Description

The SIEMENS 6DD2920-3AW1 is a high-performance thyristor electronics module from the SIMADYN D series, serving as the critical firing control interface between the digital controller and high-power thyristor (SCR) bridges in large DC drive systems. This module is the “trigger commander” that generates precise, high-voltage gate pulses to control the conduction angle of power thyristors, enabling smooth regulation of voltage and current in demanding industrial applications.

Designed primarily for SIMOREG DC Master and other large DC drives integrated within the SIMADYN D ecosystem, the SIEMENS 6DD2920-3AW1 receives firing angle (α) commands from the processor module (PM) via the CS7-Bus backplane. It then calculates the precise firing instants synchronized with the AC line voltage and delivers robust gate pulses to the power semiconductors. Its comprehensive monitoring functions—including thyristor conduction status, fuse failure detection, and overtemperature sensing—provide real-time feedback to the processor for fault protection and system stability.

 

Application Scenarios

At a large hot rolling mill in Germany, the main stand drive—a 6,000 kW DC motor—was experiencing intermittent torque fluctuations during heavy passes, causing product thickness variations and occasional catastrophic thyristor bridge failures. The maintenance team traced the root cause to inconsistent trigger pulses from an aging firing board, where microsecond-level timing errors were causing commutation failures in the 12-pulse rectifier system. After installing a replacement SIEMENS 6DD2920-3AW1 module, the trigger pulses were restored to precise synchronization with the 50 Hz line voltage, eliminating the torque fluctuations. The mill’s electrical superintendent reported: “The new board restored our current ripple to less than 1% of rated value, and we’ve had zero thyristor failures in six months of heavy production.” This case highlights a critical pain point: in high-power drives, the SIEMENS 6DD2920-3AW1 is the unsung hero that ensures each of the 12 thyristors fires within microseconds of the ideal moment—any deviation can lead to catastrophic commutation failure and unplanned downtime costing hundreds of thousands of dollars.

For engineers maintaining legacy SIMADYN D-controlled DC drives in steel mills, mine hoists, or ship propulsion systems, the SIEMENS 6DD2920-3AW1 is the essential component for reliable firing control. Its support for 6-pulse, 12-pulse, and even 24-pulse configurations, combined with its ability to interface with fiber optic or pulse transformer outputs, makes it adaptable to a wide range of power converter topologies.

 

Parameter

Main Parameters	Value/Description
Product Model	SIEMENS 6DD2920-3AW1 (Thyristor Electronics)
Manufacturer	Siemens
Product Category	Thyristor Firing & Monitoring Module (SE20/SE21 family)
Applicable System	SIMADYN D, SIMOREG DC Master, trigger rack (TR)
Control Object	Thyristor (SCR) / Power Semiconductors – gate pulse control
Firing Pulse Type	Multi-pulse (dual narrow pulse / wide pulse), configurable
Supported Topology	6-pulse, 12-pulse, 24-pulse bridge configurations
Output Isolation	High-voltage opto-isolation / fiber optic or pulse transformer outputs
Monitoring Functions	Thyristor conduction (u_k), fuse (FU), overtemperature
Communication Interface	CS7-Bus backplane connection to PM processor
Operating Temperature	0°C to +60°C
Storage Temperature	-25°C to +70°C
Protection Class	IP20 (cabinet mount)
Product Status	End-of-Life (EOL) – replacement for legacy SIMADYN D