The Assessment Technology Of Power Grid Operation Status Based On Hybrid Measurements

The construction of smart grid has brought opportunities and challenges to the development of electric power industry. Along with the electric vehicles and large-scale grid connected power electronic devices, power grid structure will become more and more complicated, which will affect severely the state of the power grid. The security and stability of production and operation of the power system is directly relevant to the state of power grid operation state. Therefore, it is very important to study the state evaluation technology of power grid.Based on the power flow calculation of the operation state evaluation of the power grid, this paper studies the heat balance equation, which clarifies the energy conversion mechanism of the conductor of the transmission line. In addition, power components between thermal resistance model are analyzed and the heat balance equation is properly simplified. By improving Newton-Ralph power flow algorithm, the branch conductor temperature is added to the algorithm as the state variable of the system, which expands the Jacobian matrix.Through the establishment of the coupling model between imbalance quantity of reactive power, active power and temperature, voltage, phase angle, the extended Jacobian matrix is iterated continually. On the basis of this model, the power flow is analyzed. Through using MATLAB to program the function of the algorithm, the effectiveness of the proposed algorithm is verified by the simulation and analysis of IEEE 39 bus system. Simulation shows the numerical variation of line loss, line resistance and node voltage for power flow algorithm considering environmental temperature and the Newton Raphson power flow algorithm. Analysis results show that, the power flow information will change markedly considering the influence of environmental temperature. With the temperature rising, the extent of this change will be more obvious.In this paper, a comprehensive evaluation model based on Grey Osculating value is proposed by the analysis of multi-index data in power network. The subjective weight value is gained through the traditional expert weighting method-Analytic Hierarchy Process(AHP). Because the index cannot exist alone in the process of long-time running and there must be the relationship of mutual connection and interaction between each index, the objective weighting can be obtained by entropy method, variation coefficient method, CRITIC method. The way that deviation of Game Theory is minimum is used to get the objective weight. The improved Kendall harmony coefficient is introduced into subjective and objective weight to get the final weight value. By combining Grey Relational Analysis method that studies small data, poor information and uncertain problems with the traditional osculating value method. Grey Osculating value method based on geometric trend and geometric distance is proposed to analyze multi index data in Grid.For a regional power grid, the evaluation index model of power network operation is established based on safe operation, economic benefit and environmental protection and each index is given a clear definition. Through the collection and calculation of the existing power grid data, the operation situation of power grid in the five days is compared by using the grey Osculating value evaluation model. The results of the evaluation are obtained, which provides guide for the analysis of the operation condition on a specific day.