Mitigating EMI in High-Voltage (HV) Laboratories: Technical Solutions to Ensure Impulse Test Data Accuracy

  In high-voltage (HV) testing, the transient electromagnetic fields generated during discharge are extremely intense. For manufacturers and testing laboratories, high electromagnetic interference (EMI) leads to waveform distortion and data inaccuracies. The solution lies in controlling loop inductance and enhancing the EMI immunity of digital measurement systems.

Identifying Interference Sources and Root Causes of Inaccuracy

  Impulse testing involves extreme dU/dt and dI/dt rates. When the SXCY series operates at voltage levels up to 7200 kV, spatial coupling and ground potential rise are primary concerns. Inadequate shielding causes high-frequency oscillations, leading to peak voltage errors exceeding the requirements of IEC 60060.

SXCY Impulse Generator Series: Interference Suppression via Hardware Parameters

• Low-Inductance Design: Reducing loop inductance minimizes overshoot. The compact structure of the SXCY series lowers inherent inductance, reducing radiated EMI at the source.
• 1% Charging Stability: Constant-current charging ensures consistent initial energy, eliminating repeatability issues caused by voltage drift.
• Sync. Error < 2%: High synchronization accuracy prevents uncontrolled discharges and stray electromagnetic (EM) waves.

Optimization of Digital Measurement Systems for Enhanced EMI Immunity

• Fiber Optic Isolation: Signals transmitted via fiber optics prevent conducted interference from reaching the monitoring systems.
• Divider Response: Low-inductance resistive/capacitive dividers ensure precise capture of lightning impulse fronts.
• Shielding: Metal-shielded control consoles protect core components from spatial electromagnetic waves.

Conclusion: Achieving High-Repeatability Testing Standards

  For European grid institutes, selecting equipment with ≥90% efficiency and low synchronization error is fundamental. By combining the hardware consistency of the SXCY series with optical isolation, laboratories can minimize measurement uncertainty, providing credible raw data for third-party certifications