SIMULASI PENGATURAN KECEPATAN MOTOR INDUKSI 3 PHASA DENGAN DIRECT TORQUE CONTROL MENGGUNAKAN MATLAB

Induction motors are widely used in the industrial world because they have many advantages, including construction that is very simple and strong, cheap, has high efficiency, quite good power factor, and maintenance is easier. Besides the advantages of induction motors also have weaknesses, one of the disadvantages of an induction motor is not being able to maintain its speed constantly if there is a change in load. If there is a change in load, the speed of the induction motor will decrease. One method of regulating the speed of an induction motor developed in addition to vector control is the Direct Torque Control (DTC) method. The DTC control technique allows direct and separate flux and torque settings and can be done without using a speed sensor. The estimated rotor rotation, torque and flux is carried out by the DTC which is inputted with stator voltage and current. To achieve the desired flux and torque estimation is used as feedback on the control system. In this final assignment, the speed regulation of the induction motor will be simulated using the DTC method using Matlab. The results obtained through the simulation show the length of time to reach the reference speed for speeds of 500rpm and 1000 rpm is around 0.5 seconds. Keywords : Induction motor, Direct Torque Control, Matlab

Enhanced Electric Propulsion with Space Vector PWM based Induction Motor

This paper investigates the application of Space Vector Pulse Width Modulation (SVPWM) for enhanced electric propulsion systems with induction motors. Induction motors are widely used due to their robustness and efficiency, but achieving precise control over speed and torque can be challenging. Traditional scalar control methods have limitations. SVPWM is a sophisticated technique for generating inverter gate pulses that minimizes switching losses and creates a current waveform closer to a sine wave. This research explores the potential of combining SVPWM with scalar control for improved motor performance. The paper analyzes the principles of induction motor operation and the limitations of scalar control. It then introduces SVPWM and its advantages. The core focus is on the impact of the combined SVPWM-scalar control approach on speed regulation, torque control, and overall drive efficiency. The study also explores practical considerations and potential limitations of this control scheme. The research suggests that SVPWM offers a promising technique for improved electric propulsion. The findings indicate that SVPWM can lead to better overall motor performance, potentially through increased efficiency, improved torque control, or reduced torque ripple. Additionally, the research suggests that SVPWM allows for more precise speed and torque control compared to traditional methods

Torque Control Accuracy Using Different Techniques for Determination of Induction Motor Rotor Time Constant

Abstract – Induction motor (IM) drives represent a competitive solution for both industry and transports electrification. Most control solutions for induction motors currently perform the torque regulation by implementing field- oriented control (FOC) algorithms schemes defined in rotating dq coordinates. According to this scenario, the estimation of the d-axis position covers a key role to get good accuracy of the torque regulation. If considering the low-speed operation of the motor, the torque control performance is significantly affected by the accuracy in estimating the rotor time constant. According to the literature, this parameter can be computed using either the results of standard- (no-load and locked rotor tests) or flux-decay tests. However, these tests get unequal values of the rotor time constant, thus leading to a different torque control performance. Therefore, this paper aims at investigating the best value of the rotor time constant to optimize the accuracy of the FOC-based torque control. Experimental results obtained on a 4 poles IM, rated 10 kW at 6000 r/min, are presented

Analysis of overload and sensorless control capability of PM-assisted synchronous reluctance machines

Synchronous reluctance machines are a valid alternative to induction motors for industrial applications requiring variable speed regulation. To mitigate the well-known downside of their lower power factor, permanent-magnetassisted topologies are adopted. Both high-strength rare-earth magnets and low cost ferrite magnets can be used in such machines. Their design and optimization procedures have been discussed in related literature. This paper compares synchronous reluctance machines assisted with NdFeB and ferrite magnets, focusing on torque overload capability and feasibility of saliencybased position estimation algorithms. Three prototypes were realized and tested. They all have the stator of a commercial induction motor, and three custom synchronous reluctance rotors with same laminations: one has no magnets, the other two have NdFeB and ferrite magnets respectively, designed to give the same torque at rated current. Results from simulations and experiments are presented, focusing on torque and demagnetization limits in the over-current loading range. Moreover, the feasibility of saliency-based sensorless methods is investigated, both at high and low current loads. The results of the paper suggest that the ferrite-assisted solution is the candidate solution for replacing induction motors in variable speed applications

Detection and Diagnosis of Motor Stator Faults using Electric Signals from Variable Speed Drives

Motor current signature analysis has been investigated widely for diagnosing faults of induction motors. However, most of these studies are based on open loop drives. This paper examines the performance of diagnosing motor stator faults under both open and closed loop operation modes. It examines the effectiveness of conventional diagnosis features in both motor current and voltage signals using spectrum analysis. Evaluation results show that the stator fault causes an increase in the sideband amplitude of motor current signature only when the motor is under the open loop control. However, the increase in sidebands can be observed in both the current and voltage signals under the sensorless control mode, showing that it is more promising in diagnosing the stator faults under the sensorless control operation

Unified Direct-Flux Vector Control for AC Motor Drives

The paper introduces a Unified Direct-Flux Vector Control scheme suitable for sinusoidal AC motor drives. The AC drives considered here are Induction Motor, Synchronous Reluctance and synchronous Permanent Magnet motor drives, including Interior and Surface-mounted Permanent Magnet types. The proposed controller operates in stator flux coordinates: the stator flux amplitude is directly controlled by the direct voltage component, while the torque is controlled by regulating the quadrature current component. The unified direct-flux control is particularly convenient when flux-weakening is required, since it easily guarantees maximum torque production under current and voltage limitations. The hardware for control is standard and the control firmware is the same for all the motors under test with the only exception of the magnetic model used for flux estimation at low speed. Experimental results on four different drives are provided, showing the validity of the proposed unified control approac

Harmonic Reduction Using THIPWM Switching Technique with Type-2 Fuzzy on 3-Phase Motor

The development of the increasingly advanced industrial world has increased the need and use of electric motors for various purposes. In the industrial world, many electric motors are found as a driving device to drive various equipment needed, including a three-phase induction motor. The induction motor is expected to operate normally by the desired working characteristics. But it is undeniable that in its use, there are disturbances that can cause damage to the work system of the Induction motor, one of which is harmonic interference. The influence of harmonics on the induction motor causes copper and core losses which will reduce the efficiency motor and cause harmonic torque along with fundamental torque to produce vibration and noise, which considerably affect the operation three-phase induction motor. In this study, a 3-phase inverter was used with the Third Harmonic Injection pulse width modulation (THIPWM) method, with the use THIPWM Switching Method expected to increase the output voltage three-phase inverter and reduce the harmonics caused by the three-phase induction motor. In optimizing a 3-phase induction motor's speed regulation, scalar control or voltage/frequency (v/f) regulation is used. With the use THIPWM switching on this three-phase inverter, it is evident from simulation results that the harmonic value of THDV is 55.62%. THDI is 19.04%, as well the acceleration 3-phase induction motor with a rise time value of 48.547ms with steady-state error of 0.08% at set point 1200 rpm and with rise time value of 52.938ms with steady-state error 0% at set point 1000 rpm

Optimal design of switched reluctance motors

The fundamental theory of the switched reluctance motor is presented with a number of new equations. It is used to show how the practical development of a design calculation should proceed, and this leads to a discussion of physical characteristics required to achieve satisfactory performance and to reduce acoustic noise. The paper makes a few generic observations on the characteristics of successful products that use switched reluctance motors. It is written at a basic engineering level and makes no attempt to apply sophisticated optimization theory

Indirect Field Oriented Control of Induction Motors is Robustly Globally Stable

Field orientation, in one of its many forms, is an established control method for high dynamic performance AC drives. In particular, for induction motors, indirect fieldoriented control is a simple and highly reliable scheme which has become the de facto industry standard. In spite of its widespread popularity no rigorous stability proof for this controller was available in the literature. In a recent paper (Ortega et al, 1995) [Ortega, R., D. Taoutaou, R. Rabinovici and J. P. Vilain (1995). On field oriented and passivity-based control of induction motors: downward compatibility. In Proc. IFAC NOLCOS Conf., Tahoe City, CA.] we have shown that, in speed regulation tasks with constant load torque and current-fed machines, indirect field-oriented control is globally asymptotically stable provided the motor rotor resistance is exactly known. It is well known that this parameter is subject to significant changes during the machine operation, hence the question of the robustness of this stability result remained to be established. In this paper we provide some answers to this question. First, we use basic input-output theory to derive sufficient conditions on the motor and controller parameters for global boundedness of all solutions. Then, we give necessary and sufficient conditions for the uniqueness of the equilibrium point of the (nonlinear) closed loop, which interestingly enough allows for a 200% error in the rotor resistance estimate. Finally, we give conditions on the motor and controller parameters, and the speed and rotor flux norm reference values that insure (global or local) asymptotic stability or instability of the equilibrium. This analysis is based on a nonlinear change of coordinates and classical Lyapunov stability theory

Thermal analysis of induction and synchronous reluctance motors

In this paper, the thermal behavior of two induction motors (2.2 and 4 kW, four poles) and two synchronous reluctance motors [(SynRMs) transverse-laminated] are investigated and compared. Both motor types use the same stator but have different rotors. Using a lumped-parameter simulation program, a thermal analysis has been also carried out, and the obtained results have been compared with the experimental ones. A direct comparison of the thermal behavior of the two motor types has thus been made for constant load and constant average copper temperature conditions. Inasmuch as the SynRM has negligible rotor losses compared with the induction motor, it is capable of a larger rated torque, from 10% to more than 20%, depending on the relative size of end connections and motor lengt