2531 results about "DC - Direct current" patented technology

The invention relates to the technical field of active damping control, and discloses a bidirectional DC-DC power supply active damping control system and method, and the system comprises a front-end AC input rectification module, an LLC resonant circuit, and a Buck converter module: the front-end AC input rectification module is used for converting an AC input voltage into a DC voltage; the LLC resonance circuit is used for inverting the rectified direct current voltage into alternating current with a set frequency and transmitting the alternating current to a secondary side through a transformer; and the Buck converter module is used for rectifying an alternating current signal and adjusting the alternating current signal into a required direct current output voltage, and further comprises an LC filter and an active damping control module. By adopting the active damping control method, the resonance peak caused by the LC filter can be effectively suppressed without additionally adding a physical resistor, so that the fluctuation of the output voltage is limited. According to the control strategy, the problems of power loss and heating caused by a traditional passive damping method are avoided, and the energy efficiency of the system is remarkably improved.

The invention provides an elevator energy-saving device which is connected to an elevator frequency converter bus in parallel and comprises a battery pack, a BMS battery management system, a power control system, a DC-DC direct-current power source and a PLC, the DC-DC direct-current power source is connected with the BMS battery management system and connected to the elevator frequency converter bus in parallel, and the power control system is connected with the PLC. The PLC is connected with the DC-DC direct-current power supply, and the DC-DC direct-current power supply transforms the voltage accessed from the battery pack to the second preset voltage under the action of the PLC, so that the voltage of the high-voltage end is controlled to be the second preset voltage; under the action of the high-low voltage difference, when the elevator generates power, the voltage on the elevator frequency converter bus does not rise to the first preset voltage, and the current automatically flows to the elevator energy-saving device. The invention has the characteristics of energy conservation, high efficiency, reduced operation cost, stable operation, reduced power grid pressure and prolonged service life of equipment.

The invention relates to the technical field of control and regulation, in particular to a high-power direct current motor control and regulation method, which comprises the following steps of: acquiring an output voltage, an input voltage, an output current, temperature data and rotating speed data of a motor to be regulated in a current time period; determining a current load deviation factor and a current rotating speed deviation factor; acquiring a historical load deviation factor and a historical rotating speed deviation factor, and determining a current error increment according to the current load deviation factor, the historical load deviation factor, the current rotating speed deviation factor and the historical rotating speed deviation factor; correcting the proportional gain at the current moment according to the temperature fluctuation difference between the current time period and the previous time period and the current error increment; and controlling and adjusting the to-be-adjusted motor according to the target proportional gain. According to the invention, control and adjustment of the high-power DC motor are realized, and the rationality of proportional gain setting and the rationality of control and adjustment of the high-power DC motor are improved.

The invention discloses a wind-solar complementary energy storage direct current charging method and system based on liquid cooling heat dissipation, and relates to the technical field of energy storage charging. Comprising the following steps: S1, collecting wind-solar complementary energy storage data in real time, and carrying out data preprocessing; s2, converting wind-solar power generation into direct current, judging the flow direction of wind-solar power generation energy, and performing corresponding wind-solar power generation energy transmission power supply; s3, judging the limit of the output power of the charging pile, and controlling and adjusting the output of the charging pile in stages; s4, quantifying the liquid cooling flow required by heat dissipation, and performing heat source heat dissipation on the energy storage system and the charging pile; and S5, carrying out coordinated regulation and control, strategy optimization and multi-dimensional visualization on the flow direction of wind and light power generation energy, charging pile output and heat source heat dissipation. The problems that an existing charging station is difficult to deploy in remote and power transmission difficult areas, high-power charging heat dissipation and energy efficiency bottlenecks are prominent, and the efficiency of traditional air cooling and alternating current conversion is low, so that efficient, safe and green energy supplementation is difficult to achieve are solved.

The invention provides a device and method for improving charging and discharging safety, and the device comprises a bidirectional DC / DC module and a bidirectional DC / AC module which are connected with each other, and the bidirectional DC / DC module comprises a bidirectional Boost / Buck module and a bidirectional LLC module which are connected with each other; the bidirectional DC / DC module is connected with charging and discharging equipment, and the bidirectional DC / AC module is connected with a power grid; the bidirectional DC / DC module comprises a bidirectional Boost / Buck module and a bidirectional LLC module which are cascaded to realize a bidirectional DC / DC function; wherein the bidirectional Boost / Buck module is used for bidirectional step-up / step-down of direct-current voltage, and the bidirectional LLC module adopts an open-loop design and is used for electrical isolation of a charging and discharging equipment side and a power grid side. Based on the control strategy of the awakening circuit and the dormancy circuit, the working stress of the charging and discharging device is reduced, the service life attenuation of the hardware circuit is delayed, and the charging and discharging function failure is reduced, so that the purpose of improving the safety of the charging and discharging equipment is achieved.

Presented are high-voltage (HV) electrical system architectures for vehicle-to-vehicle (V2V) charging of vehicle batteries, methods for making / using such systems, and vehicles equipped with such systems. An HV electrical system for a motor vehicle includes a main HV bus that electrically connects the vehicle's traction motor(s) to the vehicle's battery pack(s), and a charging inlet port that electrically mates with and receives direct-current (DC) power from DC fast-charging (DCFC) cables of a donor vehicle and a charging station. A DC-to-DC (DC-DC) converter is interposed between and electrically connects the charging inlet port to the main HV bus. The DC-DC converter is operable in a bypass mode, in which the DC-DC converter passes therethrough DC power received from the DCFC cable of the charging station, and a vehicle-to-vehicle (V2V) mode, in which the DC-DC converter modulates DC power received from the DCFC cable of the donor vehicle.

A distributed power-sharing electric vehicle (EV) charging. The system comprises multiple chargers connected via a network. Each charger includes a power module configured to store direct current (DC) power, an output port for supplying power to an electric vehicle, and a sharing port for exchanging power with at least one neighboring charger. First and second switches are positioned between the power module and the output port, and between the power module and the sharing port. A control unit is configured to control the operation of the power module and the switches in response to an EV charging request. When the maximum charging power required by the EV exceeds the rated output power of a single charger, the system delivers power from both the power module and the neighboring charger in an idle state.

The invention discloses an anti-fouling piezoelectric ceramic membrane which comprises a support body, a coil and a piezoelectric ceramic separation layer, the support body is made of porous ceramic with a through hole in the middle; the coil is a closed loop composed of a lead coil and a crystal oscillator; the piezoelectric separation layer is coated on the inner wall of the through hole of the support body; and the coil is arranged between the support body and the piezoelectric ceramic separation layer. When a medium containing electrolyte passes through a membrane hole, the coil generates induction direct current, the direct current is converted into positive wave pulse current through the oscillator, the wound and overlapped piezoelectric ceramic membrane separation layer is excited, ultrasonic vibration is generated, and therefore the membrane dirt blocking condition is reduced, the use efficiency of the ceramic membrane is improved, and the maintenance and use cost is reduced.

The invention provides a low-modulation-ratio topological high-reliability high-voltage direct-hanging energy storage system and method.The system comprises three phases of energy storage unit chains, each phase of energy storage unit chain is formed by cascading a plurality of energy storage units, and the connecting ends of the three phases of energy storage unit chains are sequentially connected with an alternating current side filter inductor in series and then connected with a power grid; the energy storage unit comprises an H-bridge power unit, a bus capacitor, a direct current side filter inductor, a battery side pre-charging device, a direct current side contactor and a battery cluster; the direct current side positive electrode of the H-bridge power unit is sequentially connected with the direct current side contactor, the battery side pre-charging device, the battery cluster and the direct current side filter inductor in series and then is connected with the direct current side negative electrode of the H-bridge power unit, and the alternating current side positive electrode of the H-bridge power unit is sequentially connected in series. According to the invention, the high-voltage direct-hanging energy storage system can fully utilize the DC voltage redundancy to realize the frequency doubling current suppression of the battery cluster by utilizing the low modulation ratio characteristic, and the ripple current pulsation amplitude of the battery meets the national standard requirement under the condition that the device cost is not increased.

The disclosure discloses a fan lamp, including a lamp panel, a lamp assembly, a fan assembly, and a motor assembly. The lamp assembly is provided on a side of the lamp panel; the fan assembly is provided on a side of the lamp panel away from the lamp assembly; and the motor assembly includes a direct current motor, and the fan assembly is configured to rotate under the driving of the direct current motor.

The invention discloses a rapid switching emergency protection system for an aero-engine test, and the system comprises a rapid switching unit which is used for rapidly disconnecting a DC load according to a switching instruction transmitted by a controller, and switching the DC load to an emergency protection load; the measuring unit is used for measuring signals such as engine gas turbine rotating speed, free turbine rotating speed, alternating-current voltage and current, direct-current voltage and current and the like; the controller is used for carrying out fault judgment on the system according to the measurement data acquired by the measurement unit and correspondingly sending a switching instruction to the rapid switching unit when a fault occurs; the monitoring system is used for monitoring and displaying parameters and operation states of the rectifier, the bus and the direct-current load system; and the emergency protection load is in circuit connection with the rapid switching unit and is used for providing the emergency protection load when the hybrid power system is in a large state and the load is suddenly lost. According to the invention, overspeed protection of a turboshaft engine hybrid power system test is realized, so that accidents such as breakage and flying-out of turbine blades are avoided.

The invention discloses a hydrogel scaffold with multiple physical gradients. The hydrogel scaffold is prepared from the following synthetic raw materials: thermo-sensitive polyisocyanide polypeptide, silk nanofibers rich in beta lamellar structures and a conductive nanomaterial. The conductive nano material dispersion liquid and the BSNF solution are uniformly mixed according to a ratio of 1: 4; at 4 DEG C, adding a BSNF-loaded conductive nano material mixture into a PIC aqueous solution, uniformly mixing, adding into a square tank with an electrode, and applying a direct-current electric field to the hydrogel; after the electric field is removed, the temperature is raised to 25 DEG C, PIC is induced to form gel, and the conductive hydrogel stent with multiple physical gradients is obtained. The hydrogel contains multiple physical gradient structures such as rigidity, conductivity and morphology. The multi-gradient hydrogel with different patterns can be constructed by regulating and controlling the shape, the position and the electric field applying time of the electrode; the preparation method disclosed by the invention is simple, convenient to operate, simple in equipment and process requirements, low in cost and capable of realizing large-scale industrial production.

The cold rolling bending forming device comprises a bending assembly, an extruding assembly, a cutting assembly and a conveying assembly, and the bending assembly comprises a base, a first support, a second support, a third stepping motor, a lead screw, a first sliding block, a third support, a first shell, a first hydraulic rod, a second lead screw, a second stepping motor and a pressing base. The cutting assembly comprises a second shell, a fourth stepping motor, a third lead screw, a first roller, a second sliding rail, a second direct current motor, a second hydraulic rod and a cutter. The conveying assembly comprises a first lead screw, a first stepping motor, a first sliding rail, a second roller and a fourth support. The width of the bending assembly can be adjusted through the third stepping motor and the lead screw, steel plates of various sizes can be machined, and automatic production is achieved.

The invention provides a direct-current electric energy meter self-calibration method and system. The method comprises the following steps: acquiring an internal high-precision low-temperature drift voltage reference signal; converting the voltage reference signal into an analog calibration voltage signal on a sampling resistor by controlling a direct current standard voltage generation circuit according to the voltage reference signal; converting the voltage reference signal into an analog calibration current signal in a current loop by controlling a DC voltage-current conversion circuit according to the voltage reference signal; obtaining a current environment temperature, and calculating a calibration gain at the current temperature according to a preset temperature coefficient; according to a theoretical calibration value, calculating a voltage gain, a current gain and a power gain of the sampling voltage value and the sampling current value, and writing the gains into a memory; and correcting the reference voltage signal according to the obtained temperature calibration gain, and performing temperature compensation.

There is provided be a brushless direct current, BLDC, electric motor. The BLDC electric motor comprises a rotor comprising a rotor shaft and a stator arranged around the rotor shaft. The stator comprises a stator hub comprising electromagnets, and cooling channels extending in a direction that is parallel to a longitudinal direction of the rotor shaft and the cooling channels are positioned between the rotor shaft and the electromagnets.

The present invention discloses a direct-current side voltage reference value setting method and apparatus, a storage medium, and a device. During low-voltage ride-through, direct-current side operation characteristics under different power grid voltage drop conditions are carefully considered. On the basis of different power grid voltage drop conditions, a corresponding strategy is executed to reduce a direct-current voltage reference value, so that a high modulation factor can be maintained during an entire low-voltage ride-through process, switching loss of a grid-forming converter can be reduced, and output waveform quality can be improved. During high-voltage ride-through, because constant-voltage control is adopted, the grid-forming converter may lose balance points. Therefore, according to differences in power grid voltage rise amplitude, the present invention divides a direct-current side reference value setting algorithm into three conditions, and provides an algorithm for maintaining a minimum active current required to stabilize a bus voltage of the direct-current side, so as to ensure that direct-current voltage remains controllable during the entire ride-through process.

The invention relates to a direct-current illumination control technology, and provides an illumination control method and system during operation of direct-current centralized driving illumination equipment in order to solve the problem that in the existing direct-current illumination technology, each lamp corresponds to a control circuit board, and maintenance is inconvenient due to decentralized control in space. The method comprises the following steps: providing alternating-current electric energy to a distribution box through an alternating-current power supply; a switch module in the distribution box converts alternating current into direct current and supplies energy to the lamp sets, and each lamp set comprises a plurality of lamps which are distributed in the lighting space and connected in parallel. Controlling the illumination parameters of each lamp in the lamp group for illumination; monitoring and acquiring working state information of each lamp in the lamp group, wherein the working state information comprises a brightness parameter, a color temperature parameter and a color parameter; and the illumination parameters and the working state of the lamp are monitored and adjusted in real time. According to the invention, through the integrated direct current illumination control design in the distribution box, the maintenance and management difficulty of direct current illumination is simplified, and the cost is reduced.

The invention relates to a direct current motor with an anti-electromagnetic interference structure in the field of motors, which is characterized in that the surfaces of a commutator and an electric brush are blown in real time through a magnetic shielding cylinder arranged on the outer side of the commutator and an air blowing blade arranged in the magnetic shielding cylinder, and carbon powder on the surfaces of the commutator and the electric brush is cleaned; the commutator and the electric brush are subjected to synchronous blowing heat dissipation, so that the commutator and the electric brush have relatively good contact stability, the condition of contact resistance increase caused by carbon powder accumulation is reduced, the probability of arc generation between the commutator and the electric brush is reduced, and the electromagnetic compatibility of the motor is further improved; the influence of a high-frequency magnetic field generated by the arc on a rotor winding coil is reduced, and electromagnetic interference is further reduced; in addition, the insulating groove formed in the commutator improves the collecting and cleaning effects of the carbon powder, and the insulating groove is matched with the diversion disc to realize ejection of the lower contact surface of the electric brush, so that the cleaning effect of the carbon powder is further improved.

The invention relates to the technical field of charging piles, and discloses a matrix split type direct current charging pile and a power distribution method thereof, and the charging pile comprises a power control unit which is configured to control the power output of the charging pile according to the connection information of a charging gun; the charging module unit is connected with the power control unit, the matrix power distribution unit is connected with the charging module unit, the matrix power distribution unit is controlled by a power distribution mainboard, direct-current electric energy output by the charging module unit is switched to a required direct-current bus, and the direct-current electric energy is conducted to a charging gun of a terminal cabinet through a high-voltage cable to charge a vehicle end; the terminal control unit is connected with the matrix power distribution unit; and the man-machine interaction unit is connected with the power control unit. According to the invention, the output of the power of the charging pile can be accurately controlled according to the connection information of the charging gun, efficient distribution of electric energy is realized, the charging process is optimized, the phenomenon of unbalanced power output in a traditional charging pile is avoided, and the charging efficiency is improved.

The invention discloses a vehicle-mounted bidirectional power converter which comprises a pre-stage voltage stabilization module, a pre-stage driving circuit, a post-stage driving circuit, a post-stage filtering module and an electric vehicle battery module, the pre-stage voltage stabilization module is used for balancing circuit voltage and supporting reactive power, the pre-stage driving circuit is of a single-phase full-bridge AD-DC topological structure, and the post-stage filtering module is of a single-phase full-bridge AD-DC topological structure. The front-stage driving circuit is of a half-bridge type bidirectional DC-DC topological structure, the rear-stage driving circuit is of a half-bridge type bidirectional DC-DC topological structure, the front-stage driving circuit and the rear-stage driving circuit are connected together through a direct-current voltage-stabilizing bus, the size is small, the weight is light, a front stage and a rear stage do not interfere with each other, control is easy, the rear-stage filtering module is used for restraining direct-current side second harmonics, the harmonic quantity is prevented from influencing the stability of output direct-current voltage, and the output direct-current voltage is stable. According to the converter, a corresponding control method is designed, non-inductive decoupling control and a single-phase phase-locked loop of an improved loop filter are adopted, the phase of a power grid is accurately and efficiently obtained, and the converter works stably.

The invention belongs to the technical field of industrial control, and particularly relates to a brushless direct current motor high-efficiency control method and system based on an FOC algorithm, and the method comprises the steps: superposing high-frequency sine disturbance in a voltage instruction, extracting a response component, achieving the online identification of the equivalent impedance of a motor, and dynamically solving and updating the estimated values of resistance and inductance; and correcting d-axis and q-axis voltage feed-forward items in real time by using the updated parameters, and correspondingly adjusting a current loop proportion and an integral gain. The method can adapt to the time-varying characteristics of motor parameters in an industrial field, so that the accuracy of feed-forward compensation and the stability of current loop bandwidth are effectively guaranteed, and the robustness and the control precision of a control system under complicated industrial working conditions such as variable temperature and variable load are remarkably improved; and the requirements of high-end industrial equipment on high performance and high reliability of the motor driving system are met.

The embodiments include a power converter including a DC / AC conversion unit. A direct current bus is connected to the DC / AC conversion unit and a direct current source. The DC / AC conversion unit is further connected to a power grid. When a direct current bus voltage is less than or equal to a first voltage threshold, the power converter may switch to a current source mode to output first output power to the power grid, where the first output power is equal to an output power limit of the direct current source. Then, if a fluctuation amplitude of the direct current bus voltage is less than or equal to a first fluctuation threshold, the power converter may resume outputting second output power to the power grid in a voltage source mode, so that the second output power is less than or equal to the output power limit of the direct current source.

A direct-current conversion circuit, which is used for providing direct-current conversion between a first direct-current voltage and a second direct-current voltage is described. The direct-current conversion circuit comprises: a transformer, which comprises a primary-side winding and a secondary-side winding, wherein the primary-side winding comprises a center tap, and a first primary-side winding and a second primary-side winding, which are respectively connected to the center tap; a primary-side circuit, wherein a first side of the primary-side circuit is connected to the primary-side winding, a second side of the primary-side circuit comprises a first end, a second end, and a third end, and a first direct-current voltage is provided between the first end and the second end of the primary-side circuit; and a secondary-side circuit, wherein a first side of the secondary-side circuit is connected to the secondary side winding.

The invention provides a rail-mounted automobile charging device, a charging base station and a rail-mounted automobile charging system. The hanging rail type automobile charging equipment is hung on a walking guide rail hung on the top of a parking lot, a plurality of charging base stations are arranged on the line of the walking guide rail and correspond to parking spaces of the parking lot, and the automobile charging equipment comprises a charging host hanging platform capable of being hung on the walking guide rail, the limiting assembly, the pushing and collecting module and the walking track are arranged at the bottom of the platform body in a matched mode. The charging host is mounted on the lower portion of the charging host mounting platform in a loading and unloading mode and comprises a movable plug-in module, and when the movable plug-in module of the charging host and the static plug-in module of the charging base station are in butt joint and form electrical connection, the charging host is electrically connected with the charging base station, so that the charging base station supplies alternating current to the charging host; and the direct current converted by the charging host is supplied to the charging base station.

The invention discloses an offshore direct-current wind turbine generator modeling method based on an LLC resonant converter. The method comprises the following steps: establishing an offshore direct-current wind turbine generator pneumatic mechanical model; the method comprises the following steps: establishing an offshore direct current wind turbine generator converter model which comprises a DC / DC converter model which adopts an LLC resonant converter; establishing a seaborne direct current wind turbine generator controller model; and establishing an external DC power grid model. And the offshore direct-current wind turbine generator controller model transmits a control signal to the offshore direct-current wind turbine generator pneumatic mechanical model and the offshore direct-current wind turbine generator generator converter model. According to the method, the electromagnetic transient simulation model of the offshore direct-current wind turbine generator based on the LLC resonant converter, which reflects actual operation characteristics, can be established, and a reliable model basis is provided for simulation calculation of an offshore wind power access power grid.

In one embodiment, an apparatus includes a power source and a moveable charging arm coupled to the power source and comprising a charging plate for contact with an electric vehicle contact plate. The charging arm is operable to transmit direct current (DC) pulse power with testing performed between high voltage pulses directly from the charging plate to the electric vehicle contact plate to charge one or more batteries at the electric vehicle. A method for charging the electric vehicle is also disclosed herein.

The invention belongs to the technical field of direct current monitoring, and discloses a TMR-based open-close type direct current leakage current detection device, which comprises a magnetic core, one or more pairs of TMR sensors, a secondary side feedback coil and a main control circuit, and is characterized in that the magnetic core is provided with air gaps which are oppositely arranged; the TMR sensors are symmetrically arranged in the air gap; the secondary side feedback coil is wound on the surface of the magnetic core and forms closed-loop control with the main control circuit; the main control circuit comprises an acquisition feedback circuit, a secondary side detection circuit and a main control chip, the acquisition feedback circuit acquires signals of the TMR sensor under the control of the main control chip, generates feedback current and inputs the feedback current to the secondary side feedback coil, and the secondary side detection circuit is connected between the secondary side feedback coil and the main control chip. And the main control chip collects the secondary side voltage of the secondary side detection circuit and calculates to obtain the direct current leakage current. According to the invention, direct current leakage current detection with high sensitivity, low drift and strong anti-interference capability is realized under the open-close structure, and the requirements of a modern electric power system on continuity, safety and maintainability are met.

An apparatus includes a power converter to convert incoming alternating current (AC) mains power into a direct current (DC) voltage. A linear AC pump of the apparatus has an arm that reciprocates linearly back and forth to move a pair of diaphragms to pressurize air that is output from the linear AC pump. The apparatus also includes a DC motor driver having an H-bridge that receives the DC voltage from the power converter as an input and that generates a square wave as an output that is coupled to the linear AC pump to drive the arm back and forth. The pressurized air from the linear AC pump is used to inflate one or more bladders of an air mattress, for example.

A road construction machine in the form of a road paver or a feeder vehicle for conveying paving material to a road paver, the road construction machine being self-propelled and having a primary drive source, a hopper, at least one working unit and at least one electric consumer for heating the working unit, the road construction machine having an energy supply system with at least one electrical energy storage which can be charged by means of electric current generated outside the road construction machine and is present on the road construction machine as an internal power source for direct current supply to the electric consumer. Furthermore, the disclosure relates to the use of such an energy storage for direct current supply to an electric consumer of a road construction machine.

The invention discloses a battery charging and discharging power self-regulation control circuit, which relates to the technical field of battery control, and comprises a power supply module, a micro-control module, a voltage sampling and comparison module, a battery charging and discharging power self-regulation control module, a battery charging and discharging power self-regulation control module, a battery charging and discharging power self-regulation control module and a battery charging and discharging power self-regulation control module, the power regulation module compensates the direct-current electric energy, the battery module stores energy, the power regulation module and the direct-current electric energy are superposed and supply power to the battery module, during the discharging period, according to the voltage comparison condition, the power regulation module carries out voltage compensation processing on the battery module, and the battery module directly supplies power to the discharging module; and the power regulation module performs voltage balance control on the battery module. The battery charging and discharging power self-adjusting control circuit can prolong the service life of the battery, improve the charging and discharging efficiency, reduce the electric energy loss of the power adjusting module, improve the energy utilization rate and provide higher charging voltage.