Advancing High-Voltage Reliability with a 6.5 kW Planar Transformer

New 6.5 kW Planar Design for Demanding Power Electronics

Payton Planar Magnetics has engineered a 6.5 kW full‑bridge planar transformer tailored for high‑voltage, high‑frequency power conversion systems. The unit achieves a Partial Discharge (PD) extinction level of 6.5 kVrms while maintaining discharge levels below 10 pC, and it is rated for continuous operation across a broad temperature window from –55°C up to +130°C.

Transformers operating with input or output voltages above 1 kV are exposed to substantial electric field stress within their insulation structures. Under these conditions, localized PD can begin either inside the insulation itself or at material boundaries, often at levels too small to be detected by standard Hi‑Pot tests, yet still capable of undermining long‑term reliability.

Why Partial Discharge Matters in High‑Frequency Designs

As switching frequencies climb to around 100 kHz and beyond, the influence of partial discharge on insulation lifetime becomes far more severe. Repeated PD events gradually erode insulating materials, creating cumulative damage that can ultimately cause transformers to fail much sooner than expected, sometimes in a matter of hours or a few months, despite having successfully passed initial qualification and functional checks.

Payton’s Design‑Stage and Validation‑Stage PD Control

At Payton Planar Magnetics, partial discharge is treated as a critical design parameter rather than only a test criterion at the end of development. PD performance is addressed both during the magnetic design process and during formal validation, ensuring that insulation choices, structures, and clearances are optimized from the outset.

To support this approach, Payton utilizes dedicated measurement systems capable of capturing extremely low PD levels. These tools allow the team to confirm that transformers remain effectively PD‑free up to 10% above their intended continuous operating voltage, providing confidence that the insulation system can withstand real‑world stress conditions.

Through this rigorous PD‑oriented testing strategy, Payton aims to ensure that its planar transformers deliver safe, stable, and durable performance over many years of operation at the customer’s site.

This phenomenon complicates the validation of high‑voltage transformers. Units that appear to perform flawlessly on the production floor and during system‑level testing may later suffer early failures in the field if PD behavior has not been thoroughly characterized and controlled.