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Voltage Frequency Recovery And Reactive Power Allocation Based On Consensus Algorithm

Posted on:2018-08-07Degree:MasterType:Thesis
Country:ChinaCandidate:P Y CuiFull Text:PDF
GTID:2322330515962141Subject:Agricultural Electrification and Automation
Abstract/Summary:PDF Full Text Request
Today,more and more attention has been paid to clean energy based distributed generation in the world today,the micro grid is the most effective way of integrate large amout of distributed generations(DG)and applied to practice,it is the most feasible way to integration of distributed power and traditional power system.Compared with the traditional power grid,microgrid can improve the power supply stability,reliability and power quality,but the intermittent and randomness of distributed generation exposed its'limitation.The accurate control of the power,the maintenance of the stability of the voltage and the control of the frequency inverters has gradually become one of the most popular research directions in the field of micro grid.Traditional centralized control method can not solve the problem of the Various modes Micro grid of operation,for example,low controllable,the problem of controlling the complex systems induced by hard to collect information.But based on the distributed multi-agent control method has obvious advantages to solve the problems caused by a large number of distributed grid access into the grid.By using the multi agent control theory into the micro grid inverters of distributed control,this paper get some achievements about island operation of the micro grid Distributed generation,accurate power distribution and recovery control of two level voltage and frequency.The details are as follows:Aiming at the problem of voltage and frequency offset caused by traditional droop control and the actual situation of line impedance mismatch,from the limitations of microgrid and distributed power generation modeling and secondary controller,Algorithm of distributed secondary voltage,frequency recovery control strategy.In the secondary frequency recovery control,a distributed secondary frequency recovery controller considering the optimal allocation of active power is proposed.In the secondary voltage recovery control,a distributed average is considered considering the unbalanced line parameters and using dynamic consistency control Voltage recovery control strategy.The simulation proves that the proposed distributed secondary control method can guarantee the voltage amplitude and frequency recovery.Aiming at the problem of imprecise of reactive power allocation in traditional sagging control and the actual situation of line impedance mismatch,the reactive power allocation of load is analyzed from the aspects of traditional voltage/reactive droop control and impedance characteristic of microgrid transmission line.Mechanism of Circulation Suppression.Through the virtual impedance adjustment,the traditional droop control method results in the decoupling between the active power and the reactive power,and establishes the reactive power allocation control strategy based on the consistency algorithm.This algorithm finds the reactive power distribution error by multi-agent consistency algorithm.So that the reactive power distribution adaptive adjustment of the virtual impedance,in order to get in accordance with the distributed power capacity inversely proportional to the equivalent line impedance.According to the principle of proportional power distribution based on virtual impedance adjustment,the reactive power of the load between multi-distributed power generation is precisely distributed.
Keywords/Search Tags:micro grid, droop control, consensus algorithm, kuramoto model, Reactive power distribution
PDF Full Text Request
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