1917results about "Apparatus with intermediate ac conversion" patented technology

A multi-phase LLC resonant converter circuit (10) includes: first to third LLC resonant converters each including a series circuit (S1 to S3) of a first switch and a second switch that are connected in parallel to a DC power supply, a high-frequency transformer (T1 to T3) including a primary-side winding and a secondary-side winding, a resonant circuit including a resonant reactor (Lr1 to Lr3) connected between a connection point of the first switch and the second switch and one end of the primary-side winding, a resonant capacitor (Cr1 to Cr3) in which one end is connected to the other end of the primary-side winding, and a divided resonant capacitor (Cn1 to Cn3) in which one end is connected to a connection point of the primary-side winding and the resonant capacitor; a first neutral line (N1) that connects the other end of the resonant capacitor; a neutral line reactor (Ln) connected between the first neutral line and a power supply line of the DC power supply; and a second neutral line (N2) that connects the other end of the divided resonant capacitor.

A power converter configured to be connected to three or more voltage parts, includes three or more power-conversion circuitries to be connected to respective ones of the three or more voltage parts, and a multi-port transformer connected to the three or more power-conversion circuitries at respectively different ports. The three or more voltage parts include a vehicle drive battery and a plurality of alternating-current (AC) voltage parts. Each of the plurality of AC voltage parts is configured to provide at least one of power input to a multi-port transformer side and power output from the multi-port transformer side.

The invention discloses an unmanned aerial vehicle hybrid power supply system energy management method based on fuzzy double closed-loop control in the technical field. An unmanned aerial vehicle hybrid power supply system comprises a hydrogen fuel cell, a lithium battery and a double active bridge circuit, and the hydrogen fuel cell and the lithium battery serve as energy sources of the hybrid power supply system; the dual-active bridge circuit is used for connecting a hydrogen fuel cell and a lithium battery and transmitting energy to an unmanned aerial vehicle load, the energy management method comprises a fuzzy power control outer ring and a fuzzy PI current control inner ring, the fuzzy power control outer ring dynamically distributes power according to a power signal required by the unmanned aerial vehicle load, a power error signal and a lithium battery charge state, and the fuzzy PI current control inner ring controls the power to be output. The fuzzy PI current control inner loop generates an accurate driving signal according to the battery power and the voltage ratio after fuzzy distribution, a switching device of the dual active bridge circuit is driven to be switched on, energy transmission is achieved, and the problems that in existing unmanned aerial vehicle energy management, the cruising ability is insufficient, and the energy utilization efficiency is low can be effectively solved.

The embodiment of the invention discloses a unipolar battery equalization method and device for an energy storage system. The unipolar battery equalization method comprises the steps of calculating a state-of-charge value of each single battery according to a sampling value of an electrical basic physical quantity; calculating a difference value between the state-of-charge value of each single battery and an average state-of-charge value of a battery pack to which the single battery belongs; determining the single batteries of which the difference values exceed a preset equalization threshold value as unbalanced batteries; and switching on a selection switch corresponding to the unbalanced battery so as to enable the unbalanced battery to be connected with a primary side port of the multi-port converter, and setting the working state of the multi-port converter as the balanced electric quantity of the unbalanced battery. By adopting the embodiment of the invention, energy storage elements required in a multi-pole framework can be reduced, the integration level is higher, the system is simpler, the reliability of the system can be improved, and the hardware cost can be reduced.

The invention belongs to a transformer structure, and provides a direct-current transformer, a power transmission system and a control method of the power transmission system in order to solve the technical problems that a three-level circuit topology in a power module in an existing direct-current transformer is large in number of power devices, complex in structure and large in layout and wiring difficulty. Each power module comprises a first-stage circuit, a second-stage circuit, two first direct-current bus capacitors and two second direct-current bus capacitors, the two first direct-current bus capacitors are connected in series to form a first capacitor circuit, and the two second direct-current bus capacitors are connected in series to form a second capacitor circuit. The first-stage circuit comprises two first half-bridge circuits which are connected in series, and the second-stage circuit is a dual-active bridge converter based on a series half-bridge. The number of power devices is remarkably reduced, meanwhile, the layout and wiring difficulty of the whole circuit is simplified, and popularization and application of the direct-current transformer are easier.

The invention provides a frequency modulation and phase shift hybrid modulation method for high-frequency LLC and a related device, which are applied to an LLC resonant converter and comprise the following steps: setting initial parameters of the LLC resonant converter; different system working frequencies are selected; for each system working frequency, determining a required phase shift angle according to a load demand and the system working frequency; and then judging whether the gain of the converter can meet the load requirement under the phase-shifting angle and the frequency, if not, adjusting the phase-shifting angle until the load requirement is met, and if so, taking the phase-shifting angle as a parameter combination. And then calculating system loss under parameter combinations corresponding to different frequencies, and finally selecting the combination with the minimum loss as a modulation parameter basis. The phase shift control is added on the basis of the traditional frequency modulation strategy, the output voltage can be accurately controlled without changing the topology of the converter, the influence of a dead zone under high frequency on the system is reduced, the optimal working point is determined through the balanced frequency modulation and phase shift strategy, the system loss is minimized, and the operation efficiency is improved.

A resonant capacitor Crk (k is a natural number of one to n) of each circuit element has one end connected in series to a resonant reactor Lr and a primary winding N1 of a transformer T, and another end connected to the resonant capacitor Crk of another circuit element 10 so that a dimensional multiphase LLC converter having a phase difference of 360° / Pk is constructed by Pk (Pk is an optional natural number) of the circuit elements 10.

The invention discloses a bidirectional hybrid output direct-current transformer and a fault current limiting design method thereof, and the medium-voltage side and the high-voltage side of the bidirectional hybrid output direct-current transformer are respectively composed of three thyristor valve groups and three sub-module bridge arms, and are connected through a medium-frequency transformer. The thyristor valve group is formed by reversely connecting two groups of series thyristors in parallel, and the medium-voltage side sub-module bridge arm and the high-voltage side sub-module bridge arm are respectively composed of NM half-bridge sub-modules and NH half-bridge sub-modules. According to the invention, the sub-module bridge arms with strong control capability are combined with the thyristors and the diode valve groups which are low in cost, low in loss and high in power density, bidirectional power transmission and reliable turn-off of the thyristors can be realized through coordination and cooperation of the middle-voltage side bridge arms and the high-voltage side bridge arms, smooth direct current is ensured, and a filter does not need to be installed. When a short-circuit fault occurs in the outgoing submarine cable, a fault current active suppression strategy is provided, and the scheme can effectively reduce the peak value of the fault current and eliminate the current-limiting inductance.

The invention discloses a power supply intelligent management control system, and relates to the technical field of power supply management, and the system comprises a power supply processing module which is used for accessing and transmitting AC electric energy and carrying out voltage reduction, rectification filtering, inversion and transformation processing; the current sampling module is used for current sampling control, signal conversion and amplification filtering; the voltage comparison module is used for setting an overvoltage threshold value, comparing the overvoltage threshold value with the voltage and detecting the shunting degree; the power taking processing module is used for converting, amplifying and filtering the shunted sampling signals, and rectifying and storing the shunted sampling signals; the intelligent control module is used for signal receiving and module control; the electric energy adjusting module is used for adjusting voltage; and the output processing module is used for outputting filtering and electric energy superposition processing and supplying power to the output module. The intelligent management control system for the power supply can provide voltage stabilization and perform shunt power taking work and electric energy processing when a sampled signal is greater than a set threshold value, so that the safety of the system can be improved, and energy-saving power supply control can also be performed.

Embodiments of this application provide a power conversion apparatus and a charging apparatus. The power conversion apparatus includes an AC-DC conversion circuit, a power controller, and a circulating current controller. The power controller is configured to control the AC-DC conversion circuit to convert a received alternating current into a first direct current and output the first direct current. The circulating current controller is configured to send a synchronization signal to another power conversion apparatus through a controller area network CAN bus. The synchronization signal is used to synchronize a carrier of the another power conversion apparatus with a carrier of the power conversion apparatus provided in embodiments of this application. According to the technical solutions provided in embodiments of this application, a circulating current between a plurality of power conversion apparatuses connected in parallel can be suppressed. This helps improve running stability of the charging apparatus.

The present disclosure provides a control method for a resonant converter and a resonant converter, and relates to the technical field of resonant converters. The resonant converter includes a primary side switch and a corresponding rectification switch, the primary side switch is controlled by a first control signal, the rectification switch is controlled by a second control signal, and the method includes: acquiring a voltage difference value, where the voltage difference value is obtained by subtracting a voltage value of an output voltage of the resonant converter from a reference voltage value; and adjusting a turn-on dead time and / or a turn-off dead time between the first control signal and the second control signal according to the voltage difference value.

The invention discloses a solid-state transformer seamless fault-tolerant control method based on cascaded H-bridge pre-charging, and the method comprises the steps: carrying out the pre-charging of a bus capacitor of a redundant unit module based on a cascaded H-bridge, dynamically adjusting the modulation wave of a preceding-stage H-bridge of each unit module, and achieving the impact-free charging of the bus capacitor of the redundant unit module. And after the pre-charging of the redundant unit module is finished, controlling a modulation wave signal and a driving pulse of a pre-stage H bridge of the redundant unit module to intermittently charge a bus capacitor of the redundant unit module. According to the invention, the problems of long charging time of the redundant unit module, overload of the residual unit module and overlarge current impact of the alternating current inductor in the process of removing the fault unit module and inserting the redundant unit module in the cascade converter are solved. According to the method, no additional circuit needs to be added, the method is suitable for a power bidirectional flow and unidirectional flow system, quick and smooth switching of the unit modules can be achieved when a fault occurs, and reliable and stable operation of the whole system is guaranteed.

An active clamp flyback converter with safe operation is discussed. The active clamp flyback converter has a main power switch and an auxiliary switch integrated at a same IC chip. The active clamp flyback converter enables a first charge path from the power supply voltage to a floating capacitor when the main power switch is turned on. The first charge path is disabled and a second charge path from a second pin of the IC chip to the floating capacitor is enabled when a voltage at the second pin is higher than a reference voltage.

The invention discloses a charging and discharging switching method of a charging and discharging circuit, a controller and an energy storage system, in the charging and discharging circuit, switching of a charging working condition and a discharging working condition is realized through a switching circuit, and in order to realize seamless switching of charging and discharging, a first switching tube and a second switching tube in the switching circuit are switched into a first switching tube and a second switching tube in the switching circuit; the first driving signal and the second driving signal which are complementary are adopted for driving, so that the first switching tube and the second switching tube are in opposite switching states at any moment, the duty ratio change is adjusted during charging and discharging switching, seamless charging and discharging switching can be achieved during system heavy load, and the charging and discharging efficiency is improved. In addition, the first driving signal and the second driving signal are complementary, two paths of driving signals do not need to be independently generated to drive the first switching tube and the second switching tube, and therefore the control complexity of the system can be simplified.

The invention discloses a dual-mode LLC resonant converter with a wide range and a narrow frequency band and a control method of the dual-mode LLC resonant converter. The dual-mode LLC resonant converter comprises a dual-output half-bridge inverter circuit, a first LLC series resonant cavity, a second LLC series resonant cavity, a first high-frequency transformer Tr1, a second high-frequency transformer Tr2 and a variable rectification output circuit. The dual-mode LLC resonant converter and the control method thereof aim at solving the problem that an existing LLC resonant converter and a control method thereof are difficult to achieve wide-range voltage output in a narrow frequency band, by adopting the dual-mode LLC resonant converter with the wide range and the narrow frequency band and the control method of the dual-mode LLC resonant converter, voltage gain exceeding 4 times can be achieved under the condition that the switching frequency range is smaller than 2 times; the circuit has the advantages of few switching tubes, small switching loss and high conversion efficiency.

The invention relates to a vehicle-mounted power source, a battery system of a vehicle and the vehicle, at least part of devices of the vehicle-mounted power source are detachably connected with the vehicle, the vehicle-mounted power source comprises a first battery, a second battery and a third battery, the first battery is a power battery of the vehicle, and the first battery is used for supplying power to a load outside the vehicle in a detached state; the first end of the alternating current and direct current conversion device is connected with the first battery, the second end of the alternating current and direct current conversion device is suitable for being connected with the load outside the vehicle, and in the vehicle-mounted power supply, the alternating current and direct current conversion device is used for converting direct current of the first battery into alternating current and supplying the alternating current to the load outside the vehicle.

Provided in the present invention is a multi-level isolated buck type DC / DC converter, comprising two transformers, wherein a primary side of each transformer is provided with a single winding, and a secondary side thereof is provided with two windings; the primary sides of the two transformers are connected in series and are then connected to an LLC resonant circuit, so as to implement isolation and voltage regulation; the other side of the LLC resonant circuit is connected to a flying-capacitor-clamped five-level half-bridge switch network, so as to reduce voltage stress; and the secondary sides of the two transformers are each sequentially connected to a rectifier bridge and a buck circuit, output ends of the two buck circuits are in interleaved parallel connection, and the buck circuits are responsible for closed-loop voltage stabilization regulation, thereby realizing high-gain buck of the converter. Compared with conventional LLC converters, the present invention can significantly reduce voltage stress, can achieve a wider input voltage range and high-gain buck, and can significantly reduce switching loss and improve the efficiency of the converter.

A power conversion device includes: a DC / DC converter; and a control circuit unit that controls the DC / DC converter, in which the DC / DC converter includes a first power output circuit that converts first direct current power into first alternating current power, an isolation transformer that converts the first alternating current power into second alternating current power, and one or a plurality of second power output circuits, each of which converts the second alternating current power into second direct current power, and the control circuit unit includes a resonance characteristic calculator that calculates a resonance characteristic of the second power output circuits based on a load for each of the second power output circuits to output the second direct current power, and determines a drive frequency of the first power output circuit based on an output request value of the second power output circuit and the resonance characteristic that is calculated.

The invention discloses a fractional-turn winding structure applied to a boost planar transformer and a design method, and relates to a fractional-turn winding structure and a design method. The planar transformer aims to solve the problems that an existing planar transformer is large in stray capacitance and large in work loss. The fractional turn winding structure applied to the boost type planar transformer comprises three winding units, and the three winding units are sequentially arranged between a first magnetic core and a second magnetic core of the boost type planar transformer in an overlapped mode from top to bottom. The invention belongs to the technical field of power conversion.

The invention discloses a dual-active-bridge converter integrated with an energy storage battery. The dual-active-bridge converter comprises a primary side full-bridge circuit, a secondary side full-bridge circuit, a transformer T and an energy storage module, the primary side full-bridge circuit is connected with the secondary side full-bridge circuit through the transformer T. The energy storage module is connected with the secondary side full-bridge circuit. The energy storage module comprises an inductor L2 and an inductor L3, the energy storage module comprises an inductor L2, an inductor L3, a capacitor C3 and an energy storage battery B. After the inductor L2 and the inductor L3 are connected in series, the two ends of the inductor L2 and the inductor L3 are connected with the two bridge arms of the secondary full-bridge circuit respectively, and the connecting point of the inductor L2 and the inductor L3 is connected with the capacitor C3 and the energy storage battery B. According to the dual active bridge converter integrated with the energy storage battery, the problems that in the prior art, the number of DCDC converters in a direct current micro-grid is too large, and the energy storage charging and discharging efficiency is low are solved.

A triple-active bridge (TAB) converter and methods to optimize the same is disclosed. The TAB converter includes a high-frequency three-winding transformer and three active full bridges, each coupled to the high-frequency transformer through a different passive network. The converter also includes a centralized controller providing gating pulses to semiconductor switches within the active full bridges, a power pulsating buffer (PPB) configured to reduce capacitor requirements on the DC port, and an unfolder stage to convert rectified AC voltage to a pure sine wave. The centralized controller may optimize performance by varying at least one of a switching frequency, a duty cycle of bridge voltages, and a phase shift between bridge voltages. The PPB may include a buck active power decoupler with a half-bridge, inductor, and capacitors, and also a primary full bridge and a power transfer impedance block.

To provide a control device for a power converter capable of appropriately realizing a power conversion system in which a plurality of storage battery modules is electrically connected in parallel.SOLUTION: A control device 16 is applied to a power conversion system 10 in which a plurality of storage battery modules 30, 60 and 90 including storage batteries 31, 61 and 91 and power converters 40, 70 and 100 is electrically connected in parallel. The control device 16 comprises: a voltage acquisition section 16a which acquires a terminal voltage of at least one of the power converters 40, 70 and 100; and a control section 16c which performs switching control of the power converters 40, 70 and 100 in such a manner that a magnitude of the acquired terminal voltage is prevented from exceeding an upper limit voltage.SELECTED DRAWING: Figure 1

To disclose a power conversion device that can prevent occurrence of resonance on a secondary side of an insulating DC / DC converter circuit.SOLUTION: A power conversion device of the present invention comprises: a DC / DC converter having a first full-bridge circuit including a first switching leg and a second switching leg connected in parallel with a first input / output terminal pair, a second full-bridge circuit including a third switching leg and a fourth switching leg connected in parallel with a second input / output terminal pair, and a transformer including one winding connected with the first full-bridge circuit and the other winding connected with the second full-bridge circuit; and a control unit controlling the DC / DC converter. The control unit always turns on any one of a plurality of switching elements included on a low side of the full-bridge circuit on a secondary side, of the first full-bridge circuit and the second full-bridge circuit.SELECTED DRAWING: Figure 2

The utility model provides a magnetic element and a topological structure used for an interleaving flyback converter, and relates to the technical field of power electronics, and the magnetic element comprises a magnetic core structure and a coil structure. The magnetic core structure comprises an upper magnetic core base, a lower magnetic core base, N magnetic core middle columns and at least one side column, wherein the upper magnetic core base and the lower magnetic core base are oppositely arranged, the N magnetic core middle columns and the at least one side column are arranged between the upper magnetic core base and the lower magnetic core base, and N is a natural number larger than 1. The coil structure comprises N coils wound on the magnetic core middle columns respectively, the winding directions of the coils on the adjacent magnetic core middle columns are opposite, and an air gap is formed in at least one of the three positions including the position between the upper bottom face of each magnetic core middle column and the upper magnetic core base, the position between the lower bottom face of each magnetic core middle column and the lower magnetic core base and the side face of each magnetic core middle column. According to the magnetic element, the magnetic core columns are integrated on the same magnetic core base, and the winding directions of the coils of the adjacent magnetic core middle columns are opposite, so that the purposes of reducing the weight of the magnetic core and reducing the loss of the magnetic core can be achieved.

The invention discloses an underwater new energy power supply system. The power supply system comprises a plurality of new energy power generation modules and a first direct-current transformer which are arranged on the water surface, and a second direct-current transformer and a plurality of charging modules which are arranged underwater, the first direct-current transformer comprises a plurality of first sub-modules, and the low-voltage side of each first sub-module is connected with the corresponding new energy power generation module; the first direct-current transformer comprises a plurality of first sub-modules, the high-voltage sides of the first sub-modules are connected in series, the second direct-current transformer comprises a plurality of second sub-modules, the high-voltage sides of the second sub-modules are connected with the high-voltage sides of the first direct-current transformer after being connected in series, and the low-voltage sides of the second sub-modules are connected in parallel; the input end of each charging module is connected with the low-voltage side of the corresponding second sub-module, and the output end of each charging module is used for being connected with the corresponding underwater electric equipment. According to the scheme, stable electric energy supply can be provided for the underwater electric equipment, and the power supply cost of the underwater electric equipment is reduced.

The transformer is composed of a clamping circuit, a device series inverter circuit and a multi-isolation conversion rectification circuit, the clamping circuit is electrically connected with a direct current at an input end, two ends of the clamping circuit are electrically connected with the device series inverter circuit, and the device series inverter circuit is electrically connected with the multi-isolation conversion rectification circuit. And the output end connected with the device series inverter circuit is electrically connected with the multi-isolation conversion rectifier circuit. The direct current bus transformer is formed by the clamping circuit, the device series inverter circuit, the multi-isolation conversion rectification circuit and the non-isolation adjusting circuit, and the direct current bus transformer can meet the requirements of compact high-capacity direct current bus power conversion of a future data center and large-scale renewable energy direct current aluminum production or hydrogen production.

The invention relates to a direct-current transformer circuit topology based on a series three-phase bridge circuit and a control method thereof. A high-voltage side power unit comprises N three-phase series half-bridge circuits which are sequentially connected in series; the low-voltage side power unit comprises N three-phase parallel half-bridge circuits which correspond to the three-phase series half-bridge circuits and are sequentially connected in parallel, each three-phase series half-bridge circuit is connected with the corresponding three-phase parallel half-bridge circuit through a three-phase isolation transformer to form N groups of three-phase bridge modules, and meanwhile, the N groups of three-phase bridge modules are connected with the N groups of three-phase isolation transformers. A symmetrical duty ratio and phase shift hybrid control strategy is adopted to realize bidirectional flow of energy and soft switching in a full range, and intra-module and inter-module phase shift control is adopted to realize voltage sharing of a series side, reduce current ripples of a parallel side, reduce backflow power and improve the efficiency of the converter.

A system includes a converter that distributes electric energy from an energy source to a load. The converter includes a dual active bridge. The system includes interfaces coupled to the converter. The system also includes a controller system that includes the interfaces and a controller. The controller system includes processors that perform determining of modulation control attributes based on characteristics of the converter, the modulation control attributes including one or more modulation control parameters and one or more modulation control modes corresponding to one or more phase shift techniques, obtaining operational condition information within the converter, the operational condition information corresponding to a component within the converter or an output of the converter, iteratively adjusting the modulation control attributes based on the operational condition information and controlling the converter based on the iteratively adjusted modulation control attributes.

Bidirectional isolated universal topology (BIUT) high power DC-DC converter assemblies and systems balance voltages and control currents between high power DC sources and high power DC loads where at least some of the high power DC sources are alternative energy or renewable energy power supplies and high power DC loads associated with alternative energy or renewable energy. The BIUT high power DC-DC converter assemblies and systems are capable of reversing current flow direction where loads become the sources and sources become the load in DC power systems where the supplies and loads are all connected to a common DC voltage bus.

An adaptive synchronous rectification control method for a CLLLC resonant converter solves the problem of the relatively complex theoretical calculation process for synchronous rectification of a CLLLC resonant converter, and belongs to the field of CLLLC resonant converter control. Based on the circuit characteristics and operating process of the CLLLC converter, the present invention analyzes the influence of the converter's synchronous rectification drive signal on the output frequency of the converter when the converter outputs a stable output signal, derives an equation for the relationship between the change in the synchronous rectification signal and the change in the operating frequency near the ideal synchronous rectification signal, and utilizes the law of this equation to implement the synchronous rectification function of the CLLLC converter. In the rectification control, a certain disturbance signal is given to the synchronous rectification signal, and then the synchronous rectification signal of the converter is gradually brought closer to the ideal synchronous rectification state based on the change in the operating frequency before and after the converter reaches a stable output signal. The present invention does not require additional sensors and avoids complex theoretical calculations.