Stamford AVR MX341,MX341 avr for stamford

STAMFORD MX341 AVR is a two phase sensed Automatic Voltage Regulator and forms part of the excitation system for a brush-less generator. Excitation power is derived from a three-phase permanent magnet generator (PMG), to isolate the AVR control circuits from the effects of non- linear loads and to reduce radio frequency interference on the generator terminals. Sustained generator short circuit current is another feature of the PMG system. The AVR senses the voltage in the main generator winding and controls the power fed to the exciter stator and hence the main rotor to maintain the generator output voltage within the specified limits, compensating for load, speed, temperature and power factor of the generator. Soft start circuitry is included to provide a smooth controlled build up of generator output voltage.

Specification

Sensing Input

Voltage: 190-264V ac MAX,1 phase, 2 wire

Frequency: 50-60 Hz nominal

Power Input(pmg)

Voltage: 140-220V ac max,3 phase, 3 wire

Current: 3A/phase

Frequency: 100-120 Hz nominal

Output

Voltage: max 120V dc

Current: continuous 2.7A dc(see note 1)  Intermittent 6A for 10 secs

Resistance: 15 ohms minimum

Regulation: +/-1%

Thermal Drift: 0.03% per deg.C change in AVR ambient(note 3)

Soft Start Ramp Time: 3 seconds

Typical System Response

AVR response     10ms

Filed current to 90%    80ms

Machine Volts to 97%   300ms

External Voltage Adjustment: +/-10% with 1k ohm 1 watt trimmer

Under Frequency Protection

Set point 95% Hz

Slope 170% down to 30 Hz

Unit Power Dissipation: 12 watts maximum

Analogue Input

Maximum input +/- 5Vdc

Sensitivity 1V for 5% Generator Volts(adjustable)

Input resistance 1k ohm

Quadrature Droop Input

10 ohms burden

Max. sensitivity: 0.07 A for 5% droop 0PF

Max. input: 0.33 A

Over Excitation Protection

Set point 75V dc

Time delay 10 seconds(fixed)

Environmental

Vibration 20-100 Hz 50mm/sec

              100hz-2kHz 3.3g

Operation temperature -40-+70°C

Relative Humidity 0-70 °C   95%

Storage temperature: -55 to +80 °C