Tapan Manna

Presentations: 

Offshore AC Wind Topology and Design Considerations

With growing concerns over climate change and fossil fuel depletion, the exploitation of renewable energy has become paramount in electricity generation. Currently wind energy is the fastest growing power generation resource. Offshore wind farms are generally integrated into bulk power grids at the onshore point of common coupling (PCC) through the AC submarine cable. The stability of system network operation with a large penetration of wind energy has been one of the most important issues. The voltage stability of the grid is affected due to the reactive power compensation scheme and the devices used. The reactive power (Q) controls involve voltage regulation with or without active power (P) generation, reactive power (Q)/power factor (pf) control, and fault ride-through capabilities.

In this session, we will discuss global installed wind capacity, market outlook, wind farms topology, turbine types and configurations, and VAr control including the reactive power contribution by AC submarine cable and Q compensation impacts on AC submarine cable.

Design Considerations in Phase-Shifting Transformers

The phase-shifting transformer (PST) is a classic power-flow control device that has been deployed for controlling power flows and for solving unexpected grid congestions in transmission networks. The PST offers excellent features in terms of the ability to control active power (P) flow while operating by using reliable load tap changers (LTCs) and advance-retard switch (ARS).

Increasing connection of renewables has posed a new challenge in power flow control and voltage stability. With some key design considerations, the PST will be very effective in improving grid operational reliability.

This topic addresses the principles of active power flow control, and also the important design aspects of PSTs. In this session, the following design aspects will be discussed:

• Types and categories of PSTs – focusing on the most frequently used single-core and two-core symmetric type PSTs.
• Fundamental design parameters – emphasizing the rated throughput power, rated main unit design power, and the range of phase-shift angle regulation.
• Important design considerations – on phase angle rating, MVA rating, PST types, overload conditions, LTC and ARS applications, and special considerations for two core PST design.
• Circuit arrangements – mainly focusing on PSTs long-term deployment, operational flexibility with easiness of PST during maintenance or outages.
• Operational likelihood – addressing operational flexibility with several viable options.

Essential factors specific to PST projects will also be discussed.