OEM Wind turbine converter retrofit and upgrade solutions
Extend lifetime, maximize performance
Upgrades & Retrofit
Wind turbines often operate far beyond their original design life. When converters age, the choice is not always between repair and full replacement. With the right retrofit or upgrade solution, you can achieve meaningful converter lifetime extension, improve operational reliability, and access state-of-the-art control technology, at a fraction of the cost of a new converter.
ConverterTec offers wind turbine converter retrofit and upgrade solutions developed specifically for the platforms we know best, including the full range of ConverterTec & former Woodward, SEG, IDS, Efacec systems. These are used in the following series turbines: Nordex Beta, Gamma, Delta 3k, Delta 4k; RePower/Senvion MM, MD, 3XM, 5M, 6M; Ecotecnia/Alstom/GE ECO; GE 1.X; Suzlon S9.x, S11.x; Fuhrlander MD, FL2500; DeWind D4, D6; Sewind.
Our upgrade and retrofit packages are designed to integrate directly into existing converter installations, with no change to the mechanical footprint and minimal downtime.
Future-proof your converters
Aging components and obsolete parts can compromise turbine performance and increase maintenance costs. Wind turbine converter upgrades and retrofits give you access to state-of-the-art components and smart control systems that replace outdated parts seamlessly.
Tailored solutions improve operational stability, reduce unexpected failures, and extend the life of your converters, all while keeping electrical behaviour and mechanical integration consistent or even enhanced.
More uptime. Longer lifetime. Lower costs.
- Extended lifetime: Keep your converters running efficiently beyond 20 years.
- Improved reliability: Reduce unplanned downtime and service interventions.
- Higher efficiency: Modern components optimize control and power output.
- Cost savings: Avoid major replacements and lower overall maintenance costs.
- Future-ready control: Enable advanced monitoring and smarter maintenance planning.
Explore our specialized upgrade solutions
CSC4 controller
Upgrade to CSC4 and improve your operational availability with state-of-the-art control technology. Benefit from extended monitoring functions, faster remote access, and advanced troubleshooting features, all proven in over 15,000 systems worldwide.
Easy to install and service-friendly, CSC4 also helps reduce service and storage costs while boosting system stability.
Service Stack & Flexi|X
Upgrade your converter with the latest generation IGBT technology and maximize flexibility using Flexi|X. The Service Stack solution allows you to replace only the defective stack, reducing service costs, minimizing downtime, and avoiding full system replacements.
Benefit from simplified troubleshooting, improved durability, and higher efficiency, leading to better performance and lower lifecycle costs. One solution fits all, ready for RAC 3xx and ModSTACK™ systems.
Upgrade today and extend your asset life
Contact us for tailored upgrade and retrofit solutions that match your needs.
Our wind turbine converter upgrade and retrofit solutions
We offer two purpose-built upgrade and retrofit solutions for wind turbine converters. Each is designed to address a specific challenge in aging converter fleets, and both are available with full field service support for installation and commissioning.
CSC4 controller upgrade
The CSC4 is a direct upgrade for wind turbine converters equipped with legacy control systems, delivering state-of-the-art control technology with extended monitoring functions, faster remote access, and advanced troubleshooting features. The CSC4 controller has been proven in over 15,000 systems worldwide and is designed for easy installation and service-friendly operation.
Upgrading to CSC4 improves operational availability, reduces service and storage costs, and provides a stable control platform for the remaining operational life of your turbine. Compatible with the full range of ConverterTec and Woodward converter systems.
Service Stack and Flexi|X IGBT retrofit
The Service Stack and Flexi|X solution is a wind turbine converter retrofit that replaces only the power stack, not the full converter assembly. Using the latest generation IGBT technology, the Service Stack delivers improved durability, higher efficiency, and simplified troubleshooting, with lower lifecycle costs compared to full converter replacement.
The Flexi|X board maximises installation flexibility, making one solution compatible with RAC 3xx and ModSTACK systems. The result is faster service, reduced downtime, and a converter that performs better than the original for the long term.
Upgrade today and extend your asset life
Contact us for tailored upgrade and retrofit solutions that match your needs.
Why upgrade your wind turbine converter instead of replacing it
A full converter replacement is a significant capital investment, requires extended downtime for removal and installation, and may involve infrastructure changes that add further cost and complexity. For most aging converter fleets, a targeted upgrade or retrofit delivers equivalent performance improvement at a fraction of the cost.
Lower cost than replacement
Converter upgrade and retrofit solutions cost significantly less than procuring and installing a new converter. The mechanical integration remains consistent with the existing installation, which means no structural modifications, no foundation changes, and faster turnaround. For operators managing multiple turbines, the cost advantage of upgrading rather than replacing is substantial across a fleet.
Extended lifetime and lifetime extension through retrofit
Modern IGBT technology and advanced control systems can deliver significant converter lifetime extension, keeping turbines operational well beyond the original design life. For wind turbines already operating beyond 20 years, an upgrade removes the component-level constraints that would otherwise require decommissioning or full converter replacement, giving the asset a second operational life without the capital expenditure of new equipment. Converter lifetime extension through targeted retrofit is one of the most cost-effective strategies available to wind farm operators managing aging fleets.
Resolving obsolescence without replacement
When original spare parts for a converter platform become discontinued, the choice is often between upgrading the affected subsystem or replacing the entire converter. A targeted retrofit, such as the Service Stack for aging power electronics or the CSC4 for legacy control systems, resolves the obsolescence problem at component level, avoiding a full converter replacement and the associated costs and downtime.
Upgrade today and extend your asset life
Contact us for tailored upgrade and retrofit solutions that match your needs.
Wind turbine converter platforms supported for retrofit and upgrade
Our upgrade and retrofit solutions are designed for the converter platforms we know in the most depth. This includes the systems we originally engineered, as well as the wider range of converter platforms in the global wind fleet.
| Solution | Compatible platforms | Supported turbines |
| CSC4 & CSC|X controller upgrade | ConverterTec and Woodward converter systems with legacy control technology | Nordex Alpha/Beta/Gamma/Delta, REpower/Senvion MM & MD, Fuhrlaender MD & FL2500, GE 1.X, Tacke 1.5, Suedwind and other ProWind-based turbines |
| Service Stack and Flexi|X IGBT retrofit | RAC 3xx and ModSTACK systems | ConverterTec MP1 systems and compatible Woodward converter platforms |
| GE 1.X improved phase modules | GE 1.X ESS and non-ESS turbines | Line-side and rotor-side phase module replacement with state-of-the-art IGBT technology. ESS and non-ESS compatible. |
Frequently asked questions, wind turbine converter retrofit and upgrade
What is the difference between a converter retrofit and a converter upgrade?
A retrofit typically involves replacing a component or subsystem with a modern equivalent, while preserving the existing converter architecture. An upgrade typically refers to a step-change improvement in performance, functionality, or control capability. In practice, the two overlap: the Service Stack is primarily a retrofit that also delivers performance improvement, while the CSC4 is an upgrade that also resolves a retrofit need by replacing legacy control hardware. We use both terms to describe solutions that extend converter life and improve performance without full replacement.
How long can a retrofitted or upgraded wind turbine converter operate?
Converter lifetime extension depends on the specific solution and the condition of the surrounding system. The CSC4 controller upgrade and Service Stack IGBT retrofit are designed to support continued operation well beyond 20 years from the original installation date, and in many cases significantly longer. Wind turbine lifetime extension through converter retrofit is well-established practice for operators managing aging fleets. Our engineering team can assess your specific converter and operating history to provide a realistic estimate of the life extension achievable for your installation.
Which turbine platforms do you support for converter retrofits and upgrades?
Our retrofit and upgrade solutions cover ConverterTec and former Woodward, SEG, IDS converter systems, and also ProWind-based turbines from Nordex, Senvion, REpower, and Fuhrlander, as well as GE 1.X ESS and non-ESS turbines. The CSC4 controller upgrade is compatible with RAC 3xx and ModSTACK systems. Contact us with your converter platform and we will confirm which solutions apply to your installation.
Can you upgrade a GE 1.X wind turbine converter?
Yes. We supply improved phase modules for GE 1.X turbines, covering both line-side and rotor-side converter sections, in ESS and non-ESS configurations. These replacement modules use state-of-the-art IGBT technology, delivering improved thermal performance and longer component lifetime compared to the original parts. The installation is compatible with the existing converter enclosure and electrical interface.
Is a converter upgrade more cost-effective than a full replacement?
Yes. In most cases, significantly so. A full converter replacement involves capital expenditure for the new unit, extended downtime for removal and installation, and in some cases infrastructure modifications. A targeted upgrade or retrofit addresses the specific components that are limiting performance or availability, at a fraction of the cost of a new converter and with much shorter installation time. Our team can provide a cost comparison for your specific situation.