Substation autotransformers transfer the incoming high-voltage to the next lower voltage level. As an example, an incoming high-voltage of 400 kV would be transferred down to 220 kV.
In general, substation autotransformers are equipped with on-load tap-changers (OLTC). Incoming transmission lines are connected to the transformers through bushings and cables through cable boxes and cable sealing ends.
Autotransformers are built in core form with auto-connected windings, i.e., common main winding and a separate low-voltage winding.
Product scope:
- Ratings up to 1,300 MVA (sometimes higher ratings are required)
- Primary voltage up to 765 kV and higher
- Secondary voltage is generally ≤ 230kV or higher, depending on the grid configuration
- Load tap changers are generally required
- Single or three-phase
Why Hitachi Energy core intertie transformers
- Our track record of 1,400+ units delivered since 1995
- Short-circuit performance at twice the industry standard
- Proven track record in meeting customer performance requirements (ask for our test floor failure statistics)
- 12 factories, one global approach – bringing consistency, delivery performance, and technology
Why Hitachi Energy shell intertie transformers
- Design technology eliminates the risk of a hot spot
- Outstanding thermal performance resulting from directed oil flow, minimization of losses, and control of the hot spot
