DC-DC sectionalizer

Abstract

The invention provides a DC-DC sectionalizer which belongs to the technical field of microgrid. The DC-DC sectionalizer is short for a DC / DC sectionalizer which configured in a DC network topology and based on high-frequency isolation DC / DC conversion, and can substitute for a solid-state circuit breaker. The DC-DC sectionalizer adopts a dual full-bridge topological structure, and carries out AC coupling through a high-frequency transformer. Four IGBTs (insulated gate bipolar transistors) are arranged on each of a primary side and a secondary side of the DC-DC sectionalizer, are respectively distributed on a primary side and a secondary side of the high-frequency isolation transformer and has two power conversion stages. The DC-DC sectionalizer can realize protection and control functions through a control module, so that a maximal transmission power point and soft switching characteristic can be obtained in commutation process of bi-directional power flow. The DC-DC sectionalizer provided by the invention has remarkable advantages in reliable fault breaking, electric isolation, power flow control and contact with different voltage classes in comparison with the conventional DC large-power solid-state circuit breaker.

Description

technical field [0001] The invention relates to the field of micro-grid technology, in particular to a DC-DC segmenter based on a high-frequency isolation DC / DC conversion device. Background technique [0002] As a form of microgrid that connects distributed power and the main grid, DC microgrid can efficiently play the value and benefits of distributed power, and effectively isolate intermittent power disturbances, power quality problems and various problems in the main grid. effect of a failure. Therefore, research institutions at home and abroad have successively carried out the research and engineering practice of DC microgrid related theories. However, the DC system requires a large-capacity capacitor to eliminate the voltage ripple. When a short-circuit fault occurs, the transient current caused by the instantaneous discharge of the capacitor may cause damage to the equipment or misoperation of the switch, resulting in the failure of the selective protection function ...

AI Technical Summary

Problems solved by technology

However, the DC system requires a large-capacity capacitor to eliminate the voltage ripple. When a short-circuit fault occurs, the transient current caused by the instantaneous discharge of the capacitor may cause damage to the equipment or misoperation of the switch, resulting in the failure of the selective protection function and the power outage of a large number of loads and protection equipment. Deterioration of inter-coordination ability and other issues

At the same time, DC high-power solid-state circuit breakers are expensive, complicated to control, and questionable in reliability, so it is difficult to be widely used in DC microgrids

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