Variable Structure System with Sliding Mode Controller

Super-Twisting Algorithm for DC Motor Position Control via Disturbance Observer

Direct Current (DC) motors have been extensively used in many industrial applications. Therefore, the control of the speed of a DC motor is an important issue and has been studied since the early decades in the last century. This paper presents a comparison of time response specification between conventional Proportional-Integral-Derivatives (PID) controller and Linear Quadratic Regulator (LQR) for a speed control of a separately excited DC motor. The goal is to determine which control strategy delivers better performance with respect to DC motor's speed. Performance of these controllers has been verified through simulation using MATLAB/SIMULINK software package. According to the simulation results, liner quadratic regulator method gives the better performance, such as settling time, steady state error and overshoot compared to conventional PID controller. This shows the superiority of liner quadratic regulator method over conventional PID controller.

Optimal Speed Control for Direct Current Motors Using Linear Quadratic Regulator

This paper proposes a sliding mode control scheme for effective speed tracking by obtaining ripple free torque through the inner loop current control for a BLDC motor. The second order mathematical model of the BLDC motor is developed for simulation purposes. Two first order sliding controllers based on the exponential reaching law algorithm are proposed for the inner loop current control and also for outer loop speed control of the drive. Performance of the speed tracking is then compared with a classical PI (Proportional and Integral) controller implemented for the speed loop, and the advantages of the proposed sliding mode scheme related with reduction of steady state error, settling time, percentage overshoot and disturbance rejection are summarized.

Sliding mode scheme for speed and current control of brushless DC (BLDC) motor

One technology to support production speed is electric motors with high performance, efficiency, dynamic speed and good speed responses. DC motors are one type of electric motor which is used in the industry. Sliding Mode Control (SMC) is the robust non-linear control. The basic theory regarding SMC is presented. The SMC design which is implemented is the speed control of the DC motor is analyzed. The controller is implemented in simulation using MATLAB / Simulink environment. The step response and signal tracking test unit are carried out. The results show that SMC has a better performance compare to PID which is faster settling time and no overshoot and undershoot.

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Basic Tutorial on Sliding Mode Control in Speed Control of DC-motor

The main objective of this paper is to control the speed of separately excited DC Motor using a Sliding mode controller based on VSS approach. This controller is based on variable structure systems which aim at reducing the peak overshoot, steady state error and settling time of a DC Motor. In the first stage, PI controller is used to control the speed of DC Motor. A model is developed and simulated using MATLAB/SIMULINK. Later on the same is done with sliding mode controller. The speed control of DC Motor using both PI and Sliding mode controllers is studied and the results are compared. The simulation results show that Sliding mode controller is superior than PI for speed control of DC motor. Since the SMC is robust in presence of disturbances, the desired speed is perfectly tracked.

Sliding Mode Speed Control of a DC Motor

Shunt active filters (SAFs) can be used for harmonic mitigation, reactive power compensation and power factor control in electrical distribution networks. Model predictive controller (MPC) can be used to give optimum performance for SAF’s due to its inherent cost function optimization. The SAF’s reference current extraction technique in finite control set-MPC (FCS-MPC) plays a vital role in the effectiveness of the SAF’s operation. The advantage of FCS-MPC is that it closely tracks the reference and injects the required compensating currents by optimizing the SAF’s switching vector and it does not require an external modulator for pulse generation. FCS-MPC can be implemented as either an optimal switching vector MPC (OSV-MPC) or an optimal switching sequence MPC (OSS-MPC) technique. The OSV-MPC technique is simple and efficient for SAF applications. In this paper, a novel reference current extraction technique, the inverse matrix average pq-synchronous reference frame (SRF) (IMApq-SRF) technique, is proposed along with the OSV-MPC technique. Practically a two-step delay compensation is essential in the implementation of the technique for the control of an SAF. Hence in this paper a two-step horizon OSV-MPC technique is proposed along with an IMApq-SRF reference current extraction technique to improve the power quality in distribution networks. The presented results show that the proposed methodology gives optimum SAF performance under a large range of supply and load conditions. 

A Two-Step Horizon Optimum Switching Vector-Model Predictive Control with a Novel Shunt Active Filter Reference Current Extraction

Traditionally, the insulating oil’s characteristics are measured by analyzing various properties such as electrical, chemical, and physical properties. Because these methods are lacking accuracy, the spectroscopy analysis has been incorporated with conventional testing for assessing the critical properties of proposed non-edible Pungamia oil (PP) as a biodegradable insulating oil for transformer. The results are evident that PP oil’s critical characteristics are meeting the standard requirement as an insulating material for the transformer applications. DGA analysis illustrates that the combustible gas emission on mineral oil is higher than that of PP samples. From FTIR and UV–VIS analyses it is observed that the thermal withstanding ability of PP is well comparable to that of mineral oil. SEM analysis revealed that the deterioration rate of cellulose-insulating material immersed in PP is lower than that immersed in mineral oil. XRD analysis proved that crystallite reduction in mineral oil immersed cellulose-insulating material is higher than the ester oil.Abbreviations: CH4: methane; C2H2: acetylene; C2H4: ethylene; C2H6: ethane; CO: carbon monoxide; CO2: carbon dioxide; DGA: dissolved gas analysis; FTIR: Fourier transform infra-red spectroscopy; H2: Hydrogen; MO: mineral oil; NEO: natural ester oil; PO: Pungamia oil; SEM: scanning electron microscope; UV: Vis-Ultraviolet–visible spectroscopy; XRD: X-ray diffraction analysis 

Investigation of Pungamia Oil Properties Using Spectroscopy for Transformer Applications

The nonlinear characteristics of power electronic-based loads in a power system contribute a major role in the harmonics’ injection and other power quality disturbances. This affects the quality of the power supplied to consumers by distribution systems. Flexible AC transmission system (FACTS) devices at the transmission level and custom power devices at the distribution level are used for an effective power transfer. In addition to these devices, filters play a prominent role in distribution systems. This paper aims to analyze the supply voltage in the time–frequency domain to perceive the variations in signal strength, explaining the role and significance of filters in mitigating or reducing harmonics. This paper presents the significance of harmonic filters in terms of signal-processing terminology. This depicts the prominent role of filters in improving the power quality by harmonic reduction or elimination, depending upon the requirement. The mathematical transform used in this approach is the short-time Fourier transform, which results in transforming the signal into a domain giving information about time and frequency. A MATLAB Simulink environment and ‘spectrogram’ were used to simulate harmonic signals, and we analyzed them using a short-time Fourier transform. Different windows were used with varying window size lengths.

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K. Amaresh

Papers

Sliding Mode Speed Control of a DC Motor

A Two-Step Horizon Optimum Switching Vector-Model Predictive Control with a Novel Shunt Active Filter Reference Current Extraction

Investigation of Pungamia Oil Properties Using Spectroscopy for Transformer Applications

Significance of Harmonic Filters by Computation of Short-Time Fourier Transform-Based Time–Frequency Representation of Supply Voltage