672 results about "Power electronics converters" patented technology

A wind energy conversion system optimized for offshore application. Each wind turbine includes a semi-submersible hull with ballast weight that is moveable to increase the system's stability. Each wind turbine has an array of rotors distributed on a tower to distribute weight and loads and to improve power production performance where windshear is high. As much of the equipment associated with each rotor as possible is located at the base of the tower to lower the metacentric height. The equipment that may be emplaced at the bottom of the tower could include a power electronic converter, a DC to AC converter, or the entire generator with a mechanical linkage transmitting power from each rotor to the base of the tower. Rather than transmitting electrical power back to shore, it is contemplated to create energy intensive hydrogen-based products at the base of the wind turbine. Alternatively, there could be a central factory ship that utilizes the power produced by a plurality of wind turbines to create a hydrogen-based fuel. The hydrogen based fuel is transported to land and sold into existing markets as a value-added “green” product.

The invention discloses an intelligent solar cell component and a control method of an array thereof. An intelligent power electronic converter in which a microprocessor serves as a control core is arranged at a junction box of the traditional solar cell component and has a data communication function; system information such as a direct current (DC) bus voltage of a photovoltaic system, the maximal output power of other components in the same serial string and the like can be acquired through the communication function; the system information acquired through the communication function is higher than that of the maximal power point of the component; and the output voltage and the output current are automatically adjusted by a power weight matching method, so that the output energy of the component is maximized. By the method, each component can output the maximal electric energy.

The invention relates to a high-voltage direct-current direct-current (HVDC-DC) power electronic converter transformer comprising a cascade modular converter (1), a double-winding medium or high-frequency transformer (2) and a fully-controlled H bridge (3). The cascade modular converter (1) consists of two same bridge arms, and the two bridge arms are formed by connecting the same number of sub-modules end to end in a cascading way; the middle points of both the two bridge arms are respectively connected with two leads of the primary side of the double-winding medium or high-frequency transformer (2); and the secondary side of the double-winding medium or high-frequency transformer (2) is directly connected with the fully-controlled H bridge (3) or is connected in series with a resonant capacitor (5) between the double-winding medium or high-frequency transformer (2) and the fully-controlled H bridge (3). The HVDC-DC power electronic converter transformer can realize the conversion of the high-voltage DC voltage and the low-voltage DC voltage and has the electrical isolation function. Compared with the prior HVDC-DC converting device, the HVDC-DC power electronic converter transformer has the advantages of small volume and light weight.

The invention discloses a grid-connected inverter capable of reducing electrolytic capacitance, belonging to the field of inverters in power electronic converters. The inverter comprises a direct current (DC) power source, a DC/DC converter, a DC/AC converter, a bidirectional DC/DC converter, a DC-link capacitor and an energy storage capacitor. The output end of the DC power source is connected with the DC/DC converter in series, then is connected with the DC-link capacitor in parallel and finally is connected with the bidirectional input end of the bidirectional DC/DC converter and the input end of the DC/AC converter respectively. The bidirectional output end of the bidirectional DC/DC converter is connected with the two ends of the energy storage capacitor and the output end of the DC/AC converter is connected into the grid. When the instantaneous output power of the DC/AC converter is greater than or smaller than that of the DC power source, the energy storage capacitor correspondingly outputs or absorbs power. The grid-connected inverter uses less electrolytic capacitance as far as possible or does not use electrolytic capacitance and the service life of the whole inverter is lengthened.

A synchronous motor controller and method of controlling a synchronous motor without using rotor position sensors are provided. In a floating synchronous reference frame controller, phase currents are measured and a current Park vector is determined. The error between an initially arbitrary floating reference frame is reduced with a control loop. Decoupling terms based on the estimated speed of the rotor and the stator winding inductance are used to generate decoupled voltage terms in the v- and u-axis of the floating synchronous reference frame. The decoupled voltage command is converted back to a stator reference frame and applied to the synchronous motor via a power electronic converter. As a result u-axis current is minimized during transients, and a robust and accurate estimation of the current vector to be used in coordinate transformation for controlling the machine are achieved and the need for overrating of motor and inverter components is avoided.

The invention relates to a variable rotor speed wind turbine transmitting AC electric power to a utility grid. The wind turbine includes at least one AC generator and at least one power electronic converter unit. Further, it includes means for transforming at least one nominal output value of the generator to at least one different nominal input value of the at least one power electronic converter unit.

The invention also relates to a wind park and a method of transmitting AC electric power to a utility grid from a variable rotor speed wind turbine as well as a method of servicing or inspecting a variable rotor speed wind turbine.

The invention relates to a method of controlling running of a modularized multi-level converter in a low frequency model, which belongs to the technical field of controlling multi-level power electronic converters. The method comprises the following steps: setting high frequency common mode voltage and high frequency ring current both required to be superimposed, revising a switching function of a submodule and bridge arm current, obtaining an expression of capacitance voltage differential coefficient of the submodule according to volt-ampere characteristics of capacitance of the submodule, and in order to allow the capacitance voltage of the submodule to only have high-frequency component, assuming high frequency common mode voltage is known to obtain a expression of the high frequency circular current; comparing a running frequency with a critical frequency to obtain frequency model selection signals, combining an energy control and a circular current control of a phase unit of the modularized multi-level converter, determining whether the high frequency common mode voltage and the high frequency circular current are required to be superimposed to an original instruction or not according to the frequency model selection signals, and generating voltage required to be superimposed in the bridge arm of the phase unit of the high frequency circular current by controlling. The method is easy to realize and strong in universality, and provides reference for low frequency application of the modularized multi-level converter.

The present invention proposes an energy Internet-based multi-port multi-bus electric energy router topological structure and belongs to the power electronic converter field. The energy Internet-based multi-port multi-bus electric energy router topological structure can be widely applied to power transmission and distribution ends. The electric energy router topological structure is divided into three parts, namely, a high-voltage end, a middle stage and a low-voltage end. The electric energy router topological structure specifically comprises a high-voltage alternating current power transmission end and three kinds of direct-current bus output ends of which the voltage levels are 600 to 800V, 350 to 400V and 48V respectively; and the electric energy router topological structure further comprises ports such as single-phase alternating current load output ends, three-phase alternating current load output ends and renewable energy and energy storage component access ends; and the core part of the energy Internet-based multi-port multi-bus electric energy router topological structure is a modular multi-level converter and a dual-active bridge bidirectional DC/DC converter. With the energy Internet-based multi-port multi-bus electric energy router topological structure of the invention adopted, energy bi-directional flow and multi-port multi-bus design required by an electric energy router can be realized, the connection of loads, power sources and energy storage devices of different voltage levels and forms can be facilitated, electric energy transmission efficiency can be improved, and large-scale production can be facilitated.

The invention relates to a multi-port power electronic convert for energy internet, and belongs to the technical field of power electronic converters. According to the invention, the converter is composed of one static synchronous series compensator, one static synchronous compensator, one DC-DC converter and one three-phase DC-AC inverter. The static synchronous series compensator and the static synchronous compensator are both formed on the basis of a modular multi-level converter. The DC-DC converter is formed by a plurality of isolated DC-DC converters which are subject to input series and output series, and shares a high-voltage DC bus with the static synchronous series compensator and the static synchronous compensator. According to the invention, the converter integrates the functions of a unified power flow controller and the functions of a power electronic transformer, thus having complementary advantages of the unified power flow controller and the power electronic transformer and reducing cost; the converter is modularized, is easy to expand and set with a backup, and has important application potential in future energy internet.

A power generation system includes: a prime mover; an electrical machine coupled to the prime mover and configured for converting mechanical power to electrical power, the electrical machine having a power factor of less than or equal to 0.7; a reactive power supply assembly coupled to the electrical machine and configured to supply reactive power to the electrical machine; and a power electronic converter coupled to the reactive power supply assembly and configured for transferring power from the electrical machine to a grid.

The invention discloses a range-extended electric automobile using a micro gas turbine generator set. The electric automobile comprises a power electronic converter, a vehicle-mounted charger, an energy storage device, an energy management unit, an overall controller, an electromotor, a speed changer, a micro gas turbine controller, the micro gas turbine generator set and a fuel tank; and under the control of the overall controller, the fuel tank supplies fuel to the micro gas turbine generator set, and the micro gas turbine generator set generates electricity to increase the running mileage of the vehicle. The ranged-extended pure electric automobile reduces the dependence on a charging foundation facility, can adapt to running of high-speed and suburb road conditions better, improves the adaptability of the vehicle, meanwhile diversifies the energy of the vehicle, is favorable for energy safety, and solves the refrigerating and heating problems of the pure electric automobile.

A method for avoiding electrical resonance in a vehicle having a high-voltage (HV) direct current (DC) bus shared by a first and a second power electronic converter device, such as an air conditioning compressor module (ACCM) and a traction power inverter (TPIM), includes determining an impedance characteristic of the bus, defining resonance points for the bus, selecting lower and upper switching frequency boundaries for the TPIM, and preventing the TPIM from operating within a range defined by these boundaries. A vehicle includes the first and second power electronic converter device, e.g., the APPM and the TPIM, the shared HV DC, and a controller having the algorithm set forth above, wherein the controller is adapted for avoiding electrical resonance in the HV DC bus by executing the algorithm.

The invention discloses a neutral point clamped non-isolated photovoltaic grid-connected inverter, belonging to the field of power electronic converters. The inverter is constituted by an input divided capacitor branch, a neutral point clamped branch, a full-bridge switch unit and a network accessing filter branch. The inverter is characterized in that two switching tubes and an input divided capacitor are added to form a neutral point clamped branch on the basis of a basic full-bridge circuit, so that the potential of a follow current return circuit is half of a battery voltage at a follow current stage, thus eliminating leakage current of the non-isolated grid-connected inverter. Relative to the topology of an existing non-isolated photovoltaic grid-connected inverter, the inverter provided by the invention has the advantages that the maximum voltage stress of parts of power switching tubes and the voltage regulation factors of all power switching tubes are half of that of the battery voltage; electromagnetic interference and switching loss are reduced; and the inverter is applied to transformer-free isolated photovoltaic grid-connected occasions.

The invention provides a multi-infeed type AC/DC microgrid flexible interconnected system and a regulation and control method among microgrids thereof. The multi-infeed type AC/DC microgrid flexible interconnected system comprises a plurality of AC microgrids and a DC microgrid; power electronic converters are arranged among the feeder lines of the AC microgrids; and the AC microgrids are accessed into the same DC microgrid through the power electronic converters. For a plurality of feeder lines of different AC microgrids, the AC microgrids are accessed into the same DC microgrid by using the power electronic converters, so that flexible interconnection of the multi-infeed type AC/DC microgrids is realized. Due to the controllability of the power electronic equipment, tide interaction among the AC microgrids and between the AC microgrids and the DC microgrid can be realized. A distributed power supply and a load an be accessed into the DC microgrid, so that the cost of the converter is reduced; through mutual backup and mutual supply between the AC microgrids and the DC microgrid, the power supply reliability is improved; and flexible tide control between the AC microgrids and the DC microgrid at far end can be realized by using the DC microgrid, so that the system operation is optimized.

The invention discloses a common resonant induction type wide-input-range LLC resonant converter and belongs to the technical field of power electronic converters. The common resonant induction type wide-input-range LLC resonant converter comprises an input source, a primary side switch network, a common resonant inductor, two resonant capacitors, two transformers, a secondary side rectifying circuit, an output filter capacitor and an output load; the input voltage range of the converter is widened by using the dynamically adjustable topological structure. The common resonant induction type wide-input-range LLC resonant converter has a special operating mode, and has voltage gain 0.75 times of that of a traditional full-bridge LLC resonant converter, the input voltage range in the single operating mode can be reduced significantly, resonant cavity parameters are optimized, availability of the transformers is improved, device cost is reduced, the power and power density of the converter are increased, and the demand for high efficiency and high power density in wide input range applications is met.

The present invention discloses an energy router with a cascaded module voltage automatic balancing circuit, belonging to the technical field of power electronic converters. The energy router is formed by a rectifier level, a dual active bridge and an inverter level and comprises three ports which are a high voltage AC port, a low voltage AC port and a low voltage DC port to the outside. N H-bridge rectifier modules are in cascade connection to form the rectifier level, n dual active bridge modules are in cascade connection to form the dual active bridge, and the inverter level is formed by a three-phase H bridge module. Each of the dual active bridge modules is internally provided with a cascade module voltage automatic balancing circuit. According to the energy router, the control of the respective bus voltage balance of each cascade module by a controller can be avoided, the requirements of energy router controller operation sources are reduced, the number of sensors and the collection channels of the controller are reduced at the same time, and when the number of the cascade modules is large, the structure has a large advantage.

The invention discloses a control method and a control circuit of an isolated bidirectional charger, belonging to the technical field of power electronic converters. The bi-directional charger controlcircuit adopted by the method comprises a bi-directional AC/DC converter, an isolated DC/DC converter and a control unit. The power grid is connected to the battery pack through bi-directional AC/DCconverter, isolated DC/DC converter, isolated DC/DC converter using LLC converter, control unit including sampling circuit, DSP and optocoupler isolated driving circuit. The control method realizes the high efficiency of bi-directional operation and forward and backward operation of the vehicle-mounted charger, and has the advantages of high power density, high reliability, few devices and high efficiency.

The invention discloses a single-stage bidirectional isolation AC-DC converter, and belongs to the field of an electronic power electronic converter. The structures of three converters are each composed of single-phase AC sources, DC sources, Boost inductors, phase shift inductors, bus capacitors, transformers, primary power switch tubes, secondary power switch tubes and the like. The Boost inductors are connected to leg midpoints such that the integration of a bidirectional Boost PFC converter with a bridge type bidirectional converter is realized, through single-stage power transformation, two functions of PFC and isolation DC-DC transformation can be realized, and bidirectional flowing of energy is realized. The single-stage bidirectional isolation AC-DC converter, has the advantages of small power loss, high transformation efficiency, small switching loss, capability of realizing the bidirectional flowing of the energy, and the like, thereby being especially suitable for V2G and power network-storage battery energy storage systems.

The invention relates to a method for controlling three-phase four-leg converter, belonging to the field of power electronics converter. The method is that: the idea of generating switch tube control pulses of the four legs is that: the front three of the four legs adopt SPWM control or harmonic filtering technique to eliminate the 6k+/-1th harmonics (wherein, k is a natural number 1, 2, 3, 4,í¡), the control pulse for the fourth leg eliminates the phase voltage zero-sequence harmonics generated by the front three ones, by the SPWM control or harmonic filtering technique, i.e. by the mutually or approximately counteraction of the 3kth harmonics generated by the fourth leg and the 3kth harmonics generated by the front three ones. The invention eliminates all the low-order harmonics to ensure the quality of the output waveforms of the converter, applied to the application occasions of medium-high frequency output. The method makes the converter possess the advantages of low switching frequency, small total harmonic distortion (THD) of output voltage, etc.

The invention discloses a method for reducing capacitance in a single-phase pulse load AC-DC power source and belongs to the power electronic converter field. The single-phase pulse load AC-DC power source needs to implement a PFC function at an input AC side, which will introduce second harmonic current into a PFC busbar, and therefore, a large-capacitance capacitor is required to be arranged onthe PFC busbar so as to decouple the second harmonic current; the single-phase pulse load AC-DC power source also needs an output voltage under the condition of a pulse load to be stabilized within acertain range at an output side, the pulse current of the output side is transmitted to the PFC busbar, and as a result, a large-capacitance capacitor is required to decouple the pulse current; the large-capacitance capacitors for the above two purposes will reduce the power density of a converter; in order to improve the power density of the converter, a bidirectional converter is connected in parallel with the PFC output busbar so as to act as a controlled current source; the input current of the controlled current source is controlled according to a power conservation method, and at the same time, the second harmonic current and pulse current are decoupled; and therefore, the voltage ripples of a PFC busbar capacitor can be decreased, and the power density of the converter can be improved.

A power electronic converter for high/medium voltage direct current power transmission and reactive power compensation comprises a primary converter unit and an auxiliary converter unit, the primary converter unit including at least one primary converter limb including first and second DC terminals for connection in use to a DC network and an AC terminal, the or each primary converter limb defining first and second limb portions, each limb portion including at least one primary module, the or each primary module including at least one primary switching element connected to an energy storage device, the auxiliary converter unit including at least one auxiliary converter limb including at least one auxiliary module including a plurality of auxiliary switching elements connected to the energy storage device of a corresponding primary module in the first limb portion of a respective primary converter limb, the primary switching elements of the primary modules being controllable in use to switch the respective energy storage device in and out of circuit to generate a voltage waveform at the respective AC terminal.

The present invention provides a z-source inverter and its soft starting method, belonging to power electronic converter. The inverter main circuit is composed of a DC voltage source, a three-phase inverter bridge, a z-source network, a power diode, characterized in that the positive end of the three-phase inverter bridge is connected to the cathode of the DC voltage source, the negative end of the three-phase inverter bridge is connected to the Z source network. Compared with the voltage source type and the current source type inverter, the Z source inverter realizes pressure raising change function, and the upper and the lower switch tubes of the same bridge arm are directly passing, so the dead zone does not need, the circuit structure is simple, having high credibility. Compared with the traditional Z source inverter, the capacitor voltage of the Z source network in the Z source inverter has small stress, and realizing the soft start of the transformer, avoiding the problems of large voltage and current when the traditional Z source inverter starts, the work of the transformer is safe and credible, and having light volume and weight.

The invention relates to a power electronic converter (20a) for use in high voltage direct current power transmission and reactive power compensation which comprises at least one converter limb (22) including first and second DC terminals (24a, 24b) for connection in use to a DC network (26), the or each converter limb (22) including at least one first converter block (32) and at least one second converter block (34) connected between the first and second DC terminals (24a, 24b); the or each first converter block (32) including a plurality of line-commutated thyristors (36) and at least one first AC terminal (28) for connection in use to an AC network (30), the or each second converter block (34) including at least one auxiliary converter including a plurality of self-commutated switching elements; wherein the self-commutated switching elements are controllable in use to inject a voltage to modify a DC voltage presented to the DC side of the converter limb (22) and/or modify an AC voltage and an AC current on the AC side of the power electronic converter (20a).

The present invention discloses a resonant converter and a control method thereof, belonging to the field of the power electronic converter technology. The resonant converter and control method thereof are composed of an input source, an original edge LLC resonance circuit, a transformer, a secondary active Boost rectification circuit and an output load. Based on the traditional LLC resonance converter, the secondary active Boost rectification circuit is substituted for the active Boost rectification circuit so as to realize the fixed frequency phase-shifting control of a converter, the frequency conversion control of the converter and the frequency conversion and fixed frequency phase-shifting combined control to facilitate the design of magnetic elements, reduce the voltage stress of the original edge switch tube and the secondary rectifier tube so as to realize the soft switch of each power semiconductor device, improve the voltage gain range, the efficiency and the power density of the converter and satisfy the requirement of a wide voltage gain margin conversion occasion.

The invention relates to the technical field of power electronics converters, and aims to provide a direct current transformer device used for power distribution. The device comprises a high-frequency transformer, a high-voltage side converter valve and a low-voltage side converter valve, wherein the input side of the high-voltage side converter valve is directly connected with a middle-high-voltage direct current power grid, and the output side of the high-voltage side converter valve is connected with a primary side winding of the high-frequency transformer; the input side of the low-voltage side converter valve is connected with the primary side winding of the high-frequency transformer, and the output side of the low-voltage side converter valve is connected with a low-voltage direct current power grid or an energy storage system. The input sides and the output sides of the direct current transformer device are subjected to high-frequency isolation, a heavy low-frequency transformer is omitted, voltage can achieve a high level due to a modularization design, the cost is lowered, meanwhile, a redundancy design becomes simple and feasible, and the system can be repaired without outage; the switching loss of the device can be lowered by a phase shift control structure to enable the efficiency of the converter to be high; the energy of the direct current transformer system can carry out bidirectional flowing; the whole direct current transformer system has the advantages of simpleness and flexibility in control, efficiency and reliability.