HELICOPTER 300KV ESD TEST SYSTEM

The PGESD300K-DP is designed to perform high-voltage electrostatic discharge (ESD) tests up to 300 kV on helicopter-borne equipment and airborne systems, for most requirements of MIL-STD-331 C/D (fuse and fuse component environmental and performance tests, Appendix F), NATO AECTP 250 (leaflet 253), NATO AECTP 500 (leaflet 508), MIL-STD-464, JOTP-062, and DEF STAN 59-411 Part 2. It is applicable to situations where helicopters accumulate significant electrostatic charge during flight — particularly in dry or dusty environments — and where the resulting discharge upon landing or personnel contact can endanger crew, damage equipment, or initiate electro-explosive devices.

The system supports three distinct test configurations. In the first configuration, a charged electrode is discharged to a grounded equipment under test (EUT), simulating a discharge from the airframe or rotor to a ground-referenced component.

In the second configuration, the EUT is charged and subsequently discharged to a grounded electrode, simulating the discharge of a charged aircraft system to a ground reference.

In the third configuration — the high voltage corona (P-static) test which requires an optional 250 MΩ resistor — a sustained corona current is applied to the EUT to simulate the effects of precipitation static charging conditions encountered during flight. These conditions can generate broadband RF interference and degrade the performance of communication, navigation and other sensitive electronic systems.

The PGESD300K-DP charges a 1 nF ± 10 % capacitor to a nominal voltage of 300 kV ± 5 %, with an adjustable range from a few kilovolts to 300 kV and reversible polarity. The output impedance is below 1 Ω and the total circuit inductance is approximately 7.5 µH, resulting in a short circuit current exceeding 2 kA with a 3.5 m ground return wire. The maximum DC charging current is 20 mA and it is adjustable. An arcing detection stops the high voltage power supply.

In our approaching probe method, the discharge electrode is mounted on a pneumatically actuated moving arm controlled remotely by the system’s control unit. The electrode can be oriented in many directions to reach specific points on the EUT. Two mast configurations are available: the ESD-MAST-2M, a movable stand on wheels offering electrode height adjustment from 0.5 to 2 m, and the ESD-MAST-6M, a movable mast on wheels for larger systems offering height adjustment from 1.5 to 4 m or, with the extension, to 6 m. The electrode tip travel distance is 1 m. The pneumatic actuation requires a minimum air supply of 20 litres at 6 bar.

Operator safety is ensured through complete electrical isolation between the control station and the high-voltage test setup. The system is controlled via a web-based software application communicating through a USB optical extender — a fibre optic link — which eliminates any conductive path between the operator and the generator or electrode. The discharge current pulse is monitored by an embedded oscilloscope. The automatic protection circuit further reduces operator risk by continuously monitoring for arc and overload conditions and reducing the output voltage accordingly.

A full range of accessories is available: the ESDR100-300K (100 Ω, 300 kV calibration test load), the ESDR250M (250 MΩ serial resistor for the MIL-STD-331D high voltage corona test), the ESDR500-300K (500 Ω serial resistor for NATO STANAG 4235 testing, installed on the generator output), the FT300K (300 kV wall feedthrough for indoor-outdoor installation of the test setup), and the SB3G shielded enclosure (10 kHz to 3 GHz) for the protection of additional measurement instruments in the electromagnetic environment generated during testing.

The table below provides the complete technical specifications of the system: