Fed Three-phase Induction Motor Research Articles

Neutral Point Voltage Balancing Using MOPSO based Weighting Factor Tuning for FCS-MPTC of Three Level T-Type VSI Fed IM Drive

This paper proposes designing and implementing an offline optimization of weighting factors associated with the Finite Control Set Model Predictive Torque Control (FCS-MPTC) for a T-Type Multilevel Inverter (MLI) fed three-phase induction motor drive. Since the IM drive driven by T-Type MLI requires neutral point voltage balancing for reliable and acceptable performance, a regularization term with a weighting factor is added to the cost function of FCS-MPTC involving the neutral point voltage balancing. The optimized weighting factors were obtained by applying the Vikor decision-making method on the Pareto front obtained from the Multi Objective Particle Swam Optimization (MOPSO) algorithm. The improvement is shown by comparing the results of the proposed method with the conventional FCS-MPTC applied to the same IM drive. The proposed optimization methodology also showed better dynamic performance, particularly during loading. The results from MATLAB/Simulink environment show significantly improved flux ripple and almost perfect neutral point voltage balancing with the proposed optimized version.

Effect of chording on the efficiency of induction motor supplied by PWM inverter

The increasing usage of theinverter fed three-phase induction motor due to latest technological innovations in the industry demands for designing a high efficiency motor. Three-phase induction motor stator coils were short pitched and tested with pulsewidth modulation (PWM) inverter voltage supply at various switching frequencies. Various loads were varied using eddy current brake and torque is measured using torque gauge. The effect of short pitching on the efficiency of novel winding designed motor were quantified and found that the shortest pitched coil radically improves the efficiency of the motor due to attenuation of lower order harmonics and reduced copper losses.

Simulation of SPWM Fed Three-phase Induction Motor Drive Mathematical Model Using MATLAB Simulink

Three-phase induction motors are used in a vast area of applications mainly due to their simplicity, ruggedness and high reliability. With recent advancement in semiconductor technologies, the use of fixed speed induction motor drive is becoming obsolete, majority of the applications now requires inverter-based drives for variable speed operation. In the study of induction motor drive operation, mathematical models are often used to simulate the steady state and transient behavior of induction motor. However, developing such models are not as simple. One must develop the understanding of the mathematical equations to be used and also having the knowledge to solve the equations with the use of computer simulation software. To address this issue, this work presents an approach to implement the mathematical model of a Sinusoidal Pulse Width Modulation (SPWM) fed three-phase induction motor drive in MATLAB Simulink. The sub models include induction motor direct quadrature-model and a voltage source inverter fed by SPWM signal generator. The presented model implementation is able to simulate the dynamic behavior of an induction motor operation, this mathematical model implementation would be useful for further studies on the development of induction motor drive system.

A solar PV water pumping solution using a three-level cascaded inverter connected induction motor drive

This paper presents a single-stage solution for PV fed three-phase induction motor (IM) water pumping system. The given solution uses time tested, two two-level cascaded H-bridge inverters to give three-level voltage output to the IM pump drive. The proposed system is operated using the control strategy which includes Maximum Power Point Tracking (MPPT), Space Vector Pulse Width Modulation (SVPWM) and V/f control. The MPPT algorithm generates the modulation index ‘ma’ which is used to operate the cascaded inverter and generates three-level output voltage under all environmental conditions. This helps in improving the THD of IM phase current, thereby reducing the torque ripple. In addition, the ‘ma’ value is used to define the IM operating frequency. This helps in further improvement in the IM performance. All the details of the proposed system regarding the system modeling along with simulation and experiment results are given in the manuscript. In addition, the comparison of the propsoed solution with the conventional system i.e., two-level inverter connected PV pumping system is presented.

SPEED CONTROL OF THREE-PHASE IM BY V/F OPEN AND CLOSE LOOP METHOD

This paper presents the simulation method to control the speed of three phase induction motor by v/f method. Simulation model for speed control in both open loop and close loop is shown here because these motors are the most widely used electrical motor due to the reliability, cheaper cost and thew. Out of the several methods of speed control of an induction such as change of number of poles, variation in frequency, variable stator voltage, constant V/f control, variable rotor resistance, slip recovery method etc., the closed loop constant V/f speed control method is most widely used. Pulse width modulated inverter is the basic requirement of the scheme. Here first a PWM Inverter is modeled and its outputs is fed to the Induction Motor drivesA MATLAB SIMULINK MODEL was designed to successfully implement Open Loop V/f Control on a PWM-Inverter fed three-phase Induction Motor, and the torque is observed to be constant for various rotor speeds. Then a MATLAB model for Closed-Loop V/f Control on a PWM-Inverter fed 3-phase Induction Motor. It was noticed that using a Closed-Loop scheme with a Proportional Integral gave a superior way of controlling the speed of an Induction motor.

FPGA based practical implementation of NPC-MLI with SVPWM for an autonomous operation PV system with capacitor balancing

This paper presents the field programmable gate array (FPGA) based capacitor imbalancing control scheme of neutral point clamped multilevel inverters (NPC-MLI) for standalone autonomous Photo-voltaic (PV) system using innovative space vector PWM (SVPWM) scheme. The suggested vector selection based PWM offers an excellent performance to NPC-MLI to control the capacitor balancing by using selected three vector (STV) scheme. The inverter is getting input source from the PV system and the maximum power point tracking (MPPT) is capable of extracting maximum power from the PV array connected to DC-link. The real time perturb and observe (P&O) algorithm is used for tracking the maximum power point (MPP) of a Photo-voltaic (PV) generator. A Microcontroller PIC 16F876 is operated for the MPPT control algorithm. The entire inverter control algorithm is developed and designed using the very high-speed description language (VHDL) and implemented on Xilinx SPARTAN-III 3AN-XC3S400-FPGA processor. The developed scheme is verified and tested via detailed simulations and experiments for 2kW NPC-MLI fed three-phase induction motor. The simulation and experimental results are compared to previous studies. The proposed scheme offers an excellent performance with significant result in lowest % npf and THD obtained at 0.22% and 7.4% respectively and also enables the inverter to operate under unhinged PV conditions comprehensively.

Four-switch Three-phase Inverter Performance Fed Sensorless Speed Control Induction Motor Drives Using Model Reference Adaptive System

—This article presents an investigation of four-switch inverter performance fed three-phase induction motor drives. Speed estimation is based on fundamental wave models using a model reference adaptive system as a speed estimator technique. The motor is fed from a four-switch three-phase inverter. A comparative study for sensorless speed estimation using a four-switch three-phase inverter, and a six-switch inverter is simulated and experimentally investigated at different operating conditions. Also, a comparison of system performance based on the four-switch inverter and conventional six-switch inverter in terms of speed response and total harmonic distortion of stator currents is presented. Experimental and simulation results at different points of operation are presented, verifying the robustness of sensorless speed estimation at different load levels. Sensorless speed estimation based on the four-switch three-phase inverter is quite acceptable considering its speed response.

A Space-Vector-Based Hysteresis Current Controller for a General $n$-Level Inverter-Fed Drive With Nearly Constant Switching Frequency Control

A current-error space-vector-based hysteresis current controller for a general <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$n$</tex></formula> -level voltage-source inverter (VSI)-fed three-phase induction motor (IM) drive is proposed here, with control of the switching frequency variation for the full linear modulation range. The proposed current controller monitors the space-vector-based current error of an <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$n$</tex></formula> -level VSI-fed IM to keep the current error within a parabolic boundary, using the information of the current triangular sector in which the tip of the reference vector lies. Information of the reference voltage vector is estimated using the measured current-error space vectors, along the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\alpha$</tex> </formula> - and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\beta$</tex></formula> -axes. Appropriate dimension and orientation of this parabolic boundary ensure a switching frequency spectrum similar to that of a constant-switching-frequency voltage-controlled space vector pulsewidth modulation (PWM) (SVPWM)-based IM drive. Like SVPWM for multilevel inverters, the proposed controller selects inverter switching vectors, forming a triangular sector in which the tip of the reference vector stays, for the hysteresis PWM control. The sector in the <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$n$</tex></formula> -level inverter space vector diagram, in which the tip of the fundamental stator voltage stays, is precisely detected, using the sampled reference space vector estimated from the instantaneous current-error space vectors. The proposed controller retains all the advantages of a conventional hysteresis controller such as fast current control, with smooth transition to the overmodulation region. The proposed controller is implemented on a five-level VSI-fed 7.5-kW IM drive.

Are my motors oversized?

Three-phase induction motors accounts with an important share of the electricity consumption in industrialized countries. Therefore, the misapplication of such machines conducts to efficiency reduction and large amounts of energy waste. Motor oversize is one of the most frequently misapplication encountered and difficult to be fixed. The paper presents a road map to evaluate whether a direct line fed three-phase induction motor is oversized, considering not only its steady loading, but also its dynamic behavior. In addition, case studies are presented and some solutions to increase the energy efficiency of the whole motor–load system are proposed.