Stator faults are the most critical faults in induction motors as they develop quickly hence requiring fast online diagnostic methods. A number of online condition monitoring techniques are proposed in the literature to respond to such faults, including the signature analysis of the stator current, vibration monitoring, flux leakage monitoring, negative sequence components of voltage and current and sequence components monitoring based on the identification of asymmetrical behavior in a machine. Negative sequence components of voltage and current and sequence components monitoring are commonly considered for the identification of asymmetrical behavior of induction motors. Negative sequence current analysis is a sensitive technique for the detection of shorted turns as it directly measures the asymmetry produced by the fault. However, the technique is sensitive to other asymmetrical faults and disturbances, which can also produce negative sequence currents. These disturbances include sensor errors, inherent asymmetry and voltage unbalance. This paper provides a comprehensive investigation of the disturbances using a motor model along with experimental measurements under varying load conditions. Then, a new phasor compensation technique is explained to eliminate such disturbances effectively. This technique enables the accurate detection of even relatively small shorted turn faults, even at an early stage. The technique is tested experimentally, and a set of practical results are given to validate the methods developed.

A small modular nuclear reactor with passive safety features is one of the best solutions for Indonesian energy security to support the national sustainable development as in National Medium Term Development Plant (RPJMN) 2015-2019. High safety level which shown by a small radioactive release to the environment on various probable accident is the basic scientific consideration beside the economic. Reaktor Daya Eksperimental (RDE) is a 10MWt small modular nuclear reactor applying pebble bed high temperature reactor design. RDE is dedicated as a basic reference and milestone for Indonesia to become a Nuclear Power Technology Provider in the near future. Cooling passive safety features, the capability of nuclear reactor to maintain its cooling performances only by natural mechanism with no external support, is very important feature to survive even in the severest condition as occur in Fukushima accident. This paper presents the cooling passive safety features of RDE in the severest accident scenario called depressurized loss of forced cooling (DLOFC). In DLOFC, the helium which cooled the core reactor is not available as a combination of circulator shutdown and breaks which occur in the primary system. The safety analysis simulation was performed using PEBBED code including the neutronic and thermal hydraulic solver. The analysis results show that in steady-state equilibrium condition the average and maximum fuel temperature is 511.9 °C and 819 °C. When the DLOFC accident is initiated, the core temperature is increasing. After 8.2 hours, the core reach its maximum temperature at 974.9 °C and then decrease subsequently. The results show the cooling passive mechanism of RDE. Combine with the TRISO-based design of RDE, which able to contain the radioactive isotopes provided the fuel temperature is under the limiting value of 1620 °C, the cooling safety feature ensure the safety design target of RDE that there is no dangerous radioactive release to the workers, populations, and environments even in the severest accident.

Three research reactors owned by BATAN have been more than 25 years. Aging of (Structure, System and Component) SSC which is mainly related to mechanical causes become the most important issue for the sustainability and safety operation. Acoustic Emission (AE) is one of the appropriate and recommended methods by the IAEA for inspection as well as at the same time for the monitoring of mechanical SSC related. However, the advantages of AE method in detecting the acoustic emission both for the inspection and the online monitoring require a relatively complex measurement system including hardware software system for the signal detection and analysis purposes. Therefore, aim of this work was to develop an AE system based on an embedded system which capable for doing both the online monitoring and inspection of the research reactor's integrity structure. An embedded system was selected due to the possibility to install the equipment on the field in extreme environmental condition with capability to store, analyses, and send the required information for further maintenance and operation. The research was done by designing the embedded system based on the Field Programmable Gate Array (FPGA) platform, because of their execution speed and system reconfigurable opportunities. The AE embedded system is then tested to identify the AE source location and AE characteristic under tensile material testing. The developed system successfully acquire the AE elastic waveform and determine the parameter-based analysis such as the amplitude, peak, duration, rise time, counts and the average frequency both for the source location test and the tensile test.

The performance of solar panels greatly determines the electrical energy production of a solar power generation system. The decrease in performance has an impact on efficiency, output power, output voltage and current. Currently, at Universitas Pamulang a solar photovoltaic system (PV) is installed with a capacity of 2.56 kWp since 2018. However, no performance test and analysis have been conducted to determine its level of efficiency and reliability. This paper presents an experimental method used for performance testing of a 320 W mono-crystalline solar panel, measuring from 08.00 AM to 4.00 PM, using the solar survey 200R to measure solar irradiation, ambient and cell temperature. A digital multimeter CD800a was used to measure Voc and a PV200 tester used to measure voltage and current output. The results revealed that at an ambient temperature of 38°C and cell temperature 50.9°C, the intensity of solar radiation was 702.7 W/m2 and output voltage of 42.9 V with a performance of 78.37% and an efficiency of 27.73% was due to an increase cell temperature. Low-efficiency values with high cell temperatures indicate that this system requires an external solar panel cooling system.