; receiving an acknowledgment request message sent by the communication terminal after switch of the communication terminal is turned on; detecting voltage on power line between the communication terminal and an inverter corresponding to the power line communication transmitter, if voltage is within preset voltage range, sending an acknowledgment response message to the communication terminal; storing communication terminal identifier in history matching record and storing matching state of the communication terminal as successfully-matched.