AC Motor Research Articles

Operation and control schemes of a novel direct AC-AC modular multilevel converter

AC-DC-AC modular multilevel converter (MMC) and direct AC-AC MMC are two kinds of interfaces to integrating AC motors into power grid, and they are easily damaged from large capacitor voltage fluctuation with varying motor speed. Up to now, none of the methods could balance the reliability and power density of MMC-based motor drives system. To find a better solution to this problem, a novel direct AC-AC MMC topology is proposed in this paper. Operating principle of this topology is introduced and relative multi-loop feedback control method is designed for it. Then, simulation and experiments are conducted for verification. Compared with the traditional MMC with high-frequency injection method, the proposed topology has no common-mode voltage problem and the current stress is reduced by 38.5%. Compared with the half-bridge-based AC-DC-AC MMC, the number of capacitors and inductors of the proposed topology is reduced by 20.8% and 25%. In comparison with the direct AC-AC MMC (modular multilevel matrix converter), the number of power devices of the proposed topology is reduced by 28%. The proposed topology has higher reliability and power density.

Common-Mode Current Prediction and Analysis in Motor Drive Systems for the New Frequency Range of 2–150 kHz

Due to the significant advances in fast switching semiconductor devices, harmonic emissions caused by the adjustable speed drives (ASDs) have been changed in terms of frequency range and magnitude. The frequency range of 2–150 kHz has been distinguished as a new interfering frequency range, disturbing the distribution networks. This article proposes a behavioral model of an ac motor to predict the common-mode (CM) current in ASDs. An approach is presented to calculate the parameters of the model, through which the dominant impact of each element at a specific frequency is considered. Moreover, along with the proposed motor model, a system modeling strategy is presented for filter design considerations at an emerging frequency range of 2–150 kHz. To verify the effectiveness of the proposed model, real-time experiments are conducted. The results prove that the introduced model can accurately predict the resonances of the CM loop created by the motor. Consequently, the proposed model is suitable for electromagnetic interference (EMI) filter design covering the 2–150-kHz standard.

MESIN PENCACAH PLASTIK (PLASTIC SHREDDER)

Plastic type material is a material that is often used by many people in everyday life, the use of plastic materials, especially working in the world of health, industry or household, many people make plastic materials such as glass, plates, and more used as the necessities of everyday life. The sheer amount of plastic use has the potential to increase Polluttion and it is also very bad for the environment, mostly plastic materials are dumped without further processing, to reduce the impact of plastic materials needed for chopping tools to reduce the accumulation process. Using an AC motor as a drive system for chopping the plastic can make the plastic into a smaller part.

Design of New Renewable Energy Utilization Technology in Islamic Boarding Schools

Applications of solar power that are very suitable to be developed in Islamic boarding schools are lighting and activities that have recently been made extra-curricular activities and economic recovery by farming using hydroponic technology. The results of the research on solar street lighting on each component function properly according to their respective specifications and the proximity sensor detects the presence of objects within 0.5 meters, 1 meter and 1.5 meters from the sensor until the buzzer sounds for a few seconds. Furthermore, research on solar hydroponic plants using ac motors in testing ac motors using inverters has a weakness if the inverter is used for 24 hours it will reduce the life of the inverter or the inverter will be damaged faster, In addition, choosing an inverter that does not match the specifications of the motor will also have an impact on the motor itself, in this case it is necessary to pay attention to the selection of the inverter to be used. However, if you use two motors at the same time, it will reduce the impact of damage more quickly on components because the motors work alternately by setting the programmble DC timer. In both solar power applications, Based on the results of the investment analysis, the costs are quite cheap because they reduce the bill for payment each month and can return the capital for making the application. if you use two motors at the same time it will reduce the impact of damage more quickly on the components because the motors work alternately by setting the programmble DC timer. In both solar power applications, based on the results of the investment analysis, the costs are quite cheap because they reduce the bill for payment each month and can return the capital for making the application. if you use two motors at the same time it will reduce the impact of damage more quickly on the components because the motors work alternately by setting the programmble DC timer. In both solar power applications, based on the results of the investment analysis, the costs are quite cheap because they reduce the bill for payment each month and can return the capital for making the application.

Model Predictive Control based Direct Matrix Converter fed Permanent Magnet Synchronous Machine drives for Traction and Electric Mobility Applications

There have been extensive research works going on electric mobility but most of these work and the existing electric mobility systems are battery-based DC systems. In some applications of electric mobility like traction and advanced technologies like electromagnetic induction charging, AC fed systems are employed due to the innate qualities of AC power transmission. Almost all the electric mobility systems we use are AC induction or permanent magnet machines. The conventional electric mobility systems including traction having AC as their energy source use two-stage conversion i.e. A fixed AC is converted to a fixed or variable DC link using a rectifier and finally, an inverter provides a variable AC in terms of frequency and magnitude according to the control algorithm. The two-stage conversion has its pros and cons but Matrix Converter (MC) will be a suitable and efficient alternative for AC fed AC motor drives. In the case of traction and other electric mobility applications, the load torque demand plays a significant role. The predictive control technique provides a suitable solution for these kinds of special drive applications due to their selective parameter control ability. Implementation of predictive control using a matrix converter is more effective than the conventional inverter fed drives, owing to the increased viability of matrix converter switching configurations. This paper discusses the mathematical implementation and comparison of Predictive Current Control (PCC) and Predictive Torque Control (PTC) with and without weighing factor for AC fed electric mobility applications. The efficacy of both the model predictive control techniques in concern of execution time, steady-state, transient, and dynamic conditions are analysed and validated along with the influence of diverse control variables in the cost function.

A nonlinear optimal control approach for permanent magnet AC motors with non-sinusoidal back EMF

A nonlinear optimal control approach for permanent magnet AC motors with non-sinusoidal back EMF

Analysis of the physical features of the operation of stands with a closed power flow for testing v-belt gears

Currently, there are practically no sufficiently satisfactory analytical methods for predicting the reliability of newly designed machines. Basically, the task is solved on the basis of information obtained largely during resource bench tests of parts, assemblies and aggregates. The stands used for carrying out resource tests of machine transmissions can be divided according to the type of loading into open loading stands and closed loading stands. Open loading stands are driven by an AC or DC electric motor and are decelerated by a special braking system. Closed loading stands load the transmission without the use of braking systems. This article discusses the physical features of the operation of stands with a closed power flow used for testing V-belt gears, which can significantly reduce energy costs. The analysis of the application of an analytical method for predicting the reliability of newly designed machines is carried out on the basis of information obtained largely during resource bench tests of parts, assemblies and aggregates.

Natural Speed Observer for Nonsalient AC Motors

This letter addresses experimental validation of the reduced-order natural speed observer design for position sensorless drive with nonsalient permanent magnet synchronous motor. The natural speed observer and the active flux estimator are connected in a cascaded fashion, which results in a simple sensorless algorithm that needs only to tune one bandwidth parameter for flux estimation and one bandwidth parameter for speed observation. Experimental results of high speed reversal test, zero speed stopping test, and slow speed reversal test are included, where the practice of applying nonzero <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$d$</tex-math></inline-formula> -axis current at zero speed has shown to be effective for loaded zero speed stopping test, but it causes zero-speed locked-up at slow speed reversal with acceleration rate of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\rm \text{50}\,r/\text{min}/s$</tex-math></inline-formula> . Four remedies are compared to improve the slow speed reversal test and the proposed method gives almost ramp actual speed waveform, nondiverging <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$q$</tex-math></inline-formula> -axis current and smooth transition in position waveform during slow zero speed crossing. A new dynamic expression of the active flux is proposed and with the aid of the active flux concept, the proposed sensorless algorithm is also applicable to various types of ac motors.

Improved LQR Control Using PSO Optimization and Kalman Filter Estimator

The electric motor is a device that converts electrical power into mechanical power. The DC motor has some advantages compared to the AC motor on its easier way to control the speed or position and wide adjustable range. However, it still has some issues, such as uncertainty and disturbance; most existing controllers still provide bad system performance or have major drawbacks in solving these issues. The alternative solution for a control method with simple, easy to design, and can be implemented in a multi-input multi-output system is the integral state feedback control technique, such as in Linear Quadratic Regulator (LQR). The weakness of LQR control is that there is no exact method to determine the best value of matrix Q and R used to calculate the state feedback gain; trial or manual tuning method is mostly used. Therefore, this paper proposed an improved LQR control using Particle Swarm Optimization (PSO) method and the Kalman filter estimator. The PSO was used to find optimal Q and R-value, while the Kalman filter reduced the number of sensors used to measure the system state. Both performance and energy consumption were compared using the Integral of Absolute Error (IAE) and total energy consumption. The simulation results showed that the proposed method is superior in performance and energy compared to manually-tuned LQR. However, based on the hardware implementation, although the manually-tuned LQR was found to have the smallest energy consumption, the proposed method has the smallest IAE, which can reduce the IAE by 11.28% with only 1% higher energy compared to manually-tuned LQR.

Aspects of electric transmission implementation on a battle tank

In the paper, a high performance electric transmission designed for heavy military vehicles is presented. The power source is a 1300 hp gas turbine and a 200 hp supercharged diesel engine. Both engines drive a synchronous generator. The electric current supplied by the generator is rectified. Each sprocket is mounted on the output shaft of a gearbox driven by an asynchronous electric motor. An Insulated Gate Bipolar Transistors (IGBTs) inverter control AC motors in a separate way to achieve dynamic performance. Diesel engine alone is used for driving on paved roads with speeds of up to 15 km/h with low fuel consumption. Gas turbine and diesel engine are automatically coupled to the generator to reach the maximum torque and dynamic performances. The tank can thus reach a maximum speed of 70 km/h.

An Advanced Modulation Technique Featuring Common Mode Voltage Suppression for Three-Phase Neutral Point Clamped Back to Back Converters

Three-phase back-to-back converters are widely applied in various industrial, commercial, and domestic applications, such as AC motor drives. Due to the non-sinusoidal voltages they generate, a common mode voltage (CMV) appears, leading to problems in electrical drive systems and high-frequency applications. The CMV and rapid voltage changes can cause serious problems, including leakage currents flowing through the parasitic capacitors inside the motor, electromagnetic interference, shaft voltage, and bearing currents that reduce the motor’s lifespan. In general, research to reduce these effects is divided into two methods: modifying the drive system’s physical structure or improving the inverter’s control algorithm. Pulse Width Modulation (PWM) methods are commonly used in control algorithms of converters to reduce the CMV. However, adding pulse amplitude modulation to the PWM helps reduce the CMV. The technique of simultaneous pulse width and amplitude modulation of space vectors is proposed in this paper to reduce the CMV and its destructive effects in drive systems. The proposed technique is based on the elimination of zero vectors and the inherent reduction of DC link voltage by amplitude modulation leading to a further reduction of the CMV; The obtained results of applying the proposed strategy to a three-phase back-to-back NPC converter with 738-watt steady-state operating point power showed the system’s sufficient behavior with the efficiency of 98.62 percent. Finally, the transient performance of the converter from no-load to full-load condition ensures its sufficient behavior for industrial applications.

Robust speed control of inverter fed parallel connected induction motors for electric vehicle traction applications

Induction motor is a very versatile machine having a variety of advantages over other types of single-phase AC motors. In the electric vehicle traction system, inverter set up was provided by parallel connection-based induction motor based on sensor. The induction motor is modelled using the estimated parameter instead of the speed sensor to analyse the speed performance characteristics. The proposed system focuses on improving the speed control of induction motors by modified PID controller. The parallel-connected induction motor is considered in this proposed work. The modified PID controller is compared with the conventional controller. The enhanced speed performance for inverter fed induction motors in parallel are analyzed under the parameter variation also in MATLAB/Simulink also compared with conventional methods.

LCラダー回路上で励起される回転磁界を利用した交流モータ駆動法の基礎検討

LCラダー回路上で励起される回転磁界を利用した交流モータ駆動法の基礎検討

Desain Sistem Kontrol Penggerak Pintu Pagar Otomatis Di Politeknik Jambi

The gate in general as access into and out of the yard or house. Generally, the gate is opened manually by sliding it, for the mechanism of opening and closing the gate is mostly opened manually and requires human labor. So the design of the automatic turnstile drive control system was designed to facilitate users in opening and closing without bothering to push or shift the gate that consumes a lot of time and energy. Components used are in the form of an ½ hp 1 phase ac motor, gearbox and ohm switch. For how to operate it using the ohm switch as a controller by raising or lowering the switch ohm lever then the dynamo and gearbox as movers will open and close the gate. From the test results, to open or close the gate with a track length of 3.6 m takes 10 seconds. For further

Integral State Feedback Control Using Linear Quadratic Gaussian in DC-drive System

The electric motor is one of the technological developments which can support the production process. DC motor has some advantages compared to AC motor especially on the easier way to control its speed or position as well as its widely adjustable range. The main issue in the DC motor is controlling the angular speed with uncertainty and disturbance. The alternative solution of a control method with simple, easy to design, and implementable in a multi-input multi-output system is integral state feedback such as linear quadratic Gaussian (LQG). It is a combination between linear quadratic regulator and Kalman filter. One of the advantages of this method is the usage of fewer sensors compared with the original linear quadratic regulator method which uses sensors as many as the state in the system model. The design, simulation, and experimental study of the application of LQG as state feedback control in a DC-drive system have been done. Both performance and energy were analyzed and compared with conventional proportional integral derivative (PID). The gain of LQG was determined by trial whereas the PID gain is determined from MATLAB autotuning without fine-tuning. The load test and tracking test were carried out in the experiment. Both simulation and hardware tests showed the same result which LQG is superior in integral absolute error (IAE) by up to 74.37 % in loading test compared to PID. On the other side, LQG needs more energy, it consumes higher energy by 6.34 % in the load test.

Low-Cost Drive System for Electric Motors based on the IRAM Module

With the increasing use of equipment that demand electric drive systems, the need for new systems that meet requirements of compactness, versatility, safety and low cost has increased. The IRAM module is an electronic circuit that provides a driver for DC and AC motors, being extremely compact and presents high performance. In this context, this work contributes to the power electronics area, presenting a design and construction of a low cost drive system, based on IRAM module, developed for individual or simultaneous drive, up to two DC motors. To carry out the experiments, DC motors responsible for moving a welding robot, were used. Experimental results are presented to shown the feasibility of using this system.

Performance Evaluation of an Autonomously Driven Agricultural Vehicle in an Orchard Environment.

To address the problems of inefficient agricultural production and labor shortages, there has been active research to develop autonomously driven agricultural machines, using advanced sensors and ICT technology. Autonomously driven speed sprayers can also reduce accidents such as the pesticide poisoning of farmers, and vehicle overturn that frequently occur during spraying work in orchards. To develop a commercial, autonomously driven speed sprayer, we developed a prototype of an autonomously driven agricultural vehicle, and conducted performance evaluations in an orchard environment. A prototype of the agricultural vehicle was created using a rubber-tracked vehicle equipped with two AC motors. A prototype of the autonomous driving hardware consisted of a GNSS module, a motion sensor, an embedded board, and an LTE module, and it was made for less than $1000. Additional software, including a sensor fusion algorithm for positioning and a path-tracking algorithm for autonomous driving, were implemented. Then, the performance of the autonomous driving agricultural vehicle was evaluated based on two trajectories in an apple farm. The results of the field test determined the RMS, and the maximums of the path-following errors were 0.10 m, 0.34 m, respectively.

Design of a Biomimetic BLDC Driven Robotic Arm for Teleoperation &amp; Biomedical Applications

For many years, robotics research and development has been held back from the high-power AC motors of industrial automation, locked to low-power, bulky Stepper motors and simple DC Servos. As of a few years ago, Brushless DC motors started seeing use in high-end quadrupedal designs such as Boston Dynamics Cheetah, and Spot. Whilst these used expensive, proprietary control systems that were closed source and out of the reach of many small-scale researchers, developers, and hobbyists, they did demonstrate the potential of a motor-class previously only commonly thought suitable for high-RPM applications like drones and quadcopters. In 2016, an open-source custom driver platform named ODrive was started, which is now in its 3rd iteration. As of 2021, it provides all of the basic hardware and software needed to control 2 closed loop Brushless DC motors per board, using off the shelf encoders and at a reasonable, hobbyist level price point. This technology is, on paper, a huge development for plenty of low-budget robotics research applications. In this project, we design, build, and evaluate a 4 DOF robotic arm using 4 BLDC motors with ODrive control, using 3D printed parts and other components available at a low price point. This arm will be used in the future for testing tele-operative control and so it is designed to be biomimetic, modelled at 2/3 scale with similar proportions and motion capabilities to a real human arm to the elbow. The extremely small, cheap, and lightweight motors selected for this project are shown to output superior speed and torque to stepper motors multiple times their size and weight, albeit at a very significant power draw requirement. The speed and power of a BLDC through a high reduction gearbox allows extremely fast and responsive movement such that it can easily execute complex movements easily in pace with a human arm. Doi: 10.28991/HEF-2021-02-04-03 Full Text: PDF

Application of Energy-Saving for an inverter feeds three-phase induction motor

Three-phase induction motors are the most prevalent AC motors used in many applications. Operation of these motors at load power less than that of the motor full-load power leads to significant power losses and reduces the motor’s efficiency. To mitigate these losses and increase the efficiency of the three-phase induction motors at light loading conditions, energy-saving techniques should be utilized. This paper investigates a voltage control technique applied to light-loaded induction motors to save the energy using an inverter. The light load selected in this paper is a fan load of power load less than the motor full load power. Theoretical analysis, computed characteristics, and experimental verifications are presented to show the effectiveness of the proposed energy-saving technique.

DC‐link low‐frequency current and voltage ripple analysis in multiphase voltage source inverters with unbalanced load

Inverter's performance and operating mode may be negatively affected by inverter input (dc-link) current and voltage ripple. It is a common experience that even theoretically balanced loads with perfectly balanced supply voltages, such as multiphase ac motors supplied by pulse-width modulation (PWM) inverters, in practice show a certain degree of current unbalance, in the range of a few percent, which introduces a low-frequency instantaneous power oscillation. This reflects in current and voltage low-frequency ripple on the dc-link inverter side (i.e. at the double-fundamental frequency). A possible method to analyse this matter is through the symmetric sequence components. In particular, based on the first negative current sequence component and by considering the equivalent dc-link impedance calculated at the dominant double-fundamental frequency, the amplitude of the corresponding dc-link voltage ripple component is calculated in this work for a general multiphase load. Finally, the design of the dc-link capacitor in multiphase inverters is proposed considering requirements referred to the double-fundamental dc voltage ripple. The feasibility of the proposed developments has been verified for three-, five- and seven-phase inverters by both numerical simulations and comprehensive experimental tests, always showing a good matching.