ST31 Three-Phase Thyristor Control Board adopts an ARM7 industrial-grade high-performance microprocessor and a digital precision-quality design. It supports network remote control and local control, multi-unit coordinated operation or parallel redundant design, and Fuzzy-PID dynamic regulation. It integrates four regulation modes—open-loop voltage regulation, closed-loop constant voltage, constant current, and constant power—and controls thyristors to achieve constant voltage with current limiting or constant current with voltage limiting. Fault alarms and interface parameters are displayed on a touch screen or monitored via a mobile APP, and set parameters are automatically saved. The main board features phase-loss protection, power-on soft start, soft shutdown, constant-current output, constant-voltage output, overvoltage protection, overcurrent protection, short-circuit protection, and operating status indication. It implements three-phase fully controlled bridge rectification and thyristor anti-parallel AC triggering, and can trigger thyristors rated up to 5000 A. It is suitable for various load types in industrial voltage and current regulation, such as resistive loads, inductive loads, capacitive loads, and transformer primary sides.

This control module continues to lead innovation in core control algorithms and software technology in the industry. The structure and processing speed of the control software package ensure that the regulation actions of all control loops are completed within the commutation time of the six thyristor bridges in the main circuit, ensuring that the sampling time of the voltage and current loops is less than 3.33 ms (50 Hz power supply) or 2.77 ms (60 Hz power supply), thus achieving superior performance.

Basic Parameters:

◆ Operating power supply: 24 Vdc, ±15%, power above 50 W

◆ Power consumption: <5 W

◆ Main circuit voltage: 10–660 Vac

◆ Operating frequency: 40–70 Hz

◆ Voltage regulation range: 0–6500.0 V

◆ Current regulation range: 0–6500.0 A; for larger ranges, decimal point processing must be disabled

◆ Control accuracy: ±0.1% F.S. (+25 °C)

◆ Sampling resolution: 16-bit ADC

◆ Temperature drift: ≤200 ppm/°C

◆ Power supply protection: reverse connection voltage < -40 V

◆ ESD protection: ±15 kV

◆ Trigger current: ≥750 mA

◆ Trigger capacity: ≤5000 A unidirectional thyristor

◆ Dynamic response time: ≤50 ms

◆ Overshoot: ≤10%

◆ Setpoint signal: DC 0–5 V, DC 0–10 V, 4–20 mA, 10 kΩ potentiometer

◆ Three-phase unbalance: ≤0.3°

◆ Phase-shift range: 0–178°

◆ Relay contact rating: 250 Vac/10 A

◆ Isolation voltage: 1500 Vdc (input, output)

◆ Insulation resistance: ≥100 MΩ (power, input, output)

◆ Dielectric strength: 3000 VAC/1 minute (power, input, output)

◆ Applicable loads: resistive, inductive, capacitive, transformer primary side, and various other load types, as well as arc discharge control

Operating Environment Conditions:

Operating temperature: -40°C to 80°C

Storage temperature: -40°C to 85°C

Relative humidity: ≤90% RH (no frost)

Indoor installation: free from flammable, explosive, and corrosive gases, no conductive dust, vibration less than 0.5G

Atmospheric pressure: 80 kPa–106 kPa, altitude below 3,000 m; if above 3,000 m, the capacity rating should be appropriately reduced for use

Product Compliance Standards:

IEC 60947-4-2: Low-voltage switchgear and controlgear – Part 4-2: Contactors and motor-starters – AC semiconductor motor controllers and starters.

GB 14048.6-1998: Low-voltage switchgear and controlgear – Part 4-2: Contactors and motor-starters – AC semiconductor motor controllers and starters.

GB 3797-89: Electrical control equipment – Part 2: Electrical control equipment with electronic components.

IEC 61000-4: Electromagnetic compatibility (EMC) – Testing and measurement techniques.

IEC 65: Safety requirements for mains-powered electronic and related equipment for household and similar general use.