2214 results about "DC - Direct current" patented technology

The invention discloses an intelligent mobile charging automobile system and method. The system comprises a charging automobile, a large-capacity energy storage battery pack, a DC-DC direct-current converter A, a vehicle-mounted charger, a charging connection device, a charging transfer device, a ground track, a mobile phone client terminal, a scheduling center server and a charging room, wherein the scheduling center server comprises a wireless communication unit, a data receiving unit, a data processing unit and a data feedback unit; the charging automobile comprises a driving system, a whole-automobile controller, a wireless communication module, a sound-light alarm module, a tracking detection module and an obstacle avoidance detecting module. According to the intelligent mobile charging automobile system, navigation and landmark tracks are mounted and paved on the ground on the basis of the existing facilities of parking lots; the charging transfer device is mounted on the ground of the preserved charging automobile parking space; the automatic connection charging is implemented; the problem that charging stations and charging piles are inconveniently built in the existing parking lots can be solved; the system is simple and convenient; the building cost and the maintenance cost are greatly reduced; and the charging time is reduced.

Enclosed is an active and reactive coordination control method for permanent-magnet direct-driven wind turbines in the low-voltage ride-through process. Two different control strategies are employed for a grid side converter according to amplitude change of power grid voltage: when the power grid voltage is in a normal state, the grid side converter is in an active-priority maximum power tracing control mode so that the wind turbines capture wind energy to the maximum extent; when the power grid voltage is beyond the normal range, the grid side converter is in an active priority control mode so that the dynamic reactive current which is injected into an electricity system meets the requirements of grid combining. An engine side converter is in a direct-current voltage control mode based on rotor energy storage, power unbalance of the direct-current side of the engine side converter is relieved and the direct-current voltage is stabilized by utilizing the self rotating speed of the permanent-magnet direct-driven wind turbines and the change of the kinetic energy. The active and reactive coordination control for the wind turbines before or after the sudden change of the power grid voltage is realized according to the amplitude change of the power grid voltage, the fluctuation of the direct-current bus voltage is restrained by releasing or storing the rotor kinetic energy, so that the low-voltage ride-through capability of the permanent-magnet direct-driven wind turbines is improved, reactive power support is rapidly and accurately provided for the power grid, and certain support is given to restoration of the power grid voltage.

A distributed power system for delivering DC power to a plurality of loads. A plurality of power converter modules having associated therewith a DC/DC power conversion operation are provided, each disposed proximate an associated one of the loads, each of said converter modules having associated therewith a switching pulse generator for generating switching pulses. A distributed power line distributes input power to each of the modules. A data communication line distributes command data between the modules. Each of the modules includes a power regulation section for receiving the input power to generate a DC output by controlling the operation of the switching pulse generator. It also includes a processing section for interfacing with the data communication line for interfacing with the commands, the processing function operating in at least a slave mode to receive commands from the data communication bus. At least one of the modules operates in both a slave mode and a master mode. In the master mode, the processing section generates commands for transmission over the data communication line to an addressed one of the other of the modules and internally for use in the local slave mode of operation. The processing section in the slave mode of operation is operable to configure and monitor the operation of the power regulation section.

The invention discloses a high-focusing-capability multi-channel transcranial direct current stimulation device and a control method thereof. The high-focusing-capability multi-channel transcranial direct current stimulation device comprises a transcranial direct current stimulation (tDCS) electrode array, a power source and control units, wherein channel electrodes in the electrode array are connected with the power source respectively through independent control units, polarity and current strength of the channel electrodes are respectively controlled through the independent control units, and the tDCS electrode array is integrated into an electrode cap mode. The high-focusing-capability multi-channel transcranial direct current stimulation device can complete automatic optimization of stimulation parameters of the channels according to stimulation positions and types specified by users, and finally generates stimulation meeting users' requirements. A tDCS system of the high-focusing-capability multi-channel transcranial direct current stimulation device has the advantages of being capable of covering the whole head, having high focusing capability and multiple channels and the like, and is accurate in stimulation position and customizable in complex stimulation.

The invention discloses a hydraulic transmission-based method and a hydraulic transmission-based device for storing energy and realizing stabilized voltage and constant frequency in wave power generation. In the device, a floating pendulum is connected with a hydraulic cylinder, high pressure oil outputted by a non-rod cavity of the hydraulic cylinder enters a high pressure energy storing device and an oil inlet of a variable motor through a control integrated valve and through a high pressure oil tube, low pressure oil outputted by an oil outlet of the variable motor enters a low pressure big-capacity energy storing device and returns to the rod cavity of the hydraulic cylinder through the control integrated valve, the main shaft of the variable motor is connected with a permanent magnet synchronous generator, and the permanent magnet synchronous generator is connected to a rectifying module and a direct-current electric energy charging-discharging control module and then connected to a stepless unload adjustable load and a storage battery. The high pressure energy storing device and the low pressure big-capacity energy storing device realize the energy storage by absorbing the fluctuation, caused by the change of transient waves, of pressure and flow rate. A controller realizes the pressure stabilization constant frequency by the stepless unload adjustable load and the displacement of the hydraulic motor respectively. The device has the advantage of making the wave power generating device output more smoothly, more free from influence of the wave impact and have higher efficiency.

The invention discloses a four-phase brushless DC motor fault-tolerant power converter and a control method thereof. The four-phase brushless DC motor fault-tolerant power converter comprises five inverting bridge arms, six bidirectional thyristors and ten fuses, a four-phase winding is connected to the midpoints of four of the bridge arms after forming two mutually-isolated channels, and the fifth bridge arms is a redundant bridge arm and only works during fault-tolerant operation; every power tube on every bridge arm is connected in series with a corresponding fuse, which can protect the system from being burnt due to short circuit faults and can convert the short circuit faults into open circuit faults for fault tolerance when the short circuit fault occur. The midpoint of every bridge arm is connected with a bidirectional thyristor for achieving fault tolerance of the power tubes; the neutral point of the winding and the midpoint of the fifth bridge arm are also connected with one bidirectional thyristor for achieving fault tolerance of the winding. The four-phase brushless DC motor fault-tolerant power converter is applicable to a four-phase permanent-magnetic brushless DC motor and a double-salient motor and can achieve open circuit and short circuit fault tolerance of power tubes and windings.

A power supply device to supply power to a micro server includes a plurality of power supplies configured to be redundant and supply DC power, and an output unit to output the DC power output from the plurality of power supplies to the micro server, wherein one of the plurality of power supplies operates in a master mode and the remaining power supplies operate in a slave mode, and wherein if a load of the micro server is less than or equal to a first predetermined load, at least one of the power supplies that operate in the slave mode does not output the DC power.

A portable integrated self-contained rechargeable with AC-DC direct current battery system mounted within an instrument case for housing a foldable keyboard, a display and plurality of medical test and treatment modules. It optionally includes a suitable DC to AC inverter to supply AC power. The system includes at least one USB port for adding external test and treatment modules on ad hoc basis. It also includes full duplex data and information input, processing output and communications interface to and from sensors, transducers, networks and other data/information generation or consumption modules, devices and subsystems. It is also known by its three trademark names “Hospital-in-a-Box”, RK Ruskat (Stylized) and SCOMET.

The invention discloses a multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post. The multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post includes a square umbrella seat, a hollow-core support main rod, a solar energy amorphous silicon film cell panel and a plurality of plumbic acid storage batteries connected in series, the hollow-core support main rod is mounted on the square umbrella seat, is square and is made of stainless steel, the square umbrella seat is internally equipped with the plumbic acid storage batteries and a control box, and an LED illuminating lamp, vehicle traveling arrow lamps, traffic lights, network monitoring cameras, a traffic prompt sound box, a detachable direct current electric fan, a charging interface and a traffic prompt screen are arranged on the hollow-core support main rod in sequence from top to bottom. The multifunctional solar-powered intelligent monitoring traffic signal unmanned directing post provided by the invention is light in weight, foldable and movable, automatically starts a passing signal, provides clean electric power energy, obtains power supply anytime anywhere, and can be used by traffic police, border guards and personnel on duty at intersections.

The invention discloses an electric bicycle control method based on a permanent magnet brushless direct current motor. According to the method, subdivided rotor position information is used for directly starting the motor, and the switching procedure from square wave starting to sine wave starting in a traditional control method is omitted. The electric bicycle control method relates to a rotor section calculation module, a speed calculation module, an angle subdivision module, a phasing adjustment module, a speed control module, a current-limiting control module, a waveform modulation module, a three-phase inverter and a motor starting module. By the adoption of the method, control efficiency and control performance are improved, and currents passing through a motor winding are in a sine wave mode when the motor operates; compared with a traditional square wave control method, torque pulsation is small, motor running noise is low, and the service life of the motor can be prolonged; compared with a traditional space vector control method, the algorithm is simple, implementation is easy, the requirement for a microprocessor is low, and high cost performance is achieved.

The invention provides a method for preparing carbon nanohorn, belonging to the technical field of carbon nanohorn synthesis. The carbon nanohorn is prepared by the DC (direct current) arc method in the reaction atmosphere of air, CO2, CO or a gas mixture of CO/N2. The method of the invention meets the requirements for mass production and has the advantages of simple equipment and low preparation cost; moreover, the product of the method has high purity, particularly, the purity of the carbon nanahorn simply subjected to ignition and purification is higher than 94%; and the diameter of the carbon nanohorn prepared by the method of the invention is approximately 25 nanometers, and the carbon nanohorn can be aggregated into a spherical aggregate with the diameter of 50 to 80 nanometers.

The invention provides a method for diagnosing common disconnection faults of a brushless direct current motor inverter. The diagnosing process includes detecting currents of a current stage, and determining a conducting state matrix of the current stage; outputting fault bit signals according to current detection signals of the current stage; calculating a sum matrix Q of a conduction matrix in a period before the current stage, and diagnosing the number and positions of fault tubes by judging the number and positions of 0 elements in the sum matrix Q; and outputting fault types, fault tube positions and fault bits as diagnosis results. According to the method for diagnosing common disconnection faults of the brushless direct current motor inverter, faults can be detected in time and fault positions can be diagnosed when disconnection faults happen to the brushless direct current motor inverter, maintenance and changes for fault switching tubes by technical staff are facilitated, a system can be switched to a fault-tolerant operation mode to operate continuously, and the method has high practical application values in industrials of aviation, aerospace, automobiles and the like with high reliability requirements.

The invention discloses a hybrid direct current power transmission system control method and device. The hybrid direct current power transmission system adjusts in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules according to the direct current voltage of a rectifier station at the other end; or adjusting in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules according to direct current or direct current power; or adjusting in real time the total number of used submodules of a modular multilevel converter, and the output level polarity of the used submodules meanwhile according to the direct current and the direct current voltage of a rectifier station at the other end. The method can effectively control system direct current voltage and direct current, and avoid power transfer interruption of a hybrid direct current power transmission system.

The invention relates to a device and a method for generating a pulsed (intermittent), cold, atmospheric pressure plasma, preferably a thread, for precise antimicrobial plasma treatment (antisepsis, disinfection, sterilization, decontamination) of very small surfaces and cavities, including on living human and animal bodies, preferably in the field of medicine, by means of a negative direct-current corona discharge, the device comprising at least one electrode for generating high field strengths, through or around which electrode the gas to be ionized flows in a gas channel, wherein the electrically conductive structure (surface, cavity) to be treated is used as the counter-electrode. Said plasma can also be used in general for cleaning, coating, activating, and etching surfaces.

The invention relates to a rail-traffic regenerative-braking-energy comprehensive recovery and utilization device and method. The rail-traffic regenerative-braking-energy comprehensive recovery and utilization device is provided with an alternating voltage detecting module, a direct voltage detecting module, a logical control unit, a flywheel energy storage system and an inverter. The flywheel energy storage system conducts action to provide electric energy for or absorb electric energy from a traction network direct current bus according to the magnitude of a traction network direct current bus voltage value and a self SOC value state; and the inverter determines whether traction network direct current bus voltage is absorbed or not by combining the magnitude of the traction network direct current bus voltage value and the SOC state of the flywheel, if the feedback power of the inverter is relatively small, the power is fed back to a low-voltage alternating-current power supply network, and if the feedback power of the inverter is relatively large, the power is fed back to a power distribution network. According to the rail-traffic regenerative-braking-energy comprehensive recovery and utilization device and method, the quality of power-grid electric energy is prevented from being reduced after an inverter feedback device is used, by combining the infinite-capacity continuous working characteristic of the flywheel energy storage system, a part of energy which cannot be absorbed by the flywheel energy storage system after the flywheel energy storage system is fully charged is absorbed, rail-traffic train regeneration is prevented from automatically losing efficacy, and energy conservation is obvious.

The invention relates to a control device for an electric rice cooker and a control method thereof. The control device comprises an operation panel arranged on a cooker body and a control circuit of the operation panel. The operation panel is provided with a press key for starting a combination reservation mode; the control circuit comprises a power circuit module, a controller, a standby DC power module and a heating driving module; the power circuit module and the standby DC power module respectively provide a low-voltage direct current for the controller; the controller sends a command to the heating driving module to control an heating operation of a heater of the electric rice cooker; and the controller comprises a CPU for carrying out program execution, a clock and a memory, wherein the memory comprises a plurality of sets of preset data storages and one set of operational data storages and the inside of each set of data storages is provided with a function storage W, a cooking time storage t and a starting time storage T. The control device of the invention has simple operation. A user presets multiple cooking data to be carried out each day as required, and when a preset time is reached, a power supply of the electric rice cooker only needs to be powered on so as to complete the presetting function. The control method of the invention is convenient and practical.

The invention discloses a method for aging of a low-voltage, high-current and non-isolated DC-DC power supply. In the method, the output end of an AC-DC direct-current power supply is provided with a front-end voltage conversion unit which is used for converting the DC voltage output by the AC-DC direct-current power supply into a plurality of output voltages electrically isolated from the DC voltage output by the AC-DC direct-current power supply, the output voltages are respectively connected with the input ends of a plurality of aging DC-DC power supplies, the voltage obtained through serial connection of the output voltages of the aging DC-DC power supplies is converted into a DC voltage output identical to the DC voltage output of the AC-DC direct-current power supply through an energy recovery unit and is then connected to the input end of the front-end voltage conversion unit. Due to the combination of the front-end voltage conversion unit, the aging power supplies and the energy recovery unit, the invention realizes the high-efficiency aging test for the non-isolated DC-DC power supply with a low output voltage and a high output current, and can recycle more than 80 percent of the output power of the aging power supplies, thereby achieving good energy-saving effect, and filling the gap in the industry.

The invention discloses an electric field carrier distribution type driving system and a control method thereof. A main controller of the system is an embedding type microcontroller based on an ARM kernel, each wheel is driven by a brushless direct current hub motor in an independent mode, each brake mechanism is driven by a direct current motor for brake, each steering mechanism is driven by a direct current motor for steering, and the main controller conducts calculating according to steering signals and speed signals input by the outside, and then conducts driving control on the motors. The method comprises the steps that speed of the direct current motors for steering and speed of the direct current motors for brake are controlled in a PWM control mode, speed of the brushless direct current hub motors through UART serial interfaces, a plurality of motors are simultaneously controlled through the non-cross coupled algorithm, and the fact that the direct current motors for steering have higher priority than the brushless direct current hub motors and the direct current motors for brake is set in a control process. The electric field carrier distribution type driving system can simultaneously drive and control the plurality of motors, and achieves matching rationalization and high efficiency of whole carrier power.

The invention relates to a nine-phase permanent magnet electric driving reconstruction type vehicular charging system for an electric automobile. The nine-phase permanent magnet electric driving reconstruction type vehicular charging system comprises a three-phase power source, a shift switch, a nine-phase permanent magnet motor winding of a nine-phase permanent magnet motor, a capacitor, three-phase bank voltage type inverters, a relay and an accumulator. The charging system sufficiently utilizes an original nine-phase inverter, a nine-phase permanent magnet motor winding, a control and sensor unit and the like of the electric automobile, and rectification, inversion and power-factor correction are completed by optimizing topology, and the total function integration of motor driving, highpower factor charging, harmonic suppression and the like is achieved. When charging is conducted, three independent neutral points of a six-phase winding are utilized to serve as a three-phase alternating current interface, the six-phase winding serves as a filter inductor of a three-phase AC/DC rectifier, and a self-inductor of a remaining three-phase winding is reconstructed to be an energy-storage inductor of a three-phase staggered DC/DC converter. The two sets of three-phase voltage type inverters achieve an AC/DC rectification function, and the one set of three-phase voltage type inverter achieves a DC/DC direct current transformation function.

The invention discloses a combined current-limiting direct-current circuit breaker for a direct-current power grid. The combined current-limiting direct-current circuit breaker comprises a current-carrying transfer branch and a current-limiting blocking branch; the current-carrying transfer branch is formed by connecting an ultra-fast mechanical switch and a load converter switch in series, one end of the current-carrying transfer branch is connected with a direct-current bus of a direct-current power grid, and the other end of the current-carrying transfer branch is connected to the direct-current power transmission line of the direct-current power grid in series; the current-limiting blocking branch comprises a current-limiting branch, a main circuit breaker branch and an energy absorption branch, one end of the main circuit breaker branch and one end of the energy absorption branch are connected in series with one end of the current-limiting branch after the main circuit breaker branch and the energy absorption branch are connected in parallel, and the other end of the current-limiting branch is connected to a potential point A1; and the other end of the main circuit breaker branch and the other end of the energy absorption branch are connected with a potential point A2 after the main circuit breaker branch and the energy absorption branch are connected in parallel. According to the invention, an expensive cutoff assembly can be separated from the circuit breaker for sharing, and the investment cost and the occupied area can be effectively reduced. A thyristor in the current-limiting blocking branch can share voltage to ground, and a charging resistor and a current-limiting inductor can effectively reduce the acceleration of a fault current and reduce the breaking current of the circuit breaker.

The invention relates to a regenerative power energy feedback method for an elevator and a device thereof. The device comprises an inverter, a network voltage detection unit, a network current detection unit, a DSP control unit and a direct current voltage measuring unit, wherein the inverter is formed by connecting an IGBC controllable bridge circuit with an electric reactor; the direct current output end of the variable-frequence governor of the elevator is connected with the direct current end of the IGBC controllable bridge circuit; the output voltage of the inverter is merged into a power network supplying the power for the variable-frequence governor of the elevator to work through the electric reactor; the input end of the network voltage detection unit and the input end of the network current detection unit are respectively connected to the power network supplying power for the variable-frequence governor of the elevator to work; the output end of the network voltage detection unit and the output end of the network current detection unit are respectively connected with the DSP control unit; the DSP control unit is connected with the control end of the IGBC controllable bridge circuit through an IGBT driver; and the direct current output of the variable-frequence governor of the elevator is connected with the DSP control unit through the direct current voltage detection unit.