Performance and Analysis of Indirect Torque Control-Based Three-Phase Induction Motor

Induction motors are widely used in industrial processes, vehicles and automation. Three-phase induction motors can be used for traction systems on electric locomotives. In this case, the speed control system is an important thing that must be applied to the propulsion system. This study aimed to test the indirect torque control for a Three-phase induction motor. A proportional integral (PI) controller was applied for speed controller. The indirect torque control system was modeled and simulated using PSIM software. According to the result, the control method showed a good performance. The speed could be maintained even the speed reference was changing or a load was applied. The steady state error of the speed response was just 0.1% with rise time around 0.06 s. The stator current went up to 39.5 A in starting condition. The stator current reached 12 A rms when the load of 10 Nm was applied. Then, the current rose to 15.7 A rms when the load was increased to 40 Nm and the current came down to 12.8 A rms when the load was decreased to 20 Nm.

Design and Implementation of Real-Time Flood Early Warning System (FEWS) Based on IoT Blynk Application

Disaster occurrence in Indonesia needs attention and role from all parties including the community to reduce the risks. Disaster mitigation is one of the ways to reduce the disaster risk through awareness, capacity building, and the development of physical facilities, for example by applying disaster mitigation technology (early warning system, EWS). EWS is one of the effective methods to minimize losses due to disasters by providing warning based on certain parameters for disasters which usually occur such as floods. This research promotes a real-time IoT-based EWS flood warning system (Flood Early Warning System, FEWS) using Arduino and Blynk as well as Global System for Mobile Communication network (GSM) as the communication medium. The steps for implementing FEWS system in real locations are also discussed in this paper. Parameters such as water level, temperature, and humidity as well as rain conditions that are read by the EWS sensor can be accessed in real-time by using android based Blynk application that has been created. The result of the measurement of average temperature, humidity, and water level were 28.6 oC, 63.7 %, and 54.5 cm. Based on this analysis, the parameters indicated that the water level is in normal condition and there are no signs indicating that there will be flooding in the 30 days observation. Based on the data collected by the sensor, FEWS can report four conditions, namely Normal, Waspada Banjir (Advisory), Siaga Banjir (Watch), and Awas Banjir (Warning) that will be sent immediately to the Blynk FEWS application user that has been created.

Comparison and Analysis of Neural Solver Methods for Differential Equations in Physical Systems

Differential equations are ubiquitous in many fields of study, yet not all equations, whether ordinary or partial, can be solved analytically. Traditional numerical methods such as time-stepping schemes have been devised to approximate these solutions. With the advent of modern deep learning, neural networks have become a viable alternative to traditional numerical methods. By reformulating the problem as an optimisation task, neural networks can be trained in a semi-supervised learning fashion to approximate nonlinear solutions. In this paper, neural solvers are implemented in TensorFlow for a variety of differential equations, namely: linear and nonlinear ordinary differential equations of the first and second order; Poisson’s equation, the heat equation, and the inviscid Burgers’ equation. Different methods, such as the naive and ansatz formulations, are contrasted, and their overall performance is analysed. Experimental data is also used to validate the neural solutions on test cases, specifically: the spring-mass system and Gauss’s law for electric fields. The errors of the neural solvers against exact solutions are investigated and found to surpass traditional schemes in certain cases. Although neural solvers will not replace the computational speed offered by traditional schemes in the near future, they remain a feasible, easy-to-implement substitute when all else fails.

Power Outage Sensing Device based on IOT for Service Quality Evaluation in the PLN Distribution System

In overcoming electrical disturbances, PLN implements an equipment protection system that aims to reduce the areas experiencing power outage. However, this protection system has not been integrated with the SCADA system. As a parameter to maintain customer service continuity, PLN uses customer-based indexes, i.e., the Customer Average Interruption Duration Index (CAIDI) and Customer Average Interruption Frequency Index (CAIFI). In the calculation of those index values, the record of power outage occurrence at PLN is still not accurate because the duration and frequency of power outage based on customer complaints. In this study, a Power Outage Sensing device is installed on the secondary distribution system transformer 380/220 which can ensure the location, record the frequency and duration of power outage and serve customers in real time based on IOT using WEMOS D1 and optocoupler sensors which can then be accessed on a web. In its implementation, all power outage is recorded in the database and can be accessed on the web interface. This device can speed up the recovery of disturbances in the system after an outage and perform accurate CAIDI and CAIFI index calculations as customer service evaluations.

Development of Integrated Distribution and Inventory System Simulation Model Using Mobile Depot

Distribution activities are carried out to move an item from one point to another. Product distribution activities are conducted from the production area to the distribution or warehouse area, then from the warehouse to the retailer or consumer. Distribution activities can be established using various modes of land, river, ocean, and air transportation. Land transportation is greatly influenced by road conditions. River and sea transportation excels in carrying capacity which leads to the reduction of distribution costs. The disadvantages of water transportation are longer moving duration and dependence on weather. A warehouse is a typical facility used to accommodate inventory. Inventory system will generate holding costs. River transportation with a large carrying capacity can be used as a distribution medium and temporary warehouse. The land route in the West Kalimantan region is suitable for trucks with a moderate carrying capacity. River routes in West Kalimantan can reach several strategic areas, and river conditions have appropriate specifications for transportation mode with large capacities. The distribution and inventory system integration model using a mobile depot has been proposed in previous studies. Therefore, this research focuses on developing a simulation model for the aforementioned system. The results of this study are expected to provide information about the optimal value of the model configuration and strategy.

Humanoid Robot Application as COVID-19 Symptoms Checker Using Computer Vision and Multiple Sensors

Novel Corona Virus (nCoV) infects human’s respiratory system. It spreads easily when an infected person makes a close contact with other people. To prevent its massive spread, it is necessary to ensure anyone coming to a certain place is not being infected. The symptoms include high body temperature (≥37.5°C) and low oxygen saturation level (≤95%). This day, most places only check the human body temperature. Thus, the authors are interested to make an attempt to design a system that is able to measure both human body temperature and oxygen saturation level. This work also applies the 7-DoF Upper-Body of Humanoid Robot to prevent virus spread from and to the employee. The system will detect the coming of visitors by using face detection. It requires 7.24 seconds to detect the visitor without a mask, and 1.26 second when the visitor wears a mask. The body temperature measurement was done using GY-906 temperature sensor with an error of 0.51%. For the oxygen saturation level measurement, MAX30100 pulse oximeter module was applied and showed an error of 0.78%. In addition, the upper-body of humanoid robot will perform some gestures to instruct the visitors in every process of the system. The implemented 7-DoF upper-body of humanoid robot has 93.33% gesture comprehension rate. In conclusion, the overall system has been tested and showed success rate up to 75%.

Performance Analysis of VRLA Battery for DC Load at Telecommunication Base Station

The high level of power outage in Sukabumi-Cianjur area has influenced the operations of telecommunication industry in the vicinity. This has shortened the battery life at the Base Station (BTS). This study aims to analyze the performance of a (new) VRLA battery against a DC load (BTS) to support the continuity of BTS operation in case of a power outage. The research method used is a (new) battery charge-discharge procedure. Parameters are analyzed by determining the on-site battery discharge duration, the pressure at the battery terminals between cells during backup, and the capacity of the rectifier module to support fast charging. To support fast charging, the rectifier with the formula N+1 and C-rate is 10% and C15 is 15% of the battery capacity. The internal impedance value is 3.4 mΩ and the battery terminal pressure (torque) is 9-11 N/m. The battery performance analysis of the four BTS shows that two of them managed to do a backup, while the other two did not provide good performance.

Web-based Application Forecasting of Components and Tools for Practicum in Telecommunication Engineering Laboratory/ Workshop of State Polytechnic of Sriwijaya

State Polytechnic of Sriwijaya is an Indonesian vocational institution that incorporates practical learning into all of its existing study programs. In each laboratory of the study program, students will find the supporting components and resources they need for practicum. Telecommunication engineering is one of them. Currently, the component retrieval and tool borrowing system is still manual, both in the retrieval and return stages, by filling out the given hard-file form sheet. Therefore, a web-based inventory monitoring application is required for laboratory technicians. The creation of this application implements the Prototype Method. The implementation of this method aims to make the application that is created to fit the needs of the user. This system helps laboratory technicians and Telecommunication Engineering students in the process of component retrieval and tool borrowing to be more organized and scheduled and can store reports in the form of soft-files. This information system can also be used by students to monitor the number of components and tools available in real-time. This application are also equipped with forecasting the number of practicum components to kwowing the needs of student practicum in the next year. Forecasting was created using the Weighted Moving Average method. Black box testing is carried out in each menu on the application and gives valid results so that the application can be used.

Designing a Firing Control System on S-60 57mm Cannon

The firing system on the S-60 57mm cannon uses the foot of the cannon crew, which is very dangerous with the position of the crew on top of the cannon when firing. So, a firing system that can be remotely controlled by a computer is required. The design of the S-60 57mm gun firing control system uses a personal computer (PC) as the firing command input, with data communication using WiFi received by the Atmega8535 microcontroller as a voltage regulator for solenoids. The solenoid has a tensile force to drive the hydraulic system where the actuator functions to drive the firing cylinder. Accelero sensor MMA7361, as a variable controller in firing, provides input data simulating the tilt position of the cannon, the position of the 0g sensor is simulated by the cannon in a balanced position. From the test results, there is a difference in sensor designation data with arc angles i.e., angle X by 2.83 degrees and angle Y by 1.86 degrees. The magnetic field produced by the solenoid 0.53 T can attract a maximum load of 20 kg. By changing the distance ratio of mechanical lever to 39.11 cm and 8.89 cm, the solenoid can drive an 88-kg firing cylinder.

Reliability Evaluation of Kumpai Feeder Distribution System at PT. PLN (Persero) ULP Siantan

The research on reliability index of a feeder aims to evaluate the reliability level of a feeder using the Reliability Index Assessment (RIA) method. This method evaluates the reliability of a 20 kV distribution network by calculating the reliability indexes of each load point. The evaluation results show the reliability index value per section of the Kumpai Feeder at PT. PLN (Persero) ULP Siantan within one year. The SAIFI values are 0.0092; 0.0012; 12,477; 0.0596; 0.0204; 0.0470; 0.0155; 0.0728, the SAIDI values are 0.0277; 0.0042; 37,746; 0.1862; 0.0741; 0.1524; 0.0493; 0.2209, the CAIDI values are 3.0108; 3.5; 3,025; 3.1241; 3.6323; 3.2425; 3.1806; 3.0343, the MAIFI values are 0; 5,480; 0.2145; 0.0020; 0.0038; 0.0042; 0.0006; 0.0014. The calculation results show that the 20 kV distribution system at PT. PLN (Persero) ULP Siantan at the Kumpai Feeder can be categorized as unreliable. Because the SAIFI value of this feeder exceeds the standard set by PT. PLN (Persero) which are 12.477 times/customer/year and 3.2 times/customer/year, respectively. The factors affecting the reliability index of the Kumpai feeder are the number and duration of blackouts, the number of customers, and the length of the distribution system channel.