2377 results about "Dc current" patented technology

To provide various techniques for preventing a theft of electric cables in a photovoltaic power generation facility.SOLUTION: There is provided a theft prevention system of electric cables in a photovoltaic power generation facility. The theft prevention system includes a power conditioner, a string part, and a processor. The power conditioner includes a resistance measurement part. The resistance measurement part can acquire measurement data. The measurement data is the data indicating a resistance value of a circuit including the string part. The string part includes a plurality of cell parts and is electrically connected to the power conditioner at least via the electric cables. The cell parts can acquire sunlight energy by conversion into a direct current. The processor acquires the measurement data from the resistance measurement part. Data related to a theft of the electric cables is output in response to a change in the resistance value indicated by the measurement data.SELECTED DRAWING: Figure 1

The present invention discloses a transformer fault diagnosis technology based on knowledge mapping, which relates to the field of fault diagnosis technology and includes the following steps: S1, obtaining transformer multimodal data and performing data preprocessing; S2, establishing a memory-enhanced early warning model to predict transformer operation data; S3, transformer fault diagnosis. The present invention comprehensively considers online monitoring data or offline test data such as transformer oil dissolved gas data, oil temperature, partial discharge signal, core or clamp grounding current, DC current, infrared spectrum, winding deformation curve, ambient temperature and humidity, etc., performs fault diagnosis on the predicted multimodal data, and predicts possible future transformer faults.

The invention discloses a battery impedance online monitoring system and method. The system comprises a sinusoidal signal generation circuit, a voltage-current conversion circuit, a signal processing module and an impedance calculation module, the sinusoidal signal generation circuit generates a frequency-controllable sinusoidal signal through direct digital frequency synthesis (DDS) and is used for controlling a battery disturbance signal; the voltage-to-current conversion circuit realizes the adjustment of the output current of the voltage-to-current conversion circuit by controlling the input voltage of the voltage-to-current conversion circuit; the signal processing module collects a voltage response signal of a battery to be detected, carries out signal processing of direct current removal and noise removal, converts an analog signal into a digital signal through an AD sampling circuit, and inputs the digital signal to the impedance calculation module. And the impedance calculation module is used for calculating the impedance of the battery by identifying the amplitude and the phase of the acquired signal. According to the invention, the direct current superposed with sine disturbance is extracted from the battery through the voltage-current conversion circuit, and the device can be used for the online measurement of the impedance of the battery under the working conditions of battery offline, constant-current charging and discharging and the like.

A system includes: an alternating current (AC) to direct current (DC) converter (AC-DC converter), the AC-DC converter connectable to a line voltage; and a DC to DC converter (DC-DC converter) connected to the AC-DC converter, the DC-DC converter including: a high voltage buck-boost converter having a secondary side connectable to a high voltage battery; a low voltage buck-boost converter having a secondary side connectable to a low voltage battery; and one or more transformers having a primary side connected to the AC-DC converter, a secondary side connected to a primary side of the high voltage buck-boost converter, and a tertiary side connected to a primary side of the low voltage buck-boost converter.

A fault managed power method and system are provided, which includes a source, downstream component(s) and a power cable for delivering electrical energy, including electrical pulse(s) or DC current / voltage and electrical pulse(s), from the source to the downstream component(s). The cable is isolated from upstream and downstream noise or signals using low-pass filters, which are arranged upstream and downstream of the power cable. The method and system can measure electrical activity on the cable using an impedance sensor tank circuit; detect for an electrical disturbance on the cable corresponding to an occurrence of a fault resulting from body contact with the cable or other faults, based on the measurements from the sensor, when the pulses or the DC current / voltage and pulses are supplied to the cable; and in response to detection of the occurrence of the fault, interrupt the supply of electrical energy to the cable, via an upstream switch(es).

The invention provides a DC charging pile metering anomaly detection method, and belongs to the field of charging pile intelligent detection. The method comprises the following steps: acquiring a DC voltage signal, a DC current signal, a voltage ripple signal and a current ripple signal of a DC charging pile in real time; meanwhile, the temperature of a charging pile metering chip is obtained; inputting the data into the constructed and trained DC charging pile metering anomaly detection model, and outputting a state prediction result; the direct-current charging pile metering anomaly detection model is newly designed and comprises a time sequence convolution module, a time sequence enhancement module, a time sequence optimization module and a prediction output module, final anomaly detection is completed through cooperation of the four modules, meanwhile, a dynamic weight optimization strategy is designed to conduct joint training on the constructed modules, and the detection accuracy is improved. And the overall performance of the model is ensured to be optimal. According to the invention, subtle changes and abnormal modes in the measurement data of the DC charging pile can be more accurately captured, the detection precision and efficiency are improved, and the labor cost is saved.

A radio frequency to direct current (RF-DC) converter for harvesting radio frequency energy includes an antenna circuit, and a plurality of cross-coupled differential-drive (CCDD) rectifier stage. The antenna circuit receives RF signals and outputs a positive signal at a positive RF terminal and outputs a negative signal output at a negative RF terminal. Each CCDD rectifier stage includes a first NMOS transistor, a first PMOS transistor, a second NMOS transistor and a second PMOS transistor. Each CCDD rectifier stage further includes two flying capacitors and two body capacitors. An input terminal is connected to a connection point between a source terminal of the first NMOS transistor and a source terminal of the second NMOS transistor. An output terminal is connected to a connection point between a source terminal of the first PMOS transistor and a source terminal of the second PMOS transistor.

The invention discloses a direct current measurement system based on a diamond NV color center, and the system comprises a drive control module which is used for controlling a laser excitation module to emit laser, transmitting the laser to the NV color center of a diamond substrate, and enabling the NV color center to emit fluorescence; the microwave excitation module generates a frequency modulation microwave signal based on a to-be-detected electrified conductor magnetic field, and the frequency modulation microwave signal performs microwave modulation on the electron spin state of the NV color center; the magnetism gathering module is used for gathering magnetism around the electrified wire to be measured to form a stable and uniform magnetic field for NV color center measurement; the photoelectric detection module is used for collecting fluorescence emitted by the NV color center; the fluorescence analysis processing module is used for analyzing the intensity and the frequency of the fluorescence; determining the magnetic field of the electrified conductor according to the fluorescence intensity and frequency; and determining the current value of the to-be-measured electrified conductor based on the magnetic field. Under the condition that the module space is saved, the accuracy and the stability of module operation are ensured.

A bulk capacitor assembly for an inverter includes a stacked busbar, the stacked busbar including a first direct current (DC) busbar and a second DC busbar; one or more first capacitors on a first side of the stacked busbar, the one or more first capacitors electrically connected to the first DC busbar and the second DC busbar; and one or more second capacitors on a second side of the stacked busbar, the first side being opposite to the second side, the one or more second capacitors electrically connected to the first DC busbar and the second DC busbar.

The invention provides a mutual inductor loop resistance dynamic compensation correction method and device, and relates to the technical field of circuit testing, and the method comprises the steps: constructing a structural feature tensor and an environmental interference tensor according to the structural parameter information and environmental parameters of a primary winding and a secondary winding; training a dynamic compensation model based on the structural feature tensor, the environmental interference tensor and historical loop resistance test data; injecting a set direct current into the primary winding, obtaining an initial voltage signal sequence at two ends of the primary winding, and constructing a test state tensor in combination with the current loop current and the real-time environment parameters; inputting the test state tensor into the dynamic compensation model, and outputting a non-target resistance compensation value at the current moment; and based on the non-target resistance compensation value, correcting an initial loop resistance value obtained by calculating the initial voltage signal sequence to obtain a compensation resistance value of the target mutual inductor loop. According to the invention, the accuracy of mutual inductance loop resistance testing can be improved.

A bidirectional on-board charger includes a direct current bus, two bus capacitors, a power factor correction circuit, and a controller. The power factor correction circuit includes: a first bridge arm; and three second bridge arms, separately connected in series between the positive electrode and the negative electrode of the direct current bus. The controller is configured to: control the first switch (K1) to be turned off, and control at least one of the second bridge arms to output a direct current to charge a power battery; or control the first switch (K1) to be turned on, and control a midpoint of at least one of the second bridge arms to output an alternating current to supply power to an alternating current load. A Vehicle power system and an electric vehicle are further disclosed. The charger reduces circuit costs.

The invention discloses an energy storage participation power grid frequency modulation method, a simulation system and equipment, and relates to the field of power grid frequency modulation. The method comprises the following steps of: establishing an energy storage optimization model which takes the charge-discharge loss cost of the energy storage system and the minimum charge state differentiation degree between energy storage batteries in the energy storage system as an optimization target; when the frequency of the power system is changed, active power compensation required by frequency modulation is determined; according to the direct current of each energy storage battery at the current moment, the charge and discharge loss cost and the charge state differentiation degree are determined respectively; when an active power output instruction of the energy storage battery is calculated by adopting a model prediction control method, obtaining an active power increment of each energy storage battery in a prediction time domain based on an energy storage optimization model by utilizing the output power and the direct current voltage of the energy storage battery at the current moment, and distributing the active power increment to the energy storage battery; and the operation of the energy storage battery is close to the control requirement of the energy storage optimization model. The frequency modulation active power in the energy storage power station can be reasonably distributed, and the service life of the energy storage system is prolonged.

The invention discloses a fault processing method for an offshore wind power direct current parallel sending-out system through a DRU-MMC. The fault processing method comprises the steps that direct current energy consumption devices are arranged at direct current outlets of respective land MMC converter stations of a DRU-HVDC system and an MMC-HVDC system; when the alternating current power grid at the receiving end has an alternating current fault, the direct current energy consumption device is controlled to adopt a direct current voltage suppression strategy; when the DRU-HVDC system and the MMC-HVDC system respectively have direct current faults, different locking and circuit breaker disconnection time sequence control strategies are adopted, and in the direct current fault ride-through period, a direct current suppression strategy and a direct current voltage suppression strategy are controlled to be adopted by a direct current energy consumption device of the DRU-HVDC system. Therefore, the fault ride-through capability of the DRU-MMC direct current parallel sending-out system of the offshore wind power can be effectively improved, and stable operation of the system is ensured.

The invention relates to the technical field of high-voltage direct-current transmission, and discloses a reactive power support control method and system for a CLCC converter under an alternating-current fault, in order to fully explore the power support potential of the CLCC, the method comprises the following steps: firstly, starting from the forced commutation process of the CLCC during the fault period, analyzing that the trigger angle and the power have the multi-quadrant regulation and control capability; secondly, a direct current operable range and a trigger angle regulation and control range are determined; a power operation domain in the range is established; then, determining a trigger angle compensation amount and a control mode by taking no influence on active power transmitted to a receiving end alternating current system as a target; according to the method provided by the invention, the direct-current voltage and the direct-current transmission power of the inverter side during the alternating-current fault period can be kept unchanged, the voltage drop of the converter bus during the alternating-current fault period can be reduced, and the quick and stable recovery of the alternating-current voltage is facilitated.

A vehicle to load inverter module (V2LIM) based onboard charger (OBC). The V2LIM based OBC may include an alternating current to direct current (AC / DC) converter having an AC / DC input and an AC / DC output, a direct current to direct current (DC / DC) converter having a DC / DC input and a DC / DC output, and a direct current to alternating current (DC / AC) converter having a DC / AC input and a DC / AC output, and a controller configured for controlling the AC / DC converter, the DC / DC converter, and the DC / AC converter according to a split-phase load powering mode.

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.

A multi-level direct current converter, a voltage control method for a flying capacitor, and a control apparatus are provided. The multi-level direct current converter includes a controller, a flying capacitor, two switching transistor groups, and an inductor. The method for controlling a flying capacitor includes: in response to that an absolute value of a difference between a sampling voltage and a reference voltage of the flying capacitor is greater than a first threshold, adjusting a duty cycle difference between first switching transistors in two switching transistor groups or a phase difference between carriers of first switching transistors in two switching transistor groups based on a magnitude of an inductor current. According to this application, a voltage of the flying capacitor can be controlled, to improve operation stability of the multi-level direct current converter.

The invention relates to a method for passive arc suppression in an electrical treatment of plants, comprising the step: (S400) Applying a pulse-width modulated direct electrical current (I) to the plants.

An extreme fast-charging (XFC) system for electric vehicles includes (i) a direct current (DC) electric power bus and (ii) an electric vehicle (EV) charging station electrically coupled to the DC electric power bus without use of rectification circuitry. A method for XFC of one or more EVs includes (i) using a controller, electrically coupling one or more batteries to a DC electric power bus and (ii) powering one or more EV charging stations electrically coupled to the DC electric power bus without converting DC electric power on the DC electric power bus to alternating current (AC).

An electronic device includes a wireless charging receive coil configured to transduce, into an alternating current (AC) power signal, a magnetic field generated by a wireless charging transmit coil of an external device; an active rectifier configured to convert the AC signal received at an AC side of the active rectifier into a direct current (DC) power signal output at a DC side of the active rectifier, the active rectifier comprising a plurality of switches; a first modulation capacitor connected to an upper rail of the AC side; a second modulation capacitor connected to a lower rail of the AC side; and a controller configured to adjust an impedance of the computing device to communicate with the external device by at least controlling the plurality of switches to cause the first modulation capacitor and the second modulation capacitor to charge during separate time periods.

The invention discloses an alternating-current and direct-current fault protection method of a hybrid commutation converter valve and related equipment thereof, and relates to the technical field of high-voltage direct-current power transmission. The method comprises the steps of obtaining an AC voltage of an AC side, a target trigger angle of a hybrid commutation converter valve and a DC current of a DC side, and determining an extinction angle margin risk factor and a volt-second area margin risk factor according to at least one of the above, the extinction angle margin risk factor being used for representing a commutation success margin, and the volt-second area margin risk factor being used for representing a target trigger angle of the hybrid commutation converter valve; the volt-second area margin risk factor is used for representing the commutation driving capability; determining a commutation failure risk index based on the extinction angle margin risk factor, the volt-second area margin risk factor and the prediction confidence factor; and when the commutation failure risk index is abnormal, controlling and triggering the hybrid commutation converter valve to enter a corresponding commutation enhancement mode or an active turn-off mode based on the commutation failure risk index. According to the embodiment of the invention, active intervention can be carried out before the commutation failure is caused by the AC / DC fault, so that the commutation failure can be fully resisted.

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.

The invention belongs to the technical field of display, and provides a pixel driving circuit and a display panel, data voltage is accessed through a compensation circuit, the data voltage is compared with at least one reference voltage, a target voltage interval where the data voltage is located is judged according to a comparison result, and compensation direct current is output according to the target voltage interval; the pixel driving circuit responds to access of a selection signal and outputs a driving current according to the data voltage and the compensation direct current so as to lighten a light-emitting element; wherein the current of the compensation direct current is in negative correlation with a value in the target voltage interval; therefore, the driving capability of the line scanning driving circuit is enhanced, the possibility of influence of parasitic parameters RC on signals is reduced, and the accuracy of data voltage transmission is improved.

The present invention provides an alternating current / direct current multi-air-gap magnetoresistive current sensor and a current measurement method. The alternating current / direct current multi-air-gap magnetoresistive current sensor comprises: a magnetic-to-electric conversion unit used for acquiring a magnetic field signal of a target current-carrying wire to which a current to be measured is introduced, converting the magnetic field signal into an electric signal and then outputting the electric signal to a signal processing unit, wherein the magnetic-to-electric conversion unit uses a multi-air-gap band-based closed-loop iron core type structure; the signal processing unit used for amplifying the electric signal and then outputting the electric signal to a feedback compensation unit; and the feedback compensation unit used for adjusting a feedback current on the basis of the amplified voltage signal to enable a novel magnetoresistive element to always work at zero magnetic flux, measuring the value of the feedback current, on the basis of the value of the feedback current, obtaining the value of the current to be measured, and outputting the value of the current to be measured. According to the alternating current / direct current multi-air-gap magnetoresistive current sensor and the current measurement method provided by the embodiments of the present invention, the measurement performance of the current sensor is improved and the problem of the difficulty in achieving both high accuracy and a wide frequency domain of alternating current / direct current measurement is solved.

The invention discloses a method and a device for tracing a commutation failure fault of a high-voltage direct-current power transmission system, and the method comprises the steps: taking three electrical quantity signals, namely an alternating-current voltage, a direct-current current and a direct-current voltage, of an inversion side of the high-voltage direct-current power transmission system as source data when the commutation failure occurs; extracting an optimal fault feature of the source data by adopting a fault feature extraction model and a feature screening algorithm based on feature density; and finally, in combination with a commutation fault detection model and the optimal fault characteristics, obtaining a fault type causing commutation failure of the high-voltage direct-current power transmission system. Through the above design, fault tracing of the commutation failure can be realized, and in the tracing process, the optimal fault features are extracted by using the machine learning model and the feature screening algorithm based on the feature density, so that interference of human subjective experience on feature extraction can be reduced, and the effectiveness of fault tracing is improved; therefore, the method is very suitable for large-scale application and popularization.

A marine AC generator system includes a marine generator driven by an internal combustion engine and configured to generate an AC current and a rectifier configured to rectify the AC current to provide a DC current. At least one battery is configured to receive and be charged by the DC current. A battery powered inverter is configured to be powered by the at least one battery and to generate a variable current output frequency such that an AC electrical power is provided to a load when the marine generator is not running.

An electrical system includes a battery, temperature sensor, and battery charging station connectable to the battery and to an alternating current (AC) power supply. The charging station includes connected battery charging and heating circuits. The charging circuit includes a first plurality of power switches configured to rectify an AC input voltage from the power supply into a direct current (DC) voltage for charging the battery during a battery charging mode. The heating circuit includes a voltage bus, transformer, series switch, and a second plurality of power switches downstream of the transformer. The heating circuit generates an AC battery current from the DC voltage and injects the same into the battery during a battery heating mode. An electronic controller controls the power switches and the series switch to perform the charging and heating modes, doing so via a corresponding method.

The invention discloses a low-loss superconducting motor and a design method thereof, and belongs to the technical field of superconducting motors. A low-loss superconducting motor comprises a vacuum chamber, a stator assembly and a rotor assembly are arranged in the vacuum chamber, and a protective cover is arranged between the stator assembly and the rotor assembly. One of the stator assembly and the rotor assembly is provided with a constant conductor coil, the other one is provided with a superconductor coil, the superconductor coil applies direct current, and the constant conductor coil applies alternating current. Meanwhile, the invention discloses a design method based on the superconducting motor, the low-loss superconducting motor and the design method thereof are adopted, an air gap between the stator assembly and the rotor assembly is small, a high magnetic field is easy to achieve, Joule loss of a common conductor coil is reduced, an air or water cooling pipeline can be omitted, and temperature control is easy.

A power supply system (5) for a plurality of electrolyzers (2, 3, 4) is proposed. The power supply system (5) comprises: - main input terminals (6) intended to be connected to a grid (G), - an AC / AC power converter (7), - a control circuit (10), - a plurality of supply branches (12, 13, 14), - each supply branch (12, 13, 14) comprising a branch transformer (21, 22, 23) including a primary circuit connected to input terminals (15, 16, 17) of the said supply branch and at least one secondary circuit, and at least one rectifier (24, 25, 26) connected to the secondary circuit of the branch transformer, the rectifier comprising output terminals (30, 31, 32) connected to a set of output terminals (18, 19, 20) of the said supply branch to supply the output terminals of the said supply branch with a DC current.

The invention provides a broadband electric field sensor, an electric field sensor assembly and an electric field detection method.The broadband electric field sensor comprises a substrate, at least one dynamic induction electrode and at least one static induction electrode, the substrate comprises an entity area and a concave area, and the dynamic induction electrodes and the static induction electrodes are arranged at intervals; one part of the dynamic induction electrode is attached to the entity area, the other part of the dynamic induction electrode is located on the concave area, one part of the static induction electrode is attached to the entity area, the other part of the static induction electrode is located on the concave area, and the dynamic induction electrode obtains at least one direct current signal of a current electric field according to an excitation signal; the static induction electrode obtains at least one alternating current signal of the current electric field at least according to charges induced in the current electric field. The direct current signal and the alternating current signal can be obtained at the same time, good detection of a direct current electric field and an alternating current electric field is achieved, the sensitive degree of electric field detection is improved, and the detection frequency band of the electric field sensor is widened.