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102 results about "Critical voltage" patented technology

Critical Disruptive Voltage is defined as the minimum phase to neutral voltage required for the Corona discharge to start.

Reactive power feedback control-based control method for commutation failure in hybrid cascaded high-voltage direct-current power transmission system, storage medium and electronic apparatus

The present application provides a reactive power feedback control-based control method for a commutation failure in a hybrid cascaded high-voltage direct-current power transmission system, a storage medium and an electronic apparatus, and particularly relates to a reactive power feedback control-based control method for a commutation failure in a hybrid cascade high-voltage direct-current power transmission system. The method mainly comprises the following steps: acquiring power data of a hybrid cascaded high-voltage direct-current power transmission system; calculating the reactive power supply of an inverter-side MMC-end alternating-current system, the reactive power supply of an inverter-side alternating-current filter, and the reactive power supply of an inverter-side LCC-end alternating-current system; solving a reactive power control instruction of an inverter-side MMC converter; and, on the basis of a critical voltage, determining whether to implement the reactive power feedback control-based control method for a commutation failure in the hybrid cascaded power transmission system. The method can effectively reduce the probability of commutation failures in hybrid cascaded power transmission systems, thus guaranteeing safe and stable operation of large-scale power grids.
Owner:SOUTHWEST JIAOTONG UNIV

Calibration method and device of real-time clock, equipment and medium

The invention discloses a real-time clock calibration method, device and equipment and a medium, and relates to the technical field of electric vehicle charging time calibration, and the method comprises the steps: obtaining a clock calibration parameter based on a preset time interval; executing a compensation error calculation process based on the clock calibration parameter to obtain a compensation error; and when a sleep instruction is received and it is determined that the vehicle is not in the sleep state, the compensation error is utilized to calibrate the wake-up timestamp, and a target wake-up timestamp is obtained. The method is used for solving the problem that in the prior art, when the vehicle is in the dormant state, the vehicle cannot be normally used due to the fact that the vehicle stops for a long time or exhausts the electric quantity of the storage battery in the dormant state, the target awakening timestamp is determined when the dormant instruction is received, the dormant vehicle control unit is awakened at the target awakening timestamp, and the dormant vehicle control unit is awakened at the target awakening timestamp. Therefore, the vehicle controller controls the high-voltage system to charge the storage battery, and the problem that the vehicle cannot be normally used due to the fact that the voltage of the storage battery is lower than the critical voltage is solved.
Owner:E-QUALITY INTELLIGENT TECHNOLOGY WUXI CO LTD

Voltage droop control optimization method and system based on parameter self-adaption and medium

The invention relates to the technical field of droop control, in particular to a voltage droop control optimization method and system based on parameter self-adaption and a medium, and the method comprises the steps: dynamically recognizing a voltage sensitive interval according to voltage fluctuation characteristics, determining critical voltage distribution data, and determining a switching trigger condition of a current power grid control mode according to the critical voltage distribution data; analyzing the correlation degree between the current power grid control mode switching event and the power grid stability based on the switching trigger condition to obtain a switching behavior risk level; reconstructing voltage droop control parameter adjustment direction logic based on the switching behavior risk level, and generating a stable direction vector; calibrating the original droop control output signal according to the stable direction vector, and generating a self-adaptive droop control output instruction; and distributing the adaptive droop control output instruction to each substation node for voltage regulation. The voltage droop control parameters are adaptively optimized through the real-time running state of the power grid, and parameter adaptive optimization of voltage droop control is achieved.
Owner:STATE GRID ECONOMIC TECH RES INST CO LTD +1

Display device

The invention provides a display device. The display device comprises a plurality of driving transistors, a sensing circuit and a control circuit, the control circuit is coupled with a plurality of driving transistors arranged on the substrate and the sensing circuit; the plurality of driving transistors drive the plurality of light-emitting components; the sensing circuit comprises a thermistor; the sensing circuit generates a sensing voltage according to an input voltage. The control circuit generates a bias voltage according to the sensing voltage based on a plurality of reference tables associated with the resistance, the temperature and the critical voltage value of each driving transistor, and drives the plurality of driving transistors according to the bias voltage, so as to prevent the display frame from being abnormal due to the change of the temperature.
Owner:AU OPTRONICS CORP

Low dropout regulator with output voltage switching circuit

The invention discloses a low dropout regulator with an output voltage switching circuit. The low-dropout linear voltage stabilizing circuit outputs a voltage stabilizing signal according to the voltage difference between the voltage of the second end of the transistor and the voltage of a voltage stabilizing critical voltage signal or the voltage difference between the voltage of the second end of the transistor and a reference voltage. The switch error amplification circuit outputs a pull-up control signal according to the difference between the voltage of the second end of the transistor and the voltage of a voltage pull-up switching signal. When the voltage selection circuit selects the voltage stabilization signal, the transistor operates according to the voltage stabilization signal to adjust the output voltage of the low dropout regulator. When the voltage selection circuit selects the pull-up control signal, the switch assembly is turned on according to the pull-up control signal, so that the input voltage directly pulls up the output voltage of the low dropout regulator.
Owner:ANPEC ELECTRONICS CORPORATION

Droop control method and system based on parameter self-adaption

The invention discloses a parameter self-adaption-based droop control method and system. The method comprises the steps of obtaining a first critical voltage value and a second critical voltage value of a grid-connected system in a critical stable state; the system power angle corresponding to the first critical voltage value is a critical power angle; the system power angle corresponding to the second critical voltage value is a rated power angle, and the reactive power droop coefficient of the droop converter is the minimum reactive power droop coefficient under normal operation; when the power grid voltage is smaller than the first critical voltage value and not smaller than the second critical voltage value, the reactive droop coefficient is adjusted in a self-adaptive mode with the purpose that the system power angle reaches the rated power angle; and when the voltage of the power grid is smaller than a second critical voltage value, adaptively adjusting the reactive power reference value by taking the system power angle reaching the rated power angle as a target, and constraining the active power reference value according to the capacity of the droop converter. By adopting the embodiment of the invention, the system can be ensured to stably operate at a balance point for a long time, and the grid-connected capacity in the transient process of the system is ensured at the same time.
Owner:STATE GRID ECONOMIC TECH RES INST CO LTD +1

Coordinated operation method and system of distributed phase modifier and networking SVG (static var generator)

The invention belongs to the technical field of safety and stability of a power system, and relates to a coordinated operation method and system of a distributed phase modifier and a network-forming SVG (Static Var Generator). According to the invention, by obtaining the current-limiting critical voltage coefficient and the equivalent critical voltage coefficient, the cooperative operation effect of the distributed phase modifier and the network-forming SVG and the supporting capability of the system voltage support are improved; when the residual voltage coefficient is smaller than the equivalent critical voltage coefficient, the reactive power supporting capacity provided by the phase modifier is high, the phase modifier is smoothly put into operation, and the impact on the system caused by the put-in of the phase modifier is reduced; when the residual voltage coefficient is greater than the equivalent critical voltage coefficient, the phase modifier starts to smoothly exit from operation, and the impact on the system caused by the deduction of the phase modifier is reduced; and when the residual voltage coefficient is greater than the current-limiting critical voltage coefficient, the networking SVG quits the current-limiting link, the phase modifier completely quits operation, and the margin of transient reactive power regulation of the system is improved. According to the invention, safe and effective cooperative work of the network-forming SVG and the distributed phase modifier is realized.
Owner:STATE GRID ECONOMIC TECH RES INST CO LTD +3

Power distribution network line voltage regulating device locating and sizing method and device based on voltage space-time distribution characteristics

The invention relates to a power distribution network line voltage regulating device locating and sizing method and device based on voltage space-time distribution characteristics. The method comprises the following steps: screening out the lowest voltage value and the highest voltage value in a line all the year round, and respectively extracting power distribution outlet voltages under corresponding time sections; voltage distribution models from a power distribution outlet to a user corresponding to the annual minimum voltage value and a user corresponding to the annual maximum voltage value are constructed respectively, and then the installation distances under the corresponding working conditions are calculated according to the critical voltage values of the voltage regulating device under the different working conditions; determining a target installation position according to the first installation distance and / or the second installation distance based on the power distribution network line out-of-limit condition; and searching a tower near the target installation position along the power distribution network line as an installation tower of the voltage regulating device, and determining the capacity of the voltage regulating device according to the load of the line at the rear end of the installation tower. According to the invention, the problem of voltage out-of-limit caused by factors such as power supply radius increase and distributed power supply access of a medium-voltage or low-voltage line can be effectively solved.
Owner:STATE GRID SHANGHAI ENERGY INTERCONNECTION RES INST CO LTD

Rapid commutation failure identification method and system for anticipated fault set example

The invention discloses a rapid commutation failure identification method and system for an anticipated fault set example, and the method comprises the steps: employing a rapid classification commutation failure identification method integrating analysis and numerical simulation, carrying out the recognition and analysis of a first-level rapid commutation failure, and carrying out the analysis of a direct current of which the extinction angle or critical voltage does not meet the commutation failure requirement, but the subsequent commutation failure risk exists; if yes, further numerical simulation is carried out, second-layer grading fast commutation failure identification analysis is carried out according to the change of the extinction angle and the voltage, at most four-stage fast commutation failure identification analysis is carried out, the coupling influence of direct current control protection and an alternating current network is considered under the electromechanical simulation scale, and less numerical simulation iteration is adopted, so that the identification accuracy is improved. The direct current which may have the commutation failure within four cycles of the anticipated fault is quickly recognized stage by stage, so that the recognition robustness is effectively considered on the basis of quick commutation failure recognition analysis.
Owner:NARI TECH CO LTD

A PWM-based high-speed switching valve hysteresis compensation control method

This invention proposes a hysteresis compensation control method for high-speed switching valves based on PWM, belonging to the field of high-speed switching valve control. Its key feature is that the working cycle of the high-speed switching valve is divided into four stages. The rising and falling edges of the reference PWM control the opening and closing times of the high-speed switching valve, while the loading signal consists of on-compensation PWM, excitation PWM, opening-hold PWM, and closing compensation PWM. By varying the pressure before the valve, the critical voltage values ​​for opening and closing the valve core are obtained, thereby controlling the amplitudes of the on-compensation PWM and opening-hold PWM to reduce the hysteresis time and current consumption of the valve core response. The duty cycle of the excitation PWM is determined by the derivative of the pressure before the valve, and the duty cycles of the on-compensation PWM and closing compensation PWM are obtained based on the coil current, accelerating the valve core response speed and optimizing current consumption. This invention can improve the response speed of high-speed switching valves, reduce energy consumption, and expand the frequency response range, offering advantages such as high response, low power consumption, low cost, and small footprint.
Owner:CENT SOUTH UNIV

Constant power to constant voltage control method and system for achieving full charge and full discharge of a flow battery

The application relates to a constant-power-to-constant-voltage control method and system for realizing full charging and full discharging of a flow battery. The method mainly comprises the following steps: collecting flow battery operation parameters in real time, wherein the collected operation parameters include stack terminal voltage, electrolyte temperature and battery cycle number; dynamically calculating a critical voltage threshold according to the electrolyte temperature, the battery cycle number and a rated voltage; switching from a constant-power mode to a constant-voltage mode when the real-time stack terminal voltage reaches or exceeds the critical voltage threshold; and dynamically adjusting the power output through a PID adjustment mechanism to stabilize the stack terminal voltage at the critical voltage threshold in the constant-voltage mode. The application dynamically determines the switching time of the constant-power-to-constant-voltage mode and accurately controls the voltage in the constant-voltage stage, thereby realizing the purpose of safe full charging and full discharging of the battery, and improving the energy storage utilization rate and the battery cycle life.
Owner:ENERFLOW TECH CO LTD

Mixed-mode operation method applied to direct-current power converter

According to the mixed mode operation method applied to the DC power converter, the DC power converter receives an input voltage, and the size of the input voltage is between a minimum voltage and a maximum voltage. The mixed-mode operation method comprises the steps that when the input voltage is larger than the lower critical voltage and smaller than the upper critical voltage, the direct-current power converter operates in a series resonance conversion mode; when the input voltage is smaller than the lower critical voltage, the DC power converter operates in an inductance-inductance-capacitance conversion mode. When the input voltage is greater than the upper critical voltage, the DC power converter operates in an inductance-inductance-capacitance conversion mode.
Owner:APD SHENZHEN DK INC

A fast prediction method considering the risk of commutation failure caused by harmonics

The present invention relates to a rapid prediction method considering the risk of commutation failure caused by harmonics, and belongs to the technical field of high-voltage direct current transmission operation analysis. The commutation voltage is reconstructed based on a method of virtual three-phase construction, and the separation of fundamental signal and harmonic signal is realized. The reconstructed signal is subjected to the rapid extraction of harmonic characteristic quantity by using the curve fitting method. By comparing the actual value of the harmonic with the critical value, it can be predicted whether the DC system has the risk of commutation failure. If the actual value is greater than the critical voltage, the system has the risk of commutation failure. Otherwise, the system has no risk of commutation failure. Different from the traditional method, the method of the present invention reduces the error between the actual value and the theoretical value, improves the accuracy of the prediction criterion, and realizes the rapid prediction of the risk of commutation failure caused by harmonics. The proposed method lays the foundation for the timely action of the subsequent control and protection system, and has positive significance for preventing the subsequent continuous commutation failure.
Owner:SHANDONG UNIV

Display device and pixel driving method thereof

The invention discloses a display device and a pixel driving method thereof. The display device includes a pixel array, a source driver, a sensing circuit, a computing circuit, and a switching circuit. The pixel array has a plurality of pixel circuits and a plurality of source lines coupled to the pixel circuits, wherein each pixel circuit has a light emitting element and a driving transistor located on a current path. The switching circuit couples the source lines to one of the source driver and the sensing circuit. In the sensing mode, the sensing circuit senses the conduction current of the driving transistor in each pixel circuit to provide sensing voltage, and the calculation circuit judges the critical voltage offset and carrier mobility attenuation of the driving transistor in each pixel circuit based on the sensing voltage to correct the data voltage provided by the source driver.
Owner:AU OPTRONICS CORP

A power operation critical edge intelligent early warning system, device and method

This invention relates to the field of power early warning technology, and in particular to an intelligent early warning system, device, and method for critical edges of power operations. The system includes a live-line identification and positioning module, an electric field critical voltage zoning module, a live-line distance measurement module, and a power operation critical early warning module. It utilizes an image acquisition unit to acquire real-time image frames of the environment where the worker is located and performs live-line identification and positioning of the worker to obtain the worker's real-time live-line spatial location. Combined with a field strength sensing unit, it performs live-line positioning voltage strength measurement and critical voltage level assessment of the corresponding real-time operation process of the power worker to obtain the critical voltage level zoning of each worker. It uses a radar ranging unit to measure the live-line distance and performs power operation early warning processing through an early warning unit to execute corresponding power operation critical edge safety early warning work. This invention can realize integrated intelligent early warning for critical edges of power operations, effectively improving early warning efficiency.
Owner:JINING POWER SUPPLY CO OF STATE GRID SHANDONG ELECTRIC POWER CO

Power supply circuit and undershoot suppression circuit thereof

The invention provides a power supply circuit and an undershoot suppression circuit thereof. The power supply circuit generates an output voltage. The undershoot suppression circuit includes a rising edge determination circuit, a falling edge determination circuit, and a pulse generation circuit. The rising edge decision circuit detects a difference voltage between the output voltage and a reference voltage, and outputs a clock control signal of a first voltage level when the difference voltage is greater than a critical voltage. The falling edge decision circuit detects the output voltage and outputs a reset signal of a first voltage level when the output voltage is not less than the reference voltage. The pulse generator generates an undershoot suppression pulse according to a clock control signal of a first voltage level and a reset signal of the first voltage level, so that the output voltage is close to the reference voltage. The undershoot suppression circuit can automatically control the output period of the undershoot suppression pulse according to the voltage level of the output voltage. Therefore, the power supply circuit adopting the undershoot suppression circuit has the advantages of automatically optimizing the transient response capability of the load and the like.
Owner:POWERX SEMICONDUCTOR CORPORATION

Amplification circuit and voltage generation circuit

The invention relates to an amplifier circuit and a voltage generating circuit. An amplifier circuit includes a floating inverting amplifier and a voltage generating circuit. The critical voltage of a transistor in the floating inverting amplifier varies with environmental conditions. The voltage generating circuit is coupled to the floating inverting amplifier, the voltage generating circuit is used for providing a working voltage to the floating inverting amplifier, the working voltage provided by the voltage generating circuit is linearly related to the critical voltage, and the voltage generating circuit enables the variation of the working voltage to track the variation of the critical voltage.
Owner:REALTEK SEMICON CORP

A method and system for measuring the surface tension of cloud droplets in aerosol activation to cloud processes

The present application belongs to the technical field of aerosol measurement, and particularly relates to a method and system for measuring the surface tension of cloud droplets in the process of aerosol activation into clouds. The method comprises: building a system for measuring the surface tension of cloud droplets, including a cloud condensation nucleus counter, electrode plates, a high-voltage power supply, a condensation nucleus particle counter, and a differential mobility analyzer; applying a high-voltage electric field to cause positive and negative ions in the droplets to split under the traction of the electric field; aerosol samples are converted into droplets by absorbing water vapor in a cloud chamber, and the droplets split under the traction of the high-voltage electric field; the number concentration of the droplets in the outflow sample is measured by the condensation nucleus particle counter; the critical voltage at which the droplets split is obtained by fitting the graph of the number concentration of the droplets versus the voltage intensity; and the surface tension of the droplets is calculated according to the quantitative relationship between the critical voltage and the surface tension of the droplets. The present application can be used in atmospheric chemical transport simulation and climate models to evaluate the influence of the surface tension of cloud droplets on the number concentration and particle size of the cloud droplets.
Owner:FUDAN UNIVERSITY

A method of measuring the instantaneous speed of an engine

This application discloses a method for measuring instantaneous engine speed. The engine is equipped with a flywheel and a speed sensor. The flywheel has signal holes evenly distributed around its circumference, and also has missing hole positions. The speed sensor collects the sensing signals triggered by the signal holes during rotation. The method includes the following steps: Step 1: Obtain the interval angle between adjacent signal holes around the circumference of the flywheel; Step 2: During flywheel rotation, acquire and store the sensing signals using an oscilloscope to obtain the correspondence between the sensing signals and time; Step 3: Eliminate the offset of the sensing signals; Step 4: Obtain the positive and negative critical voltage values ​​and corresponding sampling times of the voltages adjacent to the falling edge of the sensing signals; Step 5: Obtain the time corresponding to 0 potential using interpolation; Step 6: Calculate the instantaneous speed based on the time difference between adjacent 0 potentials and the angle between the corresponding signal holes of the flywheel, and arrange the instantaneous speeds in chronological order to obtain a more accurate correspondence between instantaneous speed and time.
Owner:SHANGHAI NEW POWER AUTOMOTIVE TECH CO LTD

Method for controlling an electric parking brake and / or an electric parking lock of a vehicle, in particular a motor vehicle

Method for controlling an electric parking brake and / or an electric parking lock of a vehicle, in particular a motor vehicle, wherein the parking brake and the parking lock are electrically controlled and / or electrically operated for the respective engagement and / or disengagement, wherein an electrical vehicle electrical system for providing electrical energy, in particular a 12V low-voltage network, is provided and / or available for the respective control of the parking brake and / or the parking lock, wherein the voltage level of the electrical vehicle electrical system is monitored, in particular continuously, wherein a first critical voltage state (I) is reached when a first specific voltage level is undershot, and wherein a rolling protection of the vehicle is achieved by a corresponding first specific control of the parking brake and / or the parking lock.when the first critical voltage state (I) of the vehicle electrical system is determined and / or detected, characterized in that a second critical voltage state (II) of the vehicle electrical system, which differs from the first critical voltage state (I), can be determined and / or detected when a second specific voltage level is undershot, wherein the second specific voltage level is lower than the first specific voltage level, and that the vehicle's roll-prevention is then implemented by a corresponding second specific control of the parking brake and / or the parking lock, which differs from the first specific control, when the second critical voltage state (II) is determined and / or detected.
Owner:VOLKSWAGEN AG

Double-gate carbon-based device, carbon-based integrated circuit and preparation method thereof

PendingCN121793562ASolve the problem that complementary logic is difficult to implementAchieve differential matchingCarbon nanotubeEngineering physics
The invention provides a double-gate carbon-based device, a carbon-based integrated circuit and a preparation method of the double-gate carbon-based device. The double-gate carbon-based device comprises a bottom gate conductive channel; the bottom gate structure comprises a bottom gate conductive layer and a bottom gate dielectric layer, the bottom gate conductive layer is located on the bottom gate conductive channel and electrically connected with the bottom gate conductive channel, and the bottom gate dielectric layer is located on the bottom gate conductive layer; the channel layer is positioned on the bottom gate dielectric layer and is made of a carbon nanotube; the top gate structure comprises a top gate dielectric layer and a top gate conductive layer, the top gate dielectric layer is located on the channel layer, and the top gate conductive layer is located on the top gate dielectric layer; a source structure contacting one end of the channel layer; and a drain structure contacting the other end of the channel layer. The top gate structure is used as a switch structure for controlling the conduction and cut-off of the carbon-based device, and the bottom gate structure is used for regulating and controlling the threshold voltage of the carbon-based device according to a threshold regulation and control signal transmitted by the bottom gate conductive channel so as to set the critical voltage of the carbon-based device switched from the cut-off state to the conduction state.
Owner:PEKING UNIV CHONGQING CARBON-BASED INTEGRATED CIRCUIT RES INST

A method, device, medium and equipment for screening an abnormal flash chip

The application provides a screening method, device, medium and equipment for an abnormal Flash chip. The method comprises the following steps: performing data abnormal voltage criticality test on a to-be-tested chip to determine a critical voltage value of the to-be-tested chip, wherein the to-be-tested chip is a to-be-tested Flash chip; determining whether the critical voltage value is greater than a voltage threshold value, wherein the voltage threshold value corresponds to a target gear of a negative bias voltage of the to-be-tested chip; and determining that the negative bias voltage of the to-be-tested chip is abnormal if the critical voltage value is greater than the voltage threshold value. In the case that the negative bias voltage cannot be directly measured, the safety of the negative bias voltage of the to-be-tested chip is evaluated from the side through the critical voltage value of the to-be-tested chip, so that the screening of the abnormal Flash chip is realized, and the accuracy of the screening result is ensured.
Owner:PUYA SEMICON SHANGHAI CO LTD

Current surge control device and power supply starting equipment

The invention discloses a current surge control device and power starting equipment with a surge suppression function. The power starting equipment comprises a power supply device and the current surge control device. The power supply device generates an alternating current signal which changes periodically. The current surge control device comprises a rectifier, a voltage detector, a time sequence control module and a switching device. The rectifier rectifies the AC signal to generate a rectified voltage. The voltage detector generates a trigger signal according to a magnitude relationship between a voltage value of the rectified voltage and a critical voltage. The sequential control module generates a starting signal with a rising positive edge corresponding to a voltage zero point of the AC signal according to the trigger signal, and the switching device receives the AC signal and generates an output voltage according to the starting signal. The voltage detector enables the time sequence control module to generate a starting signal at the time point when the voltage of the alternating current signal is zero according to the relation between the divided voltage and the critical voltage so as to start the switching device, and therefore the effect of restraining the surge current is achieved.
Owner:TOP VICTORY INVESTMENTS LTD

Charging pile intelligent control method and system based on Internet of Things

The invention relates to the technical field of intelligent control, and discloses a charging pile intelligent control method and system based on the Internet of Things, and the method comprises the steps: collecting the real-time data of an electric vehicle battery through a charging pile sensor, and carrying out the smoothing processing, and obtaining a battery state sequence; calculating a current polarization voltage according to the sequence; determining a lithium precipitation critical voltage threshold based on the battery temperature and the state of charge; if the current polarization voltage reaches or exceeds the threshold value, predicting a future change trend of the polarization voltage by using a neural network model and performing risk assessment; dynamically adjusting a charging strategy according to an evaluation result, and calculating a new maximum allowable current; the charging pile control parameters are updated to generate an optimized charging curve; and finally monitoring the battery response, and determining a final charging strategy according to the polarization voltage stability. According to the method, real-time and accurate prevention and control of the lithium precipitation risk in the rapid charging process can be realized, the charging safety is remarkably improved, and the service life of the battery is remarkably prolonged.
Owner:BEIJING QIANFEIYIN COMMUNICATION ENGINEERING CO LTD

A control method, device and system for suppressing DC continuous commutation failure

The present invention discloses a control method, device, and system for suppressing continuous DC commutation failure in the field of power electronics control, aiming to address the problem of continuous DC commutation failure on the inverter side of a UHV hybrid cascade DC transmission system. The method comprises: obtaining the AC bus voltage at the receiving end of the UHV hybrid cascade DC transmission system, as well as the upper and lower limits of the critical commutation failure voltage; based on the comparison result of the AC bus voltage and the upper and lower limits of the critical commutation failure voltage, coordinating the switching states of the phase regulator excitation control module and the MMC reactive power regulation module to meet preset requirements; wherein the phase regulator excitation control module controls the phase regulator to generate reactive power compensation; and the MMC reactive power regulation module controls each MMC to increase its reactive power output. The present invention can fully utilize the MMC's own reactive power regulation capabilities and the reactive power compensation capabilities under the phase regulator's transient excitation control, suppressing continuous DC commutation failure and improving the transient characteristics of the UHV hybrid cascade DC transmission system after a fault.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD +2

Relay fault detection test method and related assembly

The invention discloses a relay fault detection test method and a related component, and the method comprises the steps: adjusting the output voltage of a second power supply, enabling the voltage of a second detection end of a BMS to change, namely, enabling the output voltage of the second power supply to be adjusted with a first preset voltage as a reference, after the BMS outputs the preset instruction, whether the state of the relay is changed or not can be determined according to the voltage difference between the first detection end and the second detection end, namely whether the BMS detects the fault of the relay or not is determined. When the second power supply outputs the first preset voltage, the BMS determines that the relay is in the first preset state after outputting the preset instruction, and when the BMS outputs the preset instruction after adjusting the output voltage of the second power supply according to the preset step length, the state of the relay can be determined to change. The fault triggering critical voltage for triggering the BMS to recognize the fault of the relay can be determined as the first preset voltage, and the BMS is determined to trigger and detect the fault of the relay according to the preset proportion.
Owner:HANGZHOU JIGAO INTELLIGENT ELECTRONIC TECH CO LTD

Photovoltaic grid-connected system harmonic suppression method and system based on MPPT variable step size control strategy

The invention discloses a photovoltaic grid-connected system harmonic suppression method and system based on an MPPT variable step size control strategy, and the method comprises the steps: obtaining a voltage value corresponding to the maximum power point of a photovoltaic array, and a preset first disturbance step size and a preset second disturbance step size; calculating a first critical voltage threshold value and a second critical voltage threshold value based on the voltage value corresponding to the maximum power point of the photovoltaic array and the first disturbance step length; dividing a power-voltage curve corresponding to the photovoltaic array into three intervals based on the first critical voltage threshold and the second critical voltage threshold; and aiming at each interval, finding the maximum power point as a target, combining the first disturbance step length and the second disturbance step length, adopting a tracking step length strategy corresponding to each interval, adjusting the output voltage of the photovoltaic array acquired in real time, and generating a final output voltage instruction value. According to the invention, the output voltage is more stable, the total harmonic distortion of the grid-connected current is obviously reduced, and low-frequency and high-frequency harmonics can be reduced.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD +1

Electrolytic capacitor-free permanent magnet synchronous motor copper loss optimization control method and device based on MTPA method

The invention discloses an MTPA method-based copper loss optimization control method and device for a permanent magnet synchronous motor without an electrolytic capacitor, and belongs to the field of permanent magnet synchronous motors. The method comprises the steps that q-axis reference current is made to fluctuate in a frequency doubling mode along with bus voltage, and it is ensured that a system obtains a high power factor; the method comprises the following steps: calculating MTPA critical voltage and weak magnetic control critical voltage by combining operation constraint conditions of a permanent magnet synchronous motor without an electrolytic capacitor, dividing each bus voltage fluctuation period into three working areas, namely a weak magnetic control area, a buffer area and an MTPA control area, and giving d-axis reference current in one bus voltage fluctuation period in sections; a feed-forward power compensation mechanism is introduced, the grid-side current quality is improved, and a PWM signal used for controlling the duty ratio of an inverter is generated. The effective improvement of the grid-side current performance is realized, and the MTPA control method can be utilized to reduce the copper loss to the greatest extent.
Owner:HUAZHONG UNIV OF SCI & TECH

A method and system for durability prediction optimization of warm sofc cathode materials

The application discloses a kind of warm SOFC cathode material endurance prediction optimization method and system, it is related to data processing technical field, including: obtaining critical voltage and standard voltage;First prediction time point, second prediction time point and first time interval are obtained, first output voltage is obtained, second output voltage is obtained, first linear endurance is obtained;First optimization time point, second optimization time point and second time interval are obtained, third output voltage is obtained, fourth output voltage is obtained, and second linear endurance is obtained;Based on optimization model, first output voltage, second output voltage, third output voltage, fourth output voltage, first time interval, second time interval and critical voltage, obtain the decay parameter, and according to decay parameter, first linear endurance and second linear endurance, obtain target endurance.The application has the advantages of good prediction effect, accurate and reliable and scientific and stable.
Owner:成都烁克科技有限公司

Self-adaptive charging method and system for small battery of electric vehicle

The invention discloses a self-adaptive charging method and system for a small battery of an electric vehicle, and the method comprises the steps: judging whether the vehicle is in a power-off state or not and whether the current time is preset or not when the replacement of the small battery is detected; if yes, the small battery management system EBS continuously awakens the gateway GWM, and the gateway GWM awakens the whole vehicle network; and when the EBS detects that the voltage of the small battery is reduced to the critical voltage V1 of the vehicle controller, the EBS stores the corresponding electric quantity value SOC1 of the small battery at the moment, sends out a charging warning, charges the small battery, and sleeps until the small battery is fully charged. The EBS can obtain a new charging MAP through interpolation according to the comparison between the SOC and voltage of the current small battery and the charging MAP of the original small battery. According to the invention, the charging MAP can be automatically changed according to the replaced small battery, unnecessary charging times are avoided, and meanwhile, small battery feed can be avoided.
Owner:QINGYU AUTOMOBILE TECH (TAICANG) CO LTD