AEP taps Siemens to modernize high-voltage system in Texas

Cary, NC | Jun 29, 2015

  • Siemens will upgrade 20-year-old Welsh high voltage direct current (HVDC) back-to-back system in Titus County, TX
  • Upgrade will improve power delivery and reliability to enable the facility to operate at peak efficiency
  • First Siemens HVDC modernization project in the U.S.

American Electric Power (AEP), one of the largest electric utilities in the U.S. serving 5 million customers in 11 states, has chosen Siemens to modernize its High Voltage Direct Current (HVDC) back-to-back system at its 600MW Welsh HVDC station in Titus County, Texas. Siemens will upgrade its 20-year-old system by installing new control and protection technologies, replacing the cooling, heating and ventilation, and incorporating new harmonic filters and shunt reactors. Managing harmonics will maintain power quality standards, and ensure the efficient and reliable operation of the Welsh HVDC station. This will be the first Siemens mid-life control and protection HVDC modernization in the U.S.


“Modernizing these critical HVDC systems allows AEP to provide more reliable, consistent power to their customers in the South,” said Brian Gemmell, vice president of Siemens Transmission Solutions. “We’re extremely proud that Siemens is able to continue its 20-year technology partnership with AEP by installing state-of-the-art technologies that help utilities meet the challenges of our modern and continuously evolving grid.”


Both the Electric Reliability Council of Texas (ERCOT) and Southwest Power Pool grids have seen major changes in the way power is dispatched and network operation since the original Welsh facility was installed. These changes have led to increased levels of harmonics seen on the systems. Harmonics result in a disruption to the normal operation of the network that can lead to interruptions of the power supply. The new harmonic filters being supplied by Siemens will help the system operators control the increased level of harmonics and create more reliable power delivery.


The latest Siemens SIMATIC TDC controls, included as part of the modernization project, are a fully digital offering resulting in faster and more accurate operation. The controls will improve the reliability and availability of the station to facilitate power exchange between the Electric Reliability Council of Texas (ERCOT) and Southwest Power Pool networks. In addition, the new harmonic filters will allow the plant to accommodate to changes in the operation of the connected networks that have increased the level of harmonics since the plant was initially built.


Siemens installed the original HVDC classic station in 1994. The new upgrade will be fully completed by May 2017.


This press release and a press picture / press pictures/ further material is available at


For further information on Siemens HVDC technology, please see


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Siemens AG (Berlin and Munich) is a global technology powerhouse that has stood for engineering excellence, innovation, quality, reliability and internationality for more than 165 years. The company is active in more than 200 countries, focusing on the areas of electrification, automation and digitalization. One of the world’s largest producers of energy-efficient, resource-saving technologies, Siemens is No. 1 in offshore wind turbine construction, a leading supplier of combined cycle turbines for power generation, a leading provider of power transmission solutions and a pioneer in infrastructure solutions and automation and software solutions for industry. The company is also a leading supplier of medical imaging equipment – such as computed tomography and magnetic resonance imaging systems – and a leader in laboratory diagnostics as well as clinical IT. In fiscal 2013, which ended on September 30, 2013, revenue from continuing operations totaled €75.9 billion and income from continuing operations €4.2 billion. At the end of September 2013, Siemens had around 362,000 employees worldwide on the basis of continuing operations. Further information is available on the Internet at


Siemens Corporation is a U.S. subsidiary of Siemens AG, a global technology powerhouse that has stood for engineering excellence, innovation, quality, reliability and internationality for more than 165 years. With 343,000 employees in more than 200 countries, Siemens reported worldwide revenue of approximately $98 billion in fiscal 2014. Siemens in the USA reported revenue of $22.2 billion, including $5.2 billion in exports, and employs approximately 46,000 people throughout all 50 states and Puerto Rico.