73 results about "Electric power conversion" patented technology

The invention belongs to the technical field of power electronic conversion, and particularly discloses an MMC-STATCOM system direct optimization model prediction control method and system, and the method comprises the steps: respectively calculating a differential mode voltage and a common mode voltage between an upper bridge arm and a lower bridge arm of each phase; third harmonic voltage is injected into the upper bridge arm and the lower bridge arm of each phase to obtain upper bridge arm voltage and lower bridge arm voltage of a newly-added third voltage component of each phase; and based on the obtained voltage of the upper and lower bridge arms of the newly added three-time voltage component, determining the input number of the sub-modules of the upper and lower bridge arms of each phase by adopting a nearest level approximation modulation strategy, and determining the input sub-module of each bridge arm according to the capacitor voltage sequence of each sub-module of the bridge arms and the current direction. According to the method, on the basis of keeping a discrete control structure, direct injection of third harmonic voltage under an MPC framework is achieved, and higher real-time performance and expandability are achieved.

The invention relates to the technical field of power electronic conversion, in particular to a seamless switching control method and system for grid-connected and off-grid modes of an energy storage converter, and the method comprises the following steps: mode pre-judgment, seamless switching, virtual inertia and damping simulation and re-grid-connected pre-synchronization. The system comprises a multi-mode detection and pre-judgment module, a unified multi-mode controller, a state synchronization and observer module and a phase-locked loop-free synchronizer. According to the method, the whole process control problem from grid connection to grid disconnection and then grid connection is solved, the seamless degree of switching reaches a new level, and the active supporting capacity and friendly grid connection performance of the energy storage converter serving as a micro-grid core control unit are comprehensively improved; and the method has an important value for promoting the construction and development of a high-reliability micro-grid.

An arrangement for electric power conversion and an electric drive comprises a power converter that includes three legs, an electric motor including three open-end stator windings respectively having first and second ends, and a power switch. The first ends of the stator windings are coupled to respective legs of the three legs of the power converter, and the second ends of the stator windings are coupled together and have a same electric potential. The power switch is configured to selectively disconnect one of the second ends of the stator windings from all other second ends to establish at most two distinct electric potentials. The at most two distinct electric potentials are coupled to respective legs of a power grid interface coupled to the arrangement.

An electric power conversion apparatus includes: an electric power input terminal; an electric power output terminal; an electric power conversion circuit; a sensor circuit generating a detection voltage corresponding to a voltage at the electric power output terminal; a control circuit operable based on a first power supply voltage, including an input terminal to receive the detection voltage, and controlling operation of the electric power conversion circuit; and a power supply circuit generating the first power supply voltage and a second power supply voltage. The sensor circuit includes: resistors provided in a path coupling the electric power output terminal to a reference node, the resistors being coupled in series via first and second intermediate nodes, the second intermediate node being coupled to the input terminal; and a first diode including an anode coupled to the first intermediate node, and a cathode to be supplied with the second power supply voltage.

A switching control unit is applicable to an electric power conversion apparatus. The electric power conversion apparatus includes: a transformer; an inverter circuit including first switching devices; a synchronous rectifying circuit including second switching devices serving as rectifying devices; and a smoothing circuit. The switching control unit includes: a first current detection circuit detecting a peak current value of a secondary current; a second current detection circuit detecting an output current value; and a control circuit controlling respective operations of the first switching devices of the inverter circuit and respective operations of the second switching devices of the synchronous rectifying circuit. The control circuit sets a timing of switching from an on-state to an off-state of each of the second switching devices based on the peak current value detected by the first current detection circuit and the output current value detected by the second current detection circuit.

An electric power conversion system comprising: an alternating current (AC) source comprising a plurality of AC terminals for conducting AC power; a voltage source electrically coupled to the AC terminals; and a controller operably coupled to the voltage source, the controller being configured to: operate the voltage source to apply a fault reducing voltage at the AC terminals that reduces an AC line-to-line fault current (If).

The invention discloses a generator parallel operation control method and system based on carrier synchronization, and belongs to the technical field of power electronic conversion. A generator parallel operation control method based on carrier synchronization is characterized in that the method is applied to a system comprising a synchronous enabling unit, a synchronous signal transmitter and a plurality of parallel converters connected with the synchronous enabling unit and the synchronous signal transmitter respectively, and the method comprises the following steps: for each converter, determining a counting difference value and sending the synchronous enabling unit; the synchronous enabling unit feeds back an adjusting signal to the corresponding converter based on a comparison result of the difference value sent by the carrier wave processor of each converter and a count value threshold until the difference values sent by the carrier wave processors of all converters are smaller than the count value threshold; then, synchronous enable signals are sent to the converters respectively; and each converter drives the IGBT to realize current conversion based on the synchronous enable signal. According to the method, synchronous impact and circulation are reduced by simulating dynamic approximation of a carrier and an actual carrier.

A main frame part (6Aa) has a first end section (ED1) having a first dimension along a second direction intersecting a first direction. A main terminal part (6Ab) of a lead frame (6A) is directly adjacent to the main frame part (6Aa) in a third direction intersecting the first and second directions. The main terminal part (6Ab) has a second end section (ED2) connected to the first end section (ED1) of the main frame part (6Aa). An outer edge of a resin mold part (4) has an extension section (4e) extending in the second direction. The main frame part (6Aa) has, between a first power semiconductor chip (2a) and the main terminal part (6Ab) in the third direction, a first slit (5) or a first groove that extends over a third dimension in the second direction and has a fourth dimension that is less than the third dimension in the third direction.

An electric power conversion device for a power storage device includes a first control device, an electric power conversion circuit that is configured to output electric power to the power storage device, a drive circuit that generates a drive signal for the electric power conversion circuit by using power supply electric power, a shutoff circuit that shuts off supply of the power supply electric power to the drive circuit, and a detection circuit. The detection circuit is configured to output a shutoff signal to the first control device based on a fact that the shutoff by the shutoff circuit is completed. The shutoff signal indicates that the supply of the power supply electric power to the drive circuit is shut off.

This electric power conversion device comprises: a converter circuit that rectifies an AC voltage into a DC voltage; a voltage adjustment board that has a voltage adjustment circuit that steps up or steps down the DC voltage; and an inverter board that has an inverter circuit that converts the stepped-up or stepped-down DC voltage into an AC voltage and supplies the AC voltage to a motor. The inverter board and the voltage adjustment board are separately constituted.

The utility model relates to the technical field of energy storage, in particular to a mobile energy storage all-in-one machine, which comprises a mobile box body, an energy storage bin and a control bin which are arranged in parallel are arranged in the mobile box body, and the control bin comprises an electric power control area, an electric power conversion area and an electric power output and input area which are sequentially arranged from bottom to top; a PC insulating strip is arranged at the bottom of the energy storage bin, AB structural adhesive is arranged at the top of the energy storage bin, and a battery cell module is arranged between the PC insulating strip and the AB structural adhesive; the power control area is provided with a BMS, a fuse and a circuit breaker. The power conversion area is provided with a PCS inverter element; the power output and input area is provided with a docking station, a communication connector assembly and a fast charging and photovoltaic connector assembly. The mobile energy storage all-in-one machine is high in integration level, has the advantages of being small in size and light in weight, and meanwhile reduces manufacturing and installation cost.

A method (300) for controlling a wind turbine generator (104) connected to an electric power grid (102), wherein the wind turbine generator (104) comprises an electric generator (126) and a power converter arrangement (132) for electric power conversion, wherein the method (300) comprises: in response to an indication of a fault condition affecting the wind turbine generator (104), comparing (304) one or more determined electric currents at one or more first locations (162) to one or more determined electric currents at one or more second locations (164), the first and second locations (162, 164) being spaced apart from one another and located between the electric generator (126) and the electric power grid (102); and based on the comparison of the determined electric currents at the first and second locations (162, 164) and if the determined electric current at the first location (162) is different from the determined electric current at the second location (164), terminating (306) an electric power conversion of the power converter arrangement (132).

The utility model discloses a battery on-line capacity checking system based on a dual active bridge (DAB), relates to the field of electric power conversion, and solves the problems that a post-stage load device has a power failure risk and an abnormal battery cannot be rapidly positioned during the capacity checking operation switching period of a conventional capacity checking device. According to the technical scheme, the system is characterized by comprising a plurality of to-be-tested batteries, an electric switch device and a plurality of capacity checking devices, a plurality of batteries to be tested are connected in series and then connected to a direct current bus through an electric switch device, each battery to be tested is connected in parallel with a capacity checking device, and the capacity checking devices are connected with the direct current bus; the capacity checking device carries out charge and discharge capacity checking on a to-be-tested battery based on a dual active bridge (DAB) structure. The capacity checking device based on the dual-active-bridge DAB topology is additionally arranged, parallel capacity checking is carried out on a single battery, online capacity checking is achieved, redundant and complex switching operation is not needed, capacity checking can be carried out on one or more batteries, the risk of load power failure can be greatly reduced, and the abnormal condition of a certain battery can be rapidly known.

The application provides a single-stage conversion-based cascaded electric energy router, and belongs to the field of electric power conversion. There are two modular architectures, one is AC side star series connection and DC side parallel connection, and the other is AC side cascade connection and DC side parallel connection, and the latter can be connected to (or separated from) a medium-voltage DC power grid. The conversion module is an isolated AC-DC single-stage conversion topology, which comprises an inductor, a commutating half-bridge (not included in the second architecture), two groups of conversion bridges, a transformer with a tap, a DC blocking capacitor and a bus capacitor and the like. The primary winding of the transformer is connected with the AC side conversion bridge at both ends, the middle tap is connected to the AC voltage end through an inductor in series, and the secondary winding is connected with the DC side conversion bridge through the DC blocking capacitor. The AC side of the conversion module adopts staggered SPWM modulation, the DC side adopts phase shift control, and the modules are staggered or synchronized. The scheme has the following advantages: the topology is simple and efficient, and can improve reliability and dynamic characteristics; the utilization rate of the AC side DC bus voltage is high, and the DC side can realize zero voltage soft switching.

The utility model relates to a subway vehicle-mounted brake resistor waste heat recovery system based on thermoelectric power generation, which comprises a vehicle-mounted brake resistor box, a thermoelectric power generation assembly, a liquid cooling temperature control system and an electric power conversion control system, the liquid cooling temperature control system comprises a liquid cooling device and a temperature control center, the liquid cooling device is arranged on the surface of the thermoelectric power generation sheet assembly and electrically connected to the temperature control center, the liquid cooling device is used for improving the power generation efficiency of the thermoelectric power generation assembly, and the power conversion system is used for converting direct current generated by the thermoelectric power generation assembly into a stable power supply used by conventional electric equipment of the vehicle. The device has the advantages that waste heat generated by the brake resistor can be effectively recycled and converted, the thermoelectric power generation efficiency can be improved to the maximum degree through the temperature difference, and the double benefits of heat dissipation and energy conservation are achieved.

An electric power conversion device including: a voltage conversion circuit that converts a DC voltage; an inverter circuit that converts the DC voltage into an AC voltage; a negative electrode bus bar commonly connected to the voltage conversion circuit and the inverter circuit; a first positive electrode bus bar connected to the voltage conversion circuit; a second positive electrode bus bar connected d to the inverter circuit; a housing that accommodates the voltage conversion circuit and the inverter circuit; and a first heat dissipation member provided in the housing, in which the first positive electrode bus bar, the second positive electrode bus bar, and the negative electrode bus bar are stacked and electrically insulated from each other, the first positive electrode bus bar and the second positive electrode bus bar are opposite to the first heat dissipation member across an insulating member, and at least one of the first positive electrode bus bar and the second positive electrode bus bar is in thermal contact with the first heat dissipation member via the insulating member and the first heat conductive member.

The invention discloses a modular energy storage bidirectional converter, and particularly relates to the technical field of energy storage conversion, the modular energy storage bidirectional converter comprises a shell, a synchronous inclination assembly, a synchronous longitudinal assembly and a synchronous vertical assembly, the inner wall of the shell is fixedly provided with a plurality of stacked energy storage batteries, and one side of each energy storage battery is slidably provided with a linkage strip; a plurality of hinge strips are fixedly connected to one side of the linkage strip, a main plug is installed above each hinge strip, a main socket is inserted into the top end of each main plug, and the synchronous inclination assembly is located outside the main plugs. According to the invention, the synchronous inclination assembly is adopted, so that batch synchronous fastening maintenance of a plurality of inclined main plugs, a plurality of longitudinal plugs and a plurality of vertical communication heads can be realized, and the self-maintenance efficiency of the bidirectional converter is greatly improved, thereby solving the problem of low self-maintenance efficiency of the bidirectional converter.

A current detection device detects an electric current. The current detection device includes a first conducting portion, a second conducting portion, and a current sensor. An electric current flows through the first conducting portion in a specific direction. The second conducting portion is provided at a position separated from the first conducting portion in the specific direction and through which an electric current flows in the specific direction. The current sensor detects an electric current flowing through the first conducting portion. The current sensor is located at a position aligned with the first conducting portion in an orthogonal direction orthogonal to the specific direction and separated from the second conducting portion in the specific direction. The current sensor includes a sensor element which detects a magnetic flux generated by the electric current flowing through the first conducting portion and an element protector which protects the sensor element.

An electric power conversion apparatus includes: an input power terminal; a switching circuit; a first driving circuit configured to perform a first driving operation of driving the switching circuit, and configured to stop the first driving operation, based on a first driving control signal; a transformer including first and second windings; a rectifying circuit configured to rectify a signal supplied from the second winding and including a first rectification switching device turning on and off based on a first driving signal; a second driving circuit configured to perform a second driving operation that includes driving the first rectification switching device through the first driving signal, and configured to stop the second driving operation based on a second driving control signal; a signal generation circuit configured to generate the first driving control signal, based on a control signal and the first driving signal; a smoothing circuit; and an output power terminal.

This electric power conversion device comprises: a plurality of semiconductor packages that each have a built-in semiconductor element and have a first surface and a second surface on opposite sides from each other; a wiring board that is bonded to the first surface with an electrically conductive bonding material interposed therebetween; and a heat dissipation member that is connected to the second surface with a heat conduction member interposed therebetween, wherein each semiconductor package has, around the portion where the bonding material is disposed on the first surface, a protrusion that protrudes in a direction away from the heat dissipation member and that keeps the distance between the first surface and the wiring substrate constant.

This invention belongs to the field of power electronic converter technology, specifically disclosing a direct optimization model predictive control method and system for an MMC-STATCOM system. The method includes: calculating the differential-mode voltage and common-mode voltage between the upper and lower arms of each phase; injecting third harmonic voltage into the upper and lower arms of each phase to obtain the upper and lower arm voltages of the newly added third voltage component for each phase; based on the obtained upper and lower arm voltages of the newly added third voltage component, determining the number of sub-modules to be engaged in each phase's upper and lower arms using a nearest-level approximation modulation strategy; sorting the sub-modules according to the capacitor voltage of each sub-module in the arm; and determining the engaged sub-modules for each arm according to the current direction. This invention, while maintaining the discrete control structure, achieves direct injection of third harmonic voltage under the MPC framework, exhibiting higher real-time performance and scalability.

Peak concentration of the carrier accumulation layer is equal to or higher than 1.0E16 / cm3. A bottom part of the trench is positioned inside the n-type carrier accumulation layer. When a concentration ratio is a result of division of a concentration of the carrier accumulation layer by a concentration of the drift layer at a depth of the bottom part of the trench, the depth of the bottom part of the trench is a position at which the concentration ratio is larger than one and equal to or smaller than 10.

The embodiment of the invention relates to the field of electric power systems, and discloses a protection method, system and equipment for an electric power conversion and interconnection system, and the protection method comprises the steps: dividing the electric power conversion and interconnection system into different protection types according to an area where a protection signal is located; different protection strategies are configured for the protection types respectively; the protection strategy is used for controlling a corresponding protection switch to trip; in response to a protection signal for the power conversion and interconnection system, determining a protection type corresponding to the protection signal; and according to the protection type corresponding to the protection signal, determining a protection strategy correspondingly executed by the protection type, and according to the protection strategy, controlling a corresponding protection switch to trip. According to the protection method disclosed by the invention, the problem of over-protection or untimely protection is solved, and at least the technical effects of graded protection, adoption of corresponding protection strategies after faults in different areas inside, and immediate protection and accurate protection can be achieved.

An electric power conversion device (20) comprises: inverter circuits (2A, 2B) for converting DC electric power from a DC power supply (4) into n-phase (n≥3) AC electric power, and driving an AC load (1; a smoothing capacitor (3) that is provided between the DC electric power supply (4) and the inverter circuits (2A, 2B); and a control unit (7) for driving the inverter circuits (2A, 2B). The control unit (7) is configured to calculate a modulation wave phase (θmu) on the basis of the operation state (θre) of the AC load (1) and a voltage command value that corresponds to the operation of the AC load (1), and perform control so as to change the carrier phase of a predetermined phase among the n carrier phases (Su, Sv, Sw) in a specific pattern on the basis of the modulation wave phase (θmu).

Disclosed is an electric power conversion device including a plurality of power modules stacked in one direction, and a plurality of cooling channels disposed between or outside the power modules such that at least one surface of each of the plurality of cooling channels is in contact with one surface or a remaining surface of one of the power modules, wherein a cooling medium from outside is introduced into internal cooling channels disposed between the power modules, and the cooling medium discharged from the internal cooling channels is introduced into outermost cooling channels disposed outside the power modules.

An electric power converter control device controls an electric power converter that performs electric power conversion between a direct current electric power supply and a motor, the electric power converter control device including: a magnetic flux command value generator configured to obtain a magnetic flux command value based on a torque command value and a rotation detection value indicating the rotational speed of the motor; a direct current voltage value generator configured to obtain a direct current voltage value indicating an output voltage of the direct current electric power supply based on at least a modulation rate coefficient targeted by the electric power converter and the magnetic flux command value; and a current command value generator configured to obtain a current command value for controlling the motor based on the torque command value, the rotation detection value, and the direct current voltage value.

The invention discloses a battery heat preservation system and an energy storage control method for an extremely cold environment, and belongs to the technical field of polar region energy and energy storage, and the system comprises four modules, namely a composite heat preservation module, a hybrid energy supply module, an electric power conversion and control module and an intelligent monitoring module. The composite heat preservation module adopts a vacuum heat insulation plate and polyurethane foam composite structure, so that the temperature in the battery box is maintained at-20 DEG C or above, and the extremely cold capacity retention rate of the lithium storage battery is improved; the hybrid energy supply module realizes automatic charging and discharging switching and bus voltage stabilization of the lithium storage battery by virtue of a bidirectional DC-DC converter; the intelligent monitoring module takes a single-chip microcomputer as a core, monitors electrical parameters in real time, cuts off relay protection during overvoltage and overcurrent, and has the capability of full-year day-and-night automatic operation. The problems of poor heat preservation, low energy efficiency and insufficient reliability of a small energy storage system in an extremely cold area are solved, a lithium storage battery cooperative energy supply heating strategy is provided, and the system has the advantages of being compact in structure, intelligent in control and high in adaptability.

A control unit (33) comprises multiple bidirectional switches (TSW) and a control unit (33). The control unit is capable of controlling multiple bidirectional switches (TSW) in accordance with a first switching sequence or a second switching sequence. In specified periods, the control unit (33) controls the multiple bidirectional switches in accordance with the first switching sequence. In transient periods, the control unit (33) controls the multiple bidirectional switches in accordance with the second switching sequence. The quantity of combinations stipulated in the second switching sequence pertaining to the on / off states of the multiple bidirectional switches (TSW) is lesser than the quantity of combinations stipulated in the first switching sequence pertaining to the on / off states of the multiple bidirectional switches (TSW).

A DC / DC converter unit (10) comprises: a first arm that includes a first switching element (Q1) and a second switching element (Q2) connected in series, and is connected in parallel to a DC electric power supply (SB1) and a first smoothing capacitor (C1); a second arm that includes a third switching element (Q3) and a fourth switching element (Q4) connected in series, and is connected in parallel to a DC bus (Bdc) and a second smoothing capacitor (C2); and an inductor (L1) connected to a midpoint of the first arm and a midpoint of the second arm. A control unit (11) estimates a temperature change of the inductor (L1) on the basis of an electric current detected by an inductor electric current detection unit (A3), and corrects the duty ratios of the first switching element (Q1) to the fourth switching element (Q4) on the basis of the estimated temperature change.

An electric power conversion apparatus includes: first and second power terminals, a switching circuit, a voltage detection circuit, and a control circuit. The voltage detection circuit applies a predetermined voltage to a second node in a path coupling input and output nodes. The input node is coupled to a first node in the apparatus. The output node outputs a voltage corresponding to a voltage at the first node. In a second period before a first period, the control circuit controls a switching operation to cause electric power to be supplied from the second power terminal toward the first power terminal. In a third period before the second period, the control circuit controls the operation of the voltage detection circuit to cause the predetermined voltage to be applied to the second node, and diagnoses the voltage detection circuit, based on the voltage at the output node of the voltage detection circuit.