72 results about "Power quality control" patented technology

The invention discloses a self-adaptive harmonic current suppression method for harmonic waves of a photovoltaic inverter, which belongs to the technical field of power quality control of a power system and comprises the following steps of: compensating a control strategy through a self-adaptive harmonic component of the photovoltaic inverter by adopting a'detection-reverse injection 'framework; the difference between the residual apparent capacity of the inverter after fundamental wave power supply and the borne harmonic power is used as an adaptive quantity, and the total harmonic distortion rate of the grid-connected point is reduced to the maximum extent on the premise of no overload; the method comprises the following steps: firstly, constructing a real-time harmonic detector based on a cascade generalized integrator; secondly, an inverter impedance model is established from the aspect of impedance stability, and a control parameter stability boundary is determined; then, a self-adaptive harmonic control strategy is introduced into the single-inverter grid-connected system, and a reasonable parameter setting method is provided on the basis of considering stability limitation; afterwards, a capacity-matched harmonic power distribution algorithm is provided for a multi-inverter parallel system, and the efficiency and operation stability of a photovoltaic grid-connected power generation system are improved.

The invention discloses an AC / DC power distribution network power quality control method and device, and the method comprises the steps: collecting power quality data in an AC / DC power distribution network, carrying out the feature analysis of the power quality data, and obtaining a current feature parameter and a voltage abnormality identifier; carrying out differential compression processing on the power quality data based on the current characteristic parameters and the voltage abnormity identification; transmitting the compressed data and feature information through a redundant channel comprising a main communication link and a standby communication link; and generating electric energy quality alarm information according to the transmitted data, and performing power grid operation decision control according to the information. According to the method, the electric energy quality data of the plurality of Internet of Things electric energy quality sensors in the AC / DC power distribution network are collected, and harmonic analysis is performed on the current waveform of the electric energy quality data, so that the accuracy and robustness of feature extraction are ensured; therefore, the requirements of the modern AC / DC hybrid power distribution network for high-precision, high-reliability and quick-response power quality control can be met.

The invention belongs to the technical field of electric energy quality control, and provides an energy storage type medium-voltage voltage sag and interruption treatment device and a control method thereof.The energy storage type medium-voltage voltage sag and interruption treatment device is arranged between a large power grid and a load in series and comprises a series converter PCS1, a parallel converter PCS2, an energy storage module, an injection type series transformer T1, a parallel transformer T2, a bypass static switch STS and a bypass relay KM1; wherein the injection type series transformer T1 is connected with a large power grid, and the parallel transformer T2 is connected with a load; the series converter PCS1 is connected with the injection type series transformer T1 through the bypass static switch STS and the bypass relay KM1, and compensation voltage is generated in real time through the injection type series transformer T1; the parallel converter PCS2 is respectively connected with the parallel transformer T2 and the common direct current busbar; and the energy storage module is arranged on the common direct current busbar between the series converter PCS1 and the parallel converter PCS2 in parallel.

The invention relates to the technical field of generator control, and discloses an intelligent vehicle-mounted high-power self-generating control method and system. The method comprises the following steps: acquiring operating parameters of a generator set, performing high-precision digital processing, realizing constant-rotating-speed control through cooperation of multiple controllers based on a rotating-speed fluctuation characteristic value, performing power factor correction through coordinate transformation and active rectification to obtain a direct-current bus voltage, performing precise voltage stabilization by adopting a multi-phase interleaving converter, and outputting the direct-current bus voltage. And finally, outputting a high-quality three-phase alternating-current power supply through space vector modulation and closed-loop feedback control. The technical problems in the prior art that the power supply quality control capability is insufficient, the intelligent level is low, the environmental adaptability is poor, the load adaptability is limited, and the maneuverability is limited are solved.

The invention discloses a harmonic suppression method and system based on feedforward control and virtual impedance, and belongs to the field of electric energy quality control, and the method comprises the steps: constructing a harmonic extraction model based on the cascading of double third-order generalized integrators, and obtaining a voltage harmonic component based on the harmonic extraction model and real-time power grid data; based on a preset power outer loop control strategy, a preset voltage and current double closed loop control strategy, a preset harmonic voltage feed-forward control strategy and the voltage harmonic component, constructing a network construction type charging pile control model, and obtaining an initial output current; obtaining each virtual impedance based on the initial output current, the harmonic extraction model and the voltage harmonic component; and obtaining a harmonic suppression model based on each virtual impedance and the network construction type charging pile control model, so as to obtain a harmonic suppression output current based on the harmonic suppression model and the real-time power grid data. According to the harmonic suppression method and system based on feedforward control and virtual impedance provided by the invention, grid-connected output current harmonics controlled by a network-forming type charging pile are effectively suppressed.

The invention discloses a dynamic voltage recovery and flicker suppression method based on light-storage cooperation, and relates to the technical field of power quality control of a power distribution network, and the method comprises the steps: obtaining a dynamic topological structure and a node impedance spectrum of the power distribution network in real time; calculating the vulnerability index of each node based on the data; generating a risk thermodynamic diagram according to the vulnerability index; proactive power scheduling is performed on the energy storage system based on a thermodynamic diagram, node impedance characteristics can be actively shaped and optimized in combination with impedance, the system comprises an intelligent monitoring unit, a central control platform, the energy storage system and a communication network, weak links of the system can be accurately recognized, the problems that a voltage disturbance propagation path is uncertain and the early warning adaptability is poor are solved, and the system reliability is improved. The perspectiveness and the accuracy of voltage disturbance suppression are improved, and the voltage stability and the power supply reliability of the power distribution network are enhanced.

The invention discloses an electric energy quality optimization method and system based on carrier modulation, and relates to the field of electric energy quality optimization, and the method comprises the steps: obtaining bridge arm information of a distributed energy storage type electric energy quality controller, and determining a carrier amplitude adjustment strategy; determining a target zero-sequence component needing to be injected through carrier characteristics based on the carrier amplitude adjustment strategy; according to the target zero-sequence component, performing superposition on the original modulation wave to generate a target modulation wave; adjusting the power of the power grid based on the target modulating wave, and carrying out dynamic compensation on the capacitance voltage deviation; the harmonic suppression capability is improved, and the power distribution dynamic response efficiency is enhanced, so that the optimization of the electric energy quality is realized, and the problem that the real-time performance and the reliability of the electric energy quality regulation are reduced due to the limitation of harmonic compensation and the lack of real-time dynamic response in the conventional pulse width modulation method is solved.

The invention discloses a power quality control method for a power distribution network. The method comprises the following steps: monitoring power quality parameters of a target node of the power distribution network in real time; analyzing and identifying the current power quality state based on the monitoring parameters; generating a compensation control instruction according to the state in combination with a preset control target or a dynamically adjusted control strategy; outputting the instruction to at least one electric energy quality adjusting device on the power distribution network; and triggering the device to execute the instruction, and performing dynamic compensation adjustment on the power quality parameters of the power distribution network. The method can realize effective management and control of the power quality of the power distribution network, and improves the power supply stability.

The invention provides a passive device parameter design method suitable for suppressing multi-mode broadband oscillation of a double-high power distribution network, and relates to the technical field of power distribution network electric energy quality treatment. According to the method, port impedance modeling is performed on the power distribution network, a node admittance matrix is established, and a key node for oscillation suppression is determined in combination with modal analysis; port admittance parameters of the passive device are equivalently injected into the node admittance matrix in parallel at the key node, iterative optimization is performed on the port admittance parameters by using a particle swarm algorithm, and a passive device parameter fitting result is obtained by taking a damping coefficient greater than or equal to zero point 2 and a resonance angular frequency satisfying an integral multiple of a 2-hundred product circumference rate as an optimization target; the resonance peak weakening effect is verified by constructing a frequency response model before and after the passive device is accessed. According to the method, systematized and collaborative suppression of multi-mode broadband oscillation is realized, and the stability of the double-high power distribution network is remarkably improved.

The invention provides an electric energy quality control method and system based on an energy storage system, relates to the technical field of electric energy quality control, and aims to identify collaborative disturbance attributes during voltage sag and three-phase imbalance through dynamic distortion information, perform scheduling amplitude limiting compensation on the collaborative disturbance attributes, and improve the control accuracy of the electric energy quality. Obtaining a layered amplitude limiting inflection point when the electric energy in the energy storage system is intelligently scheduled in the load-storage balance constraint region; carrying out fusion correction on the circulation out-of-limit deviation, generating a dynamic peak regulation criterion when the power grid carries out energy storage transfer adjustment in multiple time scales, and further determining a regulation and control guidance strategy during electric energy balance regulation and control in the energy storage system according to the dynamic peak regulation criterion; and performing tolerance adaptation control on the power quality of the power distribution network in the composite disturbance scene according to the hierarchical amplitude limiting inflection point and the regulation and control guidance strategy. According to the invention, tolerance adaptation control can be carried out on the power quality of the power distribution network in a composite disturbance scene, so that the power quality management and control efficiency under the participation of an energy storage system is improved.

The invention discloses a distribution network on-line ice melting reactive compensation method and system based on magnetic control switch grading compensation, and relates to the field of disaster prevention and reduction and electric energy quality control of an electric power system. The problems of reactive unbalance, voltage fluctuation and harmonic pollution in the ice melting process are solved. The core is that a Z-type grounding transformer zero-sequence ice melting topology and a magnetically controlled switch grading compensation topology are integrated, and line ice melting is realized by constructing a zero-sequence ice melting loop; a double-state control strategy of blocking-state high-damping standby and conducting-state inrush-current-free switching of a magnetically-controlled switch branch is designed, and integration of reactive compensation and harmonic filtering is achieved by combining resonance tuning; the number of compensation branch switching groups is dynamically adjusted by adopting split-phase independent nine-zone graph closed-loop hierarchical control. According to the invention, ice melting and reactive compensation co-topology operation is realized, the stability of a power grid is improved, the device loss and the operation and maintenance cost are reduced, the mobile ice melting requirement is met, and the engineering practicability is high.

The invention discloses an electric energy quality adjusting device and method, and relates to the technical field of power electronics and electric energy quality control, and the method comprises the following steps: connecting a three-level topological inverter of a series structure with a transformer, adjusting the amplitude and phase of an output voltage in real time, and achieving the voltage compensation and power flow adjustment between AC ports in a power supply system; and starting the three-level topological inverter with the parallel structure, detecting the load side current, and separating and extracting the reactive current component, the harmonic current component and the three-phase unbalanced current. According to the invention, through cooperative control of a series-parallel topological structure, integrated adjustment of multi-dimensional electric energy quality parameters such as voltage, reactive power, harmonic waves and imbalance is realized; an ARM + FPGA dual-core control architecture and an electronic bypass mechanism are adopted, so that the response speed and the operation stability of the system are remarkably improved; in combination with P + repetitive control and PI control strategies, the harmonic compensation precision and the bus voltage control capability are improved, and the method has good adaptivity and real-time performance.

The invention provides a medium-voltage chain type energy storage system topology and a control method thereof, and relates to the technical field of power system electric energy quality control and new energy grid connection. The method has a sag supporting function and can be used for a medium-voltage power distribution network. The medium-voltage chain type energy storage system topologically integrates a three-phase parallel side chain type STATCOM (static synchronous compensator), a three-phase series side chain type STATCOM and an energy storage device, and comprises a transformer secondary winding in triangular connection. The three-phase parallel side chained STATCOM adopts positive and negative sequence voltage and current double-loop control, the three-phase series side chained STATCOM adopts an interphase direct-current voltage equalizing strategy of zero-sequence component injection through an angle connection winding, and the chained STATCOMs on the two sides both adopt a network construction type control method. The parallel side chain type STATCOM, the series side chain type STATCOM, the energy storage device and the triangular connection secondary winding are integrated, and a network construction type control strategy is combined, so that the operation stability and the electric energy quality of the system in a medium-voltage scene are improved, and a grid-connected point sag support function and direct-current voltage balance control of the chain type device are realized.

The invention relates to the technical field of power quality monitoring and management, and discloses a power distribution network power quality control method and computer equipment. The method comprises the following steps: acquiring real-time operation data of a power distribution network and an original electric energy quality signal of a disturbance node, decomposing the signal and determining an optimal decomposition modal number by taking minimization of a total variance as a target; determining a key time sequence feature set based on the optimal decomposition mode number and a preset disturbance type label; reasoning by taking a disturbance node as a starting point in the topological structure of the power distribution network to obtain a disturbance propagation path, and determining a voltage change rate of each node; screening candidate measures based on the voltage change rate, the feature set and a threshold value, and constructing a judgment matrix in combination with a preset evaluation index; determining a priority weight based on the judgment matrix so as to determine an optimal governance device; and determining dynamic output parameters according to the index measured values, the reference values and the real-time data, and controlling the optimal treatment equipment to operate according to the dynamic output parameters. The accuracy of controlling the power quality disturbance of the power distribution network can be improved.

This invention discloses a method for suppressing DC bus voltage fluctuations in a renewable energy hydrogen production system, relating to the field of renewable energy electrolysis hydrogen production technology. The method includes: real-time acquisition of system operating parameters; estimation of bus voltage disturbance power based on a disturbance observer and frequency decomposition; prediction of load power using ARIMA and LSTM models and calculation of prediction deviation; dynamic setting of upper and lower limits of the bus voltage control range based on the prediction deviation and operating status; construction of a multi-objective optimization function, comprehensively considering bus voltage disturbance power, prediction deviation, and control limits, to solve for the power regulation commands of battery storage, fuel cells, and electrolyzers; and execution of power regulation control to achieve bus voltage stability. This invention can improve the graded response capability to voltage disturbances, the accuracy of load power change prediction, the adaptability of control boundaries, and the overall operational stability of the system, and is suitable for power quality control of hydrogen production systems under multi-source fluctuation scenarios.

The invention discloses an MAS-based power quality controller cooperative control method and system, and belongs to the technical field of power quality controller cooperative control. Intelligent agents are introduced into a power distribution network, each equipment node in the power distribution network is detected and analyzed by the intelligent agents, and corresponding tasks are allocated to the corresponding intelligent agents according to analysis results; therefore, cooperative control is carried out on the series-side converter and the parallel-side converter of the electric energy quality controller, the series-side converter helps the parallel-side converter to carry out auxiliary compensation, resources of the series-side converter are fully utilized, the task pressure of reactive compensation and harmonic suppression of the parallel-side converter is relieved, and the service life of the electric energy quality controller is prolonged. And the working efficiency of the electric energy quality controller is also improved.

The application discloses an active power filter control method for preventing resonance, and relates to the technical field of power quality control.The method injects a harmonic current with a frequency of a pre-judged harmonic frequency into a power supply circuit, compares the change in the grid-side current and the load-side current before and after the injection, obtains a sensitive frequency point, separates the harmonic component corresponding to the sensitive frequency point from the harmonic components corresponding to other frequencies, and respectively generates compensation currents, wherein the harmonic component corresponding to the sensitive frequency point is adjusted through a feedback coefficient, different compensation currents are superimposed to obtain a comprehensive compensation current, the comprehensive compensation current is used to offset the load harmonic current, and the grid-side current is ensured to be undistorted.The technical scheme in the application can realize harmonic impedance adjustment, effectively prevent harmonic amplification, avoid passive element burning or power supply failure, and enhance the safety and reliability of power supply.

This invention discloses a method for improving the transient characteristics of wind turbines based on wind-storage integration. Aiming to improve the grid adaptability and power quality of wind turbines, this invention adopts the following scheme: when the grid connection point voltage of the wind turbine is detected to be in a low-voltage ride-through state, the wind-storage integration system switches to low-voltage ride-through mode; when the grid connection point voltage of the wind turbine is detected to be in a high-voltage ride-through state, the wind-storage integration system switches to high-voltage ride-through mode; when there is no trigger signal, the wind-storage integration system is in power quality mode. The advantage is that it integrates the fault ride-through control algorithms and power quality control algorithms of energy storage and wind turbines based on the wind-storage integration hardware topology, achieving unified coordination of the wind-storage integration control system and improving the transient characteristics of the wind turbine.

The invention relates to a power quality control circuit, a power quality control method, computer equipment, a computer readable storage medium and a computer program product. The electric energy quality control circuit comprises a parallel side converter circuit used for generating a compensation current used for suppressing a harmonic current in a power grid load current based on a first low-frequency large-capacity inverter and a high-frequency small-capacity inverter, and inputting the compensation current into a unidirectional transformer circuit; the series side converter circuit is used for generating compensation voltage for stabilizing load voltage in the power grid based on a second low-frequency high-capacity inverter and inputting the compensation voltage into the one-way transformer circuit; and the unidirectional transformer circuit is used for inputting the compensation current and the compensation voltage into the power grid. By adopting the electric energy quality control circuit, the operation efficiency of the electric energy quality control device can be improved under the condition that the cost of the electric energy quality control device is not obviously increased.

The invention relates to the technical field of power system automation and electric energy quality control, in particular to an electric energy quality optimization control method and system based on distributed collaborative decision. The method comprises the following steps: deploying synchronous phasor measurement units and corresponding edge intelligent decision nodes at a plurality of nodes of a power grid, and constructing a distributed network; each node calculates an electric energy quality characteristic index based on local data; dynamic role negotiation is carried out through local communication, and a leading controller is determined; the dominant controller fuses strategies and confidence information of local and adjacent nodes to generate a cooperative control strategy; and finally, equipment such as a static var generator and an active power filter is controlled to perform coordinated execution. Through a decentralized collaborative decision-making mechanism, the defects that centralized control is slow in response and low in reliability are overcome, rapid self-adaptive treatment on voltage sag, harmonic waves and other problems is achieved, and the response speed, the treatment success rate and the system robustness are remarkably improved.

The application discloses a power quality control method and device based on disturbance classification, equipment and medium. Among them, the method comprises the following steps: obtaining the original three-phase voltage data of the transformer, and performing a preprocessing operation on the original three-phase voltage data to obtain preprocessed three-phase voltage data; the voltage disturbance feature is extracted from the preprocessed three-phase voltage data; based on the voltage disturbance feature, the abnormality detection is carried out, and the voltage disturbance classification result is determined through the abnormality detection result and the voltage disturbance feature; the target device control strategy is determined based on the voltage disturbance classification result, so as to control the power quality through the target device control strategy. The technical scheme can determine the target device control strategy according to the analysis of the voltage disturbance feature, realize the accurate control of the power quality problem, and improve the accuracy of the power quality management.

The invention relates to the technical field of new energy storage and micro-grid control, and discloses an energy storage device and method for an offshore wind-light-fish complementary system, and the device comprises a battery module, a power conversion system, an energy management system, a temperature control system, and a high-voltage box. The battery module is arranged in the middle and has a sealed liquid cooling structure, the power conversion system is used for electric energy conversion, and the energy management system is used for cooperatively scheduling charging and discharging based on wind-light-fish multi-source data; a heat preservation, dehumidification and explosion-proof mechanism is integrated in the device, and a temperature control system is accurately adjusted through a closed loop; the method includes multi-energy scheduling, thermal management, power quality control and black start. Through dew point control dehumidification and directional jet cooling, the problem of large temperature difference between offshore high-humidity condensation and the battery is effectively solved; and the harmonic elimination algorithm is combined to optimize modulation, so that the electric energy quality, the power supply stability and the adaptive capacity of the system under severe working conditions in a weak power grid are improved.

The application relates to the technical field of power quality monitoring and treatment, and discloses a power quality control method for a power distribution network and computer equipment. The method comprises the following steps: acquiring real-time operation data of the power distribution network and original power quality signals of a disturbance node, decomposing the signals and determining an optimal decomposition modal number with the minimum total variance as the target; determining a key time sequence feature set based on the optimal decomposition modal number and a preset disturbance type label; reasoning a disturbance propagation path from the disturbance node as the starting point in the topology structure of the power distribution network, and determining the voltage change rate of each node; screening candidate measures based on the voltage change rate, the feature set and a threshold value, combining a preset evaluation index to construct a judgment matrix; determining a priority weight based on the judgment matrix to determine optimal treatment equipment; and determining dynamic output parameters according to index measured values, reference values and real-time data, and controlling the optimal treatment equipment to operate according to the dynamic output parameters. The application can improve the accuracy of controlling power quality disturbances of the power distribution network.

The invention discloses a power distribution network voltage sag sag domain analysis method considering distributed power supply access, and relates to the technical field of power system electric energy quality control. According to the method, a power distribution network asymmetric short circuit three-sequence equivalent model containing a distributed power supply and sensitive equipment is constructed, a looped network is split based on a voltage lowest node when a looped network structure exists, and a voltage sag sag domain general equation and a characteristic equation under any line fault condition are established; and further through sag subsystem division and Kron order reduction processing, an order reduction node impedance matrix about fault position parameters is formed, and the fault position parameters enabling the residual voltage of the sensitive nodes to reach a preset threshold value are determined by adopting an optimization iteration mode, so that the voltage sag sag domain boundary is accurately obtained. The method can give consideration to the calculation precision and efficiency, and is suitable for the voltage sag analysis of the power distribution network containing the distributed power supply and the complex topological structure.

The present application belongs to the technical field of power quality control, and particularly relates to a refining furnace transformer reactive power compensation and harmonic suppression collaborative optimization method and system, comprising the following steps: S1, real-time signal acquisition and feature extraction: real-time acquisition of voltage signals and current signals in a refining furnace transformer power supply system, decomposition of the current signals, extraction of the root mean square value of the fundamental reactive current and characteristic harmonics, and real-time calculation of the instantaneous arc impedance; S2, robust evaluation of transient arc dispersion: based on the pre-constructed reference impedance characteristic sequence and the real-time acquired arc impedance transient sequence. The present application solves the problem of excessive sensitivity of the index to noise in the traditional method, guarantees the reliability and stability of the dynamic weight distribution, and completely avoids the compensation system oscillation and misjudgment caused by noise.

The invention provides a voltage sag treatment circuit and a control method thereof, and relates to the technical field of power electronics and electric energy quality control. According to the circuit, a super capacitor and a lithium battery are boosted through a DC / DC converter, are connected to the same direct current bus, are converted into alternating current through a DC / AC inverter, are filtered through an LC circuit, and are connected with a sensitive load in parallel through a bidirectional thyristor. According to the circuit matching method, rapid response to the voltage sag caused by the sensitive load can be realized by combining the advantages of low cost, rapid response of the super capacitor and large capacity of the lithium battery, and the circuit matching method has considerable stable anti-interference capability so as to realize rapid and effective treatment of the voltage sag.

The invention provides an energy router and a control method and control device thereof. The energy router comprises a photovoltaic interface, an energy storage interface, an AC power grid interface, a first conversion unit and a second conversion unit. The first conversion unit is used for converting the voltage level of the first direct current received by the photovoltaic interface and transmitting the second direct current to the energy storage interface. The second conversion unit is used for rectifying the first alternating current from the alternating current power grid interface into third direct current and transmitting the third direct current to the energy storage interface. According to the invention, energy routing between different interfaces can be realized, and high flexibility is realized. Through different conversion units, the functions of voltage level conversion, electrical isolation, energy transmission and the like can be realized, power flow control, electric energy quality control and the like can also be realized, and the actual requirements of a shore power system are met.

The invention discloses a method for calculating the line loss of a high-proportion new energy access power distribution network, and belongs to the technical field of calculation of the line loss of the high-proportion new energy access power distribution network. The calculation method for the line loss of the high-proportion new energy access power distribution network comprises the following steps: S1, carrying out preliminary data acquisition and preprocessing by the calculation method for the line loss of the high-proportion new energy access power distribution network, and providing basic line parameters for all other modules by a module; according to the method for calculating the line loss of the high-proportion new energy access power distribution network, the change characteristics of the line loss of the power electronic power distribution network accessed by the high-proportion distributed power supply and the optimization mechanism are calculated; comprising the aspects of network loss change characteristics and a line loss optimization mechanism under a deterministic model, an uncertainty processing scheme, a line loss and electric energy quality regulation and control method and the like, and a line loss regulation and control scheme based on an evolutionary algorithm is established aiming at the electric energy quality problem caused by high-proportion distributed power supply and nonlinear load grid connection.

The invention belongs to the technical field of electric energy quality control, and particularly relates to a reactive compensation and harmonic suppression collaborative optimization method and system for a refining furnace transformer, and the method comprises the following steps: S1, real-time signal collection and feature extraction: collecting a voltage signal and a current signal in a power supply system of the refining furnace transformer in real time, decomposing the current signal, and carrying out feature extraction; extracting a fundamental wave reactive current and a root-mean-square value of a characteristic harmonic wave, and calculating instantaneous arc impedance in real time; and S2, robust evaluation of transient arc dispersion is carried out based on a pre-constructed reference impedance characteristic sequence and an arc impedance transient sequence obtained in real time. According to the method, the problem that indexes are excessively sensitive to noise in a traditional method is solved, the reliability and stability of dynamic weight distribution are guaranteed, and compensation system oscillation and misjudgment caused by noise are thoroughly avoided.