Research content -Grid connection-
One of the topic in Power Electronics Lab is the research about grid-tied systems, where AC power is supplied from DC power sources such as grid-tied solar battery or grid-tied fuel cell. In particular, we put our effort into the realization of circuit topologies and control method in order to achieve the system requirements, i.e. compact size, long lifetime and high efficiency.
Research on power decoupling
In the conventional grid-tied systems, electrolytic capacitors are applied in order to stabilize DC-link voltage. However, the employment of the electrolytic capacitors not only limits system lifetime but also increases system volume. In order to solve these problems, active power decoupling is applied. By using active power decoupling, it is possible to substitute film capacitors or ceramic capacitors for the electrolytic capacitors. Thus, it is possible to minimize the system and extend the lifetime.
High-performance disturbance compensation for inverter control
In order to minimize interconnected inductors, SiC (Silicon carbide) or GaN (Gallium nitride) are recently applied into the grid-tied systems instead of conventional Silicon devices. However, the minimization of interconnected inductors causes the reduction of disturbance suppression. In order to solve this problem, a high-performance disturbance compensation is applied. By using this method, the inverter-output-current distortion is suppressed. Moreover, it is possible to realize the fault-ride-through (FRT) capability during the grid failures such as voltage sag.
