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1489 results about "Grid voltage" patented technology

Grid voltage. [′grid ‚vōl·tij] (electronics) The voltage between a grid and the cathode of an electron tube.

Fault ride-through hierarchical control method for network construction type converter

The invention discloses a fault ride-through hierarchical control method for a network-constructed converter, and the method comprises the steps: introducing a virtual resistor formed by fault current negative feedback into the voltage and current inner loop control of the network-constructed converter based on VSG control through a current inner loop dynamic amplitude limiting control layer after the converter enters a fault ride-through state, the size of the virtual resistor is adjusted in real time along with the amplitude of the fault current so as to carry out dynamic current limiting control on the virtual resistor; and the power outer loop dynamic compensation control layer dynamically adjusts an active power instruction value and a reactive power instruction value of the network construction type converter based on VSG control during the fault ride-through period according to the voltage drop degree of the power grid after the converter enters the fault ride-through state. And respectively performing active-frequency control and reactive-voltage control based on the active power instruction value and the reactive power instruction value. In addition, the method also comprises a state coupling and parameter self-adaption module. According to the method, the GFM converter can have better dynamic performance in the fault recovery stage.
Owner:WUHAN UNIV OF TECH +2

Split direct current charging multi-split group charging and group control system

The invention provides a split type direct current charging multi-split group charging and group control control system, and belongs to the technical field of split type direct current charging piles. The split type direct current charging system comprising a main control cabinet, a power distribution unit, a charging pile terminal and other hardware architectures is constructed; a voltage monitoring unit, a current sensor module, a harmonic filter and other multi-dimensional sensor networks are integrated to acquire power grid state data in real time, and a sliding time window method is used to carry out segmented analysis on the data to extract power grid characteristic parameters; establishing a multi-objective optimization model comprising a power balance equation and a power grid stability equation to calculate an optimal power distribution matrix, adopting a neural network to realize intelligent distribution and dynamic balance adjustment of the power of each charging pile terminal, and starting an emergency power redistribution mechanism to ensure stable operation of the system when the power grid is detected to be abnormal. The technical problem of unbalanced power distribution of the multi-pile charging system caused by power grid voltage fluctuation and harmonic pollution is solved.
Owner:QINGDAO HIGH TECH COMM

Dynamic power regulation and control method and system for electric vehicle charging pile

The invention relates to a dynamic power regulation and control method and system for an electric vehicle charging pile, and the method comprises the following steps: S1, based on the real-time operation data of a charging pile cluster, employing a multi-source information fusion technology, collecting a power grid voltage fluctuation signal through a Hall sensor disposed at a charging pile end, and combining with the battery charge state data transmitted by a vehicle-mounted BMS, and eliminating noise interference by using an improved Kalman filtering algorithm, and realizing multi-dimensional data fusion by using a D-S evidence theory to generate a multi-source working condition feature set. The method has the advantages that the power grid voltage fluctuation signal and the battery charge state data are integrated through the multi-source information fusion technology, the improved Kalman filtering algorithm is adopted to eliminate noise interference, multi-dimensional data fusion is achieved in combination with the D-S evidence theory, the integrity and reliability of working condition feature extraction are remarkably improved, and the working condition feature extraction efficiency is improved. And the LSTM-ARIMA hybrid prediction model is utilized to synchronously process the nonlinear features and the periodic rules.
Owner:DONGGUAN KUANNENG NEW ENERGY TECHNOLOGY CO LTD

Intelligent distributed energy storage cluster collaborative management system

The invention relates to the technical field of distributed energy storage and intelligent power grid control, in particular to an intelligent distributed energy storage cluster collaborative management system. Comprising a state acquisition module used for acquiring local power grid state parameters of an edge computing node in real time; the power grid state parameters comprise power grid frequency, power grid voltage and a heartbeat communication state with the cloud management platform; the risk calculation module is used for calculating quantified island risk indexes; the mode judgment module is used for determining a current operation mode decision; the mode switching module is used for switching the system from a vertical cooperative mode to a horizontal autonomous mode when the island risk index is greater than an island switching threshold value; and when the island risk index is smaller than or equal to the island switching threshold value, the system is maintained to operate in the vertical cooperation mode. According to the system, misjudgment and missed judgment of a traditional single threshold value mode are overcome, it is ensured that the mode switching module can be switched to the horizontal autonomous mode from the vertical cooperative mode in time under the real risk, and decision making is accurate and reliable.
Owner:SHAANXI XINGZHENGWEI NEW ENERGY TECH CO LTD

Accurate zero crossing point control method for built-in relay of large-current electric energy meter

The invention discloses an accurate zero crossing point control method for a built-in relay of a large-current electric energy meter, which relates to the technical field of power electronics and intelligent metering and comprises the following steps of: receiving a power grid voltage digital signal, determining a voltage zero crossing point by comparing symbol changes of adjacent sampling values, establishing a phase corresponding relation between voltage and current, and calculating a current phase corresponding relation; generating current zero crossing point prediction data; when a relay switching instruction is received, the specific moment of the next current zero crossing point is calculated, and the control signal sending moment is determined; a relay driving control signal is sent, the actual action completion moment of the relay is collected, the deviation from the expected zero crossing moment is calculated, and the mechanical action delay time parameter of the relay is corrected. By predicting the current zero-crossing time and considering the mechanical action delay characteristic of the relay, accurate switching of the built-in relay at the actual current zero-crossing point is achieved, meanwhile, the self-adaptive adjusting capacity is achieved, the arc energy during large-current switching is reduced, the service life of the relay is prolonged, and the reliability of the electric energy meter is improved.
Owner:GUIZHOU POWER GRID CO LTD

Improved energy storage converter network following control algorithm

The invention relates to the technical field of energy storage cooperative control, and discloses an improved energy storage converter grid following control algorithm, which comprises the following steps of: 1, extracting positive sequence and negative sequence components of three-phase voltage of a power grid through a double-sequence decoupling phase-locked loop, and acquiring a positive sequence axis component signal by adopting forward rotation coordinate transformation; and 2, when frequency locking is carried out based on the positive sequence axis component signal, extracting a voltage amplitude corresponding to the positive sequence axis component signal, and inputting the voltage amplitude to a feed-forward passivation module. An active power regulation technical scheme based on a frequency deviation threshold value is adopted, the technical effect of simulating the primary frequency modulation characteristic of a network-forming converter is achieved by detecting the power grid frequency deviation in real time and generating an active power compensation signal, and the defect that traditional network-following control lacks frequency active supporting capacity is overcome. And the converter can spontaneously increase the active power to stabilize the power grid frequency when the power grid frequency drops.
Owner:BEIJING HYPERSTRONG TECH CO LTD

Fault ride-through test method of offshore wind power flexible direct output system

The invention discloses a fault ride-through test method for an offshore wind power flexible direct output system, and the method comprises the steps: building a fault equivalent circuit of the offshore wind power flexible direct output system, analyzing the operation characteristics of an AC power grid side under a low-voltage fault, and determining the incidence relation between the DC side excess energy and the power grid voltage drop; establishing a model representing each component in the fault equivalent circuit, wherein the components at least comprise a machine-side converter, a grid-side converter, a direct-current capacitor and an unloading resistor; when a low-voltage fault of an alternating-current power grid side is detected, executing the following cooperative control based on the model: synchronously starting unloading resistance control and reactive power support control, wherein an unloading resistor dissipates excess energy of a direct-current side through a direct-current chopper; the grid-side converter injects a capacitive reactive current which is deeply matched with the voltage drop of the power grid so as to improve the voltage of a grid-connected point; and if the direct-current voltage continuously exceeds the preset threshold value, starting power prompt drop control, and reducing the output power of the unit according to a gradient until the system recovers to be stable.
Owner:STATE GRID FUJIAN ELECTRIC POWER RES INST +2

Phase modifier unit state monitoring and load control method and system for reactive power compensation of power grid

The invention discloses a phase modifier unit state monitoring and load control method and system for reactive power compensation of a power grid, belongs to the technical field of automatic control of power systems, and mainly solves the problem that service life loss is aggravated or a control target is single due to the fact that the health state of equipment is not fully considered when an existing phase modifier unit responds to reactive power requirements of the power grid. The method comprises the following steps of: calculating reactive vacancy and extracting vibration frequency band energy characteristics by acquiring voltage and frequency of a power grid as well as vibration, temperature and exciting current signals of a unit in real time, and constructing a health state index HSI in combination with self-adaptive wavelet basis selection; taking minimum equipment life loss and optimal power grid voltage stability as multiple objectives, dynamically generating a load control instruction by adopting a particle swarm algorithm, realizing weight adaptive adjustment based on HSI, and introducing an online life loss model as a constraint condition; finally, reactive power output is adjusted through an excitation system, and cooperative control of power grid stability and equipment life extension is achieved.
Owner:GUONENG LIAONING NEW ENERGY DEVELOPMENT CO LTD

Transformer on-load voltage regulation control method

The invention relates to the technical field of on-load voltage regulation, in particular to a transformer on-load voltage regulation control method. According to the technical scheme, the transformer on-load voltage regulation control method comprises the following steps that S1, a transformer cluster running in parallel is decomposed into distributed intelligent nodes, and each node executes local voltage prediction and constraint condition management; s2, adopting a distributed model prediction control framework, and cooperatively solving a voltage regulation optimization target through an edge calculation unit; s3, a harmonic disturbance signal with a preset amplitude is injected into the transformer, equivalent impedance is dynamically identified based on response data, and virtual impedance compensation is triggered; and S4, establishing a hierarchical cooperative control architecture, and realizing clock synchronization, dynamic weight distribution and multi-objective optimization decision among nodes. Through a cooperative mechanism of distributed predictive control and dynamic impedance compensation, the response speed and the regulation precision of the on-load voltage regulation system to the power grid voltage fluctuation are remarkably improved, and the voltage out-of-limit problem under the complex working conditions of new energy grid connection, load sudden change and the like is effectively solved.
Owner:STATE GRID HEBEI ELECTRIC POWER CO LTD +1

Power decoupling method for cooperative control of voltage feed-forward compensation and adaptive virtual impedance

The invention relates to the technical field of new energy power system control, and relates to a power decoupling method for cooperative control of voltage feed-forward compensation and adaptive virtual impedance. The method comprises the following steps: acquiring a power grid current and a power grid voltage, and calculating a reactive power measured value and an active power measured value of a power grid; virtual synchronous machine control is carried out, and a voltage feed-forward pre-compensation item is introduced into a reactive power control loop; calculating a reactive power control loop after VSG compensation, and obtaining VSG output side voltage and instantaneous angular frequency; self-adaptive virtual impedance control is adopted, a self-adaptive virtual impedance reference value is calculated, line impedance is dynamically adjusted, and a voltage loop input instruction voltage is calculated according to the line impedance; and adjusting the output performance of the inverter according to the instruction voltage. According to the invention, the problem of power fluctuation caused by VSG output voltage amplitude variation is effectively solved, and the dynamic influence of a power coupling item is weakened.
Owner:SHANDONG UNIV

Three-phase four-wire inverter control method, controller and inversion control system

The invention belongs to the technical field of power electronics of power supply or power distribution, and provides a control method of a three-phase four-wire inverter, a controller and an inversion control system. A first control component is generated by using a phase angle, an inversion side three-phase current sampling value and a proportional integral compensator; a second control component and a third control component are generated by using a power grid voltage angular frequency, a neutral line current sampling value, a repetitive controller and a proportional resonance controller, the three control components are combined to control an inverter power switch tube, a proportional integral compensator is still adopted, the algorithm is simple, parameters are easy to design, and the reliability is high. And meanwhile, a repetitive-proportional resonance (RC-PR) composite controller is utilized to realize suppression of neutral line fundamental wave and harmonic current, and the method has faster dynamic response to load abrupt change, so that optimization of dynamic performance and steady-state performance is realized.
Owner:SHANGHAI ZHUOYANG ENERGY STORAGE TECH CO LTD

Low-voltage ride-through control method based on reactive power synchronous networking type grid-connected converter

The invention provides a low-voltage ride-through control method for a grid-forming type grid-connected converter based on reactive power synchronization, and belongs to the technical field of converter low-voltage ride-through control. When the voltage of a power grid drops, a current amplitude limiting module in the power grid sends a control switching signal to trigger low-voltage ride-through control, and the low-voltage ride-through control is switched to a reactive power synchronization mode; a reactive power synchronous control gain KQs is calculated according to an inner loop gain coefficient Kcp, a current amplitude limiting value, a power grid voltage Vg and a grid side inductance Lgi, a virtual power angle reference value is generated by combining a set reactive power direct current component reference value QN, so that a power angle delta is stabilized in a range close to a normal working point, and a control effect is verified by comparing with a traditional method. According to the method, the system can quickly recover to a normal working state regardless of the duration of the fault and the severity of the fault, meanwhile, the system can effectively work under different power grid fault levels, and the robustness of the system is further enhanced.
Owner:STATE GRID JIBEI ELECTRIC POWER COMPANY

Dynamic virtual resistance control-based fault ride-through method and system for network construction type converter

The invention relates to the technical field of network construction type converter control, in particular to a network construction type converter fault ride-through method and system based on dynamic virtual resistance control, and the method comprises the steps: adding a control link based on virtual impedance in a network construction type converter control system; detecting the actual value of the power grid voltage, and judging whether the power grid voltage drops or not; detecting the current amplitude output by the grid-forming converter in real time, and judging whether the current amplitude exceeds a set value or not; if one of the two conditions is met, a virtual impedance control link is started: stage-type current limiting control is performed on the virtual resistor, and the size of the virtual resistor provided by the network-forming converter to the power system is adjusted in real time along with the amplitude of the fault current; and when the power grid voltage recovers and the current amplitude is smaller than the set value, the virtual resistor staged current-limiting control exits. According to the invention, the amplitude limiting of the fault current in the fault ride-through of the network-constructed converter can be realized, so that the fault ride-through capability and transient stability of the network-constructed converter are improved.
Owner:STATE GRID JIANGSU ELECTRIC POWER CO LTD +3

Energy feedback high-power-factor air conditioner compressor driving system

The invention belongs to the technical field of power electronics, and relates to an energy feedback high-power-factor air conditioner compressor driving system. Comprising a direct-current bus, a direct-current bus electrolytic capacitor, a motor driving circuit, a shutdown energy feedback circuit, a permanent magnet synchronous motor and a motor control module, wherein the two ends of the direct-current bus electrolytic capacitor are connected with the positive electrode and the negative electrode of the direct-current bus respectively; in the energy feedback control module for driving the combined switch device in the shutdown energy feedback circuit, the motor driving circuit and the shutdown energy feedback circuit, the second connecting end I of each phase of bridge arm is connected with the positive electrode of the direct-current bus, and the second connecting end II of each phase of bridge arm is connected with the negative electrode of the direct-current bus; the first connecting end of the phase bridge arm of the shutdown energy feedback circuit is connected with the phase power grid voltage through the phase filter inductor. The method can maintain the stability of the DC bus voltage, and reduces the influence of the power grid voltage fluctuation and the air conditioner compressor load fluctuation.
Owner:QINGDAO HISENSE NETWORK ENERGY CO LTD +1

Industrial power grid voltage fluctuation suppression method and system

The invention relates to the technical field of electric energy quality management of an electric power system, and discloses an industrial power grid voltage fluctuation suppression method and system, and the method comprises the steps: firstly building a system-level voltage and current forward transmission model composed of a power unit, a filter circuit and power grid impedance which are cascaded; reversely constructing a feedforward controller based on a voltage and current forward transfer model, and generating a main compensation voltage instruction according to the power grid disturbance quantity detected in real time; state parameters of each power unit are obtained, a differential equation is constructed, and a comprehensive real-time health degree index is obtained through fuzzy reasoning; dynamically correcting an equivalent impedance parameter in the forward transfer model by using the index, and calculating a voltage distribution weight of each unit; and decomposing the total compensation voltage instruction into each unit modulation signal according to the weight. Through systematic modeling, intelligent state evaluation and dynamic fault-tolerant distribution, high-speed, accurate and high-reliability suppression of the voltage fluctuation of the industrial power grid is realized.
Owner:NANJING COLLEGE OF INFORMATION TECH +5

Intelligent peak regulation method with optimized combination of energy storage and conventional peak regulation means

The invention discloses an intelligent peak regulation method with optimized combination of energy storage and conventional peak regulation means, and the method comprises the following steps: building a holographic situation awareness layer: capturing the voltage, current phase angle and frequency deviation of a power grid, and monitoring the pressure fluctuation in a diesel engine cylinder; data transmission and preprocessing: encrypting data of the miniature phasor measurement unit and the quantum sensor by using a quantum key distribution technology; the self-adaptive decision engine is used for performing Nash equilibrium calculation by utilizing a federal reinforcement learning architecture, through a local Agent based on a power generation / energy storage unit state autonomous optimization control strategy and in combination with a digital twin platform, solving multi-target conflicts of economy, reliability and carbon emission, and generating a global optimal scheduling instruction; the execution control layer is used for tracking resonance points and dispersing harmonic energy spectrums; dynamic topology reconstruction: a harmonic source is positioned by using a digital twin platform, and the topology of the energy storage system is automatically switched according to the harmonic frequency and position; continuously optimizing the digital twin platform; and full-process closed-loop feedback and self-learning are carried out.
Owner:STATE GRID GANSU ELECTRIC POWER CORP +1

Self-adaptive filtering method and system for intelligent electric energy meter

The invention discloses a self-adaptive filtering method and system for an intelligent electric energy meter, and relates to the technical field of power grid signal processing, and the method comprises the steps: obtaining a power grid voltage and current signal set collected by a target intelligent electric energy meter historically, and obtaining a signal noise spectrum data set and a noise level evaluation result through spectrum analysis and noise level evaluation; if the result exceeds a preset noise threshold value, identifying an interference type and building a noise adaptive filtering multi-channel, integrating and deploying the noise adaptive filtering multi-channel into a target intelligent electric meter to complete signal filtering test and effect evaluation, and dynamically optimizing and generating an electric energy meter adaptive filtering multi-channel based on the obtained multi-channel filtering effect index parameter; and finally, signal filtering closed-loop control is realized. The technical problem that a traditional electric energy meter is weak in filtering pertinence and cannot adapt to dynamic noise of a power grid in electric power related scenes with complex dynamic interference is solved, and the technical effects that the electric variable measurement accuracy of the electric energy meter is improved, and the adaptive capacity of the electric energy meter to different interference scenes is enhanced are achieved.
Owner:NANJING SIYU ELECTRIC TECH CO LTD

Multi-parameter photovoltaic grid-connected voltage stability control method, system, equipment and medium

The invention relates to the technical field of voltage sensitivity photovoltaic stability regulation and control of a power distribution network, in particular to a multi-parameter photovoltaic grid-connected voltage stability control method, system equipment and a medium, and aims to improve the transient modeling precision by constructing a second-order equivalent transient model of a photovoltaic system and decoupling a mapping relation between phase-locked loop parameters and equivalent inertia and damping; quantifying a transient stability boundary under voltage disturbance based on a phase-locked loop sensitive parameter, and determining a photovoltaic power angle critical safety threshold; for the whole voltage fluctuation process, dynamically and cooperatively regulating and controlling phase-locked loop parameters according to the voltage and frequency of the power grid; equivalent damping and inertia suppression oscillation are enhanced in the voltage drop period, inertia acceleration recovery is reduced while high damping is maintained in the voltage recovery period, rated parameters are reset in the steady state, the transient stability of the system for coping with voltage sag is remarkably improved, and the risk of power angle instability is avoided.
Owner:GUIZHOU POWER GRID CO LTD +1

High-linearity grid voltage bootstrap circuit

A high-linearity grid voltage bootstrap circuit relates to the technical field of analog-to-digital conversion and comprises a first charge pump boosting unit, a second charge pump boosting unit and a grid voltage bootstrap unit, working states of a sampling switch are divided into a sampling state and a holding state, an input voltage VIN is boosted to a VG through the grid voltage bootstrap unit in a sampling stage, and the sampling switch is switched on; and the holding stage sampling switch is cut off, and charges are injected to the upper polar plates of the capacitors C3 and C4 of the gate voltage bootstrap unit through the first charge pump boosting unit and the second charge pump boosting unit respectively. According to the invention, the problem that the actual gate-source voltage is reduced due to the grid parasitic capacitance of the sampling switch is solved, and the layout area occupation is greatly reduced while the bootstrap voltage is improved; the proportion of the capacitor C3 and the capacitor C4 can be flexibly set to obtain the required bootstrap voltage; and the problem that the on-resistance of the sampling switch is increased due to the reduction of the gate-source voltage can be solved, and the linearity of the sampling switch is improved.
Owner:CHENGDU SINO MICROELECTRONICS TECH CO LTD

Low-voltage ride-through control method for network construction type converter

The invention is suitable for the technical field of power electronics and power transmission, and provides a low voltage ride-through control method and system for a network construction type converter, and the method comprises the steps: carrying out the conventional VSG control according to a VSG control strategy, and continuously monitoring the difference between the voltage of a power grid and a set reference value, so as to judge whether a fault occurs or not; when it is detected that the power grid breaks down, homodyne control is carried out on an active power control ring and a reactive power control ring of the grid-forming type converter so as to fix the phase and the amplitude of the output voltage of the converter; calculating and injecting a positive sequence compensation voltage and a negative sequence compensation voltage according to the drop degree of the power grid voltage; and according to the predicted impact current value, dynamically calculating and inputting adaptive virtual impedance. The power angle and the voltage in the fault period can be ensured to be stable, transient overcurrent is effectively restrained, and large power fluctuation is not caused.
Owner:HUNAN UNIV OF TECH

Fault voltage ride-through optimization method and system for network construction type energy storage converter

The invention belongs to the technical field of new energy, and particularly relates to a fault voltage ride-through optimization method and system for a network construction type energy storage converter. Carrying out positive and negative sequence separation and Clark-Park coordinate transformation on the three-phase power grid voltage and the inversion current, calculating active power and reactive power of the network-forming type energy storage converter, and carrying out power loop control to obtain three-phase reference voltage and angular velocity; performing voltage loop control, and dynamically adjusting a positive sequence active current and a positive sequence reactive current according to whether a low-voltage-crossing indication signal exists or not; performing positive-sequence current loop control and negative-sequence current loop control, and then performing inverse Clark-park conversion to obtain positive-sequence three-phase reference voltage and negative-sequence three-phase reference voltage; and superposing the positive-sequence three-phase reference voltage and the negative-sequence three-phase reference voltage for PWM (Pulse Width Modulation). According to the invention, when the power grid voltage is unbalanced due to a fault, the oscillation of the direct current side voltage and power caused by the negative sequence component is eliminated, and the power angle stability is improved and the fault current is suppressed by dynamically adjusting the related reference value during the fault voltage ride-through period.
Owner:HKUST DIGITAL (SHANGHAI) ENERGY TECH CO LTD

VSG transient stability control method based on PSS power angle compensation and integral reactive loop cooperation

The invention discloses a VSG transient stability control method based on PSS power angle compensation and integral reactive loop cooperation, and the method comprises the steps: constructing an improved rotor motion equation compensation mechanism based on a power system stabilizer, and based on the dynamic parameters of the voltages vabc and pcc at a PCC point and the currents iabc and pcc flowing into the PCC point which are collected in real time, carrying out the compensation of the current iabc and pcc at the PCC point under the condition that the working condition is that the voltage of a power grid drops greatly. The dynamic characteristic of active power is ensured; constructing a PSS parameter optimization method based on zero point position constraint; an integral link is embedded in the traditional voltage-reactive droop characteristic, integral reactive loop control is constructed, and steady-state voltage deviation is eliminated; the output compensation power angle delta and the output voltage amplitude E are cooperatively applied and converted into dq-axis voltage components Ed and Eq, the dq-axis voltage components Ed and Eq are sent to a voltage and current double closed loop, a driving signal is generated through SVPWM, and the stability of the system is enhanced.
Owner:NANJING NORMAL UNIVERSITY

VSG-based low-voltage ride-through hybrid control method for network construction type converter

The invention discloses a VSG-based low-voltage ride-through hybrid control method for a network-building converter. The method comprises the following steps: acquiring grid-connected point voltage and output current of a grid-forming converter in real time, and judging whether to enter a low-voltage ride-through state according to a grid voltage drop degree; in the initial stage of a fault, a current reference saturation mode is adopted to quickly limit the output current of the converter so as to prevent a power device from being damaged by overcurrent; in the fault duration stage, a dynamic self-adaptive virtual impedance and reactive power reference coordinated regulation mechanism is introduced, so that the converter gradually recovers the reactive power injection capability while limiting the fault current, thereby realizing effective support for the grid-connected point voltage; when the voltage of the power grid drops seriously, the capacity of the inverter can be reserved for the reactive power support by temporarily reducing the output of the active power. According to the method, the current protection and voltage support requirements during the fault period are considered, and the operation stability and the power grid adaptive capacity of the grid-forming converter in the low voltage ride-through process are improved.
Owner:HEBEI UNIV OF TECH

Droop control inverter current limiting control method and system

The present application belongs to the grid-connected converter technical field, disclose a kind of droop control inverter current-limiting control method and system, the virtual impedance size and active reference value restriction condition when the fault current is equal to current-limiting value are accurately obtained by phasor analysis, virtual impedance-current difference proportional coefficient and active reference value-current difference proportional coefficient are designed considering the most serious situation of current-limiting, proportional increase virtual impedance and reduce active reference value with the change of adaptive current at fault, can meet the current-limiting requirement under different depth grid voltage drop.The current-limiting control method proposed in the present application is adaptive to fault current, without fault detection device, the transient stability of inverter is enhanced due to the reduction of active reference value at fault, and the fault current is indirectly limited by adjusting virtual impedance and active reference value, the voltage source characteristics of droop control inverter are retained, and the system fault ride-through capability is significantly enhanced.
Owner:HUAZHONG UNIV OF SCI & TECH

Cooperative control method and equipment for virtual power plant to participate in voltage safety of power distribution network

The invention provides a cooperative control method and device for a virtual power plant to participate in voltage safety of a power distribution network, and the method comprises the steps: collecting multi-source heterogeneous data, and carrying out the preprocessing of the data, and constructing a key feature set; inputting the key feature set into a trained artificial intelligence prediction model to output a dynamic prediction value; inputting the dynamic predicted value, the real-time operation data of the power distribution network and the available regulation capacity of the virtual power plant into a trained machine learning evaluation model, obtaining the voltage out-of-limit risk probability of each node of the power distribution network, and dividing the voltage safety risk level according to the probability; constructing a comprehensive cost index based on the grade, and solving to generate a cooperative control instruction set by using a reinforcement learning algorithm under the condition that constraints are met; and acquiring an actual operation response after the instruction is executed, and adjusting internal parameters of the model based on a deviation between the actual operation response and an expected target. Based on the method, the invention further provides cooperative control equipment. According to the invention, closed-loop management from data-driven prediction and intelligent risk assessment to collaborative optimization control is realized.
Owner:STATE GRID SHANDONG ELECTRIC POWER CO

Efficient rectification conversion system and control method thereof

The invention relates to the technical field of power electronic conversion, and discloses a high-efficiency rectification conversion system and a control method thereof, and the system comprises the following modules: a detection module, an input compatible module, a hybrid power device module, a control module, a thermal management module and a frequency modulation module. The control method comprises the following steps: acquiring input power grid voltage, output current and load state parameters; calculating an input voltage phase difference; dynamically selecting the type and channel configuration of the silicon carbide or gallium nitride power device according to the load rate; outputting a device configuration instruction and a switching frequency control instruction; adjusting the cooling system through the evaluated thermal state of the conversion system; and the control module receives the control instruction output by the control module and is used for implementing a corresponding pulse width modulation strategy. According to the method, a multi-system power grid identification and self-adaptive topology switching strategy is adopted, the technical effect of automatically configuring the optimal rectification architecture under different input types is achieved, and the problems of response delay and poor compatibility of the method in the environment of variable power grid types are solved.
Owner:SHENZHEN WEFT FIGURE HONGDA IND CO LTD

Island micro-grid voltage frequency control method and system based on deep reinforcement learning

The invention discloses an island micro-grid voltage frequency control method and system based on deep reinforcement learning, and the method comprises the steps: S1, building a mathematical model of a distributed power supply grid-connected inverter in an island micro-grid, employing droop control as an inverter control strategy, and building a voltage and current double-closed-loop model based on droop control; s2, designing a secondary voltage controller based on a deep Q network algorithm based on the mathematical model established in S1; s3, designing a secondary frequency controller based on a DQN algorithm based on the mathematical model established in S1 and the secondary voltage controller in S2; and S4, establishing an island micro-grid model containing multi-distributed power supply access, and embedding the voltage controller and the frequency controller trained in the S2 and the S3 into the island micro-grid for online application so as to realize voltage and frequency control of the island micro-grid. The method has the advantages of eliminating voltage and frequency deviation and the like.
Owner:STATE GRID HUNAN ELECTRIC POWER CO LTD ELECTRIC POWER SCI RES INST +2

Phase modifier energy storage excitation control method, system and controller

The invention provides a phase modifier energy storage excitation control method and system and a controller. The method comprises the following steps: acquiring original phase modifier parameters, original power grid parameters and original energy storage system parameters; generating a power grid operation state according to the original phase modifier parameters, the original power grid parameters and the original energy storage system parameters; adjusting the energy storage system and the flexible excitation power unit according to the power grid operation state and a cooperative control strategy, and obtaining the adjusted current phase modifier parameters and the adjusted current power grid parameters; damping control is carried out according to current phase modifier parameters and current power grid parameters through preset double damping channels, data can be monitored and analyzed in real time, a cooperative control strategy is adopted, an energy storage system is effectively utilized to improve the transient stability of the phase modifier, and the effect of suppressing subsynchronous oscillation is enhanced through cooperative control of the double damping channels. Therefore, the dynamic stability of the grid voltage is improved.
Owner:ELECTRIC POWER RESEARCH INSTITUTE OF STATE GRID JIBEI ELECTRIC POWER CO LTD +2

Energy storage EMS cooperative control method and system based on fault ride-through and dynamic reconstruction

The invention discloses an energy storage EMS cooperative control method and system based on fault ride-through and dynamic reconstruction, and relates to the technical field of monitoring analysis, and the method comprises the steps: collecting power grid operation state parameters and energy storage system core data, and the power grid operation state parameters comprise a power grid voltage deviation value; the power grid voltage deviation value is compared with a preset threshold value, when the power grid voltage deviation value exceeds the preset threshold value, a multi-energy cooperative power distribution strategy is started, power support is provided, in the power support process, the series-parallel topology of the energy storage system is dynamically reconstructed through the IGBT matrix switch group, and after dynamic reconstruction, the power support is provided for the energy storage system. The DC link voltage is adjusted through the H-bridge converter group; and in the fault recovery stage, monitoring the recovery condition of the operation state parameters of the power grid, and when the voltage deviation of the power grid is within a normal range, gradually reducing the power support strength, and switching to a conventional operation mode according to a preset sequence to realize the cooperative control of the energy storage EMS. The method has the effect of improving the cooperative control efficiency.
Owner:ZHONGHE DIGITAL ENERGY (JIANGSU) CO LTD

Automobile fastener production energy consumption optimization control method and system

The invention discloses an automobile fastener production energy consumption optimization control method and system, and relates to the technical field of fastener production, and the method comprises the following steps: obtaining a real-time current waveform signal and a power grid fundamental wave voltage signal of an inversion unit in an energy feedback link, building a phase dynamic drift model through a time difference analysis algorithm, and carrying out the calculation of the phase dynamic drift model; continuous mapping of energy flow direction change is formed on a time axis; and based on the established phase dynamic drift model, extracting an offset rate continuous change section between the current waveform and the power grid fundamental wave, constructing a phase trend prediction function by using a sliding window algorithm, and converting the time characteristic of the energy flow direction change into a phase prediction signal trajectory. Through phase dynamic drift modeling and lead compensation control, synchronization of feedback current and power grid voltage is realized, and ripple current and element stress are reduced; and through energy density change rate extraction and dynamic filtering regulation and control, the energy flow is stable and continuous, and efficient and energy-saving control over fastener production is achieved.
Owner:ZHEJIANG RUIQIANG AUTO PARTS CO LTD