HT INDUSTRIAL AUTOMATION LIMITED

STAMFORD NEWAGE AvK Voltage Regulator AVR COSIMAT N+

STAMFORD AVK COSIMAT N+ AVR Datasheet.PDF

The STAMFORD COSIMAT N+ AVR is an analogue, 3-phase sensing, auxiliary winding powered automatic voltage regulator (AVR) for improved motor starting performance and sustained short circuit current.

The COSIMAT N+ is provided as an option for alternators in the STAMFORD AvK portfolio, used in STAMFORD DSG and DIG series alternators

The ”COSIMAT N+” is a compact voltage regulator designed to control synchronous alternators both in single and parallel operation. In single operation, the alternator voltage is held constant irrespective of power, frequency and temperature. When operated in parallel with the mains or with other alternators, a stable reactive power is produced. Via its power stage, the ”COSIMAT N+” adjusts the excitation current to match the operating conditions.

The main features of the ”COSIMAT N+” are: l Integrated measuring transformers for three-phase measurement of the alternator voltage up to 500 V AC (external conductor voltage). Stable reactive power thanks to current-voltage vector measuring system (droop). A load-relieved current transformer is required in alternator phase ”V”. Internal and external alternator voltage set-point adjustment. PID control amplifier with large adjustment range.

Disproportionate drop in desired value when alternator operates at under frequency.

Permanent monitoring of the actuator and time limit on the max. possible excitation current.

Internal protection devices trip whenever a fault occurs, thus separating the excitation field from its energy source. Compact construction with interchangeable power stage. Fully potted in to protect it from environmental effects. Long life thanks to high-quality components.

With the use of additional modules it is possible to intervene in set-point and actual value formation via the ”COSIMAT N+” signal inputs:

There are a large number of additional modules available for a wide variety of control applications e.g. cos phi regulation of a synchronous alternator or motor or Limitation of start-up current when connecting up a large asynchronous motor to the alternator or

Cable compensation via load current detection or measured value of the external alternator voltage. Its additional modules make the "COSIMAT N+" suitable for various applications on test rigs, in power-train technology etc. (see 5.2 Additional modules).

Diagram for COSIMAT N+ STAMFORD AVR:

Adjusting elements and their effects of STAMFORD AVK AVR COSIMAT N+