Öl- und Gasforschung

Abstrakt

Fault Protection and Dynamic Control Strategy for Microgrids with High Renewable Energy

Dehua Zheng

Microgrid is a group of interconnected loads and distributed energy
resources (including microturbines, diesel generators, energy
storage, renewable resources, and all other kinds of distributed energy
resources) at distribution level with defined electrical boundaries
that has black start capacity and can operate in island mode
and/or grid-connected mode. Because of the uncertainty, intermittent,
and discontinuity of the renewable resources, transient
disturbance and dynamic disturbance exist in the microgrid. For
the fault current is small in the system and the microgrid has very
little inertia, the disturbance control and fault protection of microgrids
are more difficult than the ones of traditional grids.The most
challenging part of protection and dynamic control of microgrids
is how to distinguish whether a fault or disturbance is occurring
in the system. In the microgrid, there may appear transient characteristics
similar to the transient and dynamic disturbance at the
initial faults. If there is a fault, the transient disturbance control
should be used to prevent the system from collapsing and make
sure the right breakers should be tripped. But if there are transient
and dynamic disturbances, even the initial characteristics
of the transient and dynamic are very similar to the fault ones,
the breakers should not be tripped. So that Mr. Zheng has been
leading his team to propose and develop the dynamic disturbance
control, transient disturbance control and fault protection technologies,
and they all have been well applied in practical projects.
The microgrid dynamic disturbance control technology, transient
disturbance control technology and fault protection technology
have been evaluated by domestic and foreign experts as reaching
the international leading level.