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3636 results about "Voltage source" patented technology

A voltage source is a two-terminal device which can maintain a fixed voltage. An ideal voltage source can maintain the fixed voltage independent of the load resistance or the output current. However, a real-world voltage source cannot supply unlimited current. A voltage source is the dual of a current source. Real-world sources of electrical energy, such as batteries, generators, can be modeled for analysis purposes as a combination of an ideal voltage source and additional combinations of impedance elements.

Virtual synchronous control method and apparatus for energy storage system, device, and storage medium

The present application relates to a virtual synchronous control method and apparatus for an energy storage system, a device, and a storage medium. The method comprises: controlling an output voltage of a direct-current energy storage valve on the basis of an output electrical signal measurement value of a direct-current side of a voltage source converter and an output voltage reference value of the direct-current energy storage valve; further, controlling an output signal of an alternating-current side of the voltage source converter on the basis of a grid connection point electrical signal measurement value and a grid connection point electrical signal reference value of the voltage source converter. It can thus be seen that the embodiments of the present application implement a virtual synchronous control method independently controlling a voltage source converter and a direct-current energy storage valve in an energy storage system, so that the method can be applied to virtual synchronous control of a high-voltage direct-current direct-mounted energy storage system. In addition, by means of independently controlling the voltage source converter and the direct-current energy storage valve in the energy storage system, the voltage source converter does not need to be configured to take into account both direct-current side control and alternating-current side control, so that the complexity of a control loop of the voltage source converter can be simplified.
Owner:CONTEMPORARY AMPEREX FUTURE ENERGY RES INST (SHANGHAI) LTD +1

Insulation detection method of electric automobile

The invention discloses an insulation detection method for an electric automobile, belongs to the technical field of high-voltage safety monitoring of the electric automobile, and solves the problem that the insulation detection precision is reduced due to electromagnetic interference, impedance fluctuation and capacitive effect coupling in a dynamic load switching process. According to the scheme, a test sequence of discrete frequency points is applied to a high-voltage system; measuring a response current value through a current sensor and calculating a ground distributed capacitance value; connecting a test voltage source between positive and negative electrodes of the high-voltage system through a coupling circuit; applying a first pulse signal during no-load, dynamically setting the width according to the capacitance value, measuring a first response current value, and calculating an initial insulation resistance value; a second pulse signal with the same parameter is applied in the load state window, a second response current value is measured, and differential filtering is carried out in combination with the initial value to eliminate load noise; and comparing the filtered insulation resistance value with a threshold value, and outputting a fault signal when the insulation resistance value is lower than the threshold value. The method is used for monitoring the insulation state of the high-voltage system in real time and accurately early warning faults.
Owner:GUANGXI TECHCAL COLLEGE OF MACHINERY & ELECTRICITY +1

Online temperature self-compensation calibration method and circuit for force measurement transmitter

The invention relates to the technical field of field data acquisition, in particular to an on-line temperature self-compensation calibration method and circuit for a force measurement transmitter. The calibration method comprises the steps that a working strain gauge and a temperature compensation gauge are synchronously excited through a two-way precision constant current source, the working strain gauge and the temperature compensation gauge are consistent in material parameter and are located in the same temperature field, and output current values of the two-way precision constant current source are equal and are controlled by a high-precision reference voltage source and a sampling resistor in a closed-loop mode. According to the invention, differential signals of the working strain gauge and the temperature compensation gauge are decoupled in real time through double-path precise constant-current source excitation and synchronous ADC acquisition technologies, gradient compensation is carried out on the temperature change rate in combination with a dynamic weighting algorithm, a lag error of traditional fixed coefficient compensation in a transient temperature field is effectively eliminated, and the accuracy of temperature compensation is improved. And online self-compensation of the temperature drift of the strain gauge is realized.
Owner:BENGBU COLLEGE

Plasma processing system configured to deliver a pulsed voltage wavform

A plasma processing system includes a pulsed voltage source configured to generate a pulsed voltage waveform having a first frequency. The plasma processing system includes a radio frequency source configured to generate a radio frequency waveform having a second frequency that is higher than the first frequency. The plasma processing system includes a junction box enclosure electrically coupling the pulsed voltage source to a direct current conductor coupled to a substrate support and further electrically coupling the pulsed voltage source to a radio frequency conductor coupled to a radio frequency baseplate. The junction box enclosure includes a pulsed voltage filter circuit coupled between the radio frequency source and the radio frequency conductor and operable to filter the pulsed voltage waveform. The junction box enclosure further includes a radio frequency filter circuit coupled between the pulsed voltage source and the direct current conductor and operable to filter the radio frequency waveform.
Owner:APPLIED MATERIALS INC

Method for estimating capacity ratio of network constructing / following fan hybrid system considering power coupling

The invention discloses a power coupling-considered capacity ratio estimation method for a network-constructing / network-following multi-machine hybrid system, and the method comprises the steps: building a GFL-GFM hybrid system model, combining VSG power coupling small signal modeling and a dynamic relative gain matrix (DRGA), and quantifying the coupling strength of active / reactive power to output voltage; the frequency domain impedance characteristic of the GFM converter is simplified, and an ideal voltage source series equivalent reactance equivalent model is constructed; deriving an analytical relationship between a generalized short-circuit ratio (gSCR) and a capacity ratio based on the model, and generating a ratio formula in combination with engineering boundary sub-scenes to form a ratio range suitable for multiple scenes; for coupling time-varying characteristics, a closed-loop mechanism of'mixed mode-coupling sensing-correction calculation-execution feedback 'is constructed, and the ratio is dynamically adjusted. According to the method, coupling quantization and multi-machine coordination control are deeply fused, the problem that the external characteristic model precision and the multi-working-condition adaptability are difficult to consider under complex environment coupling is effectively solved, and the engineering applicability of the hybrid fan system is enhanced.
Owner:LIAOYANG POWER SUPPLY COMPANY OF STATE GRID LIAONING ELECTRIC POWER SUPPLY +1

High-frequency circulating current calculation method for cascade coupling parallel structure of motor simulator

The invention provides a high-frequency circulating current calculation method for a motor simulator cascade coupling parallel structure, and the method comprises the following steps: building an equivalent decoupling circuit model of each branch in the cascade coupling parallel structure based on the voltage relation of each branch in the motor simulator cascade coupling parallel structure, wherein the equivalent decoupling circuit of each branch comprises an equivalent voltage source and an equivalent leakage inductor which are connected in series, and the equivalent leakage inductor is determined based on self-inductance and mutual inductance of a choking coil of each branch; a plurality of duty ratio intervals are divided between 0 and 1, and the number of the duty ratio intervals is equal to the number of the branches in the cascade coupling parallel structure; and using the equivalent decoupling circuit model to calculate the high-frequency circulation of each corresponding branch when the duty ratio of the modulation signal of the motor simulator is in each duty ratio interval. According to the method provided by the invention, the high-frequency circulating current of the cascade coupling parallel structure of the motor simulator can be accurately calculated, and effective support is provided for targeted design of a high-frequency circulating current suppression scheme.
Owner:HARBIN INST OF TECH AT WEIHAI

Resonant converter switching between different operational state modes

A resonant converter switching between different operational state modes is provided. The resonant converter includes a first transistor, a second transistor, a control circuit, a resonant circuit, a transformer and an output stage circuit. A first terminal of the first transistor and a second terminal of the second transistor are connected to positive and negative terminals of an input voltage source, respectively. A first terminal of the second transistor is connected to a second terminal of the first transistor. The resonant circuit is connected to the second terminal of the first transistor and the transformer. The transformer is connected to a load through the output stage circuit. The control circuit modulates frequencies or duty cycles of conduction time control signals that are outputted to the first and second transistors to different values for switching the resonant converter between the operational state modes.
Owner:NAT TAIWAN UNIV OF SCI & TECH

Source network load storage coordinated control system and method for high-capacity multi-configuration network type energy storage combined transportation

The invention discloses a source network load storage coordination control system and method for high-capacity multi-network energy storage combined transportation. The system comprises a master station layer which is responsible for receiving a superior scheduling instruction, issuing an emergency control instruction, and performing economic optimization scheduling and rapid coordination control on photovoltaic and energy storage resources; the substation layer is responsible for accessing photovoltaic, load and energy storage resource information and decomposing and issuing superior instructions to realize a local frequency voltage control function; and the terminal layer is used for receiving a generator tripping command or a power regulation command issued by the emergency state monitoring device. The system can effectively improve the network-related performance of a new energy station, enhance the stability and reliability of a power grid, improve the absorption capability of new energy, and optimize the economical efficiency of the system. Through combined operation of the network construction type energy storage equipment and the new energy, effective support for the power grid is realized, the problem of coordination control of parallel operation of multiple voltage sources is solved, oscillation and circulation are avoided, and the overall performance and the power supply guarantee capability of the system are improved.
Owner:SHENNONGJIA FOREST REGION POWER SUPPLY CO LTD HUBEI ELECTRIC POWER CO

Transient current capability improvement control system and method of wind and light power generation system

The invention provides a transient current capability improvement control system and method of a wind and light power generation system. The system comprises a self-synchronizing voltage source control module, a junction temperature prediction module, a transient current improvement control module, a current instruction calculation module and a transient current precise control module. According to the invention, online observation of the junction temperature of the wind-solar converter power device can be realized, the maximum short-circuit current which can be output can be accurately predicted, the DC bus voltage, the switching frequency and the modulation strategy are adjusted when the power grid has a fault, the junction temperature of the power device is reduced, and the transient current endurance capability of the power device is improved. And the transient current is accurately controlled to limit the utilization of the transient capability of the power device.
Owner:SHANGHAI JIAOTONG UNIV

Device and method for extracting CO2 from air

A device for extracting CO2 from air comprises at least one extraction reactor (12) through which CO2-containing air (L) flows in an adsorption operation, having an adsorption surface; a heating arrangement (40) for heating the at least one extraction reactor (12) at least in the region of its adsorption surface to a temperature above an extraction gas desorption temperature in a heating / desorption operation; and at least one extraction gas storage (48) for storing CO2 desorbed from the at least one extraction reactor (12) in the heating / desorption operation. The extraction reactor (12) comprises at least one substrate with a plurality of flowable cells or flow channels of a porous structure, wherein the adsorption surface is formed on the substrate, and wherein the at least one substrate is electrically conductive and can be heated by applying an electrical voltage.wherein the heating arrangement (40) comprises the at least one substrate and a voltage source (42) for applying an electrical voltage to the at least one substrate.
Owner:PUREM GMBH

Low-power and fast wake-up band-gap voltage reference circuit

The low-power fast wake-up band-gap reference voltage circuit operates in three phases: dormant, wake-up, and steady-state phases. The circuit enters wake-up subsequent to receipt of an enable signal which causes a one-shot timer to generate a slew enable signal pulse having a predetermined period. To a band-gap voltage reference circuitry comprising an operational amplifier, there is connected, at the wake-up phase, a boost circuitry, operative under the control of the slew enable signal that connects one or more of the one or more boost circuits to a band-gap voltage reference. Thereby, during the brief wake-up phase, more current is consumed to accelerate the response of the circuit. Upon completion of the wake-up phase the boost circuitry is disconnected under the control of the slew enable signal and for as long as the enable signal is active, the circuit is operative in a low-power mode.
Owner:WEEBIT NANO LTD

Fault ride-through control method for network construction type converter

The invention provides a fault ride-through control method for a network construction type converter, and belongs to the technical field of energy storage converters and the like. The method comprises the following steps: firstly, measuring PCC voltage and power grid side current, calculating amplitudes of the PCC voltage and the power grid side current, and then judging whether the PCC voltage drops below a set threshold value or not; if not, keeping the active power reference and the voltage amplitude reference unchanged; and if so, performing active power reference modification: judging whether a current limiting strategy is triggered, if not, locking the PCC voltage reference as a measured value, and if so, gradually decreasing the PCC voltage reference by an increment value based on the measured value. According to the invention, accurate evaluation of the existence of the stable equilibrium point is realized; meanwhile, an improved fault ride-through control method is provided, active power reference and voltage amplitude reference are dynamically modified, so that the grid-forming converter is transited to a new stable balance point during a fault period, and current limiting, transient synchronization stability improvement, PCC voltage source characteristic maintenance and maximum fault current output can be taken into account.
Owner:SUZHOU MINGYAN INTELLIGENT CONTROL TECHNOLOGY CO LTD

Active island detection method and system based on harmonic impedance characteristic identification

The invention discloses an active island detection method and system based on harmonic impedance characteristic identification, and the method comprises the steps: analyzing the harmonic impedance difference of grid-connected points in a grid-connected state and an island state, and building a state criterion based on resonant frequency deviation and impedance amplitude through the comparison of the frequency response characteristics of island impedance and grid-connected impedance; fitting the grid impedance into an RLC parallel model in a selected frequency band, and mapping the topological difference of the power grid into a parameter difference; embedding a low-voltage ride-through strategy in the control of the voltage source converter, and adjusting reactive current in a grading manner according to the voltage drop degree of a grid-connected point; fundamental waves and harmonic waves are separated through a cascade notch filter, two synchronous harmonic waves are injected into the system through constant current control, and it is ensured that injection signals of a multi-voltage source converter are in the same phase in a phase locking link; and solving an overdetermined equation set based on the double-frequency response data to identify RLC parameters, setting an island criterion, and synchronously completing island judgment in a low-voltage ride-through time window. Detection precision is improved, dynamic response is optimized, and power generation efficiency is improved.
Owner:TONGCHUAN POWER SUPPLY CO OF STATE GRID SHAANXI ELECTRIC POWER CO LTD

Phase-loss self-fault-tolerant control method for phase-shift-free dual three-phase permanent magnet synchronous motor

The invention discloses an open-phase self-fault-tolerant control method for a phase-shift-free dual three-phase permanent magnet synchronous motor. The method can automatically adjust a current distribution relation in the case of an open-phase fault and suppress torque pulsation in combination with neutral point voltage compensation. Comprising the following steps: driving two pairs of three-phase winding modules of the phase-shift-free DTP-PMSM in parallel by adopting two two-level three-phase voltage source inverters, and providing a mathematical model of the motor; current distribution is automatically adjusted; compensating the voltage of the neutral point, and calculating the offset of the fault module; the current is redistributed to suppress the torque ripple after the fault, and the secondary oblique wave component generated by the phase failure fault is eliminated; a current loop controller is improved through dead-beat predictive control; the speed ring controller is optimally designed into an improved sliding mode controller; an improved double-loop controller system is formed by combining improved sliding mode control and dead-beat prediction control, high-gain parameters are set to improve the dynamic response performance of the system, and a new self-fault-tolerant control system is formed.
Owner:ZHEJIANG UNIV OF TECH

Layered coordinated scheduling method and device for main and distribution networks considering unified power flow controller and flexible alternating-current and direct-current interconnection

The invention discloses a main and distribution network hierarchical coordinated scheduling method and device considering a unified power flow controller and flexible alternating current and direct current interconnection, which are used for solving the technical problem of poor system dynamic stability of a main and distribution network caused by the existing main and distribution network coordinated scheduling technology based on the unified power flow controller. The method comprises the steps of obtaining main and distribution network power flow data and a topological structure, and generating an initial main network power reference instruction, a node power-voltage sensitivity matrix and converter reference power in combination with a double-voltage source equivalent model of a preset UPFC; and obtaining an initial node cluster converter power instruction and a UPFC active power regulation instruction by using the data and the sensitivity matrix based on a Newton-Raphson method combined power flow model. And calculating a weight coefficient through the initial main network power reference instruction and the UPFC regulation instruction, and correcting the initial instruction and the converter reference power according to the weight coefficient. And finally, a main and distribution network hierarchical coordinated scheduling scheme is formed.
Owner:ZHUHAI POWER SUPPLY BUREAU GUANGDONG POWER GIRD CO

Plasma ion three-dimensional flow velocity distribution detection system and method

The invention discloses a plasma ion three-dimensional flow velocity distribution detection system and method, and belongs to the technical field of plasma diagnosis. The system comprises a Mach probe, a controllable voltage source, a sampling resistor and a voltage acquisition system, the Mach probe, the sampling resistor and the controllable voltage source are connected in series through wires to form a loop, and the voltage acquisition system is connected in parallel with the controllable voltage source and the sampling resistor and is used for acquiring the voltage of the controllable voltage source and the sampling resistor. According to the detection method, on the basis of the multi-axis vector synthesis principle, ion flow velocity components in different planes are obtained by inserting a Mach probe in the three-axis direction, and a three-dimensional flow velocity component is calculated through a vector synthesis algorithm. According to the invention, the local flow field structure in the ion source can be diagnosed, the spatial distribution characteristic of the ion flow velocity can be revealed, the spatial resolution is high, the velocity information of particles can be directly provided, the three-dimensional data of the ion flow velocity measurement can be synthesized without complex optical path rotation or multiple scanning, and the experimental device is simple and low in cost.
Owner:HEFEI INSTITUTE OF PHYSICAL SCIENCE CHINESE ACADEMY OF SCIENCES

Operation control method and system of self-synchronizing voltage source centralized photovoltaic inverter

The invention provides a stable operation control method and system for a self-synchronizing voltage source centralized photovoltaic inverter, and the method comprises the steps: detecting the change rate of the DC voltage of the centralized photovoltaic inverter and the output active power of a photovoltaic panel in real time, and when the ratio of the change rate of the DC voltage to the change rate of the output active power of the photovoltaic panel exceeds a threshold value, starting the control of the stable operation of the photovoltaic inverter. A system working mode is converted from a power control mode to a voltage control mode, and a power given value and a direct-current voltage given value of a control system are adjusted in real time. A synchronous angular frequency is obtained by adding an output value of the deviation of the active power through a proportional controller and a power grid frequency value, and the phase of an output modulation voltage of a grid-connected converter is obtained after integration, so that the grid-connected power of the photovoltaic inverter is adjusted. The working points of the photovoltaic inverter can stably operate on all the working points of the photovoltaic power-voltage characteristic curve, it is ensured that the photovoltaic inverter is located at the maximum power point all the time, and then stable operation control over the self-synchronizing voltage source centralized photovoltaic inverter is achieved.
Owner:SHANGHAI JIAOTONG UNIV +1

Band-gap reference voltage source

The invention relates to the technical field of integrated circuits, in particular to a band-gap reference voltage source, which comprises a high-order compensation circuit, a low-order compensation circuit, a low-order compensation circuit, a low-order compensation circuit and a low-order reference circuit, the band-gap reference circuit is used for generating a positive temperature coefficient voltage and a negative temperature coefficient voltage, performing first-order temperature compensation on the negative temperature coefficient voltage by using the positive temperature coefficient voltage, performing high-order curvature compensation on the negative temperature coefficient voltage based on the target compensation current, determining the compensated voltage as a reference voltage and outputting the reference voltage; according to the band-gap reference voltage source, high-order compensation is introduced through the sub-threshold MOS tube, the negative temperature coefficient voltage can be well reduced, the reference voltage with the temperature coefficient approximate to zero is obtained, and practicability is high.
Owner:CHONGQING GIGACHIP TECH CO LTD

Intelligent calibration system for voltage monitor

The invention relates to the technical field of voltage calibration, and discloses an intelligent calibration system for a voltage monitor, and the system comprises an environment temperature control module which is used for obtaining the environment temperature deviation and driving a temperature control device to enable the temperature to be stable; the internal reference integrity detection module is used for collecting and screening an internal reference voltage sample and outputting a sampling gain parameter; the temperature zone segmentation fitting module is used for modeling the temperature voltage sample according to the temperature zone and outputting a temperature compensation coefficient vector; the multi-point automatic calibration module is used for performing segmentation fitting based on the correction voltage and the residual error and outputting an initial gain coefficient and a bias parameter; the drift prediction fine tuning module is used for updating a gain coefficient and a bias parameter in real time through a recursive least square algorithm; and the external reference closed-loop verification module is used for judging the calibration effectiveness based on an external voltage source and triggering closed-loop optimization. According to the invention, high-precision, self-adaptive and traceable full-process automatic calibration of the voltage monitor in a complex environment is realized.
Owner:XIAMEN YILI TIANLONG TECH CO LTD

Resistor-based voltage-withstanding on-state voltage drop measurement circuit for junction temperature monitoring, and monitoring method

Disclosed in the present invention are a resistor-based voltage-withstanding on-state voltage drop measurement circuit for junction temperature monitoring, and a monitoring method. The measurement circuit comprises: a high-resistance series high-voltage resistor RL; switching diodes D1 and D2; a low-voltage MOSFET M1; a phase inverter U1; a three-state gate U2; an RC delay circuit consisting of a resistor R1 and a capacitor C1; current-limiting resistors R2 and R3; auxiliary voltage sources VDD and VCC; an operational amplifier U3; and an isolation operational amplifier U4. The monitoring method comprises: designing an on-state voltage drop sampling circuit based on a high-resistance resistor, and performing parameter selection on the basis of an actual application scenario; measuring a collector current and on-state voltage drop model at different junction temperatures under offline conditions, so as to provide a calculation model for online monitoring; and under online conditions, performing online monitoring of junction temperature on the basis of the model obtained by means of performing testing under the offline conditions. The present invention has the advantages of being low cost, having high reliability, and adaptability to on-state voltage drop measurement at a high voltage and within a wide ambient temperature range.
Owner:SOUTHWEST JIAOTONG UNIV

Parallel three-level converter model prediction control method and system

The invention relates to the technical field of parallel three-level converter control, and provides a parallel three-level converter model prediction control method and system, and the method comprises the steps: enabling a parallel three-level converter to be modeled as a series connection of an equivalent voltage source and an equivalent filter inductor according to the Thevenin theorem, enabling the parallel three-level converter to be equivalent to a five-level converter, and enabling the parallel three-level converter to be connected in parallel; a three-layer optimization control strategy is adopted; in the first layer, a candidate vector closest to a reference voltage vector is selected as an optimal five-level basic vector so as to track a parallel total output current; in the second layer, a redundant five-level voltage vector is selected to balance the neutral-point voltage; and in the third layer, selecting the candidate switching state which enables the circulating current suppression value function to be the minimum as the optimal redundant three-level switching state so as to suppress the circulating current. The method can effectively reduce output current harmonics under low switching frequency, and balance of neutral-point voltage and effective suppression of circulating current are realized to ensure safe and stable operation of a parallel converter system.
Owner:SHANDONG UNIV

Sensor controller, electronic device, and control method of sensor controller

The present disclosure relates to a sensor controller including transmission drivers each having a negative and a positive power supply terminal, each of the transmission drivers being configured to generate a signal waveform transitioning between first potential and second potential and output the signal waveform to a corresponding detection electrode, and an intermediate potential supply unit having a potential generation circuit that includes a voltage source or a capacitive element separate from the transmission drivers, the intermediate potential supply unit being configured to output a voltage from the potential generation circuit at first timings at which a potential of a signal waveform starts to transition from the first potential to the second potential or from the second potential to the first potential, to supply the intermediate potential between the first potential and the second potential to at least one of the positive or the negative power supply terminal.
Owner:WACOM CO LTD

Weight coefficient-free model prediction control system and method for permanent magnet synchronous motor

The invention discloses a weight coefficient-free model prediction control system and method for a permanent magnet synchronous motor, and particularly belongs to the field of permanent magnet synchronous motor control. The control system comprises a direct current voltage source, a three-phase converter, a permanent magnet synchronous motor, a rotating speed outer ring PI control module, an MTPA flux linkage calculation module and a model prediction control module. The control method comprises the following implementation steps: firstly, establishing a torque and flux linkage prediction model of the permanent magnet synchronous motor; then, a reference torque amplitude value and a reference flux linkage amplitude value are obtained through a rotating speed outer ring PI controller and a maximum torque per ampere (MTPA) calculation module respectively; secondly, constructing an independent torque cost function and a flux linkage cost function according to the torque error and the flux linkage error, and forming a cascade form; evaluating the switching states by using a cost function, selecting two vectors from the eight switching states of the converter by using the independent cost function of the torque (or flux linkage), and selecting an optimal vector from the two vectors by using the independent cost function of the flux linkage (or torque); and finally, the execution sequence of the torque and flux linkage cost function is alternated in each subsequent period. Compared with the prior art, the method avoids complex weight coefficient design through a cost function cascading mode, alternates the execution sequence of the cost functions in each period, dynamically balances the weights of the two control targets, and reduces the number of calculation times.
Owner:INNER MONGOLIA UNIV OF TECH

Sine constant current source excitation method for eddy current displacement sensor

The invention discloses an eddy current displacement sensor sine constant current source excitation method, and belongs to the technical field of sensor measurement and control. The method comprises the following steps: S1, generating positive and negative symmetric reference voltages through a reference voltage source circuit; s2, outputting a square wave control signal with adjustable frequency by the control chip, and driving a switching circuit to generate a square wave taking the positive and negative reference voltage as a level; s3, processing the square wave through a filter circuit to obtain a standard sine wave voltage signal; and S4, converting the sine voltage signal into sine constant current source excitation through a Howland current source circuit, and outputting the sine constant current source excitation to a sensor probe coil. According to the invention, through combination of digital control and analog conversion, the circuit structure is simplified, the cost is significantly reduced, and convenient adjustment of the output frequency and high stability and precision of the output current are realized at the same time.
Owner:HUNAN AEROSPACE ELECTROMECHANICAL EQUIP & SPECIAL MATERIAL INST

Balanced current controlled self-synchronizing voltage source control method and system

The invention relates to the technical field of self-synchronizing voltage source control, and discloses a balance current controlled self-synchronizing voltage source control method and system. The method comprises the following steps: acquiring and preprocessing operation data of a grid-connected inverter to obtain active / reactive components of voltage and current of a filter element; generating a three-phase terminal voltage instruction of the self-synchronizing voltage source based on the components, and determining a current instruction signal in combination with the grid-connected voltage; a three-phase modulation signal is generated through adjustment of a PIR controller and coordinate inverse transformation, then a filter inductance value is calculated according to the ripple characteristic of the modulation signal and a switching period, a filter capacitance value is determined by combining resonant frequency, and finally accurate control of the self-synchronizing voltage source is realized according to a filter parameter. By dynamically calculating the matching parameters of the filter inductance and the filter capacitance, the active regulation and control capability of the output impedance characteristic of the inverter is enhanced, and the resonance risk during the impedance change of the power grid is effectively inhibited. The technical problem that the stability is limited due to insufficient impedance regulation and control in the prior art is solved.
Owner:MAOMING POWER SUPPLY BUREAU GUANGDONG POWER GRID CORP

Accelerated simulation solving method and system for controllable self-recovery energy dissipation device

The invention provides an accelerated simulation solving method and system for a controllable self-recovery energy dissipation device, and the method comprises the steps: S1, enabling an inductance element between a nonlinear network and a linear network in a hybrid cascade DC power transmission system to be equivalent to a short transmission line, and building circuit models for the linear network and the nonlinear network respectively; s2, obtaining the value of the current controlled voltage source based on the node voltage of the previous simulation time step of the linear and nonlinear networks, the value of the controlled voltage source and the information interaction format; s3, node voltage solving is carried out based on the value of the controlled voltage source of the current simulation time step to obtain the node voltage of the current simulation time step, if the number of iterations is met, the operation is stopped, and otherwise, the step S2 is executed; the nonlinear network comprises a controllable self-recovery energy dissipation device; according to the invention, the energy dissipation device and the linear main circuit in the circuit system are decoupled in a sub-network manner, the calculation amount is reduced, and the iterative algorithm is used for solving, so that the high-efficiency and high-precision simulation of a nonlinear network and a linear network is ensured.
Owner:GLOBAL ENERGY INTERCONNECTION RES INST CO LTD

Voltage source type energy storage small signal stability analysis method based on virtual synchronous machine

The invention discloses a voltage source type energy storage small signal stability analysis method based on a virtual synchronous machine. A small signal state space model including active control, reactive control, double closed-loop control and a lithium battery energy storage module is established, a characteristic value analysis method is used for solving a state matrix characteristic root, system stability is evaluated, and an oscillation mode is identified. By drawing characteristic root trajectories of key parameters such as virtual rotational inertia, virtual damping coefficients and double-closed-loop PI parameters, an influence rule of the parameters on system stability is analyzed. According to the method, the dynamic response characteristics of the system can be accurately quantified, theoretical support is provided for control strategy optimization and parameter design of the voltage source type energy storage system, and the stability and reliability of a power grid in a renewable energy source grid-connected scene are effectively improved.
Owner:XINJIANG UNIVERSITY

Power distribution network station area inverter switching control method and system based on double-layer MPC

The invention discloses a double-layer MPC-based power distribution network area inverter switching control method and system, and the method comprises the steps: obtaining the operation parameters and equipment parameters of an area power distribution network, and building a voltage source type inverter system model considering the frequency fluctuation; constructing an outer-layer model, and generating an output voltage reference value of an inverter grid-connected mode and an output voltage reference value of a grid construction mode according to the operation parameters and the equipment parameters; calculating a synchronous decision signal, and switching the working mode of the inverter; calculating a parallel system bus voltage reference value and an output current reference value of the current sampling period; and constructing an inner-layer model, calculating a predicted value and a reference value of voltage and current in a next sampling period, constructing a value function cost optimization model according to a deviation degree between the predicted value and the reference value, generating an optimal switching state, and controlling the power distribution network area inverter. Dynamic response and stability are both considered, seamless switching of the voltage source type inverter is achieved, meanwhile, voltage out-of-limit is avoided, and the stability of a power system is improved.
Owner:STATE GRID JIBEI ELECTRIC POWER CO LTD TANGSHAN POWER SUPPLY CO +2

Image sensors having high dynamic range pixels

An image sensor may include an array of imaging pixels arranged in rows and columns. Each imaging pixel may include a photodiode, an overflow capacitor, an overflow transistor that is interposed between the photodiode and the overflow capacitor, a floating diffusion region, a transfer transistor that is interposed between the photodiode and the floating diffusion region, a voltage supply, and a reset transistor that is interposed between the floating diffusion region and the voltage supply. The voltage supply may provide a voltage at a first magnitude that is less than the pinning voltage for a first portion of a reset period and may provide the voltage at a second magnitude that is greater than the pinning voltage for a second portion of the reset period.
Owner:SEMICON COMPONENTS IND LLC

IDC power utilization guarantee method and system

The invention provides an IDC power utilization guarantee method and system, and relates to the technical field of electric power systems.A lithium battery energy storage system is built into an independent voltage source to be connected with a target power grid in parallel, and power utilization strategy analysis is conducted on IDC load requirements, electricity price information of the target power grid and characteristic information of the lithium battery energy storage system; and analyzing the power grid operation data set, the IDC load data set and the energy storage system operation data set based on the IDC power utilization strategy to obtain IDC power utilization strategy parameters to carry out IDC power utilization guarantee monitoring, and carrying out dynamic feedback adjustment. The technical problems that in the prior art, an electricity utilization strategy is not flexible, and real-time monitoring and dynamic adjustment are lacked, so that IDC electricity utilization guarantee efficiency is low, and safety is low are solved. The technical effect of double guarantee of power utilization efficiency optimization and power supply safety of the data center is achieved.
Owner:JIANGXI XINGNENG ENERGY STORAGE TECH CO LTD