Configuration Optimization And Application Of Shunt Active Power Filter In Distribution Network

With the deepening of power system reform,high efficiency and energy saving have also become one of its development goals.This article takes the efficient and energy-saving application of shunt active power filter(SAPF)as the starting point,conducts in-depth research on its installation and use,and puts forward the optimization goal of efficient and energy-saving.The main research content of this paper involves two aspects: the optimization of the access scheme of the shunt APF and the optimization of the output compensation during the actual operation.It provides a more complete method of SAPF access configuration optimization and operation capacity configuration optimization in the power system.First,according to the distribution network impedance parameters and network structure,a simplified model of its harmonic domain is established,and the relationship between the voltage of each node and the branch harmonic voltage source and current source is derived.It proposes the establishment of an alternative busbar library for SAPF with perturbation analysis.On this basis,for the small distribution network only need to install a single SAPF for harmonic control,comprehensive consideration of capacity cost and harmonic network loss,the use of multiple methods to construct two single-objective optimization functions,combined with Kuhn-Tucker ’s theorem and the dichotomy iterative idea to optimize the access configuration of a single SAPF.According to this method,the installation capacity and location of a single SAPF can be determined,which can make the harmonic control cost of the small distribution network more economical and the harmonic loss is less.Secondly,for large-scale distribution networks where multiple SAPFs need to be installed for harmonic management,the optimization objectives are divided into two aspects with regard to capacity,number,location,and harmonic current configuration at the time of installation.The first layer combines the alternative bus library obtained by the perturbation analysis method to determine the best installed access capacity and number of units that can enable "SAPF to meet the national standards of power quality with the lowest possible equipment cost.The second layer completes the optimization goal of the lowest harmonic network loss on the basis of the first layer,and determines the best installation location and the best injection of each harmonic current.For large distribution networks,this method can ensure that the installation of multiple SAPFs with the lowest total cost of the device to meet the system voltage distortion within the allowable range of national standards,while reducing harmonic network losses to the greatest extent.It can obtain the harmonic control effect that meets the national standard in a more economical situation,and at the same time reduce the power loss caused by harmonics as much as possible.Finally,for the situation that SAPF cannot fully compensate harmonics and reactive power during operation,a control strategy based on recursive discrete Fourier(RDFT)algorithm and second-order generalized integrator(SOGI)is proposed to adaptively The output capacity of SAPF is optimally configured to distribute the harmonic currents reasonably.Calculate the effective value of each harmonic current to be compensated by RDFT calculation.According to the remaining capacity of SAPF,adaptively adjust the number and coefficient of harmonic current compensation.Use SOGI to extract the harmonic current that can actually be compensated,and then use the combined control strategy of PI control and repetitive control to track the command current centrally.This process optimizes the configuration of the SAPF output capacity without changing the hardware,so that it approaches the rated capacity,improves the device utilization,and maximizes the SAPF governance effect when the capacity is limited during operation.