TMEICA ARND-3115A18

Description

Technical Specifications:

• Model: ARND-3115A18
• Type: Digital AVR — Automatic Voltage Regulator
• Application: Brushless excitation, synchronous generators
• Input Signals: Generator PT voltage, generator CT current, frequency, start/stop, PSS input, remote setpoint
• Output: Programmable firing pulses (6-pulse or 12-pulse)
• Voltage Regulation Accuracy: ±0.25% (steady state) — superior to ARND-3110
• Response Time: < 10 ms (improved transient response vs. 3110)
• Firing Angle Range: 0°–180°, resolution 0.1°
• Communication: RS-485 Modbus RTU, Ethernet TCP/IP (built-in)
• Remote Setpoint: 4–20 mA or 0–10 VDC analog input
• Power Supply: 110/220 VAC, 50/60 Hz, or 24 VDC
• Operating Temperature: -20°C to +55°C (extended range vs. 3110)
• Protocols: IEC 61850 (optional), DNP3.0 (optional)
• Dimensions: Standard panel-mount, 1/4 DIN or full DIN
• Weight: Approximately 1.8 kg
• Compliance: IEC 60034, IEEE 421.5, IEC 61850

Functional Features:

• All features of ARND-3110 plus:
• Built-in Ethernet port for SCADA integration (no external gateway needed)
• Dual voltage regulator channels (main + backup) with automatic transfer
• Event logging: 100 events with timestamps
• Self-diagnostic with fault code display
• Adaptive PID with auto-tuning
• Load compensation function
• Harmonic monitoring (up to 15th harmonic)

Structural Characteristics:

• Enclosure: Die-cast aluminum, IP40 rating (higher than 3110’s IP20)
• Terminals: Spring-clamp terminals for faster wiring
• Display: 8-character LCD with backlight (upgraded from 4-digit LED on 3110)
• Status LEDs: Run, Fault, Comm, Firing, Sync

Working Principle: Same core principle as ARND-3110 — digital PID control of SCR firing angle. The ARND-3115A18 adds a second independent control channel that runs in parallel. If the primary channel fails, the backup channel takes over within one cycle (< 16 ms at 60 Hz). The Ethernet interface allows direct Modbus TCP or IEC 61850 MMS communication with plant DCS/SCADA. The adaptive PID auto-tunes gains based on observed system response during commissioning.

Advantages:

• Dual-channel redundancy — highest availability in the ARND series
• Ethernet native — eliminates need for protocol converter
• Extended temperature range for harsh environments
• Harmonic monitoring helps detect generator winding faults early

Applicable Industries: Critical power generation (data centers, hospitals, military), large hydro stations, combined cycle gas turbines, industrial cogeneration

Installation Requirements:

• Same as ARND-3110 with additions:
• Ethernet cable: Cat5e or better, max 100 m to switch
• Dual PT inputs required for redundancy (two separate PT circuits)
• Shielded firing pulse cables, max 50 m
• Ground impedance: < 0.5 Ohm for critical installations

Usage Precautions:

• Configure redundancy mode (active/standby or parallel) before commissioning
• Update firmware via Ethernet only — do not use RS-485 for firmware updates
• Verify both PT circuits independently before enabling dual-channel mode
• Clean air filter on enclosure every 6 months in dusty environments