Abstract: The present disclosure provides a conversion system with a high voltage side and a low voltage side, including: a plurality of power units, each power unit including: a plurality of DC/DC converters, when in normal operation, one part of DC/DC converters being in a working state and other DC/DC converters being in a cold backup state; a plurality of bypass circuits connected in parallel to the corresponding DC/DC converters; a detection unit connected to each DC/DC converter, and detects the DC/DC converter; and a control unit coupled to the detection unit and each of the plurality of DC/DC converters; and a main control unit coupled with each control unit and configured to receive the preset signal of respective control unit and outputs a bypass signal and a release signal to the corresponding control unit according to the preset signal.

Abstract: A modular multilevel converter system, and a voltage detection method and an open-circuit fault diagnosis method thereof are disclosed. The modular multilevel converter system includes: N sub-modules sequentially cascaded, where N is an integer greater than or equal to 2, each of the sub-modules comprising at least one bridge arm and a capacitor connected in parallel to the bridge arm, the capacitor having a positive terminal and a negative terminal; and a voltage detection unit for detecting a voltage between at least two adjacent sub-modules in the N sub-modules, the voltage detection unit being connected between the positive terminal of the capacitor of the first sub-module and the negative terminal of the capacitor of the last sub-module in the at least two sub-modules.

Abstract: Disclosed are a control method and control system for a modular multilevel converter and a power transmission system. The control method comprises: calculating an actual capacitor voltage of the sub-module; calculating a reference capacitor voltage of the sub-module; dividing the plurality of sub-modules into a plurality of modules, reference capacitor voltages of the sub-modules in the same module are the same, and reference capacitor voltages of the sub-modules from different modules are different; sorting in the module to obtain a first voltage sequence; sorting among different modules to obtain a second voltage sequence; and determining the sub-modules to be switched on or switched off according to charging and discharging states of the sub-module, the first voltage sequence and the second voltage sequence, until an actual level of the bridge arm is consistent with a desired level, wherein the desired level changes using a first preset value as a step.

Abstract: A conversion device comprises: an inductor electrically connected to the AC power grid; a first-stage converter configured to output a bus voltage according to the AC power grid, wherein the first-stage converter comprises an N-level alternating current-direct current (AC-DC) converter, and the N-level AC-DC converter comprises a plurality of switch bridge arms, wherein both an upper bridge arm and a lower bridge arm of each of the plurality of switch bridge arms of the N-level AC-DC converter include a plurality of semiconductor devices connected in series, and a rated withstand voltage Vsemi of each of the semiconductor devices is greater than or equal to (Vbus*?)/((N?1)*Nseries*?); and a second-stage converter configured to convert the bus voltage into an output voltage to supply energy to the load.

Abstract: A conversion device includes: an inductor connected to the AC power grid; a first-stage converter configured to output a bus voltage based on the AC power grid; a second-stage converter configured to convert the bus voltage into an output voltage to the load; and a filtering network, wherein a first resistance-capacitance circuit is disposed between the first and third terminals of the filtering network, a second resistance-capacitance circuit is disposed between the second and third terminals of the filtering network, the first terminal of the filtering network is connected to the AC power grid, the second terminal of the filtering network is connected to the bus or the second terminal of the second-stage converter, and the third terminal of the filtering network is grounded through a first capacitor.

Abstract: A modular power supply system is configured to include: a main controller, configured to output a main control signal; N local controllers, wherein each of the local controllers is configured to receive the main control signal to output at least one local control signal; N auxiliary power supplies, in one-to-one correspondence with the N local controllers, wherein each of the auxiliary power supplies is configured to provide power to the corresponding local controller, and N power units, in one-to-one correspondence with the N local controllers, wherein each of the power units includes a first end and a second end, the second end of each of the power units is connected to the first end of an adjacent one of the power units, each of the power units is configured to include M power converters, each of the power converters is configured to operate according to the local control signal.

Abstract: A modular power supply system includes: a main controller, configured to output a main control signal; N local controllers, wherein each of the local controllers is configured to receive the main control signal to output at least one local control signal; and N power units, in one-to-one correspondence with the N local controllers, wherein each of the power units includes a first end and a second end, and the second end of each of the power units is connected to the first end of an adjacent one of the power units, each of the power units is configured to include M power converters, wherein each of the power converters includes a third end and a fourth end, the fourth end of each of the power converters is connected to the third end of an adjacent one of the power converters.

Abstract: Disclosed is a surge control circuit, including: an absorption circuit including an absorption element and a bypass switch which are connected in series, a switch group connected in parallel to both ends of the absorption circuit and a first control circuit electrically connected to the switch group and bypass switch respectively. Normally, the first control circuit controls the switch group and the bypass switch to turn on simultaneously, makes the current flow through the switch group; when detecting the current is greater than or equal to the first preset current value, or the current increase rate is greater than or equal to the preset current rate of change, the first control circuit controls the switch group to turn off, makes the current flow through the absorption circuit; when detecting the current is less than the second preset current value, the first control circuit controls the bypass switch to turn off.

Abstract: A transformer includes a magnetic core, a first winding and at least one second winding. The magnetic core has a window through which the first winding passes through without contacting the magnetic core. The second winding passes through the window of the magnetic core and is wound on the magnetic core. The second winding has a distance from the first winding, and a semi-conductive part is disposed between the second winding and the magnetic core. The present disclosure can effectively lower the risk of partial discharge between the second winding and the magnetic core, and thus the transformer of the present disclosure has high reliability.

Abstract: A magnetic assembly includes a magnetic core and a winding. The magnetic core comprises an upper cover, a lower cover and at least one core column provided between the upper cover and the lower cover, the core column presents a prismatic shape and has at least two lateral surfaces, the lateral surfaces intersect with each other to form at least two longitudinal ridges, and the longitudinal ridge extends along the longitudinal direction of the core column. The winding, winding around the core column, a first semi-conductive component is provided between the core column and the winding at the position corresponding to the longitudinal ridge.

Abstract: Disclosed is a circuit breaker apparatus, including a first switching assembly, a first controller, a second switching assembly and a second controller. The first switching assembly is connected in series between a positive pole of a power supply and a load. The first switching assembly includes multiple first switching units in series. The first controller is electrically connected to a first pre-set reference potential of the first switching assembly. The first controller is electromagnetically coupled with each first switching unit through a first transformer unit. The second switching assembly is connected in series between a negative pole of the power supply and the load. The second switching assembly includes multiple second switching units in series. The second controller is electrically connected to a second pre-set reference potential of the second switching assembly. The second controller is electromagnetically coupled with each second switching unit through a second transformer unit.

Abstract: A modular power supply system, includes: a main controller, configured to output a main control signal; N local controllers, wherein each of the local controllers is configured to receive the main control signal to output at least one local control signal; and N power units, in one-to-one correspondence with the N local controllers, wherein each of the power units includes a first end and a second end, the second end of each of the power units is connected to the first end of an adjacent one of the power units, each of the power units includes M power converters, and each of the power converters is configured to operate according to the local control signal output by a corresponding local controller, wherein each of the power units further includes: M sampling circuits, configured to sample positive DC bus voltages and negative DC bus voltages of the M power converters respectively.

Abstract: The invention relates to a transformer and a method for manufacturing the same. The transformer includes a magnetic core having a body part and a hollow part passing through the body part; a first winding wound around the body part of the magnetic core through the hollow part and including two first leads; a first infiltration material member enclosing the body part and the first winding through the hollow part, with the two first leads being exposed; a second winding wound around the first infiltration material member through the hollow part, isolated from the first winding, and including two second leads; a shell including an accommodating space, in which the magnetic core, the first winding, the first infiltration material, and the second winding are accommodated; and a pouring sealant poured into the accommodating space and maintaining the first leads and the second leads to be exposed outside the shell.

Abstract: The present disclosure mainly provides a clamping circuit, coupled to a first end and a second end of a switching transistor through a first node and a second node, comprising: an RCD circuit, comprising a first resistor and a first capacitor connected in parallel between the second node and a third node, and a diode having a negative electrode coupled to the third node; and a first stabilivolt diode, having a negative electrode coupled to the first node and a positive electrode coupled to a positive electrode of the diode at a fourth node.

Abstract: The present disclosure provides a gate circuit and a gate drive circuit for a power semiconductor switch, including: a zener diode and a charge dissipation circuit. A first end of the zener diode is connected to a first end of the charge dissipation circuit and a gate of the power semiconductor switch, a second end of the zener diode is connected to a second end of the charge dissipation circuit and a second end of the power semiconductor switch. A first parasitic capacitor is formed between a first end and the gate of the power semiconductor switch, and a second parasitic capacitor is formed between the gate and the second end of the power semiconductor switch.

Abstract: The present disclosure discloses a method of discharging a bus capacitor in a power converter, the method comprising: outputting a plurality of pulse control signals to the corresponding plurality of power semiconductor switch groups when the working state of the power converter is in a discharge state and the state of the main circuit breaker is open to control the ON and OFF of the plurality of power semiconductor switch groups, respectively, so as to form a discharge loop between the positive terminal and the negative terminal of the bus capacitor within at least a preset time, thereby causing the bus capacitor to discharge. Since a discharge loop is formed by the bus capacitor and the bridge arms and the energy of the bus capacitor is consumed by a power device, thereby the peak value and discharge rate of discharge current can be effectively controlled without adding additional discharge elements.

Abstract: The present disclosure provides a conversion system with a high voltage side and a low voltage side, including: a plurality of power units, each power unit including: a plurality of DC/DC converters, when in normal operation, one part of DC/DC converters being in a working state and other DC/DC converters being in a cold backup state; a plurality of bypass circuits connected in parallel to the corresponding DC/DC converters; a detection unit connected to each DC/DC converter, and detects the DC/DC converter; and a control unit coupled to the detection unit and each of the plurality of DC/DC converters; and a main control unit coupled with each control unit and configured to receive the preset signal of respective control unit and outputs a bypass signal and a release signal to the corresponding control unit according to the preset signal.

Abstract: A power unit includes: a DC/DC conversion circuit; a bypass circuit, including a mechanical switch, an impedance network, and a semiconductor switch, wherein the semiconductor switch and the impedance network are connected in series to form a series branch, the series branch, the mechanic switch and the DC/DC conversion circuit are connected in parallel between a positive end and a negative end at one side of the power unit; a detecting unit, configured to detect a working signal of the DC/DC conversion circuit and generate a detection signal according to the working signal; and a controller, configured to, when the fault occurs in the DC/DC conversion circuit, output a first control signal to a control end of the mechanical switch and output a second control signal to a control end of the semiconductor switch.

Abstract: A control method of a multilevel converter includes: classifying power modules that start working, need to update an output state or stop working to form m power module groups; and controlling power modules in a same one of the power module groups to start working, update the output state or stop working at the same time, and sequentially controlling the m power module groups to start working, or update the output state or stop working, according to a preset time interval. The number of power modules in each power module group is less than or equal to a preset value, causing a change value of an output level of the each power module group to be less than or equal to a preset voltage value.

Abstract: Disclosed is a surge control circuit, including: an absorption circuit including an absorption element and a bypass switch which are connected in series, a switch group connected in parallel to both ends of the absorption circuit and a first control circuit electrically connected to the switch group and bypass switch respectively. Normally, the first control circuit controls the switch group and the bypass switch to turn on simultaneously, makes the current flow through the switch group; when detecting the current is greater than or equal to the first preset current value, or the current increase rate is greater than or equal to the preset current rate of change, the first control circuit controls the switch group to turn off, makes the current flow through the absorption circuit; when detecting the current is less than the second preset current value, the first control circuit controls the bypass switch to turn off.