48 results about "Critical voltage" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The present application relates to the technical field of charging time calibration for electric vehicles, and discloses a real-time clock calibration method and apparatus, a device, and a medium. The method comprises: acquiring clock calibration parameters on the basis of a preset time interval; executing a compensation error calculation process on the basis of the clock calibration parameters to obtain a compensation error; and upon receiving a sleep instruction and determining that a vehicle is not in a sleep state, calibrating a wake-up timestamp by using the compensation error, to obtain a target wake-up timestamp. The present application is used for solving the problem in the prior art that, when a vehicle is in a sleep state, the depletion of battery power due to long-term parking or a prolonged sleep state of the vehicle results in the vehicle being unable to function properly; thus, when a sleep instruction is received, a target wake-up timestamp can be determined, in order to wake up a sleep vehicle control unit at the target wake-up timestamp, so that the vehicle control unit controls a high-voltage system to charge the battery, thereby solving the problem of the vehicle being unable to function properly due to the battery voltage falling below a critical voltage.

The application relates to the technical field of intelligent control, and discloses a charging pile intelligent control method and system based on the Internet of Things, which comprises the following steps: collecting real-time data of an electric vehicle battery through a charging pile sensor and performing smoothing processing to obtain 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, predicting the future change trend of the polarization voltage by using a neural network model and performing risk assessment; dynamically adjusting a charging strategy according to the assessment result, calculating a new maximum allowable current; updating charging pile control parameters according to the new maximum allowable current to generate an optimized charging curve; and finally monitoring the battery response and determining a final charging strategy according to the polarization voltage stability. The method can realize real-time and accurate prevention and control of the lithium precipitation risk in the fast charging process, and significantly improves the charging safety and the battery life.

The invention provides a memory management method and a memory controller. The method is applied to a memory controller, and in response to a failure of a read operation performed on a physical page, a voltage offset identification operation is performed on the physical page to obtain an offset attribute, and the offset attribute is used for indicating a main offset trend of a critical voltage distribution of the physical page. And recording an offset attribute of the entity page, and obtaining target data and a data attribute corresponding to the target data based on the write-in instruction. And according to the data attribute of the target data, selecting a target entity page of which the offset attribute corresponds to the data attribute from a plurality of entity pages of the memory module, so as to write the target data into the target entity page. The method can allocate the storage entities according to the actual offset condition of the storage unit, prolong the service life of the memory and improve the data reliability.

A controller applied to an LLC resonant power converter is disclosed. The controller includes a critical voltage generating circuit and a gate control signal generating circuit. The critical voltage generating circuit generates an upper critical voltage and a lower critical voltage according to a reference voltage, a feedback voltage and a phase of a gate control signal. The gate control signal generating circuit turns off an upper bridge control signal according to a detection voltage and the upper critical voltage, or turns off a lower bridge control signal according to the detection voltage and the lower critical voltage. An upper bridge switch of the LLC resonant power converter is turned on according to the upper bridge control signal, and a lower bridge switch of the LLC resonant power converter is turned on according to the lower bridge control signal. The present application can compensate for the offset of the output load detection caused by the delay of the internal and external elements of the controller, so as to greatly improve the accuracy of the over-current protection and reduce the output load entering the standby mode.

The application provides a method, device, system and electronic equipment for actively shutting down a hybrid DC power transmission system. The method comprises: obtaining a set of power grid voltage coefficients of the hybrid DC power transmission system within a first preset time period; obtaining an effective value of an outlet end of a converter transformer on an AC side of a converter valve in a plurality of DC power transmission lines of a receiving end AC power grid at a first time, to obtain a first target effective value; determining an effective value of a controllable commutation converter valve at a second time according to the set of power grid voltage coefficients and the first target effective value, to obtain a second target effective value; obtaining a set of critical voltages of the hybrid DC power transmission system within a second preset time period; determining whether a commutation failure fault will occur in the controllable commutation DC power transmission line at the second time according to the set of critical voltages, the first target effective value and the second target effective value; and controlling the controllable commutation converter valve to shut down in the case that the commutation failure fault will occur in the controllable commutation DC power transmission line at the second time.

The invention discloses a distributed new energy collaborative fault voltage support control method and system, and relates to the field of power distribution networks, and the method comprises the steps: determining the voltage drop between two nodes based on the obtained active power, reactive power and grid-connected point voltage of photovoltaic input, and the line resistance and line reactance between the two nodes; when it is detected that the voltage drop of the grid-connected point reaches a preset threshold value, entering an initial compensation stage, introducing a dynamic compensation coefficient into the photovoltaic system, determining an initial reactive current, and injecting the initial reactive current into a power grid to support the voltage of the power grid; when it is detected that the voltage drop of the grid-connected point is larger than a preset threshold value, critical voltage is obtained, and a coordinated compensation stage is entered; when the obtained voltage drop is smaller than the critical voltage, active current and reactive current are distributed according to the impedance ratio so as to support the power grid voltage; otherwise, the initial compensation coefficient and the adjustment coefficient are introduced into the photovoltaic system to increase the reactive current so as to support the power grid voltage.

The invention discloses a trench gate field effect transistor, a chip and electronic equipment. The trench gate field effect transistor comprises a substrate, a drift layer, a first ion doping layer, a second ion doping layer, a gate electrode, an isolation layer, a drain electrode, a source electrode and a first interlayer dielectric layer. The drain electrode, the substrate, the drift layer, the first ion doping layer, the second ion doping layer and the source electrode are sequentially stacked; the doping types of the first ion doping layer and the second ion doping layer are different; the first interlayer dielectric layer is located between the grid electrode and the isolation layer. Because the first interlayer dielectric layer generally has a high capacitance value, compared with an isolation layer only arranged between the grid electrode and the drift layer and between the first ion doping layer and the second ion doping layer, the first interlayer dielectric layer is additionally arranged between the grid electrode and the isolation layer, so that the conductivity of the trench gate field effect transistor can be effectively improved, the critical voltage and the breakdown voltage are reduced, and the reliability of the trench gate field effect transistor is improved. And the leakage current and the conduction impedance are reduced.

The invention relates to the technical field of power systems, and discloses a power electronization load modeling method, device and equipment considering a converter and a storage medium, and the method comprises the steps: obtaining a double-loop control strategy of a plurality of power electronization loads to be modeled; for each double-loop control strategy, determining a double-loop control structure of the converter based on the double-loop control strategy, and determining a critical voltage value based on the double-loop control structure; for each power electronic load, obtaining a preset protection delay and a preset protection voltage threshold value of a built-in converter; dividing load operation conditions of the power electronic load based on the preset protection delay, the preset protection voltage threshold and the critical voltage value, wherein the load operation conditions comprise a stable operation condition, a transient regulation condition and a protection condition; and constructing a total load model of the power electronic load based on the load operation condition and the common physical structure. A load model capable of accurately describing external performance of a load is established based on a load operation condition division mechanism in combination with a common physical structure.

The invention relates to a 12T-SRAM (Static Random Access Memory) storage unit for ultra-low-voltage rapid read-write, and relates to the technical field of memory integrated circuits, the 12T-SRAM storage unit comprises eight NMOS (N-channel Metal Oxide Semiconductor) transistors (N1, N2, N3, N4, N5, N6, N7 and N8) and four PMOS (P-channel Metal Oxide Semiconductor) transistors (P1, P2, P3 and P4); a writing word line WWL controls the transistors N6 and N5; a read-write control signal WL controls PMOS (P-channel Metal Oxide Semiconductor) tubes P4 and P3; an inversion signal WL'is read and written to control NMOS (N-channel Metal Oxide Semiconductor) tubes N4 and N3; a read word line RWL controls transistors N8 and N7; the writing bit line BL and the writing bit line non-BLB are respectively connected with the N5 and the N6; the read bit line RBL and the read bit line non-RBLB are respectively connected with the N7 and the N8; a bit line is directly driven to read by combining a dynamic cut-off feedback device with an internal phase inverter, and complex latch writing is simplified into direct driving of the phase inverter, so that the flip critical voltage is remarkably reduced; under the ultra-low-voltage working condition, the SRAM still has strong write-in capability and higher write-in speed, and the problem of write-in failure of a traditional SRAM under the near-threshold voltage is effectively solved.

The invention discloses a CT induction power taking circuit and method. The circuit comprises a voltage doubling rectifying module, an energy storage module and a voltage monitoring output module which are connected in sequence. Wherein the voltage monitoring output module cooperatively controls a framework of a low dropout linear regulator through a first voltage monitoring chip and a second voltage monitoring chip, and logically combines output signals of the first voltage monitoring chip and the second voltage monitoring chip through a voltage dividing unit. According to the method, automatic switching of four stages of system power-on, power supply maintenance, safe turn-off and cyclic restart is realized through the circuit. The core of the low dropout linear regulator is that when the main energy storage voltage is insufficient, the power supply is maintained by using the energy storage of the auxiliary energy storage capacitor and the second voltage monitoring chip, and the low dropout linear regulator is reliably turned off until the voltages of the two are insufficient, so that the problem of'dead zone 'caused by repeated start and stop of the low dropout linear regulator near the critical voltage in the prior art is thoroughly solved. The device has the advantages of being low in induction electricity taking starting current, high in electricity taking efficiency and stable and reliable in work.

An apparatus for detecting an attack on, or degradation of, an electric circuit is disclosed herein. The apparatus comprises a voltage level detector configured to determine whether the voltage level of the electric circuit exceeds a maximum selected threshold value, and to generate a first binary voltage limitation signal having if the voltage level exceeds the maximum selected threshold value. The apparatus also comprises a marginal voltage level detector configured to determine whether the voltage level of the electric circuit exceeds a marginal selected threshold value, the marginal selected threshold value being less than the maximum selected threshold value, and to generate a second binary voltage limitation signal having if the voltage level exceeds the marginal selected threshold value. A safety monitoring system monitors the first and second binary voltage limitation signals and is configured to determine that a possible attack or degradation has taken place based on at least one of the first binary voltage limitation signal and the second binary voltage limitation signal.

The embodiment of the application provides a pulse charging method, a pulse charging device, an electronic device and a storage medium, and belongs to the technical field of battery charging. The method comprises the following steps: performing first pulse charging on a target battery in a first pulse charging mode through a first current control parameter, and obtaining a first battery performance parameter of the target battery in the first pulse charging; performing state estimation on the target battery according to the first battery performance parameter, to obtain a state of charge and a health state of the target battery; updating the first current control parameter according to the state of charge, the health state and a preset lithium precipitation critical voltage, to obtain a second current control parameter; and switching the target battery from the first pulse charging mode to a second pulse charging mode according to the second current control parameter, to perform second pulse charging on the target battery in the second pulse charging mode. The embodiment of the application can realize adaptive pulse charging.

The invention relates to a dynamic cooperative flashover control method and system for an electric precipitator, and belongs to the technical field of electric precipitator power supply control. The method comprises the following steps: collecting dust concentrations of an inlet and an outlet of the electric dust remover and secondary voltage and secondary current data of each internal electric field, setting flashover frequency values of the head and tail electric fields according to a comparison result of the dust concentration values and a preset mapping curve, and calculating flashover frequency set values of each internal electric field by adopting a gradient coefficient; when flashover occurs in the single electric field, the closing duration time of the high-voltage power supply is controlled according to the charge release time constant of the dust layer, and then the flashover critical voltage is recovered through the two-stage boosting process; when flashover occurs in the multiple electric fields at the same time, the flashover electric field voltage is dynamically reduced according to the flashover voltage and the real-time frequency, and the normal electric field voltage is correspondingly increased; according to the method, optimal distribution of global energy can be realized, so that the dust removal efficiency is improved, and flashover is inhibited.

This invention relates to a method and apparatus for site selection and capacity determination of voltage regulating devices in distribution network lines based on the spatiotemporal distribution characteristics of voltage. The method includes: screening out the lowest and highest voltage values ​​of the line throughout the year, and extracting the distribution outlet voltage at the corresponding time segment; constructing voltage distribution models from the distribution outlet to the users corresponding to the lowest and highest voltage values ​​of the year, respectively; calculating the installation distance under different operating conditions based on the critical voltage values ​​of the voltage regulating device; determining the target installation location based on the distribution network line's over-limit conditions using a first installation distance and / or a second installation distance; locating towers near the target installation location along the distribution network line as the installation towers for the voltage regulating device, and determining the capacity of the voltage regulating device based on the load of the line downstream of the installation tower. This invention can effectively solve the voltage over-limit problem in medium-voltage or low-voltage lines caused by factors such as increased power supply radius and distributed power source access.

The invention relates to a constant power-to-constant voltage control method and system for realizing full charge and full discharge of a flow battery. The method mainly comprises the following steps: collecting operation parameters of the flow battery in real time, wherein the collected operation parameters comprise pile end voltage, electrolyte temperature and battery cycle index; dynamically calculating a critical voltage threshold according to the electrolyte temperature, the battery cycle index and the rated voltage; when the real-time voltage at the electric pile end reaches or exceeds a critical voltage threshold value, switching from a constant power mode to a constant voltage mode; and in the constant voltage mode, the power output is dynamically adjusted through a PID adjusting mechanism, so that the voltage at the pile end is stabilized at a critical voltage threshold. By dynamically judging the switching opportunity from constant power to constant voltage and accurately regulating and controlling the voltage in the constant voltage stage, the purpose of safe full charging and discharging of the battery is achieved, the energy storage utilization rate is increased, and the cycle life of the battery is prolonged.

The present application provides an alternator and a rectifying device thereof. The rectifying device includes a transistor and a gate voltage control circuit. The transistor is controlled by a gate voltage. The gate voltage control circuit generates the gate voltage according to a voltage difference between an input voltage and a rectified voltage. The gate voltage control circuit determines whether the voltage difference is less than a second default threshold voltage within a first time interval after the voltage difference drops to a first default threshold voltage to decide whether to provide the gate voltage to turn on the transistor. When the transistor is turned on, the voltage difference is substantially equal to a first reference voltage. The gate voltage control circuit adjusts the gate voltage to make the voltage difference substantially equal to a second reference voltage in a second time interval.

The present invention discloses a method for optimizing the reactive power control of a controllable phase-shifting converter under non-overlimit conditions. This method first collects the fixed parameters and real-time parameters of the CLCC and calculates the real-time voltage drop degree coefficient k. Then, the critical voltage drop degree coefficient k1 is determined by solving a quartic equation of one variable. Next, according to the comparison result of k and k1, the theoretical commutation angle μ that maximizes the fundamental reactive current is adaptively selected: when k≥k1, μ takes the extreme point μ0; when 0≤k<k1, μ takes the maximum value of 60°. Finally, with the constraint that the natural commutation angle takes the maximum value, the optimal trigger angle α is obtained by solving the DC current constraint equation of the CLCC backwards. The present invention can quickly and accurately calculate the trigger angle corresponding to the maximum reactive power while ensuring commutation reliability and device safety, significantly improving the emergency reactive power support ability of the CLCC during AC faults and enhancing the transient stability of the system.

A pixel circuit comprises a light emitting diode, a pulse wave width modulation circuit, a pulse wave amplitude modulation circuit and a light emitting drive circuit. The light-emitting diode is provided with an anode and a cathode for receiving system high voltage; the pulse wave width modulation circuit provides pulse wave width control voltage; the pulse wave amplitude modulation circuit provides driving current; the light-emitting driving circuit comprises a first transistor for receiving pulse width control voltage and driving current and a voltage compensation circuit for performing critical voltage compensation on the first transistor; the pulse wave amplitude modulation circuit comprises a second transistor for providing driving current and a circuit which is used for carrying out critical voltage compensation on the second transistor and is composed of a transistor and a capacitor.

The invention discloses an anti-single-particle gate-through VDMOS device containing a composite gate dielectric structure and a preparation method of the anti-single-particle gate-through VDMOS device, the composite gate dielectric structure is a SiO2 / high-K dielectric / Si3N4 sandwich gate structure, the interface quality is ensured by the bottom layer of thin SiO2, and the electric field intensity of a gate is greatly reduced by the middle high-K dielectric; the silicon-rich Si3N4 on the top layer serves as a charge trap buffer layer and can absorb transient charges generated by single particle incidence. According to the structure, through a triple mechanism of charge shunting, electric field suppression and interface optimization, the critical voltage value of single-particle gate-through is improved, the gate leakage current is reduced, the switching speed is optimized, the threshold voltage drift is greatly suppressed, the problem that single-particle gate-through failure is likely to happen to a traditional gate oxide under heavy ion bombardment can be solved, and the reliability of the gate oxide is improved. The method can be applied to aerospace satellite power supplies, nuclear power station control chips and other scenes, and is especially suitable for space high-energy particle environments.