Papers by Keyword: Inverter

Abstract: In this study, we introduce the impact of gamma irradiation on 4H-SiC based transistor-transistor logic (TTL) inverters. These monolithic bipolar inverters have been successfully demonstrated in a broad spectrum of temperature and supply voltage conditions. In this iteration of experiments, attempts made to the processing to increase beta values. The gamma radiation tests from a ⁶⁰Co source were conducted under various operation conditions and measured in-situ under different biasing conditions. The Silicon Carbide Integrated circuits ( SiC ICs) show excellent tolerance properties to gamma radiation up to doses of nearly 1 MRad. Comparable Si BJT-based TTL inverters show considerable degradation already at one order of magnitude lower doses, clearly demonstrating the superior radiation hardness of 4H-SiC ICs.

Abstract: This research focuses on regulating the speed of a single-phase induction motor in making biopellets from empty palm oil bunches. Bio-pellets are a renewable energy fuel source. Power consumption in induction motors at constant speed is greater and this can cause waste of electrical energy. To overcome this problem, we need a way to save electrical energy, especially in operating electric motors. One effort to save electrical energy when operating an induction motor is to use an inverter. From the research results, it is known that the power of an induction motor operated without using an inverter is 0.610 kW with electrical energy of 0.603 kWh and using an inverter is 0.376 kW with electrical energy of 0.396 kWh. The electrical energy use of a single phase induction motor using an inverter is 0.207 kWh lower than without an inverter with electrical energy savings of 34.32% or Rp. 8,395.92 in one month.

Abstract: Application of multi-pulse multilevel inverters is considered in this paper for distributed generation. A five-level twelve-pulse neutral point clamped inverter has been combined with a proton exchange membrane fuel cell in order to investigate load following characteristics of the fuel cell. The fuel cell implemented with a three-phase multi-pulse multilevel inverter is adept of delivering single-phase and three-phase loads both in islanded and grid-connected approach. Changes in power demand from no-load to full-load (120 kW) have been applied to study the characteristics of the system from the perspective of how it can follow the load changes in load demand. It has been observed that the fuel cell model is adept of following power request as per requirement; however, there is a response time of few seconds, because the reformer for the fuel cell requires time to generate fuel and the fuel cell requires time for chemical reactions to take place in it. Implementations of six-pulse and twelve-pulse five-level neutral point clamped and flying capacitor inverters show that total harmonic distortions for six-pulse and twelve-pulse five-level neutral point clamped inverters to be 1.066219% and 0.406149% respectively as compared to 2.466889% and 1.5104075% for flying capacitor inverters. It has been observed that with twelve-pulse neutral point clamped inverter, the output voltage waveform is smoother and close to sinewave. The results of the research work is presented with analyses to validate that multi-pulse multilevel neutral point clamped inverter is a better way out for the fuel cell power generation model as this type of inverters produces smoother waveforms to improve power quality with lower harmonics.

Abstract: Inverter based Distributed Energy Resources lack the inertia and damping features of synchronous generators dominated traditional power system. The growing penetration of renewable energy technologies coupled with their inherent intermittency also constitute grid instability challenge due to insignificant inertia and damping. The virtual inertia machine methods for the control of inverter based Distributed Energy Resources present the required inertia support that mimics the dynamic performance of a typical synchronous generator. These control methods provide excellent improvement in the stability of the grid. Several studies and implementations have been carried out on providing virtual inertia support for inverters in steady-state and under balanced grid voltage, however there is a need to investigate the dynamic performances during voltage sags occasioned by faults and other grid transients. Due to the low overvoltage and overcurrent tolerance capabilities of inverters, this investigation is important to observe the inverter transient behavior while ensuring the protection of constituent power electronic switches. Consequently, this work carried out an investigation to assess the two methods of Virtual Inertia Machine in ensuring the inverter sustained grid connection in compliance with grid codes, fault current limitation and fault recovery.

Abstract: This paper extends a previously presented SiC power module design philosophy to critical, higher-level components for increased system performance, namely the DC bussing and DC link capacitor design. The DC bussing is essential to connect the DC bulk capacitors to the high-speed power modules and it is imperative that low inductance is maintained while current carrying capability and temperature be maintained. Often, high frequency capacitors are added to systems to increase performance by compensating for extra stray inductance that the DC bussing can introduce. However, issues that may arise by doing such are presented and it is shown that the best solution is to optimize the DC bus structure rather than compensate for a poor design. Finally, the implemented bussing is shown and full power system results presented for the inverter stack-up design.

Abstract: Full SiC half-bridge power modules (HPMs) applicable to a real electric vehicle 40-kW permanent magnetic in-wheel motor with an internal diameter of 159 mm have been designed, prototyped and characterized for the first time in the NEDO-SIP program. The prototyped HPMs are extremely compact in size at D35.7×W18.8×H8.0 mm and capable of withstanding junction temperatures up to nearly 200°C. Double-pulse tests revealed that the tested HPM showed steady switching behavior even at 600 V/160 A.

Abstract: A transconductance-like behavior similar to that of junction semiconductor devices is observed in photonically excited wide bandgap (WBG) semi-insulating material without a junction. This property offers the possibility of power electronic devices capable of virtually unlimited voltage and current carrying capability due to intrinsic electrical isolation of the controlling voltage from the switched high voltage. A proof of concept experiment demonstrated the transconductance-like property in burst mode switching to >16 kV, 50% duty cycle, and 75 kHz. Our eventual goal is to combine the light source, optics and the WBG material to form a compact module that is functionally equivalent to junction power electronic devices. In this paper, we present the background, our generalized approach for implementing photoconductive switching for potential applications to high repetition rate (>50 kHz), high voltage (>15 kV) power switching, our associated material measurements, and our path forward to multi-10s of ampere devices.

Abstract: In recent days environmental pollution has become a severe problem for the mankind. Many of the scientists are conducting various researches to find out the possible measures for environment safety. Among the very serious problems growing rapidly along with the technology is the need of utilizing the solar energy before the fossil fuels get vanished. The main factors are considered as irradiance, temperature. Further a control method is surely needed for the solar energy conversion system as its efficiency changes rapidly with climate changes. In this paper the solar arrays are controlled by maximum power point tracking system (MPPT) along with the high frequency dc-dc converter.

Abstract: In this work, the use of SiC MOSFETs is proposed for the implementation of the H-bridge Voltage Source Inverter (VSI) of Inductive Power Transfer Systems (IPTSs) in order to successfully support potential capacitive loading. Conventional power semiconductor devices are prevented from feeding capacitive loads because of the occurrence of current overshoots and voltage spikes due to the reverse recovery phenomenon of the antiparallel diodes. Operation of the VSI under capacitive load can be caused in IPTSs during resonant frequency tracking or misalignment between the coupled coils, due to the existence of resonant circuits. Experiments conducted with both Si and SiC MOSFETs show the superiority of the latter in terms of system stability, endurance in high power and avoidance of catastrophic failure.

Abstract: A 300 W/ 50 Hz single-phase sine wave with a 555 timer IC controller was designed, simulated, implemented and tested to investigate output AC power quality. An input 12 VDC power supply, which simulates PV-Wind power source, was connected to the inverter circuit and charge-discharge energy storage was also studied. Results of simulation show that as well as the experiment result is obtained.This paper is present the advantage ofhybrid system wind &solar together in power supply system from the integration between time andlocation. It showsthe evolution of wind-solar in single-phase sine wave power inverter and provides the structure of information and communications technology and equipment.Some main techniques such as the circuit topology and operation modes of the key link, algorithm of the intelligent control charging and discharging and so on.