Specialty in designing SMART Power Flow Controller for Grid Applications

 

Vision: Serve the society by fulfilling its need for power flow control technology.

Mission: Educate the customers through publications, tutorials, seminars, and webinars in order to generate their own functional requirements and provide cost-effective solutions.

Guiding principles: Be the best in what we do; treat others the way we like to be treated.

 

A SMART Power Flow Controller (SPFC) enhances the controllability in an electric power transmission system by using functional requirements and cost-effective solutions. A SPFC is derived from utilizing the best features of all the technical concepts that are developed in the power flow control area until now. It does not discriminate any solution based on whether it uses power electronics or not or whether it is stationary or rotating.

The functional requirements for a SPFC may be to reduce the reactive power flow in an electric transmission line within a permissible limit while maintaining the voltage stability and increase the active power flow to the line’s thermal limit. In this case, the SPFC controls the flows of active power and reactive power in a transmission line independently.

 

Advances in power electronics have made it possible to control the flows of active power and reactive power independently in an electric transmission line. The power electronics-based power flow controller is capable of providing responses in the range of milliseconds; however, the experiences from the last two decades show that the needed response time is in seconds in most utility applications. Therefore, it is desirable to redesign the independent power flow controller that meets the functional requirements to provide responses in seconds, which will reduce the cost to a fractional amount of the cost of power electronics-based solutions. This was the motivation to develop a SMART power flow controller whose objectives are as follows.

S – specific (design a power flow controller that meets utilities’ needs)

M – measurable (high reliability, high efficiency, cost-effectiveness, component non-obsolescence, and portability)

A – attainable (realistic expectation about the outcome)

R – relevant (efficient power grid)

T – time-bound (delivery milestones).

A SPFC, shown in the figure, modifies the effective impedance (both resistance and reactance) of the transmission line between its two ends, which results in an independent control of active and reactive power flows in the line so that the useful active power flow is maximized while the less desirable reactive power flow is minimized in the controlled path.

 

Independent control of active and reactive power flows leads to

• reduction in reactive power flow, resulting in a reduction of losses in generators, transformers, and transmission lines, which increases the overall system efficiency
• Lower loss reduces global warming
  
• freeing up the generators, transformers, and transmission lines to carry more active power
  
• power flow through the desired transmission paths that have high impedances, low power flow, and low line utilization
  
• avoidance of grid congestion by redirecting excess power flow from an overloaded line to underloaded lines, instead of tripping the overloaded line when power flow is needed the most
  
• delayed construction of new, expensive, high-voltage electric transmission lines.
  

To meet the power industry’s present need for the most economical ways to transfer bulk power along a desired path, the SPFC offers essential features, such as

• high reliability with the lowest number of components that are free from becoming obsolete
• fast enough response for utility applications
• easy relocation to wherever it is needed the most, since the need for power flow control may change with time due to new generation, load, and so on
• lowest installation and operating costs with the highest efficiency
• interoperability so that components from various suppliers can be used, resulting in a global manufacturing standard, ease of maintenance, and ultimately lower cost to consumers.

It is now possible to control the electric power flow through an existing transmission line in the most cost-effective way by using Sen Transformers (ST).  Placed at strategic locations, the ST controls the power flow in a highly efficient and reliable manner.  As a result, in many cases, we would not have to build new, expensive transmission lines for many years to come, saving both the cost of the new lines and the environment.