Operation analysis of high efficiency grid connected bi-directional power conversion system for various storage battery systems with bi-directional switch circuit topology
In recent years, there is an increasing demand for various types of storage battery systems, such as home battery systems, V2H(Vehicle-to-Home)/V2G(Vehicle-to-Grid) systems, and UPS systems. Performance requirements for the power conversion system within these storage battery systems are small size, light weight and high efficiency. We propose a new power conversion system so called the GAP-D3 converter that is a bi-directional power control system, comprising of a bi-directional switch circuit topology with natural commutation switching mode. This paper describes the features of GAP-D3 converter including this new current compensation control with simulation and experimental results.
A compact GaN Bi-directional switching diode with a GaN Bi-directional power switch and an Isolated gate driver
A compact and fast GaN bi-directional switching diode is described, which is integrated with a GaN/Si bi-directional power switch and a Drive-by-Microwave (DBM) isolated gate driver using a microwave wireless power transfer. The fabricated 600V 15A GaN bi-directional switching diode exhibits its low Ron of 160 mΩ under 85 °C ambient temperature without an external heat sink. The compact 12mm × 25.5mm × 3mm module also has a cooling pad to directly release heat from the GaN bi-directional power switch. By the fabricated module, the 1.0 MHz fast current direction switching was successfully realized with constant low power consumption of 0.8W thank to a gate power sharing technic by the DBM gate driver.
Flow in a branching open channel: a review
Branching channel flow refers to any side water withdrawals from rivers or main channels. Branching channels have wide application in many practical projects, such as irrigation and drainage network systems, water and waste water treatment plants, and many water resources projects. In the last decades, extensive theoretical and experimental investigations of the branching open channels have been carried out to understand the characteristics of this branching flow, varying from case studies to theoretical and experimental investigations. The objectives of this paper are to review and summarise the relevant literatures regarding branching channel flow. These literatures were reviewed based on flow characteristics, physical characteristics, and modeling of the branching flow. Investigations of the flow into branching channel show that the branching discharge depends on many interlinked parameters. It increases with the decreasing of the main channel flow velocity and Froude number at the upstream of the branch channel junction. Also it increases with the increasing of the branch channel bed slope. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to an increase of water depth at the downstream of the main channel. From the review, it is important to highlight that most of the study concentrated on flow characteristics in a right angle branch channel with a rigid boundary. Investigations on different branching angles with movable bed have still to be explored.