QNX and ForceControl 6.0 High-Voltage Pulse Power Supply Monitoring
This paper details the design of a high-voltage pulse power supply monitoring system for the EAST tokamak neutral beam injection (NBI) heating system. The system manages a 100 kV / 100 A pulse power supply using 104 series-connected 1.1 kV / 100 A modules with Pulse Step Modulation (PSM) technology. A hybrid real-time control and supervisory system was implemented using QNX and ForceControl 6.0, ensuring fast turn-on (<20 µs), turn-off (<5 µs), and safe operation under high voltage, with optical fiber communication for isolation and reliability.
🔧 System Overview #
The system integrates:
- QNX (Field & Remote PCs) for deterministic real-time control.
- ForceControl 6.0 (Monitoring PC) for HMI and supervisory functions.
- Optical fiber communication to electrically isolate high-voltage pulse modules.
- DSP + CPLD boards in each module for fast IGBT/thyristor switching and local control.
Simulation and testing with 15 pulse modules validated system performance and real-time reliability.
🏗 System Architecture #
Hardware Structure #
- Remote Control PC (QNX): Sets voltage waveforms, collects feedback.
- Field Control PC (QNX): Executes core real-time control, module switching computation, feedback loops, and protection mechanisms.
- Monitoring PC (Windows + ForceControl 6.0): Supervisory visualization, status monitoring, fault handling via optical fiber TCP/IP.
- High-speed I/O cards (A/D MIC-3714, D/I-O CPCI-7249) for precise data acquisition.
- DSP + CPLD boards in each module for fast switching control.
Software Design #
Real-Time Control (QNX) #
- Receives preset waveform from Remote PC.
- Computes module turn-on counts per time step.
- Outputs control signals via digital I/O cards.
- Implements closed-loop feedback and fast over-current protection (>180 A cutoff).
- Ensures synchronized pulse sequence across all modules.
Supervisory Monitoring (ForceControl 6.0) #
- Monitors 8 digital and 3 analog signals per module.
- Displays module status, voltage/current trends, and alarms.
- Supports manual control and fault handling.
- Optical fiber TCP/IP ensures low-latency, safe communication with 15 power modules.
⚡ Simulation and Testing #
- Sequential and simultaneous turn-on/off of 15 modules demonstrated precise timing.
- Turn-off delay from IGBT command to voltage zero ≈ 3 µs, meeting <5 µs specification.
- Minor overshoot observed due to module differences, within acceptable limits.
- High-voltage probe and oscilloscope confirmed accuracy of voltage steps and synchronization.
🏁 Conclusion #
The QNX + ForceControl 6.0 hybrid system achieves:
- Deterministic real-time control of 100 kV / 100 A pulse modules.
- Safe, synchronized operation across multiple modules.
- Comprehensive monitoring, fast protection, and optical isolation.
- Scalability for future NBI system upgrades.
Innovation Highlights:
- Hybrid QNX real-time control with ForceControl supervisory monitoring.
- Optical fiber isolation for high-voltage safety.
- High-speed IGBT module control with synchronized sequencing.
🔮 Modern Perspective (2026) #
Upgrades could include:
- QNX SDP 8.x for enhanced multi-core and safety-certified profiles.
- EtherCAT / TSN for tighter fieldbus synchronization.
- Modern web-based SCADA HMIs or Ignition integration.
- Containerized RTPs with enhanced trace and core dump tools for maintainability.
This architecture provides a robust, safe, and high-performance solution for EAST tokamak NBI pulse power systems.