57results about How to "Improve voltage pass rate" patented technology

The invention discloses a mold splitting type voltage control method for a wind power plant cluster, and belongs to the technical field of automatic voltage control of electrical power systems. According to the technical scheme, two control modes of a wind power plant are defined according to the voltage of a grid joint point and current reactive power regulation capacity of the wind power plant, and a wind power plant cluster control center under different control modes sends different control instructions to each wind power plant. The method carries out coordination control on other wind power plants in a cluster according to real-time sensitivity relations among the wind power plants of the wind power plant cluster when a certain wind power plant is insufficient in reactive power regulation capacity. The mold splitting type voltage control method for the wind power plant cluster can be integrated in a control system of the wind power plant cluster control center, and supplies supporting for voltage control of a regional power grid of the wind power plant cluster.

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 a power distribution network multi-objective probabilistic reactive power optimization method. The method includes the following steps that: a stochastic model is constructed according to the predetermined stochastic factors of a power distribution network; probabilistic power flow is calculated, so that the probabilistic density function of node voltage can be obtained; the voltage entropy of the power distribution network is calculated according to the probabilistic density function of the node voltage; and a multi-objective probabilistic reactive power optimization model is constructed and solved. With the power distribution network multi-objective probabilistic reactive power optimization method provided by the technical schemes provided by the invention adopted, the probabilistic distribution of the node voltage is more centralized compared with probabilistic distribution obtained by using a single-objective reactive power optimization method, and the voltage percent of pass of a system can be improved.

The invention relates to a transformer substation voltage reactive power control system and the method thereof. The invention is characterized in that, with the adoption of a fifteen area diagram control method, the system collects the electrical information such as current, voltage, active power, reactive power, COS Phi, switch position, etc. through a RTU. The electrical information will enter into the control process, when meeting the switching-in requirement. The collected real-time voltage and real-time reactive power are respectively compared with a voltage limiting value and a reactive limiting value to confirm the position of the current system at the fifteen area diagram. If a switched capacitor group or a transformer-conditioning shift is confirmed to meet the control requirement according to the control strategy, then the switched capacitor group or transformer-conditioning shift will carry out the conditioning exit of the transformer-conditioning shift or the switching exit of the capacitor to control the transformer or the capacitor group. The invention can effectively lower the consumption of the prior equipment, promote the voltage qualified rate, eliminate the burden of the working personnel and is applied in the reactive voltage automatic control of the transformer substation.

The invention discloses a regional power grid automatic voltage control (AVC) method. An AVC system conducts classification and partitioning through PAS network modeling according to a distribution state of a power system voltage reactive space, the classification is conducted according to voltage levels of the power grid, and the partitioning is conducted according to a local area feature of reactive balance. An AVC system control mode gives priority to a sequence of first optimal control of area voltage, then correction control of voltage of all levels and finally the area reactive optimal control. The area voltage optimal control is optimizing of center point bus voltage level in a correction system. The correction control of the voltage of all levels is optimizing of node voltage level in an optimizing correction system. By arranging a classification partitioning control strategy on a traditional AVC and by adding a load predicting link and a link of diagnosing an electric control attribute of a device current state, the control strategy is predictable. Meanwhile, advanced control is achieved according to a device operating state, and device movement delay is reduced.

The invention discloses a power quality management method for an active distribution network. The method comprises a step of grasping the output characteristics of distributed small hydropower and photovoltaic units through investigation, a step of integrating and analyzing the historical data of an electricity consumption information collection system by using big data mining technology, a step of performing the coordinated control of power quality, a step of performing power quality optimization, and a step of performing active power distribution. According to the method, the distribution network is hierarchically and regionally controlled based on an active distribution network radial structure, a distributed power source and a reactive power regulating device are fully used, the powerquality control of the active distribution network is achieved by using a top-down manner, the voltage is always in a safe interval, and the quality of the power supply is ensured.

The invention discloses a voltage reactive treatment system and method for a power distribution network area. The integrative reactive compensation and the dispersed reactive compensation are combined on the power distribution network side, compensation capacities of compensation points are determined according to a global control strategy, and network reactive power and node voltage are reasonably adjusted, so that a power grid operates in an optimal operating mode, and the user power supply quality of the power distribution network area can be improved remarkably within a short period with least investment. By means of the global control strategy, the optimal compensation scheme of the dispersed reactive compensation is determined; the voltage reactive treatment system and method are of great significance on lowering network losses, improving system voltage qualified rate and improving quality of electric energy, and are beneficial to construction of a strong energy-saving type power distribution network.

The invention discloses a method for evaluating the running condition of a distribution network regulation and control integrated system, which includes the four steps as follows: (1) determining theevaluation index selecting principle of the distribution network regulation and control integrated system; (2) determining the evaluation index grading principle of the distribution network regulationand control integrated system; (3) based on an analytic hierarchy process and a fuzzy comprehensive evaluation approach, calculating the value of each sub index, getting a comprehensive score, and evaluating the running condition of the system according to the score; and (4) displaying the evaluation result through a radar chart analysis approach. Dynamic monitoring, evaluation and comprehensivedisplay of the important indexes of the running state and application situation of a master station system are realized. Effective guidance is provided for users to improve the level of automation application and the level of operation and maintenance of regional distribution networks.

An automatic voltage control method for power supply is to divide bus voltage U into seven control areas, and the operation mode of reactive equipment is controlled automatically according to three voltage changing trends of rising, remaining unchanged, and dropping measured actually at the bus in each control area, i.e realizing the accurate control of bus voltage by switching on or switching off the capacitor set and by regulating the on-load voltage regulation switch for obtaining relatively ideal reactive tide and better on-specification rate of voltage.

The present invention is reactive voltage remote sensing and remote controlling and optimizing control method for power network. The control process includes the following steps: acquiring the data of the power stations with the monitoring preliminary machine; feeding the data into state estimating module; feeding data from the state estimating module to the capacitor optimized throw-in and throw-off calculation module; judging whether to have successful optimization based on the calculation result; for judgment result 'Yes', executing remote control and remote regulation; for judgment result 'No', executing reactive in-situ balance analysis and forming capacitor throwing-in and throwing-off measure and feeding the data from the state estimating module for judging whether to have out-of-limit bus voltage; for judgment result 'No', returning the data to power station; for judgment result 'Yes', and performing the transformer tapping regulation while feeding the data to power station.

The invention relates to the technical field of automatic voltage control in an electric system, in particular to a relaxation reactive voltage optimizing system based on province-district coordination and a working method of the relaxation reactive voltage optimizing system. At the present stage, local areas are administered by a dispatcher control center, the voltage regulation capacity can not be used sufficiently, and even voltage quality is affected because the regulation effects among the areas are opposite. The relaxation reactive voltage optimizing system comprises an obtaining module, a calculating module, a sending module, a processing module and a receiving module, wherein the obtaining module is used for obtaining a power grid model and real-time data; the calculating module is used for performing state estimation on collected data and performing relaxation voltage reactive power optimization calculation to obtain a coordination strategy; the sending module is used for sending the coordination strategy to a district dispatcher; according to the processing module, the coordination strategy is received by the district dispatcher and then processed to control actions, and if a province dispatcher is needed for matching, the upper and lower bounds of expected voltage are reported; according to the receiving module, a voltage coordinating request of the district dispatcher is received by the province dispatcher and serves as the optimization constraint of next circulation. According to the technical scheme, on the premise of ensuring qualified voltage, regulating frequency of a discrete device is reduced, network loss is effectively reduced, and convergence reliability of an optimization algorithm is improved.

The invention discloses a control method suitable for intelligent load phase change, and belongs to the field of power supply control. The method comprises the following steps that: firstly, confirming one phase with the largest total current after each phase of total current is sorted as a default phase X; after a phase change command is received, according to the phase change command, switchingto a Y phase, and conducting a thyristor X on the default phase; then, disconnecting a contactor X on the default phase; disconnecting the thyristor X on the default phase; conducting a thyristor Y; closing the contactor X; disconnecting the thyristor Y; and therefore, finishing a phase change operation. The control method not only considers a three-phase unbalance degree index but also considersindexes, including voltage, reactive power and the like, and a court is under a stable state with a higher voltage percent of pass and a higher power factor. By use of the control method, a three-phase unbalance problem in the court can be effectively lowered, the loss of a distribution transformer is lowered, a situation that the electric equipment of a user is damaged is lowered, the operation noise of the court transformer is obviously lowered, and customer satisfaction degree is improved. The control method can be widely used for the control and regulation field of power grid operation quality.

The invention discloses a distributed power supply site selection optimization method based on power distribution network probabilistic load flow calculation. The method comprises the following steps:S1, constructing a multi-objective optimization model considering dynamic characteristics of a power distribution network; S2, extracting a sample from the original data through a Latin hypercube sampling method; S3, taking the sampled samples as input, and performing probabilistic load flow calculation on the power distribution network in different operation states; and S4, performing scheme optimization on distributed power supply site selection based on a vector evaluation genetic algorithm. According to the invention, power distribution network planning personnel can reasonably arrange the distribution points and the operation mode of the distributed photovoltaic power supply, the scientificity of power distribution network planning decision making can be improved, the rising effect on the voltage when the distributed photovoltaic power supply is accessed can be fully utilized, the network loss is reduced, and the power supply stability is improved.

The invention discloses a tail-end low-voltage compensation device at the tail end of a rural power grid, and relates to the technical field of voltage regulation devices. The tail-end low-voltage compensation device comprises a tank, an input-end current acquisition device, an input-end voltage acquisition device, an output-end current acquisition device, an output-end voltage acquisition device and a voltage compensation module. States of switches S1-S3 can be changed under the control of the voltage compensation module according to current and voltage information acquired by the input-end current acquisition device, the input-end voltage acquisition device, the output-end current acquisition device and the output-end voltage acquisition device, and power can be directly supplied for users by the low-voltage power grid or can be supplied for the users after the low-voltage power grid is compensated by the voltage compensation module. The tail-end low-voltage compensation device has the advantages that the problem of excessively low voltages at the tail end of an existing rural power grid can be solved, normal electric power utilization of residents can be guaranteed, good compensation effects can be realized, and the tail-end low-voltage compensation device is simple in structure and convenient to mount and maintain.

The invention discloses an automatic voltage control-based distribution network and distributed photovoltaic power plant control method. With the method adopted, the reactive power and voltage fluctuation of a photovoltaic power station are effectively restrained, grid power flow is optimized, a voltage qualification rate is raised, an equipment utilization rate is increased, network loss is reduced, and the safety and economic operation of a power grid system is realized. According to the method, the connection of software functions can be realized with no additional hardware device needed, and green loss reduction and energy saving are realized genuinely.

The invention provides a voltage monitoring method and system based on an AVC system operation environment. Relating to the technical field of power systems, According to the invention, the power supply voltage can be continuously monitored; the monitored real-time data and all data in the monitoring time range can be displayed on the nixie tube; data information of the voltage monitor is inquired; the defects in the prior art are overcome; Design reasonableness, a wireless communication mode is combined with a wired communication mode; Statistical data of the voltage monitors installed at allmonitoring points of a power grid are transmitted to the voltage monitoring data acquisition master station system. Data of voltage, power factors and the like are uploaded to an AVC system, data sources of control and assessment are unified, statistics of monitoring data of the voltage monitor is greatly facilitated, and meanwhile the reliability and the stability of the voltage monitor in the system operation environment are improved.

The invention discloses a method for supporting power quality governance decision. The method comprises the following steps: grasping the output characteristics of distributed small hydropower and photovoltaic through investigation and research; determining a data processing rule and an optimization strategy according to historical data of an electricity consumption information collection system excavated by using the big data mining technology; researching the key technology and the manufacturing technology; manufacturing a prototype; researching an upper layer data platform and the control system technology; and performing power quality integrated monitoring and control technology engineering construction on an active power distribution network. By adoption of the method disclosed by theinvention, the conventional extensive voltage quality management mode is changed, and the method disclosed by the invention has the characteristics of improving the power receiving quality of users,realizing global voltage adjustment and improving the project investment benefit ratio.

The invention discloses a dynamic overload on-load wide-amplitude pressure regulating distribution transformer. The dynamic overload on-load wide-amplitude pressure regulating distribution transformer comprises a low-voltage paper tube, a high-voltage paper tube and an outer shell; two low-voltage coils arranged between the low-voltage paper tube and the high-voltage paper tube, and a low-voltage oil way is formed between the two low-voltage coils; an oil way between the high voltage and the low voltage is arranged between the low-voltage paper tube and the high-voltage paper tube; the high-voltage paper tube is adjacent to a first high-voltage coil, a first high voltage oil way is arranged between the first high-voltage coil and a second high-voltage coil, and a second high voltage oil way is arranged between the second high-voltage coil and a third high-voltage coil; a corrugation cooling fin is arranged in an oil tank of the transformer, an upper oil way opening and a lower oil way opening are formed in the corrugation cooling fin, and oil circulates between the upper oil way opening and the lower oil way opening. The dynamic overload on-load wide-amplitude pressure regulating distribution transformer can solve the problem that in the prior art, the distribution transformer often operates in the light load state or the unloaded state and at low voltage, and has the advantages that the good radiating effect is achieved, and the power distribution reliability is improved.