Motor Starting Research Articles

VFD-Based Coordinated Multi-Stage Centralized/Decentralized Control to Support Offshore Electrical Power Systems

This paper proposes a coordinated multi-stage centralized/decentralized control used to mitigate voltage fluctuation caused by planned direct on-line heavy induction motor start in oil and gas offshore platform. The proposed control remotely coordinates the active front-end variable frequency drives (AFE-VFDs) using a low-bandwidth communication link. It is split into three stages, in which stage 1 accurately regulates the power factor at the main feeder, stage 2 is a transitioning operating mode and stage 3 comprises the autonomous volt-var function to mitigate voltage fluctuation. The proposed control shows a centralized architecture for stages 1 and 2, and a decentralized architecture for stage 3. The proposed control is evaluated by means of simulation results considering a real case test bench of a Brazilian offshore platform, being comparatively confronted with two other literature solutions. Compared to other solutions, results show 33% and 29% of improvement in sag and swell voltage regulation at the main feeder, respectively; relief the generator field windings up to 8%, in steady state; and increase the power factor at the generator terminals from 0.92 to 0.97, using two AFE-VFDs.

Maximum power point tracking control strategy based on frequency and amplitude control for the wave energy conversion system

This paper presents a pendulum-type wave energy conversion (WEC) system, which can change its natural frequency by a center of gravity adjustment mechanism. Based on this characteristic, a frequency and amplitude control (FAC) strategy is proposed to realize the maximum power point tracking (MPPT) of the WEC system. Firstly, the natural frequency of the WEC system is adjusted according to the peak frequency of the wave spectrum to make the device resonate with the waves, which is the frequency control (FC) method. The essence of the FC method is to change the position of the mass block inside the pendulum by controlling the angular displacement of the motor, so as to change the moment of inertia and recovery stiffness of the device. Secondly, the load of the mass block is very large, which brings a great challenge to the motor starting, so this paper proposes a soft-start control strategy to solve this problem. Thirdly, a weighted average method is proposed to calculate the intrinsic impedance of the WEC system under irregular waves, and then make the mechanical resistance of the power take-off (PTO) system equal to the intrinsic impedance of the WEC system by controlling the damping torque of the generator, which is the amplitude control (AC) method. By combining the FC method and AC method, the amplitude and phase conditions can be satisfied simultaneously to realize the MPPT of the WEC system. Finally, the feasibility and accuracy of the proposed control strategies are verified by simulation results.

Measures to increase the technical resource of electrical equipment of powerful irrigation pump stations

RELEVANCE. At present, unstressed systems for launching high-voltage electric motors have been increasingly used. These systems limit the values of starting currents as well as eliminate alternating oscillations of engine electromagnetic torque. THE PURPOSE. Development of measures to improve the technical resource of electrical equipment of powerful irrigation pumping stations based on the use of soft start systems for high-voltage electric motors. METHODS. In the course of the study, methods for analyzing the technological processes of a pumping station, methods for mathematical and computer modeling of an electric drive were used. RESULTS. Computer models have been developed to study the regime characteristics of asynchronous and synchronous electric drives of pumping stations with direct and soft start of electric motors. A shockless start-up system for high-voltage electric motors of irrigation pumping stations of the first lift based on a current inverter is proposed. CONCLUSION. The reliability and durability of electrical equipment depends primarily on the technical resource, which is determined by a number of factors. The main factors influencing the technical life of the electrical equipment of large irrigation pumping stations are the transient modes that occur when the pumping units are started. The soft start system of high-voltage electric motors of irrigation pumping stations proposed in this article makes it possible to eliminate the negative impact of transient conditions on the operation of electrical equipment and, thereby, increase the technical resource and reliability of the power supply system of the pumping station as a whole.

What a difference a year makes: Objective rest/activity patterns, circadian phase markers, and sleep quality before and during the COVID-19 pandemic

ObjectivesThe COVID-19 pandemic led to numerous changes in sleep duration, quality, and timing. The goal of this study was to examine objective and self-reported changes in sleep and circadian timing before and during the pandemic. MethodsData were utilized from an ongoing longitudinal study of sleep and circadian timing with assessments at baseline and 1-year follow-up. Participants had baseline assessment between 2019 and March 2020 (before pandemic) and 12-month follow-up between September 2020 and March 2021 (during pandemic). Participants completed 7 days of wrist actigraphy, self-report questionnaires, and laboratory-collected circadian phase assessment (dim light melatonin onset). ResultsActigraphy and questionnaire data were available for 18 participants (11 women and 7 men, Mean = 38.8 years, SD = 11.8). Dim light melatonin onset was available for 11 participants. Participants demonstrated statistically significant decreases in sleep efficiency (Mean = −4.11%, SD = 3.22, P = .001), worse scores on Patient-Reported Outcome Measurement Information System sleep disturbance scale (Mean increase = 4.48, SD = 6.87, P = .017), and sleep end time delay (Mean = 22.4 mins, SD = 44.4 mins, P = .046). Chronotype was significantly correlated with change in dim light melatonin onset (r = 0.649, P = .031). This suggests that a later chronotype is associated with a greater delay in dim light melatonin onset. There were also non-significant increases in total sleep time (Mean = 12.4 mins, SD = 44.4 mins, P = .255), later dim light melatonin onset (Mean = 25.2 mins, SD = 1.15 hrs, P = .295), and earlier sleep start time (Mean = 11.4 mins, SD = 48 mins, P = .322). ConclusionOur data demonstrate objective and self-reported changes to sleep during the COVID-19 pandemic. Future studies should look at whether some individuals will require intervention to phase advance sleep when returning to previous routines such as returning to office and school settings.

0251 Sex differences in the associations of childhood obesity with sleep characteristics, access to screens, and nocturnal melatonin

Abstract Introduction Insufficient sleep and circadian rhythm alterations are associated with metabolic disorders including obesity, with increasing evidence that these associations can emerge in childhood. In parallel, screen media access in the bedroom at night has negative effects on circadian rhythms, sleep, and other behaviors, which can contribute to obesity development. In the current work, we analyzed the associations of childhood obesity with self-reported sleep characteristics, access to screens in the bedroom, and nocturnal melatonin, considering potential sex differences. Methods The study cohort is composed of 244 children 7-16 years old, among which 140 have a body mass index z-scores >2, characterized as obesity according to world health organization criteria. There are 124 girls (11.21 ± 2.42 years) and 120 boys (11.19 ± 2.22 years). Melatonin was measured through immunoassay in saliva samples, which were collected at three time points of the evening of a school day: 4h before sleep, 2h before sleep, and 1h after sleep start. The chronotype score was obtained using the Horne and Ostberg questionnaire. Participants reported the number of screens present in the bedroom at night, and their bedtimes and wakeup times during both weekdays and weekend. The sleep disturbance scale for children and an abbreviated pediatric sleep questionnaire about sleep apnea symptoms were completed by a parent. Results BMI z-scores were significantly correlated with more parent-reported sleep disturbances (p< 0.01), higher sleep apnea scores (p< 0.01), shorter sleep duration during weekdays (p< 0.01), and the number of screens in the bedroom (p=0.05) in boys but not in girls (p=0.52, p=0.15, p=0.83, and p=0.37). On the other hand, BMI z-scores were significantly correlated with melatonin level at +1h after sleep onset (p=0.05) in girls but not in boys (p=0.96). No significant correlations were observed between the BMI z-score and the pre-sleep melatonin measures. Conclusion According to our findings, there is some differentiation by sex in relationships between body weight and various sleep and circadian measures. Specifically, in boys, obesity was associated with shorter and disturbed sleep with more sleep apnea, whereas in girls, obesity was linked with lowered nocturnal melatonin expression. Support (if any)

Cardiovascular remodeling in active and controlled acromegaly: association with sleep-disordered breathing.

We hypothesized that anunfavorable cardiovascular profile in acromegaly is associated with sleep-disordered breathing (SDB), while acromegaly control improves both respiratory sleep characteristics and thecardiovascular profile. The patients underwent the assessment of breathing during sleep and cardiovascular profileassessment atthe start of the studyincluding arterial stiffness, blood pressure, echocardiography, nocturnal heart rate variability (HRV). The assessment was repeated in patients withacromegaly at 1 year after transsphenoidal adenectomy (TSA). A total of 47 patients with acromegaly and 55 control subjects were enrolled. At one year after TSA, 22 patients with acromegaly were reassessed.Multiple linear regression analysis with adjustment for age, sex and body mass index (BMI) showed the associations of insulin growth-like factor 1 (IGF-1) with obstructive apnea index (OAI: β=0.035/h, p<0.001), but not with cardiovascular parameters, in patients withacromegaly. The analysis of combined acromegaly and control dataset with adjustment for age, sex and BMI showed the association the presence of acromegaly with diastolic blood pressure (DBP; β=17.99 mmHg, p<0.001), ejection fraction (EF; β=6.23%, p=0.009), left heart remodeling (left ventricle posterior wall: β=0.81 mm, p=0.045) and the association of the presence of SDB (apnea-hypopnea index≥15/h) with left ventricular function (EF: -4.12%, p=0.040; end systolic volume: 10.12 ml, p=0.004). Control of acromegaly was accompanied by the decrease in OAI (5.9 [0.8, 14.5]/h and 1.7 [0.2, 5.1]/h, p=0.004) and nocturnal heart rate (66.1 [59.2, 69.8] bpm and 61.7 [54.0, 67.2] bpm, p=0.025) and by the increase in blood pressure (DBP: 78.0 [70.3, 86.0] mm Hg and 80.0 [80.0, 90.0] mm Hg, p=0.012). The comorbidities of acromegaly, including sleep-disordered breathing, appear to have a long-term effect on cardiovascular remodeling in active acromegaly. Future studies should investigate the applicability of the treatment of SDBfor the reduction of cardiovascular risk in acromegaly.

μPMU-based islanding detection method in power distribution systems

This paper focuses on the use of micro-phasor measurement units (μPMUs) for the prompt detection of unplanned islanding conditions. The investigated method is based on the monitoring of voltage and current phasors at distributed generation (DG) buses equipped by μPMUs. The difference between two consecutive phasors (voltage phasors and current phasors) are monitored until a perturbation occurs. When a perturbation is detected, the first phasor, called pre-disturbance phasor, is kept fixed and the second one, called post-disturbance phasor, is continuously updated with each new sample arrival. The differences between the pre-disturbance and post-disturbance phasors are calculated and summed up for a predefined time window. When this exceeds a predefined threshold, the island condition of the related bus is detected. The presented procedure can distinguish the islanding condition from other perturbations, such as motor starting, faults, and capacitor switching. The performance of the proposed procedure, as well as its sensitivity to the system conditions and predefined values, are analyzed considering a 7-bus distribution system and the IEEE 33-bus test system, both with synchronous generators and inverter-based DGs.

스타터 모터 마그넷 스위치의 화재 위험성 연구

The technology in the automobile field has steadily developed and the number of registered automobiles has also increased explosively, and automobiles have become an essential part of our daily life. An increase in the penetration rate or frequency of use of automobiles can increase the likelihood of accidents, and automobile fires are also occurring frequently. In the case of automobile fires, 458 cases have occurred in the past three years, accounting for 12.3% of the total 3,716 fires in Daegu, and about 50% of them occur inside the engine room of a car while driving or parked. In this study, we conduct various experiments on the starter motor, which is a device that uses a large current, among various causes that occur in the engine room of a car, and prove the electrical singularity and fire potential to identify the exact cause of the fire and suggest countermeasures against the car fire.

Delayed sleep phase disorder during the COVID-19 pandemic and its health implications.

Circadian rhythm sleep disorders are alterations that are characterized by a shift in the sleep-wake cycle relative to day and night, such as the delayed sleep phase disorder (DSPD), which is a retard of at least 2hours in the sleep start. Typically, the patient falls asleep after 2a.m. and wakes up after 10a.m. and with symptom of sleep onset insomnia. The prevalence of DSPD in young adults is 0.48%, increasing to 3.3% in adolescents. Interestingly, patients with COVID-19 infection report anxiety due to the intensive care unit lockdown and constant exposure to bright light. In addition, post-COVID patients have an increased risk of developing DSPD. For example, in adolescent post-COVID patients, the prevalence of DSPD increases to 63.3%. Patients with DSPD also have alterations in metabolic health, poor school performance, cognitive impairment, and a higher risk of developing other diseases. The objective of the present review is therefore to describe the characteristics of DSPD during the COVID-19 pandemic and to outline its possible implications for physical health (eg, metabolism) and mental health (eg, anxiety or depression).

ICA-Feature-Extraction-Based Fault Identification of Vehicular Starter Motor

The starter motor is responsible for providing the mechanical rotating energy for automotive operation through electromechanical conversion via battery. In case of a fault on the starter motor, the vehicle will fail to operate posing problems for the driver, especially for an emergency service vehicle like an ambulance. The starter motor and its corresponding components are prone to mechanical as well as electrical faults due to high starting torque and friction with the flywheel and gear teeth of the starter. In this paper, the focus has been given to the electrical fault of a starter motor and its effect on the operational characteristics of an automobile. The response characteristics thus obtained have been evaluated by independent component analysis (ICA) based feature extraction analysis to obtain a continuous data set for automobile fault diagnosis. The feature analysis of the response characteristics helps in easier calculation while being effective in designing a system that can help with vehicle diagnosis and quality control.

Design and Implementation of Arduino Based Star Delta Starting, F/R Direction Control and Fault Protection of Three Phase Induction Motor

Three-phase induction motors have varied usage in industrial applications. At 50 Hz the most common reduced voltage starter is Star Delta. The popular applied method to minimize the start current of an induction motor is star to delta conversion. This project is designed to remotely control the starting of the induction motor through the star to delta conversion via mobile message command. The project also enables controlling of the forward and reverses motor direction along with phase fail and overload relay trip monitoring through the mobile communication system. The vital components of this project include a Two-channel relay board, a Magnetic Contactor, an Overload Relay, a Phase fail Relay, Timer Relay, Arduino Uno, and GSM SIM900A. The GSM module connected to the microcontroller sends a start command to the motor and after the system is ready the star to delta conversion happens after a certain time by an automatic timer relay. The user receives the current status of the motor and a call if any fault occurs during operation. This design of remotely Arduino controlled star delta starter, forward/ reverse motor movement, overload, and phase failure protection is safer to be used in factories and industries where the number of induction motors is widely popular.

Computational insights on asymmetrical and receptor-mediated chunking: implications for OCD and Schizophrenia.

Repetitive thoughts and motor programs including perseveration are bridge symptoms characteristic of obsessive compulsive disorder (OCD), schizophrenia and in the co-morbid overlap of these conditions. The above pathologies are sensitive to altered activation and kinetics of dopamine and receptors that differently influence sequence learning and recall. Recognizing start and stop elements of motor and cognitive behaviors has crucial importance. During chunking, frequent components of temporal strings are concatenated into single units. We extended a published computational model (Asabuki etal. 2018), where two populationsof neurons are connected and simulated in a reservoir computing framework. These neural pools were adopted to representD1andD2 striatal neuronal populations. We investigated how specific neural and striatal circuit parameters can influence start/stop signaling and found that asymmetric intra-network connection probabilities, synaptic weights and differential time constants may contribute to signaling of start/stop elements within learned sequences. Asymmetric coupling between the striatal and neural populations was also demonstrated to be beneficial. Our modeling results predict that dynamical differences between the two dopaminergic striatal populations and the interaction between themmay play complementary roles in chunk boundary signaling. Start and stop dichotomies can arise from the larger circuit dynamics as well, since neural and intra-striatal connections only partially support a clear division of labor.

Soft start of induction electric motors using rezistor and denistor devices

In this article, it is experimentally shown that by equipping asynchronous electric motorswith a new rezistor and denistor soft starting device, it is possible to effectively limit the current. In addition, as a result of using rezistor and denistor soft starting device in practice, it was determined that electrical energy wastage is saved and mechanical breakdowns are prevented.

СПОСОБЫ И СОВРЕМЕННЫЕ УСТРОЙСТВА ПЛАВНОГО ПУСКА ВЫСОКОВОЛЬТНЫХ ДВИГАТЕЛЕЙ

The relevance In today's industry, a lot of high-voltage electric drives are used. Highvoltage electric motors are used in oil and gas production, transportation, chemical and oil refineries, energy and water supply. However, during direct start of high-voltage motors, shock mechanical and electrical loads occur on the motors themselves, connected technological mechanisms and the electrical network. In pipelines during direct starts of pump drives, hydraulic pressure waves can occur, leading to the destruction of pipes and their joints. The motor winding during one start-up can heat up to critical temperatures, which causes aging of the insulation, as well as the impossibility of restarting for several hours. Therefore, the introduction of devices for scheduled start-up of high-voltage motors allows not only to reduce mechanical and electrical loads, but also to extend the life of motors and equipment. Aim of research It was necessary to consider the existing methods of starting highvoltage synchronous and asynchronous motors, as well as to analyze the soft starters manufactured by the industry and their characteristics. Research methods The provisions of the theory of electrical circuits, the theory of electrical machines and the theory of electric drive were used. Results In the course of the work, the existing methods for starting high-voltage motors were considered, their advantages and disadvantages, and the complexity of implementation were analyzed. The modern soft starters produced by the industry and their characteristics are analyzed.

Floating, Production, Storage, and Offloading Unit: A Case Study Using Variable Frequency Drives

The use of variable frequency drives (VFD) in floating, production, storage, and offloading (FPSO) units provides well-known benefits to the power system, such as: soft-starting of motors, increase of energy-efficiency, reduction of short-circuit currents, and enhancement of the load shedding capability. The VFDs with passive front-end rectifiers are the most commonly used for these applications due to their wider commercial availability and lower cost compared to VFDs with active front-end rectifiers. However, the latter can control the exchange of reactive power with the grid, which may contribute to voltage support and power factor regulation at the electrical system. This paper presents a case study considering the Production operating mode of an FPSO unit with two VFDs connected to the largest motors (i.e., water injection pumps). Simulations of the FPSO power system are evaluated using both active and passive VFDs, considering scenarios with analysis of steady-state, start of largest motors and symmetrical three-phase short-circuit.

SLEEP QUALITY OF SCHOOLCHILDREN - RESIDENTS OF RADIOACTIVELY CONTAMINATED AREAS DURING THE COVID-19 PANDEMIC.

to assess the sleep characteristics of middle school children during the COVID-19 pandemic. Cross-sectional study of sleep characteristics of children - residents of radioactively contaminated areas of Zhytomyr and Rivne regions, who underwent a routine examination in June-July 2020, after their stay from March to June 2020 in conditions of home isolation due to quarantine restrictions during the COVID-19 pandemic. Ninety six students of comprehensive public schools, aged 10-16, took part in the study. Sleep characteristics were assessed using the Pittsburgh Sleep Quality Index (PSQI-U indicator), translated into Ukrainian. During the period of the introduction of restrictive measures due to the COVID-19 pandemic, certain disturbances of sleep characteristics were observed, the imprint of which was a moderately increased total PSQI-U indicator, which was (3.89 ± 3.20) points. It was established that 19.79 % of children had insufficient total sleep time, and 2.08 % had significant sleep deprivation. The quality of their sleep was described as «rather bad» by 32.29 %, and as «very bad» by 4.17 %; 35.42 % of children complained about sleep disturbances, 67.71 % of children had signs of daytime dysfunction, 18.75 % had symptoms of insomnia. In the logistic regression model, quite significant prognostic factors of insomnia were: female gender (OR = 2.487; 95 % CI: 1.407-4.397); subjective determination of the negative impact of the pandemic on health, regardless of whether the respondent had COVID-19 or not (OR = 1.166; 95 % CI: 1.112-1.222), as well as living in the city (OR = 1.183; 95 % CI: 1.065-315). The introduction of restrictive quarantine measures as a result of the COVID-19 pandemic led to a violation of the daily routine of schoolchildren, which modified the characteristics of sleep. In almost a third of the examined children, the duration and quality of night sleep was insufficient for the physiological restoration of the body's reserves. A late choice of the start of sleep and violations of his hygiene had a critical impact on these indicators.

Development and research of non-contact starting devices for electric consumers and motors

This article presents the analysed information about power consumers and electric motor starters in order to ensure the reliable operation of the power supply system, which is relevant today. Disadvantages of contact starters used for small power electric motors in the power supply system and advantages of non-contact starters are given. In addition, it is based on the creation of additional opportunities when using this device, that is, it creates opportunities for protection and automatic control. Contactless starters are recommended for some heavy-duty electric motors. The article describes these cases in details.

걷기 Apps을 이용한 Power Walking이 교대 여학생의 체력, 체조성 및 생활습관에 미치는 영향

In this study, 40 students out of 6 classes took a track and field class in the 2nd semester of B University in Busan, walked a 10cm extension per a step for 12 weeks, more than 3times a week, and at least 1 hour per once. Physical fitness, body composition, and exercise environment were analyzed, and the results of analysis using SPSS Ver 23.0 statistical program are as follows.BR There were significant differences between the groups on the physical fitness of teacher’s college women students in 50m running, grip strength, and 20m shuttle run. The results of body composition of teacher’s college women students between groups showed significantly differences in body fat mass, %fat, and body development index. The results of the change in the exercise environment of the walking exercise group in the group of teacher’s college women students showed significant differences in the frequency of going out, outing time, exercise frequency, number of walking steps, exercise time, and the number of other exercie participants. As a result of the change of living environment in the walking exercise group in the group of teacher’s college women students, there were significant differences in breakfast, snack frequency, sleep start time, and health interest.BR Summarizing the results, walking with a 10cm extension for 12 weeks was a valuable opportunity to directly experience the development of the body and changes in lifestyle during the semester, and bringing positive effects to school life.

RESEARCH OF STARTING MODES OF ASYNCHRONOUS MOTORS AND DEVELOPMENT OF A SOFT START DEVICE

Study of starting modes of asynchronous electric motors. The growth of their demand in industry and everyday life requires an increase in the intensity of use of new systems of the industry existing in the agricultural sector. Currently, there is an aspiration to make the technological process the most automated, as well as to create the most functional and accessible equipment for an ordinary user to understand. Electric drives consume more than 60% of the produced electricity, increasing their energy efficiency is significantly achieved by switching from an unregulated asynchronous electric drive to a regulated one, which contributes to the improvement of the quality characteristics of technological processes, provides the opportunity to automate production, and increases the level of energy and resource conservation. Recently, systems of automated control of technological processes created on the basis of advanced microprocessor equipment have been actively developed, improved and implemented. Nowadays, the method of controlling the start of engines using a frequency converter is becoming more and more common. Until recently, the method of frequency regulation of the electric drive was considered expensive and was used only for a large range of speed regulation, but with the decrease in price and improvement of frequency converters, this control system becomes an almost ideal technical solution from the point of view of controlling the operation of the pump both in the start/stop period and in normal modes. Modernization of traditional control and start-up systems can become a frequency converter with an open software platform, which allows users to refine the software, optimize it for their tasks, including developing and adding their own software modules both at the power inverter control level and at the software-logic level controller for solving local automation tasks. The wide use of asynchronous motors is explained by their advantages compared to other motors: high reliability, ease of repair, small number of structural elements, the possibility of operation from an alternating current network, ease of maintenance. Various methods are used to solve the problems that appear during the uncontrolled start of an asynchronous motor, which to one degree or another ensure the acceleration of the asynchronous motor with a given value of current, which is significantly lower than with a direct (uncontrolled) start [1]. This makes it possible to prevent the premature failure of the asynchronous motor (AD) and driven mechanisms, to increase the resource of the switching equipment, to ensure the possibility of controlling the electric drive using modern automation tools. In addition, the use of modern controlled start-up allows you to reduce the active power consumption, significantly reduce the reactive power consumption, reduce the noise level, and reduce the vibration of the electric motor. The start of asynchronous short-circuited motors by direct connection to the network is usually accompanied by a large starting current, which exceeds the nominal value by several times.

OBTAINING DECORATIVE ALKALINE-ACTIVATED CEMENT BY USING SLAGS WITH A HIGH CONTENT OF IRON OXIDE

The soft start device is designed to control the process of starting, operation and stopping of electric motors and enables smooth acceleration, smooth stopping, reduction of the starting current of the motor and coordination of the motor torque with the load moment. The article the control system of the triac device of the smooth start of an asynchronous motor with a constant load moment is considered. The control provides a reduction in the starting current and starting torque of the asynchronous motor. The principle of operation and the main technical parameters of the soft start device are described. The method of reducing power losses in power semiconductor elements of the soft start device is considered. The study of electromechanical processes in the soft start device when working with an asynchronous motor was carried out due to simulated computer modeling in the Matlab / Simulink software environment. The results of simulation modeling are given: oscillograms of input currents of the soft start device, dynamics of speed change and starting torque of an asynchronous motor. In the course of the simulation, it was established that the operation of the soft start device allows to reduce the starting current and starting torque by almost half. It is shown that the adjustment of the time to reach the full opening angle of the power switches of the soft start device and the starting angle of the opening of the power switches, which determines the acceleration dynamics of the asynchronous motor, significantly affects the value of the maximum amplitude value of the current and torque. The results of theoretical studies were implemented in a real physical prototype of the soft start device. The image of the boards of the developed soft start device is shown and its technical characteristics are indicated.