Investigation on electric load peak and valley characters and demand response evaluation based on spectral analysis

Along with rapid development of economic situation and industrial structure, electric loads become more and more complex; especially the peak and valley characters of electric load curves fluctuate more and more severely. The foundation of demond response evaluation is peak and valley characteristics of load curves. However, study on electric load peak and valley characters right now is few, conventional indexes of electric load characteristics such as load factor and peak-valley difference factor have shortages in estimating electric load peak and valley characters comprehensively. Spectral analysis method divides the time series of electric load into superposition of periodic components with different amplitude, phase and frequency. By means of measuring the importance of each periodic component, the main-cycles components in the change of power load can be found out. The paper uses spectral analysis method to analyze power load and pulls out two indexes to describe peak and valley characters of load curves. On basis of these indexes, the paper evaluates the effect of demand response. Finally the example has confirmed this new method developed on the basis of spectral analysis. Through spectral analysis method, research on load characteristics and demand response evaluation is transferred from time domain to frequency domain. In accordance with the spectrum characters of electric load curves, we can analyze the essence of load curves´ fluctuation more effectively.