61results about How to "Reduce voltage deviation" patented technology

The invention discloses a power distribution network operation aid decision analysis system and an application method thereof. The system comprises a data layer used for classifying and storing acquired external data; the platform layer is used for classifying the data stored in the data layer and building an operation module according to the type; the application layer is used for classifying thestored data according to the operation modules and the data layer built by the platform layer; risk analysis is carried out on the power distribution network and an optimization scheme is provided, the display module is also used for displaying result information of each operation module; the difference characteristic of the urban power distribution network is fully considered from the overall architecture design to the specific service function design, the power distribution network is directly operated, maintained and overhauled, corresponding measures are put forward in a targeted mode forintelligent auxiliary decision analysis of the power distribution network, and the probability of power distribution network faults and risks is reduced.

A display device including: a substrate including a display area in which pixels are positioned and a peripheral area around the display area; a common electrode and a pixel electrode that are positioned on the display area and overlapping with each other, with a first insulating layer disposed therebetween; a common voltage line positioned on or below the common electrode and contacting the common electrode; an edge common voltage line connected with the common voltage line and formed along an edge of the display area; and a first common voltage transfer line contacting the edge common voltage line in the peripheral area and configured to transfer a common voltage to the common voltage line.

The invention discloses a reactive optimization method for improving a qualified rate of a power distribution network comprising distributed photovoltaic power sources. The method mainly comprises the following steps: when the photovoltaic power sources work in an MPPT mode, by taking minimization of whole-network voltage deviations as a target, performing reactive optimization on residual capacities of photovoltaic inverters by use of a particle swarm algorithm; if an optimization result still comprises a node voltage off-limit condition, employing an improved optimization scheme: first of all, under the condition that it is ensured that whole-network voltages are qualified, by taking maximization of total active output of the photovoltaic power sources as a target, obtaining an optimal active value of each photovoltaic power source; and then by taking the result as an active output value of each photovoltaic power source and by taking the minimization of the whole-network deviations as the target, performing the reactive optimization on the residual capacities of the photovoltaic inverters again. According to the invention, operation economic benefits and reliability of the power distribution network are taken into integrated consideration, distribution of active and reactive output of the photovoltaic inverters is optimized, and the voltage qualified rate of the power distribution network comprising the photovoltaic power sources is effectively improved.

The invention provides an inverter parallel operation optimization control method. The method includes acquiring the rated capacity of each inverter in the parallel inverter system and the total load power factor angle of the parallel inverter system, determining the corresponding virtual impedance and sagging coefficient for each inverter according to the rated capacity and the total load power factor angle, determining the phase angle of each inverter based on the sagging coefficient, and then setting the same voltage amplitude for each inverter, determining the command voltage based on the voltage value, the virtual impedance, the phase angle, and the inverter output current, and controlling each inverter to output the active power and the reactive power according to the corresponding command voltage. The virtual impedance and sagging coefficient are determined by integrating the rated capacities of the inverters and the total load power factor angle of the parallel inverter system to realize the reasonable distribution of the active power and the reactive power of the inverters, the control effect of the inverters is optimized to reduce the voltage deviation, and the quality of the output energy of the inverters and the normal running of the user equipment or electric appliances are guaranteed.

Various embodiments of the invention improve the dynamic response and output voltage accuracy in buck DC-DC converters. In certain embodiments, power efficiency is improved by storing and recycling energy that is otherwise lost during successive load transient events.

The invention provides a thin film transistor liquid crystal display (TFT-LCD) array substrate, a manufacturing method and a driving method. A first public electrode bus is arranged in a display area, so that the rate control (RC) delay problem of a public electrode wire is solved, and display effect of a display screen is improved. Furthermore, the invention provides a driving method of the TFT-LCD array substrate, positive polarity and negative polarity of the display voltage are symmetrical relative to the first public electrode bus, and the display voltage on each side of the first public electrode bus can be provided in a point inversion mode. When the public electrode bus is interfered by external signals, voltage deviation values of the public electrode bus are reduced, and display effect is improved.

The present invention provides a manifold insert having a plurality of distribution guides which reduce output voltage deviation due to flow instability between unit cells and prevent local flow instability of electrodes by stably distributing the flow of fluid (such as air, hydrogen, and coolant) supplied to a fuel cell stack, thereby maintaining a stable performance of the unit cells, and a fuel cell stack comprising the same. In particular, manifold insert having distribution guides is provided, the manifold insert being configured to form a flow field from an inlet port of fluid to an outlet port connected to a fuel cell stack, the manifold insert including: a plurality of distribution guides for dividing the flow field from the inlet port to the outlet port such that the fuel cell stack is divided into a plurality of regions according to the distance from the inlet port, wherein the distribution guides have surfaces that are at least partially curved such that the flow of the fluid from the inlet port to the outlet port is changed by the curved surfaces and form a plurality of guide flow fields for guiding the fluid to the divided regions of the fuel cell stack such that the fluid is supplied to the divided regions of the fuel cell stack along the plurality of guide flow fields at different flow rates.

The invention discloses a wind power plant reactive optimization control method considering DFIG reactive output capacity. The wind power plant reactive optimization control method comprises the stepsof obtaining system data and predictive data of each DFIG in a large-scale wind power plant; by combination of a kinetic model of a wind turbine, calculating the active output predictive value of each DFIG; by combination of the DFIG reactive output characteristic, calculating the reactive output upper limit and lower limit of each DFIG; by taking the minimum wind power plant internal active power grid loss, the maximum reactive margin, and the minimum common grid-connected point voltage deviation as the target, establishing a multi-object optimization function; by taking the DFIG reactive output upper limit and lower limit, SVC reactive output upper limit and lower limit and the common grid-connected point voltage deviation as constraint conditions, establishing a constraint condition function; and solving an optimization model formed by the optimization target function and the constraint condition by adopting a genetic algorithm to form the wind power plant reactive optimization control method which can satisfy requirements.

The invention provides a distributed droop control method based on the active-disturbance-rejection control technology for a DC microgrid. A distributed power system, a load and various power electronic interface devices are included. The active-disturbance-rejection control technology is applied to a droop control strategy, active-disturbance-rejection control structures are employed by voltage and current loops, the voltage stability and current distribution of the system are achieved, and the structure is robust to the system uncertainty and external disturbance. By designing a novel secondary control strategy, the DC bus voltage deviation is reduced while the current distribution precision is guaranteed. The method is different from other proposed control methods, according to the proposed method, only the sampling of global current information at a discrete moment is needed, the communication burden is reduced, and the anti-interference performance is strong.

The invention discloses an optimization method and system for a topological structure of a power distribution network. The optimization method comprises the steps of when it is determined that the closing time of a target interconnection switch in the topological structure of the current power distribution network is less than a preset time threshold value, closing the target interconnection switch to form a loop; disconnecting a target section switch in the loop; determining a target function value after the target section switch is disconnected; traversing each section switch in the closed loop and obtaining a minimum target function value; when the minimum target function value is smaller than an initial target function value, performing interchange between the section switch in the closed loop corresponding to the minimum target function value and the target interconnection switch; taking any one interconnection switch except the target interconnection switch in the topological structure of the current power distribution network as a new target interconnection switch, and returning to perform the step of closing the target interconnection switch; and when it is determined that the preset traversing time is completed, obtaining the optimal topological structure of the power distribution network. By adoption of the optimization method and system, the voltage deviation of the power distribution network in different operating states of the power distribution network can be effectively lowered, the network loss of the power distribution network is lowered, and the power supply quality of the power distribution network is improved.

The invention discloses an optimal allocation of active distribution network resources based on the Tianniuxiu algorithm. The optimal allocation is characterized in that the time sequence of wind and photovoltaic distributed power generation output and load is considered, absorption of renewable energy is maximized through optimal allocation of the resources, active power is balanced, the Tianniuxiu algorithm is utilized for resource optimal allocation, the active power of each period is balanced according to the system demand and the economy principle, and reactive power compensation is performed to reduce power loss and voltage deviation to meet economic requirements. The optimal allocation has a certain practical value and can improve the safe and stable operation level of a system and the ability of the active distribution network to absorb the renewable energy.

Disclosed is a secondary battery system which, when charging a battery pack in a charger, makes it possible to precisely equalize the voltages of the individual cells without needing to greatly increase the capability of the voltage equalizer device. The disclosed secondary battery system is at least provided with a battery pack (1) configured by connecting multiple single secondary cells (1a), a voltage equalizer (BL) which equalizes the variation of the voltages between the single cells (1a), a charger (3) and a charger controller (CC). The charger controller (CC) is configured such that when the cell voltage of any of the multiple single cells (1a) reaches a set voltage for suppressing voltage rise, the current flowing in the entire battery pack (1) is controlled to become zero or an amount of current at which the variation in voltages between the single cells can be reduced by the aforementioned voltage equalizer. The voltage equalizer (BL) is configured so as to equalize the voltage variation between the single cells in parallel to the control exercised by the charger control device (CC).

The invention discloses an electric car distributed charge-discharge scheduling policy based on three-phase load balance. The scheduling policy is characterized in that the policy is used for eliminating adverse impacts brought by disordered charge of an electric car, and the problems of large calculation amount and strict communication bandwidth requirement of centralized management can be effectively relieved. According to the policy, an electric car charge-discharge optimization model is established, valley filling at night and V2G service provision at a load peak are realized, and then smooth system loading is performed; based on this, three-phase load balance constraint is considered to ensure safe and stable operation of a system; and finally, the control policy proposed in the invention is verified through an IEEE33 node power distribution network test system, the result indicates that distributed management can achieve a centralized control effect, peak clipping and valley filing are realized, and three-phase load imbalance is reduced.

The embodiment of the invention provides an optimization operation method of dispersed wind farms based on variable power factors. The method comprises the steps of: constructing a general load modelbased on static voltage features for a power distribution network of points of interconnection connected with the dispersed wind farms; arranging capacitors at the points of interconnection to balancereactive power regulation capabilities of the stator side and a convertor of the network set of the doubly-fed induction generator, and obtaining the power factor angle, as shown in the description,of the doubly-fed induction generator according to the general load model; according to the power factor angle as shown in the description, constructing an active power loss model and a reactive powerloss model of the dispersed wind farms after the dispersed wind farms are accessed into the points of interconnection, and analyzing the node voltage deviation influence factors after the dispersed wind farms are accessed into the points of interconnection; constructing a multi-target function of dynamic control of the power factors of the dispersed wind farms to meet the requirements that the node voltage deviations, the active power loss model and the reactive power loss model as the optimal values; and solving the multi-target function by employing the improved firefly algorithm. The optimization operation method of dispersed wind farms based on variable power factors effectively improves the operation time and the convergence rate, and improves the system performances.

The invention relates to an offshore wind power plant reactive power-voltage coordination control method based on deep reinforcement learning, and belongs to the technical field of wind power generation. The method comprises the following steps: S1, establishing an offshore wind power plant reactive power-voltage coordination control model; S2, establishing a Markov decision process model based on a wind power plant reactive power-voltage control strategy, and defining a state action and a reward function of the system; S3, training the reactive power-voltage coordination control model based on a depth deterministic gradient strategy in combination with unit random output data to realize mapping from a wind turbine unit state to a reactive power instruction; and S4, achieving an online deployment process of the offshore wind power plant reactive power-voltage coordination control strategy. Compared with a traditional method, the method does not depend on system accurate modeling, can effectively reduce the voltage deviation of the wind power plant, and has better model solving precision and instant response speed.

The embodiment of the invention provides a reactive-power voltage coordination and optimization control method and device and belongs to the technical field of reactive-power voltage optimization of active distribution networks. The reactive-power voltage coordination and optimization control method comprises the following steps: acquiring to-be-processed power grid data; dividing the to-be-processed power grid data into multiple time intervals according to a defaulting rule, and acquiring corresponding target data at each time interval; acquiring an uncertain model for corresponding preset photovoltaic power and load output at each time interval, and substituting the target data into the uncertain model; acquiring a first result output by the corresponding uncertain model at each time interval; performing iterative computations on the first results based on a Gaussian load-flow algorithm so as to acquire a third result corresponding to each time interval; and acquiring a matching value of the third result corresponding to each time interval and a preset ratio, and establishing a reactive-power optimization model by taking the third result corresponding to the matching value as anobjective function.

The invention provides a microgrid reactive automatic control method based on a convolutional neural network. According to the microgrid reactive automatic control method, an SCADA is adopted to collect real-time operation data of a microgrid system to generate two-dimensional power matrix data; the optimal reactive power of a reactive device corresponding to the two-dimensional power matrix datais calculated by utilizing the optimal power flow, and the optimal reactive power of the reactive device is used as a label value; and a convolutional neural network model is trained, so that the optimal reactive power of each reactive device can be determined according to system operation data. The method is characterized in that the two-dimensional convolution operation sparse interaction, the weight sharing and equivariant representation are utilized, the convolutional neural network model is established and model training is carried out, so as to realize automatic feature extraction on theoperation state of the microgrid, so that the optimal reactive power of each reactive device is determined; and meanwhile, the voltage deviation and the network loss during microgrid operation are taken into consideration, and the method has high economical efficiency and safety.

The invention discloses a synchronous power generator excitation control method which comprises the steps of (1) establishing each unit simplified model and sliding mode iterative learning controller model of a synchronous power generator excitation system , (2) taking an error e1 of a synchronous power generator terminal feedback voltage U and given voltage U0 as input of a sliding mode control part and an iterative learning control part, (3) superposing a sliding mode control output uSMC and iterative learning control output uILC to obtain excitation voltage Uf, (4) allowing the excitation voltage Uf to pass a power amplification unit to obtain excitation voltage UF which controls a synchronous power generator, and (5) taking UF as input of a synchronous power generator unit, and obtaining synchronous power generator actual output voltage UG, wherein the synchronous power generator actual output voltage UG is taken as the input of a voltage measurement unit to obtain the synchronous power generator terminal feedback voltage U. According to the method, the parameter adaptability and robustness of a control system can be improved.

An image forming apparatus is disclosed. Zener diode separately installed to correspond to each developing device so as to form a difference in potential between the developing bias voltage and the supply bias voltage of each developing device, is installed at a common end, so that a deviation of the developing voltage applied to the developing device affected by a deviation of Zener diode components can be reduced, resulting in an increased color image quality. In addition, the Zener diode is installed in a common end, such that the number of Zener diodes is reduced, resulting in a reduction in production costs.

A resistor having low temperature coefficient of resistance includes a resistive part and two conductive parts connected to opposite sides of the resistive part. One conductive part has a through slot and a sensing portion between the through slot and the resistive part. The through slot has two inter-connected sections. Each section extends and ends with a closed end and has a parallel component, parallel to a main current direction defined on the resistor, and a perpendicular component, perpendicular to the main current direction. Another resistor having low temperature coefficient of resistance includes a resistive part and two conductive parts connected to two sides of the resistive part respectively. Each conductive part has a protrusion block, extending outward perpendicular to a main current direction defined on the resistor, and a sensing portion at the protrusion block.

The invention discloses a source-network-charge-storage interaction based multi-voltage-level direct-current power distribution network optimization dispatching method. The method is characterized inthat a source-network-charge-storage interaction optimization concept is introduced in a direct-current power distribution network, and on the basis that the characteristics of an interactive load aredeeply analyzed, the effect of the interactive load and an energy storage technology on the photovoltaic consumption of a system is fully exerted; a direct-current power distribution network multi-objective optimization dispatching model taking the operation cost, the network loss rate and the voltage deviation as objectives is built, and the optimization model is solved by adopting a multi-objective particle swarm optimization algorithm; and multi-objective optimization results are compared and analyzed to verify that a source-network-charge-storage interaction model can enable the system torun more optimally, and collaborative optimization is carried out by utilizing the interactive load and the energy storage system, so that the operation cost, the network loss rate and the voltage deviation of the system can be greatly reduced, the photovoltaic consumption level is effectively improved, and safe and reliable operation of the direct-current power distribution network is realized.The method has the advantages of being scientific and reasonable, strong in applicability and good in effect.

The invention discloses a coordinated control method based on GPS synchronous fixed frequency for a micro-grid running in an isolated island. The method solves the problem of interactive influence between frequency stability and voltage stability and comprises the steps of 1, establishing a static droop curve of an adjustable power supply according to the maximum allowable voltage, rated working voltage and a maximum current limiting point; 2, establishing a current output response controller on the basis of first-order dynamic characteristics; 3, in order to achieve the purposes of improving system damping ratio and reasonably distributing power, establishing a typical scene droop coefficient optimization query base, and conducting dynamic optimization on droop coefficients; 4, determining adjustable power supply output of a current running scene; 5, establishing a combined optimization model of active power and reactive power, and adopting a Newton method to carry out multi-target solution; 6, determining the optimal power, voltage and current output. According to the coordinated control method based on the GPS synchronous fixed frequency for the micro-grid running in the isolated island, the synchronous fixed frequency of the micro-grid, the voltage stability and optimization control of the micro-grid, the on-site voltage control and power distribution of the micro-grid, and efficient optimization running of the micro-grid are achieved.

A distributed photovoltaic optimal configuration method based on two-stage planning comprises the following steps of firstly, establishing a photovoltaic power generation random output model, and then implementing the operations at the following two stages that at the first stage, the network loss sensitivity variance of each node in a power distribution network is calculated through a network loss sensitivity variance method; the network loss sensitivity variance values are compared and analyzed, the access sequence of the distributed photovoltaic at each node is judged, and the distributed photovoltaic capacity and an initial mounting position are calculated; and at the second stage, the distributed photovoltaic capacity and the initial mounting position serve as input of the second stage, a target function is established with the minimum annual investment and operation cost, the minimum voltage deviation and the minimum power distribution network loss generated after the distributed photovoltaic is connected into the power distribution network as targets, and finally an optimal configuration scheme is obtained. The configuration scheme obtained through the method can stabilize the photovoltaic output power fluctuation and improve the photovoltaic permeability and utilization rate and the absorption capacity of photovoltaic power generation.

The invention provides an infrared focal plane chip which comprises a substrate, an infrared sensitive layer, a reading circuit arranged on the substrate and interconnection metal connected with the infrared sensitive layer. An anti-reflection film is arranged in an n-type area of the infrared sensitive layer, a metal layer which is not transparent to infrared light is arranged in a p-type area of the infrared sensitive layer, and the metal layer is connected with a public electrode through a lead. The invention also provides an infrared focal plane detector. The invention also provides a preparation method of the infrared focal plane chip. The voltage deviation between the working points of the center pixel and the edge pixel Gpol can be reduced, so that the imaging quality of the edge pixel of the detector is improved. In addition, equipotential metal is grown in a p-type area, the same equipotential effect is achieved, the limitation that the front equipotential machining technology is limited by a planar junction and the risk that short circuit between the equipotential metal and pixels fails when a small pixel chip is machined are avoided, the effects of enhancing electric signals through light and reducing optical crosstalk can be achieved, and detector sensitivity reduction caused by light blocking is avoided.

The invention provides a multi-period decoupling friendly interactive power distribution network voltage reactive rolling optimization method. The method comprises the following steps: S1, establishing a long-period main problem optimization model about a discrete on-load tap changer (OLTC) tap; S2, establishing a series of short-time-period sub-problem rolling optimization models about continuous distributed photovoltaic (PV) power output based on a model prediction theory; and S3, adopting benders to decompose the iteration process of the main and sub problems, and solving the global optimal solution of the friendly interactive power distribution network voltage reactive power optimization model. According to the method, the uncertainty of PV power generation is fully considered, the OLTC gear change cost is further reduced, and the economical efficiency and safety of a friendly interactive power distribution network voltage optimization strategy are ensured.

The invention relates to a single-phase multifunctional rare-earth permanent magnet generator, mainly consisting of a shell, a stator, a rotor, an inverter and a control system. The stator comprises a stator iron core and an armature winding; the stator iron core is repeatedly pressed into a chute by stator punching, and the armature winding adopts concentric windings with different turns; the rotator consists of a rotating shaft, a cylindrical magnetic-permeability yoke and paired tile shape magnetic steels which respectively fix N pole and S pole respectively on the excircle of the magnetic yoke; and the control system consists of two circuits. The single-phase multifunctional rare-earth permanent magnet generator not only has the characters of small volume, light weight, high efficiency, simple structure and reliable operation, simultaneously overcomes the defects that the permanent magnet is difficult to adjust magnetic field to control voltage from the outside so as to cause that the voltage stability is poor and the waveform distortion factor is large, also can automatically switch to a first circuit of the control system for supplying power continuously when the inverter fails, realizes multifunctional and continuous power supply with more reliability and has outstanding practical value.

The invention relates to a DC microgrid distributed autonomous coordination control method capable of remarkably improving bus voltage deviation, in particular to an improved distributed autonomous coordination control method based on a DBS (DC Bus Signaling) coordination control method. The method mainly comprises the steps: sampling a DC bus voltage signal and transmitting the sampled DC signalto a local controller; amplifying the sampled voltage signal according to a proposed equivalent amplification rule, and carrying out the coordination control by taking the amplified voltage signal asa judgment basis. The purpose of equivalently amplifying the voltage signal is to reduce the voltage bias of the DC bus and prevent the problem that the normal work of the system is influenced by therepeated action of the mode switching signal due to the small actual voltage threshold interval. The method solves the problem that the traditional DBS coordination control requires a large bias of the DC bus voltage, improves the bus voltage deviation, improves the power supply reliability and the power quality of a DC microgrid, and can be applied to a DC load scene with high requirements on thepower quality.

The invention discloses a method for establishing a multi-stage coordinated voltage control model. The method comprises steps that the multi-stage coordinated voltage control model is made to be distributed on a plurality of time scales, the first stage is made to be a day-ahead two-stage robust optimization model with the uncertainty of a voltage control low load condition, the second stage is to decompose the proposed multi-stage coordinated voltage control model into a network optimization sub-problem and an energy management sub-problem, and the third stage is to redistribute a home energy management system (HEMS) to counteract the influence of real-time uncertainty so as to reduce the influence on the network voltage and carry out real-time adjustment; multi-stage coordinated voltage control is carried out on a low-voltage distribution network by coordinating residential demand response, and a problem that overvoltage is inevitably generated at a feeder line end due to high photovoltaic output when a load is low is solved; in addition, a dynamic consumption mode and a load composition of the user side cause the power consumption increase, the load variability and the demand predictability reduction, and thus higher voltage drop and loss are caused during the peak load period.

The invention relates to a direct-current micro-grid distributed autonomous coordination control method and a control system. The invention aims at increasing an anti-interference ability and work reliability of the direct-current micro-grid distributed autonomous coordination control system. The invention especially relates to a control method and a control system of an operating state and load switching when a plurality of bus micro-source units are connected in parallel. Through constructing multivariable hysteresis of a voltage and a current, a problem that a single-variable DBS coordinates and controls a voltage disturbance at a voltage segment point so as to cause mode mis-switching is solved.