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.

Self-Correcting Virtual Current Sensor Based on the Modified Luenberger Observer for Fault-Tolerant Induction Motor Drive

Fault-tolerant control (FTC) solutions are increasingly being used in modern drive systems with AC motors. Such systems provide a higher degree of security and solutions that allow the on-line detection and localization of failures, as well as the switching of the control mode to a mode that allows us to continue the operation or safely stop the drive system. As the current sensors (CSs) are necessary to ensure precise control of the AC motors, in the event of their failure, one of two strategies can be used—hardware or software redundancy. The first strategy requires the use of additional measuring sensors. For this reason, the algorithmic solution, based on the Luenberger Observer (LO), has been proposed in this article as one of the software redundancy methods. In contrast to methods presented in the literature, the proposed solution allows one not only to compensate the stator current in a phase with a faulty CS, but also to adjust the correction of current estimation based on a measured signal in the other phase with a healthy CS. Extensive simulation studies in the direct rotor flux-oriented control (DRFOC) structure with the induction motor (IM) confirm the effectiveness of the proposed method. In addition, the proposed solution allows the drive system to be controlled even if all CSs are damaged.

Development and Rationale of Two-Disk Operating Body of Agricultural Machine for Tillage

One of the main problems in the design of agricultural machines, including tillage machines, is to ensure the optimal energy intensity of various technological operations. The design, kinematic and technological parameters of rotary tillage machines have a significant impact on the indicators of the energy intensity of the process and the quality of tillage. These parameters include the diameter of the operating body of the agricultural machine, the angular speed and rotational speed of the disks, the number of cutting elements, the translational speed of the operating body, the height of the ridge formed during soil cultivation, the thickness of the cut chips. An important agrotechnical parameter of a rotary tillage machine is the ridging of the furrow bottom. The height of the ridges formed should not be less than 20 % of the depth of the cultivated soil. Currently, in order to ensure the required height of the ridges in the designs of rotary machines, there are a number of restrictions that determine the operating mode and parameters of the units. The degree of influence of the parameters of the developed operating body and the energy consumption on the quality of tillage has been assessed in the process of the research. The experiments have been carried out on an installation that included an operating body, a power unit, control and instrumentation equipment. As the power section, AC motors with a phase rotor were used, the power of which was 0.75 and 1.50 kW, and the speed of rotation was 920, 1500 and 3000 rpm. The parameters have been set that allow to reduce the energy consumption for tillage by 11–17 %, compared to existing machines, and ensure the alignment of the furrow bottom by up to 80 %.

Comparative study of frequency converters of three-phase electric motors in automatic control of technological parameter

Frequency converters of asynchronous three-phase AC motors are widely used in industry, including food production. A thorough understanding of the technical capabilities of frequency converters contributes to their efficient use. This article discusses a technical comparison of two frequency converters of three-phase electric motors of the Russian company "OWEN" and the Danish company "DANFOSS" according to the criterion of the quality of regulation of the technological parameter. For comparison, a test bench was created, in which the devices were tested in turn, under the same conditions. During the preparation and implementation of testing, it turned out that the hardware capabilities of frequency converters for their use in regulating technological parameters are the same, and the parametric capabilities are different. The frequency converter of the "OWEN" company is equipped with a PI controller, and the frequency converter from "DANFOSS" is equipped with a PID controller. As the results of testing the devices show, despite