Generators will have automatic voltage regulators to stabilise the voltage as the load on the generator changes. The DVR-2000 is an electronic, solid-state, microprocessor based control device it regulates the output voltage of a brushless ac generator by controlling the current into the generator exciter field. The solid state system is the modern equivalent of the old electromechanical system which was the first AVR for generators. This is a feed back control system that measures the output voltage of the generator, compares it with a set point and generates a signal that is used to adjust the excitation of the generator. Input power to the DVR-2000 is from a multi pole, high frequency, permanent magnet generator. As the excitation current in the winding of the generator increases its terminal voltage will also increase.
Design and mounting of the DVR 2000E Marathon Automatic Voltage Regulator
The DVR-2000 AVR MARATHON is supplied in an encapsulated package designed for behind the panel mounting. It is held in place by thread forming screws that thread into the plastic shell. LED front panel indicators indicate regulator status and system conditions. The connections are made through quarter inch, quick connect terminals on the rear panel. A 9 pin DB-9 type connector on the rear panel provides communication between the DVR-2000 and an IBM compatible PC. When the DVR-2000 voltage regulator is mounted on the generator at the factory a moulded cover is provided which allows the system to be UL 508 compliant. This removes the risk that the live terminals and heatsinks could be exposed to unintentional contact. This cover must be installed whenever the voltage regulator is energised.
Features of the DVR 2000E Marathon Automatic Voltage Regulator
The unit has four control modes:
- Automatic Voltage Regulation
- Manual or Field Current Regulation
- Power Factor regulation
- Reactive Power Regulation
It has programmable stability settings with soft start control with an adjustable time setting in AVR control mode. It has overexcitation limiting in all the control modes and an underfrequency regulation. Crowbar circuitry protects the field and there is overtemperature protection to avoid over heating of the unit. There are many other state of the art features besides these few listed.