Eka Firmansyah

RSSI based analysis of Bluetooth implementation for intra-car sensor monitoring

This research evaluates the application of Bluetooth for monitoring in-car sensors. Bluetooth technology is chosen to provide reliable communication system with low complexity and production costs. To assess connection among the predefined sensor positions in car, the RSSI (received signal strength indicator) measurement is conducted by using the HC-05 Bluetooth module as the receiver and Android smartphone as the transmitter. The measurement scenario is defined based on the link between master-station at car dashboard to all possible sensor positions. More measurements are also conducted for the coverage of Bluetooth connection in the possible longest distance of car dimensions. The measurement results show that the RSSI receptions from all sensor nodes are higher than the used receiver-sensitivity threshold. Therefore, the implementation of Bluetooth is feasible. However, in the real application, the sensitivity of the implemented Bluetooth module should be carefully considered because the signal reception has possibility to drop below typical threshold in the Bluetooth standard. Therefore, rigorous measurements assuring that all possible sensor placement scenarios should be guaranteed to result in RSSI higher than the threshold of the implemented Bluetooth hardware.

Six-step commutation with round robin state machine to alleviate error in hall-effect-sensor reading for BLDC motor control

Hall-effect sensors are commonly applied in brushless direct current (BLDC) motor control for rotor position detection. By knowing the exact position of the rotor, inverter could supply energy in synchronize to the BLDC motor state. As the motor is categorized as synchronous motor, those sensors are vital. Working out of synchronization not only makes drive system less efficient but also threaten the inverter as current requirement will be increased. Unfortunately, the sensor works in harsh environment where high current, high temperature, and high vibration are exist. Those conditions result in some incorrect position detections. In order to improve the hall-effect position accuracy, in this paper, a simple finite state machine (FSM) called round robin technique is implemented. This technique along with conventional R-C filter in the sensor line successfully suppresses error in the rotor position detection. This results in higher inverter reliability and smoother motor operation.

DC-DC converter as power supply of battery charger 100 V 300 W using 25 kHZ switching frequency

Dc-dc converter with full-bridge topology is the best option to use as power supply with high power and high voltage level. Full-bridge topology combines the voltage properties of half-bridge topology and the current properties of the push pull topology. It is an elaboration from buck converter topology with isolated transformer as galvanic isolation. The main components of the dc-dc convert full-bridge are inverter, high frequency transformer, high frequency rectifier and filter. The inverter is designed in a full-bridge topology that can transfer power greater than the half-bridge. Switching mode that used in this research is phase-shifted PWM ZVT. This switching mode will reduce the loss of switch. High frequency transformer is used to raise the level of output ac voltage from inverter that has a high frequency, the transformer also has smaller dimensions than a common transformer with the same capacity. Rectification of high frequency output transformer is done by a full-bridge rectifier using fast recovery diode. In this study, dc-dc converters used as a power supply for battery charger that is loaded with bulb lamps with 300 W power needed and also eight pieces of lead-acid batteries 12 V in series. The results showed that the efficiency of the converter dc-dc battery charger designed achieve efficiency about 95% for certain circumstances.

Fault-tolerance control for a dual-PMSM drive system

In this paper, a simple fault-tolerance control method for a dual-PMSM speed drive system is investigated. The proposed method does not require any additional hardware. By suitably changing the switching states, a fault-tolerant control dual-PMSM drive system can be achieved. The fault-tolerant system can be applied for high-reliability applications such as, electric vehicles and other electric propulsion systems. The proposed system is implemented by using TMS320F2808 digital signal processors. Several experimental results show the validity and feasibility of the proposed method.

The performance of three-phase four-wire grid-connected inverter with enhanced power quality

This paper presents the performance of grid-connected inverter when installed in three-phase four-wire distribution system. The inverter is utilized as power converter to inject power. Furthermore, this inverter is also utilized as a shunt active power filter to compensate current unbalance, load current harmonics, and load reactive power demand. It is controlled such a way therefore it draws or supplies fundamental active power from and to grid. The control mechanism is carried out by power balance theory using PI controller. The control system consists of DC voltage regulator, phase-locked loop (PLL), and hysteresis current controller. PI controller is used as DC voltage regulator, which regulates DC-link capacitor voltage to be constant. The performance of this controller is demonstrated through simulation. The results of the simulation show the capability of an inverter to inject power to grid. Particularly for nonlinear load, the current harmonics are compensated effectively.

An improved maximum efficiency control for dual-motor drive systems

A maximum efficiency control for a dual-motor drive system is presented in this paper. The torque sharing between two motors is optimized by using the perturbation and observation method. A fuzzy-logic controller is implemented for the perturbation and observation method. As a result, the step of perturbation can be adaptively modified to improve the performance. In addition, a simple calculation is used to achieve real-time efficiency measurement. The proposed method is implemented on two identical 2 kW permanent magnet synchronous motors connected in parallel. Finally, experimental results validate the proposed control scheme performance.

Implementation of on-line maximum efficiency control for a dual-motor drive system

This paper proposes an on-line maximum efficiency control method for a dual-motor drive system. By using the on-line feedback signals and doing simple computations, the output torque of each motor can be determined. Then, a maximum efficiency operation of the whole system can be achieved. The efficiency of the whole system, which includes motor efficiency and inverter efficiency, is investigated. A digital signal processor TMS-320-F2808, made by Texas Instrument Company, is used as a control center to execute the required control algorithm. The proposed method is implemented on two identical surface-mounted PMSMs. Several experimental results can validate the correctness and feasibility of the proposed method. The proposed method can be used in industrial applications due to its simplicity.

Aplikasi Magnetic Energy Recovery Switch sebagai Dynamic Voltage Restorer pada motor Induksi

Renewable energy source likes solar panel and wind turbine have intermittent character from instability power source generated. The instability power source can make dip voltage in power grid which happen in half cycle until few seconds. To stabilize the voltage in power grid from dip voltage, some methods have been developed using power electronics technology like VSI inverter, STATCOM, energy storage, OLTC, and MERS. The power electronic circuits have some advantages, such as small dimensional size and lightweight to keep voltage in power grid. In this paper, the MERS circuit was applied in induction motor which has small full bridge circuit, uncomplexity computation, and low switching frequency, so it needs low end hardware requirement. This paper proposed the use of MERS dc capacitor with 50% value from induction motor resistance. The result shows that MERS has advantage and can keep the voltage in power grid when the voltage below 39% and 15% above rated voltage (220 Vrms) with the recovery time around 0.3 second and keep the dip voltage over 1 second.

A microclimate closed house control design for broiler strain

Through all stages of growing, chickens need a certain climate quality. The old climate quality is only the actual temperature-based controlling. On modern climate, an organization called Cobb-Vantress detached three climate parameters need to be satisfied: 1) temperature, 2) humidity, and 3) wind speed. It is known that those three parameters are not independent, the area to be controlled are fast area while commonly, this available tool to control those three parameters is only the speed of the exhaust fans inside the broiler house. Therefore, controlling three parameters which were intertwined each other inside a fast area with only single actuator was the main problem of this paper. The main goal was to achieve ideal microclimate control to grow chicken inside a broiler house. Alleviating those stated problem, a method that combined PID with artificial neural network was evaluated. The retrieval of the actual climate data were used as an input parameter for the process of identifying ideal climate system and used to control the climate error based-those parameters by generating wind speed to cool the broiler house. Results shows that the climate control that can be implemented effectively to maintain the effective temperature of the broiler house at 32 to 22 degrees celcius from the day-old chick to be matured in brooding stage. To achieve a settle state in the process of tuning PID should be done to get the appropriate PID parameters. Temperature controller testing shows prototype device has linear set point response between to with maximum heating rate and maximum cooling rate.

Preliminary design of biomass fuel storage on a thermoelectric based biomass-electric energy conversion

Rural electrification in an archipelago country like Indonesia is a challenge. Indonesian government has stated that basic need of electricity is 60 kWh, however it is not easy to fulfill it. Fortunately, Indonesia is rich in biomass potency. Therefore, converting biomass energy to electricity might be a solution to the country electricity problem. A simple thermal energy harvesting system comprised of biomass burner and thermoelectric generator was investigated. Hot water storage was introduced to provide steady temperature. This paper specifically reported about the fuel storage mechanism of the proposed system. Two fuel storage mechanisms are investigated: integrated and bulk storage types. Integrated storage is a fuel storage facility that is included on energy harvesting device which useful in short-term operation, while bulk storage is located external of energy harvesting device which normally used for long-term operation. Based on the specification of pellet type, which is referred to EN 14961-1 standard, calculation shown that the largest volume of integrated fuel storage type for 168 hours of operation is 0.345 m3, while the bulk fuel storage type is 4.728 m3 for 6 months of operation.