This paper proposes a fault ride-through (FRT) operation for a single-phase grid-tied inverter with a minimized inductor in order to reduce the inverter output current overshoot. The inverter output current overshoot becomes very high at a grid voltage drop and recovery, when a low-inductance interconnected inductor is used. Hence, a grid-voltage fault stops the operation of the grid-tied inverter due to overcurrent protection. This paper proposes a high-speed freewheel mode during the voltage sag in order to reduce the inductor current overshoot. Moreover, the inductance of the interconnected inductor is designed by considering the grid voltage recovery operation of the inverter with the high-speed freewheel mode. Consequently, by using the proposed method, the grid-tied inverter continues to operate without interruption during the grid voltage fault. With the proposed method, the maximum inductor current overshoot during the voltage sag is reduced from 755% to 141%, compared with the conventional FRT operation.

A malware detection algorithm that can be embedded in IoT edge computing is proposed in this study and validated using an emulator. This algorithm, with a pattern match accelerator, reduces the computing cost while maintaining a relatively high detection accuracy. For autonomous driving, complicated IoT edge computing must have a huge amount of embedded program codes. In such a situation, the invasion of malware can lead to compromised cybersecurity. In this study, a pattern match accelerator is implemented for such issues, thereby offering IoT edge computing that detects malware automatically. Edge computing is designed to apply simply structural level analysis algorithms using HLAC mask pattern. We developed a pseudo-emulator system environment and conducted performance confirmation of the proposed technique using 641 chosen samples from six types of malware families. The algorithm's efficiencies demonstrated an identification performance of approximately 80%. In comparison to characteristic extraction using AI, the computing cost was reduced and these processes enable edge computing with high cybersecurity features.

The iron losses of three reactors are measured and compared with each other. The reactors are made of non-grain-oriented material (35H300), 6.5%Si metal (10JNEX900), and nanocrystalline soft magnetic material (FT-3M), respectively. The experiment is conducted under a condition where the supply frequency and maximum magnetic flux density are prescribed. The values are compared with those provided by the manufactures of the material and the measured iron losses of the three types of ring cores made from the respective material mentioned above. The comparison clearly indicates the dominant factor of iron loss generation.

This paper proposes a dual LLC converter based on a six-switch bridge to charge deeply depleted plug-in electric vehicle onboard battery packs. The primary-side switch network comprises an input series or parallel, and two types of transformer-independent modes. Thus, there are four operation modes. In the input series mode, normalized voltage gains are scaled to 0.5 therefore, a low output voltage can be obtained. In addition, in the input parallel mode, the normalized voltage gains are scaled to 2.0. These four modes operate at the resonant frequency at the switching frequency. Therefore, the efficiency performance can be optimized over a wide output voltage range. The validity of the proposed system is confirmed with a 1-kW prototype.

Drive train bench, which is a type of dynamometer, is used to test the power train components of a vehicle such as transmission, torque converter, etc. The test system has to simulate the vibration torque of the engine by motor control. Conventionally, a sine wave is used to simulate the vibration torque of an engine. However, the actual vibration torque waveform contains harmonic distortion components inherent in the engine. Therefore, it is desirable to have a vibration control technique capable of simulating the waveform of the engine torque more accurately. This paper proposes a novel engine torque simulated vibration control for the drive train bench system. The proposed method can achieve a shaft torque detection value that follows the desired engine pulsation torque waveform by utilizing robust resonance suppression control and a generalized periodic disturbance observer. The validity and usefulness of this technology are indicated by the theoretical explanation, simulation, and experimental results.