Papers by Keyword: Nonlinear Programming

Abstract: The paper is devoted to implementation of Newton Method for evaluating power system points of collapse. Unlike conventional optimization procedures the proposed method doesn`t exploit loading parameter but allows to calculate Saddle-Node bifurcation point of power flow equations directly. The paper shows principal concept of the proposed method implementation to simplest power system model.

Abstract: This paper, a new class of augmented Lagrange functions with the new NCP function is proposed for the minimization of a smooth function subject to inequality constraints. Under some conditions, we prove of the equivalences of the KKT point and local point and globe point between primal constrained nonlinear programming problem and the new unconstrained problem. By the character of augmented Lagrange function, the algorithm which uses alternating direction method is constructed and proved convergence.

Abstract: In this paper, a numerical procedure for plastic limit analysis of 3-D elastic-perfectly plastic bodies under complex loads is presented. The method is based on the lower-bound limit theorem and von Mises yield criterion so that the lower-bound limit analysis can be conducted by solving a nonlinear mathematical programming problem. A SQP algorithm and a dimension reduction-based technique are used to solve the discretized finite element optimization formulation. A conception of active constraint set is introduced, so that the number of constraints can be reduced greatly. The basis vectors of reduced residual stress spaces are constructed by performing an equilibrium iteration procedure of elasto-plastic finite element analysis. The numerical procedure is applied to carry out the plastic limit analysis of pipelines with part-through slots under internal pressure, bending moment and axial force. The effects of different sizes of part-through slots on the limit loads of pipelines are studied.

Abstract: The PM2.5 atmospheric pollution is becoming more and more serious. A lot of importance has been attached to its course of formation and control scheme. Especially the related research has been taken on the quantitative analysis and control. In this paper, a reasonable PM2.5 five years of treatment scheme is given for a city as an example. First of all, by using the correlation analysis, the correlation matrix of the city's 6 main AQI index were obtained on existing monitoring data. The correlation analysis is also taken on the PM2.5 and the other 5 primary AQI index. It gives the same conclusion, that is, PM2.5 is correlated with SO2, NO2, PM10 and CO. And the correlation is significantly linear. Then, by using stepwise regression analysis, the optimal regression equation about PM2.5 and 3 with comprehensive treatment and governance factors, PM10 SO2 NO2, is calculated. After converting the PM2.5 concentration into its AQI index for both the reference year and five years after target, the reference year's PM2.5, SO2, NO2, PM10 benchmark index value are also calculated. Then according to each of these 4 indicators of minimum changes, and still can meet the constraints, a nonlinear programming model and the nonlinear constraints are established and simplified as linear constraints. So, the model is transformed into a standard nonlinear programming problem. Finally, the possible annual average governance indicators are calculated. It Has a certain of practical significance for guiding the control scheme of PM2.5.

Abstract: Aiming to better network facility deployment and reduce cost, this paper proposed an optimization model for air traffic management airplane data communication network based on multi-objective nonlinear programming to optimize the communication network trunk node and analyze user subnetwork access. Using multi-objective decomposition method, a computer-aided resolution model is presented and then simulations proved its effectiveness. This model has theoretical instruction on air traffic management plane data communication network design, and can offer reference for relate studies.

Abstract: In order to improve the control capability of the power system voltage stability and to enhance spatial and temporal coordination of voltage control means, it is essential to establish the model of emergency voltage control that can globally mobilize reactive power support and voltage control potential. Focus on the long-term voltage stability of power system, the paper introduce nonlinear programming into emergency voltage control, settle the problem that how to establish the model of emergency voltage control. Based on detailed models of power system, the receding optimization model of long-term voltage stability control is established under framework of model predictive control. In order to improve the computational efficiency and reduce feedback delays, nonlinear programming sensitivity algorithm is proposed to solve receding optimization model. The proposed method can improve computational efficiency significantly which creates the condition for the emergency voltage control application to large-scale systems.

Abstract: In this paper, an effective method was proposed to formulate and solve a fuel-optimal satellites maneuver control problem using a continuous low-thrust system. The design of the bounded desired final satellite formation is a passive and periodic circular-like formation at critical inclination underperturbation, which adjusts to long-term flying formation. The nonlinear optimal control problem is converted into a nonlinear programming problem by the application of the Legendre pseudospectral method. Due to the design includes the free final time and the precise final condition constraint, fuel-optimal maneuver is more reasonable, thereby it will achieve the minimum fuel consumption.

Abstract: This paper proposes a new formulation of the preventive security-constrained optimal power flow (PSCOPF) which considers the constraints limiting the number of beforehand control actions and provides an approach to convert the proposed model to a nonlinear programming (NLP) which is more tractable by implementing an interior point algorithm (IPA). The proposed model and approach are illustrated on two standard test systems of IEEE-30 and IEEE-118. The results clearly indicate the system operation state can be changed from a given operation point to a PSCOPF satisfied operation point by exerting beforehand control actions in specified number. Furthermore, a minimum number of control actions can be obtained through this new formulation.

Abstract: This paper develops a new algorithm for the dynamic intersection control based on linear and nonlinear program. A new set of formula based on geometric construction are proposed to estimate the steady-and-oversaturation delay, which occasionally have the only one kind of controllable variable of the green splits. As a dynamic model, it can automatically adjust the split green ratio to achieve the minimal delay.Since the objective function of over-saturation delay is linear and under-saturation delay is nonlinear, the combination of linear and nonlinear program can be applied to either over-saturation or under-saturation situation. The simulation result shows that dynamic allocation of green time using LP combined with NLP can obtain less delay than using single liner programming.

Abstract: The nonlinear programming method is used to study the finite-thrust minimum-time orbital interception problem. Considering the spacecraft with fixed impulse, the Modified Equinoctial Elements are used to describe the movement of the spacecraft in the attached coordinate, and the model of the orbital interception problem is established. Then the trajectory optimization problem is solved by the nonlinear programming method. The simulations demonstrate that the minimum time orbital interception mission is well accomplished, and the spacecraft fly around the earth with maximum thrust magnitude at whole time history.