Replacement Sx460 Diesel Generator Automatic Voltage Regulator

• Conditions of Use: Diesel Generator
• Usage: Standby Unit, Common Units
• Output Type: AC Single Phase
• Cooling Method: Water Cooling
• Installation Method: Portable
• Generator Type: Diesel Generator
• Model NO.: SX460
• Warranty: 1 Year
• After-Sale Service: Yes
• in Stock: Yes
• Regulation: +/- 1.0%
• Thermal Drift: 0.05% Per Deg. C Change in AVR Ambient (Note 2)
• External Voltage Adjustment Thickness: +/-10% with 1 K Ohm 1 Watt Trimmer
• Unit Power Dissipation: 10 Watts Maximum
• Build up Voltage: 4 Volts @ AVR Terminals
• Typical System Response: AVR Response 20 Ms Filed Current to 90% 80 Ms Mach
• AVR Type: Half-Wave
• Transport Package: Netural Packing
• Specification: 0.38KG
• Trademark: Holdwell
• Origin: China
• HS Code: 8537101190
• Production Capacity: 100000

Product Description

General description

SX460 is a half-wave phase-controlled thyristor type Automatic Voltage Regulator (AVR) and forms part of the excitation system for a brush-less generator. In addition to regulating the generator voltage, the AVR circuitry includes under-speed and sensing loss protection features. Excitation power is derived directly from the generator terminals. Positive voltage build up from residual levels is ensured by the use of efficient semiconductors in the power circuitry of the AVR. The AVR is linked with the main stator windings and the exciter field windings to provide closed loop control of the output voltage with load regulation of +/- 1.0%. In addition to being powered from the main stator, the AVR also derives a sample voltage from the output windings for voltage control purposes. In response to this sample voltage, the AVR controls the power fed to the exciter field, and hence the main field, to maintain the machine output voltage within the specified limits, compensating for load, speed, temperature and power factor of the generator. A frequency measuring circuit continually monitors the generator output and provides output under-speed protection of the excitation system, by reducing the output voltage proportionally with speed below a pre-settable threshold. A manual adjustment is provided for factory setting of the under frequency roll off point, (UFRO). This can easily be changed to 50 or 60 Hz in the field by pushon link selection. Provision is made for the connection of a remote voltage trimmer, allowing the user fine control of the generator's output.

DESIGN DETAIL

The main functions of the AVR are: Potential Divider and Rectifier takes a proportion of the generator output voltage and attenuates it. This input chain of resistors includes the range potentiometer and hand trimmer which adjust the generator voltage. A rectifier converts the a.c. into d.c. for further processing. The Amplifier (Amp) compares the sensing voltage to the Reference Voltage and amplifies the difference (error) to provide a controlling signal for the power devices. The Ramp Generator and Level Detector and Driver infinitely control the conduction period of the Power Control Devices and hence provides the excitation system with the required power to maintain the generator voltage within specified limits. The Stability Circuit provides adjustable negative ac feedback to ensure good steady state and transient performance of the control system. The Low Hz Detector measures the period of each electrical cycle and causes the reference voltage to be reduced approximately linearly with speed below a presettable threshold. A Light Emitting Diode gives indication of underspeed running.
The Synchronising circuit is used to keep the Ramp Generator and Low Hz Detector locked to the generator waveform period. The Low Pass Filter prevents distorted waveforms affecting the operation of the AVR. Power Control Devices vary the amount of exciter field current in response to the error signal produced by the Amplifier. Suppression components are included to prevent sub cycle voltage spikes damaging the AVR components and also to reduce the amount of conducted noise on the generator terminals. The Power Supply provides the required voltages for the AVR circuitry.