| Electricity is an important energy source, it plays an important role in people’s lives and industrial production. At the same time, to meet the needs of social and industrial production and the electricity in people’s life. Improving the power quality is the reflect of the increase of the level of society and technology and the progress in national industry. The request of modern power system load structure,production process and electrical equipment for power quality have become higher and higher. With a lot of impact resistance and nonlinear loads used in the power system, it has brought great harmonic pollution to the power system, meanwhile, it has undermined the power quality of the grid. The accurate estimation to harmonic and inter-harmonic parameters is the premise of handling them. At the same time, harmonics, inter-harmonics signal that is one of the key technologies of active filtering and reactive power compensation is extracted quickly and accurately. In this paper, the power system harmonic is detected according to spatial spectrum estimation algorithm.Spatial spectrum estimation is an important research field of array signal processing development of the subject, focusing on research space multi-sensor array processing system to accurately estimate the parameters of the signal of interest in the space. Spatial spectrum estimation applications has been involved in many other fields, such as radar, sonar, communications, exploration, earthquake. At the same time, some papers about harmonics, inter-harmonics detection in the power system has been published. In this paper, the data processing algorithm in spatial spectrum estimation is introduced into the power system harmonics, inter-harmonic parameter detection, to do the following research on spatial spectrum estimation technique and its algorithm:1.It introduces the source of power system harmonics, the necessity of the hazards and power system harmonic detection, and the harmonic detection methods and their advantages and disadvantages.2.It introduces the spatial spectrum estimation theory, the number of source estimation algorithm, a combination of the Gerschgorin methods and TAM algorithms, as well as the contrast between the detection results of the analysis of the algorithm in the simulation of power system harmonic detection and its traditional power system harmonic detection algorithm. The factors that influence the results are analyzed by analyzing the results of data.3.Based on the theory of Estimation of Signal Parameters via Rotational Invariance Techniques, ESPRIT proposed a combination of both algorithms and will be used in the power system harmonic detection, and gives the comparison between algorithm and the traditional algorithms under different Gaussian white noise.4.Combining the theory of the beam space in spatial spectrum and finding roots of multiple signal classification algorithm are apply in theoretical knowledge and power system harmonic detection, and gives the traditional algorithm in different Gaussian performance comparison, under the influence of white noise, the harmonic detection results of the analysis of simulation results and the actual data show that the algorithm has good estimation performance.5.The proposed three algorithms are compared under different signal-to-noise ratio conditions, the results were analyzed. Experiment show that the three algorithms in power system harmonic detection is feasible. |
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