전기추진선박용 하이브리드 인버터 시스템의 제어 파워모듈

Abstract

As a countermeasure to the increase in environmental problems, the development of electric propulsion ship (EPS) technology to reduce air pollutant emissions has been on the rise. These technologies are used by hybrid EPSs, which supply power to the inverter from both the generator and the battery in parallel. Power from both sources is then converted to AC power and supplied to the electric motor to drive the propeller. In a hybrid electric propulsion inverter system, the battery, inverter, and AC motor are linked in a causal chain. Therefore, if a problem occurs in any one of the sub-systems, the entire inverter system is inoperable. Thus, a hybrid electric propulsion system must verify the status of each sub-system in real time, and the system should allow monitoring both remotely and in the field. The internal resistance of the battery varies depending on its physical characteristics and the length of time it has been in use. Therefore, remaining battery life can be estimated in advance by measuring the internal resistance. In addition, the output voltage of the inverter can be adjusted by the duty ratio of pulse width modulation(PWM) to switch from DC to AC power. Therefore, both the inverter system and its sub-systems must be monitored at all times. In this study, we implement a power module that checks and monitors the state of the hybrid electric propulsion system through the internal resistance of the battery, the output voltage and current of the inverter, and the power factor. The power module also continually regulates the output voltage by adjusting the PWM duty ratio of the inverter when the voltage to the inverter is too low due to battery failure.