top of page

Voltage dip ride through

VDRT Service

Validating Fault Ride Through Capabilities

When a short circuit fault occurs on a power system, it creates a complex sequence of events. Voltage drops suddenly, protection systems react, and voltage spikes when the fault clears. Critical equipment must continue operating through these harsh electrical transients.

Traditionally, shipowners validate fault ride through by deliberately creating a live, bolted short circuit on the main busbar. This risks equipment damage. It also only validates protection systems involved in clearing that specific test fault.

OneStep Power's Fault Ride Through service provides comprehensive validation without live short circuits. We use advanced testing devices to safely recreate electrical transients on the main bus and across the whole distribution network.

First, we perform primary injection testing to validate all current transformers and sensing devices. This ensures faults will be detected accurately.

Next, we use OneStep Power' s Generator Voltage Response Testers (GVRTs) on each generator. GVRTs temporarily reduce generator voltage output to minimum levels for a sustained period. This simulates the low-voltage transient of a real fault.

After the test duration, GVRTs restore voltage control to the generators. This allows the natural voltage overshoot as AVRs regain control. The distribution network experiences realistic fault transients from the moment of fault until voltage recovery.

Finally, our Zero Volt Tester rapidly opens and closes bus-ties to black out sections of the network completely. This validates true zero volt ride through of critical equipment.


Combining advanced testing tools creates a full fault ride through validation. All without risks of a live short circuit fault. Testing takes about 2-3 days and gives shipowners confidence in their vessel's resilience and their crew's ability to safely manage harsh electrical events.

Applicable Rule sets

MTS TECHOP-D07 (2021) ABS Guide For Dynamic Positioning (2021). Section 3 - Power Systems, Subsection 13 "Fault Ride Through Capability" Acceptance Criteria for transients as a result of the ride through are taken from Rules for Building and Classing Marine Vessels - Part 4, Vessel Systems and Machinery, Chapter 8 Electrical Systems, Section 3 Electrical Equipment, Paragraph 1.9 Voltage and Frequency Variations

VDRT Technical

Technical Specs

VDRT case study

Case Study

bottom of page