A solution to the challenge of integrating renewable energy sources into the current grid. Ampcontrol, in collaboration with Sen Engineering Solutions, has designed, manufactured, and extensively tested the world's first Sen Transformer.
The Challenge
Integrating renewable energy sources into the current grid presents many challenges, such as grid instability, voltage fluctuations, and outdated and unfit-for-purpose infrastructure. Addressing these challenges is expensive and complex; a significant investment is needed to upgrade transmission lines, substations and other power infrastructure that enable the distribution of renewable energy.
Sen Transformer looks to address these problems with a simple, cost-effective and reliable solution that would provide the same power flow control as traditional infrastructure while having the footprint of a single power transformer and without the need to replace transmission lines.
First commercial grade Sen Transformer
How Sen Transformer Operates
As we increase the active power flow in a power system, it is also crucial to provide adequate reactive power support to prevent voltage stability issues. To achieve true flexibility in modern power systems, it is, therefore, essential to independently control both active power (P) and reactive power (Q) flows. The key to independently control active and reactive power flows is to change two parameters – line voltage and its phase angle independently.
Most power flow controllers only control one parameter. As a result, these power flow controllers cannot provide independent control of active power and reactive power flows in the line as desired. A newly-developed power flow controller – Sen Transformer (ST) is capable of independently regulating both P and Q due to its ability to control two voltages – one on the direct axis for voltage regulation and the other on the quadrature axis for phase angle regulation.
The benefits of independently regulating both P and Q are enormous. Reduction in reactive power flow leads to:
- Possibility of more active power flow in the same line,
- Freed up capacity of generators and step-up transformers,
- Increased utilization and efficiencies of generators and step-up transformers,
- Less power loss in transmission lines
With Sen Transformer, it is now possible to control the active and reactive power flows independently through existing transmission lines, removing the need to build costly new lines and reducing environmental impact. The Sen Transformer can provide the same power follow control functionality as the more expensive and higher-maintenance FACTS solution while reducing the physical footprint to just the transformer of the FACTS solution, eliminating the entire power electronics inverters.
The first breakthrough in bulk power system power delivery in more than a century is finally here. Designed, manufactured and tested as specified, Sen Transformer regulates power flow, allowing increasing, decreasing and reversing active and reactive power flows independently, at the lowest possible cost to the power grid, using reliable and time-tested hardware.
The demonstration unit is designed to regulate up to ± 6.5 MVA line power in a 33 kV line. The performance was as described in “Advancements in Transformer Technology with Sen Transformer”, IEEE Power & Energy Society General Meeting, paper No. 25PESGM1323, July 2025, Austin, USA.
The Sen Transformer is planned to be further tested in a 33 kV radial line at the EPRI lab in the USA.
Sen Transformer on site
