Research On Harmonic Source Identification And Harmonic Economic Loss Assessment Method Of Power System

With the rapid development of power electronics and new energy equipment,harmonic pollution always affects many devices in the power system and brings many hazards,such as shortening the service life of devices,increasing the power loss of devices,affecting the power quality and causing a series of power accidents such as power system collapse in serious cases.Therefore,the harmonic pollution problem needs to be solved urgently.Firstly,it is necessary to accurately identify the harmonic sources to provide a theoretical basis for the subsequent harmonic treatment,which is of great significance and reference value for the power system to maintain a healthy power quality,and secondly,in order to better quantify the degree of harm caused by harmonics to the power grid,it is necessary and essential to accurately calculate the economic loss caused by harmonics,which provides a calculation basis and reference value for the power enterprises to further develop a reasonable charging scheme.This provides the calculation basis and reference value for power companies to further develop reasonable charging schemes.Firstly,this paper establishes an equivalent model for harmonic sources,and analyzes and compares the currently existing methods for modeling harmonic sources.Secondly,this paper elaborates on the widely used harmonic source identification methods and their improvement methods.By building simulation examples and verifying the rationality of these identification methods,it is found that there are certain limitations of the above methods,which provide theoretical basis and ideological inspiration for further accurate identification of harmonic sources.Then,considering the limitations and unreasonableness of the current mainstream harmonic source identification methods,a new harmonic source identification method is proposed,inspired by the idea of harmonic source segmentation,which identifies harmonic sources by comparing the differences between non-harmonic sources and harmonic sources,without contradictory results of harmonic source identification at different frequencies.And the feasibility and rationality of the proposed method are verified by building simulation cases.Finally,considering the economic loss caused by harmonics to electric power enterprises,the harm caused by harmonics needs to be assessed quantitatively.Electricity,as a commodity produced by electric power enterprises,must meet the quality requirements of the national standard "Power Quality: Harmonics in Public Power Grids"(GB/T 14549-93).In this paper,based on the quality engineering theory and IEEE Std.1459-2010 power theory,we establish the set of harmonic economic loss indexes and derive the harmonic economic loss function.Based on this basis,the economic loss caused by harmonics is calculated by combining the current national regulation of power generation cost,and finally the simulation example is set to verify its feasibility.The calculation of harmonic economic loss can quantify the degree of harm caused by harmonics to the power system to a certain extent,which has certain reference value for the subsequent management.