Full Flight Envelope Transient Main Control Loop Design Based on LMI Optimization

To solve the problem of full flight envelope transient main control loop design of turbofan engine, a design method based on linear matrix inequality (LMI) is proposed. Robust stability of the closed-loop turbofan engine system in all conditions is proved by using Lyapunov inequalities. The robust performance is ensured by gain-schedule and pole-placement. Reduced order multivariable gain-schedule and minimum trace optimization algorithm are presented to guarantee the feasibility of the design method. Full flight envelope simulations based on a nonlinear turbofan engine model were done. The results show that the maximum settling time of N1cor is 4.3s and the maximum overshoot is 1.7%. The maximum settling time of N2cor is 4.5s and the maximum overshoot is 0.1%. The robust stability and consistent performance in full flight envelope are also shown in the results.

Gain Schedule PI Fuzzy Load Frequency Control for Two-Area Electric Power System

The use of proportional integral (PI) load frequency control (LFC) to ensure the stable and reliable operation of electric power system is practical important. Any imbalance between synchronous generators and consumption loads will cause frequency unstable within the complete power system. The purpose of the load frequency control (LFC) is to keep the power system frequency and the inter-area tie power as near equilibrium point. This article introduces a gain schedule PI fuzzy load frequency control (GLFC) applying to two area electric power system. The GLFC consists of two level control systems, where the PI controller in the conventional form and its parameters are tuned in real time by fuzzy system. A fuzzy rule base is constructed in the form set of IF-THEN that describe how to choose the PI parameters under different operating conditions. The simulation has been conducted in MATLAB Simulink package. The effectiveness of the GLFC is measured by comparison with conventional PI load frequency controller.

The impact of heat gain schedules on summer overheating in typical insulated dwellings

Summer overheating is usually caused by a combination of factors, such as building location, orientation, fabric, ventilation and occupancy behaviour. People by their behaviour influence overheating through the internal heat gain mode and window opening ventilation mode. The article describes several types of occupancy profiles according to their behaviour taken from the literature: the profile of the worker, the child, the pensioner and the adventurer. From them, it is possible to disable the heat gain schedule for the whole household or apartment house. Heat gains from appliances are updated according to the modern lifestyle and current household appliances. The effect of heat gains in combination with other factors, which caused overheating, is further evaluated through the building simulation program.