Cummins STAMFORD AS440 AVR Automatic Voltage Regulator generator system

Cummins STAMFORD AS440 automatic voltage regulator (AVR) is a key component for brushless generator excitation system. Here is a detailed introduction:

Functional features

Precise voltage regulation: connected to the main stator winding and the exciter field winding, through closed-loop control, the load regulation of the generator output voltage can be controlled within ±1.0%, ensuring stable output voltage.

Multiple protection mechanisms: With underspeed protection function, the frequency measurement circuit monitors the generator output in real time. When the speed is lower than the preset threshold, the output voltage is reduced to prevent the engine from overexcitation at low speed. An overexcitation protection circuit is provided to limit overexcitation within a safe range. There is also a detection signal loss protection to enhance operational reliability.

Stable voltage establishment: The efficient semiconductors in the power circuit ensure that the output voltage can be stably established to the rated value starting from the residual magnetic voltage of the generator.

Strong adjustability: A remote voltage fine-tuning interface is provided to facilitate users to accurately control the generator output. An analog input terminal is provided for connecting a power factor controller or other compatible external devices. It is also equipped with equipment for droop CT connection, which is convenient for grid-connected operation with other similar generators.

Technical parameters

Input: The input voltage jumper can be selected as 100-130Vac 1 phase or 190-264Vac 1 phase, frequency 50-60Hz; the input power voltage is 100-264V ac 1 phase, frequency 50-60Hz universal.

Output: When the input voltage is AC 200V, the maximum output DC is 82V; the continuous output current is 4A, and the instantaneous current of 7.5A is allowed to last for 10 seconds; the minimum value of the excitation resistance is 15Ω (the minimum value is 10Ω when the power supply voltage is lower than 175V).

Others: Specifications ±1.0%; thermal drift is 0.03% for every 1°C change in AVR ambient temperature; AVR response time 20ms, 90% excitation current time 80ms, 97% output voltage time 300ms; regulation accuracy voltage adjustable range ≥±10%; external resistor 1kΩ/1W; low frequency protection set protection point 94 - 98% Hz; maximum power consumption 12W; excitation voltage AVR input terminal is 4VAC; analog input maximum allowable input value ±5V DC.

Scope of application

AS440 is provided as standard configuration for Stanford S4 and HC5 AC generators, and is also an option for UC224 and UC274 series AC generators.