Variable structure control for an isolated boost converter used in fuel cell applications

In recent years fuel cells have become prominent as an alternative source of energy to meet the society’s energy requirements. A control strategy derived from variable structure theory known as Sliding Mode Control (SMC) was proposed for an Isolated Boost topology which was mostly used in fuel cell systems. Converter operation and its detailed mathematical modelling are also presented. Then the converter with the control strategy suggested is simulated in MATLAB/SIMULINK and compared with other controllers. The results show that transient response of the converter is very fast and steady state error is reduced throughout the load change period with proposed control topology

VECTOR CONTROL SCHEME FOR INDUCTION MOTOR WITH DIFFERENT CONTROLLERS FOR NEGLECTING THE END EFFECTS IN HEV APPLICATIONS

This paper develops the application of a different control strategy to the vector control of the voltage-fed induction motor. The proposed model decomposes the control task into three loops, namely, the speed loop, the d-axis flux loop and the q -axis flux loop. Then, tracking of speed with different controllers is designed for each loop. Proportional- Integral update laws are used to adjust the control parameters, which increases the tracking performance (Z-N Method) .Simulations are obtained shows good robustness against parameter variations, high tracking performance and simplicity of implementation

Simulation of DTC-CBSVPWM fed SPMSM Drive with Five-level Diode Clamped Inverter

In this paper a simulation analysis of DTC-CBSVPWM of SPMSM drive using five-level diode clamped inverter is analyzed. It has simple structure and provides dynamic behavior comparable with classical DTC. Direct Torque Control (DTC) is an accurate controller for permanent magnet synchronous motor (PMSM) due to its robust and fast torque response in steady-state and transient operating condition. However, the main disadvantage of DTC is high ripples in stator current, flux linkage and torque due to the application of same active voltage vector during the whole sample period and possibly several consecutive sample intervals. This can be overcome by using proper modulation technique. Space Vector Modulation (SVM) which synthesizes any voltage vector lying inside the sextant gives good performance, but however the complexity involved is more in calculating angle and sector. To reduce the complexity involved in SVPWM, a novel modulation technique named Unified voltage modulation or carrier based space vector pulse width modulation (CBSVPWM) is described using the concept of effective time. By using this method the inverter output voltage is directly synthesized by the effective times and the voltage modulation task can be greatly simplified. The actual gating signals for each inverter arm can be easily deduced as a simple form using the effective time relocation algorithm