The Analysis Of Original Power Flow Model With Simplified Constraints And Network Loss Optiomal Conditions

Power flow analysis with constraints is the objective needs of the steady-state operating conditions for power system, the starting point of the constraints can be focused on the system safe and reliable protection, can be focused on the load power quality, or can be focused on efficient and economic operation. Combining with the electrical characteristics of the analysis objects and simplifying constraints to seize the analysis focuses are effective ways to improve analysis ability of the power system.Based on linear network node voltage equation, considering running constraint limits combined with the optimized conditions of network loss, the original power flow model with the current injection is established. The model follows topological constraints of the basic power flow calculation, retains the linear excitation power network and the inherent characteristics of the response, forms concise basic equations; Describing quantitatively electrical contact between system varieties using sensitivity of differential solving, close to the actual needs of the electricity network,the central point and weak bus is the key to determine the effective constraint, forming a brief congruent type running constraint, then the operating constraint equations are determined; Describing the power loss as a quadratic function with current injection, which is favorable for combination linear node voltages equations, deriving network loss rate, determining the variables of operation and optimization, taking into account the optimizing conditions, then the network loss equations are determined; Finally the basic equations, constraint equations and optimization equations are taken into account to form the equations of original power flow model.The model scale is fixed.Correction equations dimension is determined by the number of nodes in the network.The basic equation, constraint equations and optimization equations are change to maintain balanced. Jacobian is a highly sparse matrix and contains constant elements, which achieves the operation scale of general power flow containing optimization analysis. Newton method is used for iterative solution, combining the characteristics of the power system to determine the initial iteration, the effectiveness is good. Finally, the accuracy and applicability of the original power flow model are demonstrated by a series of multi-angle simulation examples. The feasibility of the effective constraints and network loss analysis are verified. The analysis of diversity and the ability of multi-voltage control are demonstrated under different constraints.