Comments on “Design of practical sliding-mode controllers with constant switching frequency for power converters”

The conventional direct torque control (DTC), based on the hysteresis controllers and the switching table, operates with a variable switching frequency, which decreases the conventional DTC performances, like the torque and flux ripples. Thus, the space vector modulation (SVM), used in the DTC, ensures a constant switching frequency and improves the DTC performances. The first aim of this paper is to present a comparison study between the DTC with an SVM (DTC-SVM) based on the Proportional Integral regulators (DTC-SVM-PI) and the DTC-SVM based on the sliding mode controllers (DTC-SVM-SMC). These two approaches are complex control algorithms which require faster micro-controllers; therefore the second objective of this paper is to present the implementation of the DTC-SVM-PI and the DTC-SVM-SMC on the Field Programmable Gate Array (FPGA), due to the parallel processing capability of the FPGAs. The two approaches are designed and simulated using the Xilinx System Generator (XSG) and implemented using an FPGA Virtex 5. The simulation results in the transient behavior and the steady state of the induction motor controlled by these two approaches are compared and discussed. The hardware FPGA implementation results show the effectiveness of the FPGA relative to the digital signal processor in terms of execution time.

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Sliding Mode Controllers for the Regulation of DC/DC Power Converters

IFAC Proceedings Volumes ◽

10.1016/s1474-6670(17)34702-x ◽

2003 ◽

Vol 36 (18) ◽

pp. 407-412

Author(s):

Rui Esteves Araújo ◽

Américo Vicente Leite ◽

Diamantino Silva Freitas

Keyword(s):

Power Converters ◽

Sliding Mode ◽

Dc Power ◽

Sliding Mode Controllers

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SLIDING MODE DESIGN OF CONTROL AND MODULATOR ELECTRONICS FOR POWER CONVERTERS

Journal of Circuits System and Computers ◽

10.1142/s0218126695000229 ◽

1995 ◽

Vol 05 (03) ◽

pp. 355-371 ◽

Cited By ~ 34

Author(s):

J. FERNANDO SILVA

Keyword(s):

Steady State ◽

Sliding Mode Control ◽

Power Converters ◽

Sliding Mode ◽

Power Converter ◽

Operating Conditions ◽

Switching Frequency ◽

Circuit Parameter ◽

Mode Control ◽

State Error

This paper presents state-of-the-art application of Sliding Mode Control theory, to improve the performance and to integrate the modulator and control electronics design of power converters. This approach eliminates conventional PWM modulators and loop linear PI regulators, reducing the converter complexity, weight and volume, which increases its power density figure. Sliding Mode Control techniques are used to obtain, from the controllability canonical system model, the control law, a linear combination of state variable errors and its derivatives, whose implementation is a simple circuit, that directly generates the drive pulses for the semiconductors. The commutation strategy implements a power converter with better performances than conventional PWM controlled ones, faster response and robustness concerning circuit parameter variations and operating conditions. This non linear control approach provides zero steady-state error and, by the subtle use of limiters, short circuit ouput current limitation. Using a simple 3 level clock, it is also shown how to obtain a sliding mode controller with constant switching frequency and zero steady-state error.

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