Yukio Yamashita

Modeling and simulation of variable speed wind generator system using boost converter of permanent magnet synchronous generator

This paper proposes the variable-speed wind generator system using the boost converter. The proposed system has three speed control modes for the wind velocity. The control mode of low wind velocity regulates the armature current of the generator with the boost converter to control the windmill speed. The control mode of middle wind velocity regulates the DC link voltage with vector controlled inverter to control the windmill speed. The control mode of high wind velocity regulates the pitch angle of the wind turbine with the pitch angle control system to control the windmill speed. The hybrid of three speed control scheme extends the variable-speed range. The proposed system simplifies the maintenance, improves the reliability, and reduces the cost in compare with variable- speed wind generation system using PWM converter.

On-Engine Validation of Mean Value Models for IC Engine Air-Path Control and Evaluation

Mean value engine models (MVEM) are well established for the study of IC engine air-path performance. Closed-loop control of the air-path is used to ensure the tracking of reference signals subject to constraints. To meet these requirements model predictive control (MPC) has been applied successfully to several air-path applications. This paper reports on the development of an MVEM and suitable MPC controller for transient performance evaluation which is then applied to the engine. A linearised prediction model is evaluated at each control time step, based on the current operating conditions, which ensures the model remains valid across a wide range of speeds and loads. This linearisation of the nonlinear model allows for the formulation of quadratic programming (QP) problems, which are efficiently solved as part of the proposed MPC algorithm. Special treatment in the measurement and calculation of the states and their derivatives is demonstrated to provide excellent tracking performance and a good match between the model and real-time experimental results. The systematic process of modelling coupled with MPC is shown to closely match test-bed performance, which verifies the methodology for studying air-path hardware alternatives.

Transient Evaluation of Two-Stage Turbocharger Configurations using Model Predictive Control

© 2015 SAE Japan. There is a trend towards increasing the degree of engine downsizing due to its potential for reducing fuel consumption and hence lowering CO2 emissions. However, downsizing introduces significant challenges for the engine airpath hardware and control, if driveability is to be maintained at an acceptable level. The transient response of the engine is affected by both the hardware selection and the associated controller. In order to understand the potential performance and limitations of the possible airpath hardware, a mean value model of the engine under consideration can be utilized. One benefit of these models is that they can be used as the basis of a model predictive controller which gives close to optimal performance with minimal tuning effort. In this paper we examine different two-stage series sequential turbocharger arrangements. The benefits of the mean value engine model, together with a model based controller are shown to observe the system and actuator constraints and demonstrate the best achievable performance for several configurations. This systematic approach to system evaluation is invaluable for comparing system performance without the risk of the controller prejudicing the result or requiring an excessive amount of tuning.