Rearch Of Time-of-Use Price Optimization Model Considering Load Variance

Time of use(TOU) price can reduce peak-valley difference and promote load rate and the reliability of power system. TOU price has brought about great social and economic benefits since the implementation. The key to the implementation effect of TOU price is whether or not peak and valley time period partition and the establishment of TOU price are reasonable, so the contents of this paper are mainly consisted of the following parts:(1)Basic theoretical research of TOU price. The first problem to the establishment of TOU price is to study the relationship between electricity price and load. Based on elasticity of demand theory, this paper constructs the relationship between elasticity price of peak, flat and valley time periods and peak and flat and valley load by price elasticity matrix of demand. Peak and valley time period partition is the basis of the establishment of TOU price, now most of the methods are based on the membership function in fuzzy mathematics, then take advantage of basic principles of peak and valley time period partition, most of the load can be detemined to belong which period, but the load around the division of peak, flat and valley time is difficult to be determined to belong which period. This paper combine two methods of the membership of peak and valley time period and load variation rate to solve the problem of the time around the division of peak, flat and valley time.At last through the example simulation, the conclusion indicated that the result of peak and valley time period partition in the paper is the same to the actual situation.(2)The establishment of TOU price optimization model. TOU price optimization model generally uses peak-valley difference to measure the effect of peak load shifting by TOU price. This paper firstly proves the impact of load variance on power line transmitting loss, then establishes the TOU price optimization model considering load variance based on that load variance can measure the overall load fluctuation better. At last through the example simulation, the conclusion indicated that electricity price of peak, flat and valley loads that this paper get can reduce peak-valley difference and load fluctuation, promote the efficiency and economy of the power grid operation, the interest of customers and power supply company also get the assurance, so the TOU price optimization model in this paper has a certain rationality and feasibility and compared with classic optimization model, the final outcome of the optimization analysis is closer to the practical conditions.(3)The solution of TOU price optimization model. Now the solving method of single-objective optimization model is already mature, in this paper, we use fmincon function in MATLAB optimization toolbox to solve single-objective optimization mode. TOU price optimization mode is a multi-objective optimization model, in general, different objective functions of the multi-objective optimization mode can’t get optimal value at the same time, it is common practice to transform a multi-objective problem into a single-objective one and solve it. During the common methods of multi-objective problem, ideal point method has obvious geometric meaning and can take into account all the functions better, above all it needn’t consider different weights of the functions, so this paper use ideal point method as the method of the multi-objective problem. At last through the example simulation, the conclusion indicated that ideal point method takes into account the two functions very well.