Basler XR2002F Voltage Regulator – Wide-Frequency Excitation for Variable-Speed Generators

The Basler XR2002F is a specialized automatic voltage regulator designed to operate from a 110 VAC sensing input with an exceptionally broad frequency range of 48 to 480 Hz. This unique capability makes it ideal for generators driven by variable-speed prime movers, such as wind turbines, hydroelectric units with fluctuating speed, or high-frequency alternators used in aircraft ground power and military applications.

Technology and Performance

The XR2002F utilizes a pulse-width modulated (PWM) excitation stage that maintains stable generator voltage despite wide variations in frequency and load. Its control algorithm incorporates frequency compensation that automatically adjusts the voltage setpoint proportionally to the frequency, preventing over-excitation at low speeds and under-excitation at high speeds. The regulator delivers a continuous field current of 5 A, with 10 A forcing for 5 seconds, sufficient for generators up to approximately 200 kVA.

Regulation accuracy is ±0.5% from no-load to full-load, and the transient response recovers to within 90% of setpoint in less than 30 milliseconds. The unit features a true RMS sensing circuit, ensuring accurate measurement even with non-linear loads.

Adjustments and Settings

Front-panel potentiometers allow adjustment of voltage setpoint, stability (gain), and droop for parallel operation. A unique frequency roll-off adjustment sets the knee frequency at which output voltage begins to decrease with falling frequency, protecting motors and other loads from excessive heating during low-frequency operation. The stability control is optimized for generators with varying inertia.

Protection and Diagnostics

Built-in protections include over-excitation limiting, short-circuit current limiting, and thermal shutdown. An under-frequency protection circuit reduces excitation when frequency drops below a preset threshold. An LED status indicator shows power-on and fault conditions, and auxiliary output contacts are available for remote annunciation.

Installation and Environmental

The XR2002F is housed in a rugged aluminum enclosure suitable for panel mounting. It operates in ambient temperatures from -40°C to +70°C and is conformally coated for resistance to humidity and corrosive gases. Terminals are clearly labeled for sensing input, field output, and auxiliary connections.

Applications

This regulator is specifically suited for variable-speed generator sets, including those driven by diesel engines with wide speed ranges, hydro turbines with fluctuating head, and wind turbines. It is also used in high-frequency power systems for aviation and testing laboratories.

Maintenance

With solid-state design, the XR2002F requires minimal maintenance. Periodic inspection of connections and cleaning of the heat sink are recommended. The unit's self-diagnostics provide immediate fault indication.

Compliance

Meets relevant IEC and military standards for EMC and environmental robustness.

Conclusion

The Basler XR2002F offers an unparalleled solution for applications demanding frequency-independent voltage regulation, combining wide-range capability with proven Basler reliability.