D-space and microcontroller based SPWM inverter for three phase induction motor

The Variable Frequency Drives (VFD) are a common type of controlling the speed of 3-phase induction motors which are based on two control modulation techniques of Voltage Source Inverter: Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SV-PWM). The SPWM control technique is known as an easier implementation, but the SV-PWM control technique can be distinguished by an easier digital realization and a better utilization of DC bus. All 3-phase PWM inverters produce a total harmonic distortion (THD) on its output, which causes electromechanical and thermal stresses. The aim of this paper is comparing the low order current harmonics while driving an unbalanced 3-phase induction motor (the case of deterioration of the insulation as a result of inter-turn short circuits between few turns of the same phase) using SPWM and SV-PWM two-level 3-phase Voltage Source Inverters (VSI). For this type of unbalanced 3-phase induction motor, the SVPWM and SV-PWM schemes are modeled and simulated using Matlab/Simulink software. A detailed comparative analysis of THD-phase currents is made for both modulation strategies at different switching frequencies while keeping the constant amplitude modulation index.

Five phase Induction Motor drive may be more suited as the electrical drive for propulsion and other emergency condition where safety and reliability are the most important criteria for choosing a drive. In this article five phase induction machine fed by SPWM inverter is modeled and simulated in MATLAB/Simulink environment. SPWM (Sinusoidal Pulse Width Modulation) based inverter technique is used here to generate any number of phase voltage with proper firing angle. By using reference frame theory and the mmf (magnetomotive force) model of induction machine, both three phase and five phase induction motor is analyzed with respect to different parameters.

This paper deals about fuzzy logic control of closed loop controlled five level Multi Level Inverter (MLI) driven three phase induction motor. Three phase Induction motor is most widely used drive in Industries, so needs proper control of speed. Induction motor is fed from five level multilevel inverter which is controlled by fuzzy logic. The closed loop consists of two loops. First inner loop is current loop and second outer loop is speed loop. The torque is varied at different times and corresponding change in speed and Total Harmonic Distortion (THD) is observed. The MLI is controlled by Sinusoidal Pulse Width Modulation (SPWM) Technique. DOI: http://dx.doi.org/10.11591/ijpeds.v3i2.3062

This research compared the performance of PWM (Pulse Width Modulation) inverter and multilevel inverter in terms of their output voltage and current total harmonic distortion (THD). The inverters were designed to have the output voltage of 220 V at 50 Hz. The input voltage for both inverters are 400 VDC. For PWM inverter, the PWM technique utilized was sinusoidal PWM (SPWM) and for multilevel converter, the number of voltage level is five with diode-clamped topology. The study included circuit implementation, analysis, and THD calculation, all of which were carried out through simulation using PSpice software. In controlling the SPWM inverter output, the adjusted parameters included amplitude modulation ratio, frequency modulation ratio, and filter components’ parameters. On the other hand, the firing angles of the switching components were designated as controlling parameters in multilevel inverter. From the study, it was found that the best THD values of the designed SPWM inverter are 4.2% (voltage) and 1.7% (current), while those of multilevel inverter are 27% and 11%, for voltage and current, respectively. Thus, it can be concluded that SPWM inverter is better than 5-level inverter for the application in solar panel due to its lower THD. In our study, 5-level inverter did not satisfy the THD requirement specified in IEEE 512-1992, i.e. 5%.

In this paper, Design and development of control circuit algorithm of 3-Φ Voltage Source Inverter (VSI) using Unipolar Sinusoidal Pulse Width Modulation (SPWM) techniques is proposed using STM32F407VGTx discovery board interfaced with MATLAB Simulink Environment. For implementing 3-Φ VSI, this method is most useful as it will eliminate complexity of control circuit algorithm occurred due to analog circuit, reduces cost, size of filter required, and improved overall inverter efficiency. Pulse width modulated voltage source inverter is preferred for high performance AC drives. The proposed control scheme and the result obtained by embedded simulations interfaced with STM32F4 microcontroller are presented and discussed. A simple hardware implementation is proposed and experimental results of SPWM based VSI are also shown. The Simulation results of the proposed scheme have excellent performance and compared with hardware results.

In order to improve the efficiency, we should know the loss characteristics of inverter-fed induction motors. We first have to accurately measure the total motor losses, and then obtain each loss component by reasonably separate the total motor losses. In this paper, the total losses of a 5.5 kW, a 22 kW, a 30 kW, a 37 kW, a 45 kW and a 55 kW induction motors under sinusoidal supply and PWM inverter supply conditions are measured. The total losses of those motor are divided into five parts based on the loss segregation procedure IEEE Std 112-B with some special considerations, such as using AC resistance to replace the dc resistance for taking skin and proximity effect into account. Finally, the characteristics of the stator I2 R losses, rotor I2R losses, friction and windage losses (F&W losses), core losses as well as stray-load losses of those motor under sinusoidal supply and PWM inverter supply conditions are analyzed.

A voltage source inverter with variable frequency and variable voltage is applied for three-phase interior permanent magnet synchronous motor (IPMSM) drive for variable speed application. To obtain the required output voltage in the line side of the inverter a suitable pulse width modulation technique is used. The most prominent PWM techniques are Sinusoidal pulse width modulation (SPWM) and Space vector pulse width modulation (SVPWM). SPWM is simple and easy method to generate pulses for inverter, whereas SVPWM is an accurate method and generate less harmonic distortion compared to SPWM. However there is a lot of complexity involved in calculation of angle and sector as the level increases with SVPWM. To overcome this a similar and easy method known as unified pulse with modulation also know as carrier based space vector pulse width modulation technique(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. In this paper an IPMSM drive using CBSVPWM is simulated using MATLAB/SIMULINK software and its performance is compared with SPWM by varying modulation index (MI). The simulation study reveals that CBSVPWM simple and easy method which utilizes dc bus voltage more effectively and generates less THD compared to SPWM.

Multilevel inverters have been important devices developed in recent years, owing to their capability to increase the voltage and power delivered to the load. Researches done based on basic inverter topologies show that, multilevel inverters have many advantages such as low power dissipation on power switches, low harmonic and low electromagnetic interference (EMI) outputs. A modified sinusoidal pulse width modulation (SPWM) modulator that reduces output harmonics is presented in this paper. The proposed modulation technique can be easily applied to any multilevel inverter topology carrying out the necessary calculations. The most common multilevel inverter topologies have been studied to define the best topology for SPWM modulation strategy. It is seen that cascaded H-bridges are the most convenient solution. The cascaded H-bridge cells have been constituted by IGBT semiconductors, and switched by the proposed 24-channel SPWM modulator to obtain 5-level output at the back-end of the 3-phase voltage source inverter (VSI). The designed H-bridge cells have a strong switching bandwidth up to 40 KHz, owing to its robustly designed modulator block. The proposed VSI in this paper also has a total harmonic distortion ratio of output current (THDi) around at 0.1% without requiring any filtering circuit. The harmonic analysis of proposed design has been executed under several working conditions such as various switching frequencies and modulation indexes. The detailed comparisons have been performed to determine the best working conditions of VSI and presented in this paper.

Conventional Sinusoidal Pulse Width Modulation (SPWM) topology is one of the essential Pulse Width Modulation (PWM) topologies used in Voltage Source Inverter (VSI) applications such as adjustable speed motor control, Uninterrupted Power Supplies (UPS) and Photovoltaic (PV) Systems. Although conventional SPWM is used in VSI applications, the output voltage waveform of VSI based on this topology contains a high content of harmonic distortion. Hence, this paper presents a modified SPWM topology with an Artificial Neural Network (ANN) technique. The ANN technique was applied to minimize the Total Harmonic Distortion (THD) present in the output voltage waveform of the VSI. The proposed system was designed and evaluated with MATLAB/Simulink software. Based on the comparative evaluation, the paper proves that the proposed system contributes to a 9.1 % reduction in the THD value of a three-phase two-level VSI's output voltage waveform.

One of the main reasons for adopting the field oriented controlled (FOC) induction machine for high performance application is its capability for easy implementation in field weakening. In a sensorless FOC induction machine, the speed estimation in Field Weakening (FW) region and the sensitivity to parameter error of the motor is a major problem. Model Reference Adaptive System (MRAS) approach is one of the best techniques to estimate the rotor speed due to its straight forward stability approach. Space vector pulse width modulated (SVM) voltage source inverter is preferred to feed the FOC induction machine rather than the traditional sinusoidal pulse width modulated (SPWM) inverter due to the full utilization of voltage and current rating of the inverter. In this paper, a sensorless FOC induction machine with MRAS scheme based on sliding mode (SM) technique to estimate the rotor speed in the FW region using SVM fed inverter is modeled. The drive system is simulated by MATLAB/Simulink and the performance of the technique is evaluated by comparing the model with FOC induction machine with sensor using SVM inverter.

The work focuses on the design and implementation of a field programmable gate array (FPGA) based voltage controller for a single-phase voltage source inverter (VSI) with an inductance-capacitance (L-C) filter. The control algorithm of the open loop and closed loop control schemes of the controller are designed using hardware descriptive languages (VHDL and VerilogHDL) and are implemented using Xilinx SPARTAN 3E FPGA. The sinusoidal pulse-width modulation (SPWM) technique is utilised to realise the controller with a provision to change the modulation index in response with varying load conditions. Suitable L-C filter is designed to minimise the undesirable frequency components in the output voltage. The efficacy of the proposed control schemes in FPGA is validated via successful interface with a prototype VSI and the experimental verification of the controllers are carried out under different loading conditions.

Since last decades, the pulse width modulation (PWM) techniques have been an intensive research subject. Also, different kinds of methodologies have been presented on inverter switching losses, inverter output current/ voltage total harmonic distortion (THD), inverter maximum output of DC bus voltage. The Sinusoidal PWM is generally used to control the inverter output voltage and it helps to maintains drive performance. The recent years have seen digital modulation mechanisms based on theory of space vector i.e. Space vector PWM (SVPWM). The SVPWM mechanism offers the enhanced amplitude modulation indexes (MI) than sinusoidal PWM along with the reduction in the harmonics of inverter output voltage and reduced communication losses. Currently, the digital control mechanisms have got more attention than the analog counterparts, as the performance and reliability of microprocessors has increased. Most of the SVPWM mechanisms are performed by using the analog or digital circuits like microcontrollers and DSPs. From the recent study, analysis gives that use of Field Programmable Gate Arrays (FPGA) can offer more efficient and faster solutions. This paper discusses the numerous existing research aspects of FPGA realization for voltage source inverter (VSI) along with the future line of research.

In the modern world with the advancement of technologies in solid-state electronics, the use of power electronics devices is playing a crucial role in the conversion and control of electric power. By using these innovative devices in 3-phase voltage source inverters, precise and smooth control over the conversion of electrical power can be achieved. But on the other hand, this leads to Total Harmonic Distortion (THD) leading to an adverse effect on the overall system performance. The optimization technique has emerged as a newly popular method for selective harmonic elimination. The main focus of this paper is on simulation study for harmonic analysis of 3-phase voltage source inverter by using particle swarm optimization (PSO) technique. By considering the expression of THD as an objective function, optimization is achieved in the PSO algorithm. This paper also discusses the harmonic analysis of the proposed inverter for conventional PWM techniques such as sinusoidal pulse width modulation (SPWM) and trapezoidal pulse width modulation (TPWM). The harmonic spectrum of the output voltage of the inverter is compared for SPWM, TPWM, and PSO by using MATLAB. From THD analysis, it is observed that PSO gives better performance than other conventional techniques.

In this thesis, a boost chopper using PV (Photovoltaics) system and PWM (Pulse Width Modulation) voltage type power converter were constructed to provide a pleasant environment to the patients in the hospital wards by controlling temperature, humidity and air-conditioning & heating. For the stable modulation of solar cell, synchronizing signal and control signal were processed using one chip microprocessor. Power converter system was constructed with booster chopper and voltage source inverter and test was carried out for both devices. Constant voltage control method was used to track a maximum power point at boost converter control. For the inverter control, synchronizing signal and control signal were processed by microprocessor for the stable modulation according to the switching theory of SPWM (Sinusoidal Pulse Width Modulation) and directions to each sector. Test was carried out for inverter control using SPWM control method. In addition, grid voltage was detected and this grid voltage and inverter output were operated at the same phase for the phase locking with PWM voltage source inverter so that surplus power could be linked to grid. This characteristic was applied on the temperature and humidity sensors in the general buildings and buildings having specific purposes such as hospitals. The good dynamic characteristic of inverter could be obtained by these applications. Also, PWM voltage inverter maintains a high power factor and low-frequency harmonic output so that power can be supplied in the load as well as system.

The sinusoidal pulse-width modulation (SPWM) technique is typically used for three-phase voltage source inverter (VSI) in low-voltage motor drives due to its simplicity and reliability. However, these VSI face increasing challenge to minimize electromagnetic interference (EMI) and increase power quality. This paper proposes a new SPWM switching based on a Bat-like reference signal that has the advantages of minimizing the output-voltage total harmonics distortion (THDv), lowering the switch rate of change in voltage (dv/dt), reducing the number of switching transitions, and increasing the peak and r.m.s. ac output voltage of the three-phase VSI. The proposed switching technique is verified using Matlab/Simulik on a 2-kW, 300-V three-phase VSI connected to an RL load. This technique shows improvement in reducing the output-voltage THDv by 36% and lowering the number of switching transition by 60% as compared to SPWM switching that is based on singlefrequency signal. Moreover, the dv/dt is low and the peak output voltage is increase by approximately 17%.