The R120 Automatic Voltage Regulator (AVR) is a critical component designed to ensure stable voltage output in synchronous generators, typically used in power generation systems. Here are the key features and functionalities of the R120 AVR:

Key Features

1. Voltage Regulation:

   • Maintains a constant output voltage despite varying load conditions, ensuring the electrical system's stability.

2. Compact Design:

   • Small and lightweight, allowing for easy integration into various generator designs.

3. Sensing Input:

   • Can sense single-phase or three-phase voltage inputs, providing versatility in application.

4. Excitation Control:

   • Controls the excitation of the generator’s field winding to regulate the output voltage.

5. Overvoltage Protection:

   • Protects the generator and connected equipment from overvoltage conditions by limiting the output voltage.

6. Stability Adjustments:

   • Includes settings for fine-tuning the system's response and stability, allowing for optimal performance under different operating conditions.

Functional Description

1. Input Voltage Sensing:

   • The AVR senses the generator's output voltage and compares it to a reference value.
   • If the output voltage deviates from the desired setpoint, the AVR adjusts the excitation current.

2. Excitation Control:

   • By increasing or decreasing the excitation current supplied to the generator’s field winding, the AVR controls the magnetic field strength.
   • This adjustment directly influences the generator's output voltage, correcting any deviations from the setpoint.

3. Protection Mechanisms:

   • The AVR includes protective features to prevent damage to the generator and connected loads.
   • Overvoltage protection mechanisms are built in to disconnect or reduce the excitation current if the voltage exceeds safe limits.

4. Stability and Response:

   • The AVR provides adjustable settings for response time and damping.
   • These settings help to balance the generator’s performance, ensuring smooth voltage regulation without oscillations or instability.

Application

The R120 AVR is commonly used in:

• Power Generation Plants: Ensures the stable operation of large generators supplying power to grids or industrial applications.
• Standby and Prime Power Generators: Provides reliable voltage regulation in backup power systems or continuous power supply generators.
• Marine and Offshore Generators: Used in generators on ships or offshore platforms where stable power is critical for operations.

Technical Specifications (Example)

• Input Voltage Range: 95-132V or 170-264V AC
• Frequency Range: 50/60 Hz
• Voltage Regulation Accuracy: ±1%
• Operating Temperature: -40°C to +70°C
• Dimensions: Typically compact for easy mounting within generator control panels

Installation and Maintenance

• Installation:

  • Mounted inside the generator control panel, with connections to the generator's sensing and excitation circuits.
  • Requires proper calibration during setup to match the generator’s characteristics and operational requirements.

• Maintenance:

  • Periodic inspection and testing to ensure optimal performance.
  • Checking connections and calibration as part of regular generator maintenance routines.