Basler XR2002/XR2002F Regulator

Basler XR2002/XR2002F PMG Voltage Regulator: In Depth Technical Analysis and Engineering Application Guide

Product positioning and model differences

The XR2002 series voltage regulator is a DC excitation control device designed for brushless generators equipped with permanent magnet generators (PMGs). This series includes two models:

XR2002 (standard type): does not have voltage limited volt/hertz (V/Hz) characteristics, suitable for standard operating conditions with low frequency compensation requirements.

XR2002F (frequency compensation type): Built in voltage limited volt/hertz (VLV/Hz) characteristics, suitable for power generation systems that are sensitive to frequency changes and require automatic voltage drop protection at low frequencies.

The two models are completely identical in appearance, wiring terminals, and installation dimensions, with the only difference being the internal frequency compensation algorithm and corresponding front panel markings.

Key technical specifications and selection points

1. DC output capability

Rated continuous output: 7 Adc @ 63 Vdc (corresponding to 440W)

Strong excitation output (1 minute): 10 Adc @ 90 Vdc (corresponding to 900W)

The output capability determines the adaptation range of the magnetic field resistance of the exciter. The manual specifies that the DC resistance of the excitation winding must be between 9 Ω and 100 Ω. If the resistance is lower than 9 Ω, a current limiting resistor must be connected in series; If the full load current exceeds 7A, a higher output level regulator needs to be selected.

2. Input power conditions

The regulator can be powered by PMG or generator terminal voltage, with different wiring methods and voltage ranges:

Power supply source phase number voltage range (full load → no load) frequency range

PMG single-phase 100-180 Vac 48-480 Hz

PMG three-phase 70-140 Vac 48-480 Hz

Generator output (isolated transformer) single-phase 90-153 Vac 48-480 Hz

Generator output (isolated transformer) three-phase 70-110 Vac 48-480 Hz

3. Voltage sensing input

The detection input is single-phase, with terminals E1 (multi tap) and E3 (common terminal). Select the corresponding E1 tap based on the rated voltage of the generator:

100-139 Vac → 120V tap

190-240 Vac → 208/240V tap

380-480 Vac → 416/480V tap

500-600 Vac → 600V tap

Important engineering reminder: Phase to phase wiring must be used for input detection, and phase to neutral wiring is prohibited, otherwise the third harmonic will seriously affect the adjustment accuracy.

Deep Analysis of Frequency Compensation Mechanism (XR2002F Only)

XR2002F provides two frequency compensation modes to address the voltage control requirements of the generator during sudden load surges or speed fluctuations.

1. Voltage/Hertz (V/Hz) characteristics

This mode is a linear relationship: when the frequency decreases, the voltage decreases proportionally to maintain a constant V/Hz ratio. This feature is mainly used to improve the system recovery performance under sudden load conditions - the voltage will not excessively rise before frequency recovery. The UF ADJ control and VOLT control on the front panel work together to adjust the characteristic curve simultaneously along the frequency axis (45-65Hz) and voltage axis. The preset inflection point at the factory is 55Hz (60Hz system).

2. Voltage limited volt/hertz (VLV/Hz) characteristics

This mode adds a linear regulation zone based on the V/Hz characteristic, which means that the regulator can still maintain precise voltage regulation even when the frequency fluctuates slightly; The voltage only decreases proportionally when the frequency drops below the inflection point. This allows the generator to maintain voltage stability even with slight speed fluctuations, balancing dynamic response and steady-state accuracy.

The inflection points of both characteristics can be adjusted through the UF ADJ knob, and the corresponding frequency range for 50Hz and 60Hz systems needs to be selected through internal jumpers.

Key points of installation and wiring engineering

1. Installation and heat dissipation

It is recommended to install the regulator vertically to facilitate convective heat dissipation. Its structure is sturdy and can be directly installed on the generator set, but the correct fasteners need to be used. Please refer to the Outline Drawing in the manual for detailed dimensions.

2. Excitation output circuit (F+, F -)

It is necessary to strictly observe the polarity connection to the magnetic field terminals of the brushless excitation machine.

It is absolutely forbidden to string the shutdown switch into the F+and F - circuits. Due to the possibility of arc damage to the regulator, the shutdown switch must be connected between terminal 53 and F+(there is already a jumper at the factory, which can be replaced with a switch).

3. Power input fuse configuration

It is strongly recommended to install high breaking capacity fuses in each input power line to protect the regulator from external short circuits or ground faults.

4. Excitation circuit (applicable only when the generator outputs power)

When the regulator is powered by the generator terminal voltage, if it is first put into operation or the residual magnetic polarity is incorrect, it needs to be excited through an external DC power supply (Field Flashing). The wiring method is: DC power supply positive pole → diode → current limiting resistor → F+, negative pole → F -. The starting excitation current should be set between 1/2 of the rated no-load excitation current and the full load value, and the calculation formula is:

Eb=IF×(RF+R51)

Among them, R51 is the current limiting resistor, and RF is the excitation winding resistor.

System debugging and parameter tuning process

1. Pre set before startup

VOLT knob: Rotate counterclockwise to minimum

STAB knob: Rotate to the middle stroke

UF ADJ knob: maintain factory preset position

Stability jumper: Both jumpers are connected to terminal C (corresponding to "medium speed" response)

Frequency compensation jumper: Connect to the corresponding terminal according to the system frequency (50/60Hz)

2. Startup and voltage establishment

Start the prime mover to the rated speed

Close the excitation shutdown switch

Slowly adjust the VOLT knob clockwise until the generator voltage reaches the rated value

If using an external remote voltage regulator resistor (R50), the jumper between terminals 6-7 should be removed and R50 should be connected

3. Stability tuning (key step)

The goal of stability tuning is to eliminate the "hunting" phenomenon of generator voltage while also considering response speed:

Under no-load conditions, rotate the TAB knob counterclockwise until the voltage fluctuates (critical instability)

Slowly rotate the TAB clockwise again until the fluctuation disappears

Alternating load switching and observing voltage recovery waveform

If there is still oscillation, the stability jumper can be adjusted in the following order to obtain a more stable response:

Jumper 1, Jumper 2, Response Speed

J1 C Fast

C C medium speed (default)

J1 J2 medium speed

C J2 is slow

4. Frequency compensation characteristic adjustment (only for XR2002F)

V/Hz mode: Adjust UF ADJ to make the UF indicator light just turn on, continue adjusting until the voltage drops to 90% of the rated value, and then use VOLT to restore the rated voltage

VLV/Hz mode: First adjust the prime mover speed to the desired inflection point frequency (such as 57Hz/60Hz system), adjust the UF ADJ to turn on the UF indicator light, and then restore the rated speed to confirm that the indicator light is off

Troubleshooting Logic and Case Analysis

The manual provides a systematic troubleshooting table, with the following typical faults and their diagnostic logic:

Fault phenomenon 1: Voltage cannot be established (PMG power supply)

Measure whether the voltage of terminals 3-4 (single-phase) or 3-4-5 (three-phase) is within the allowable range

Measure if there is approximately 63Vdc output between F+- F -

If the input voltage is normal but there is no output, the regulator is faulty

If the input voltage is abnormal, check the wiring, fuses, switches, and transformers

Fault phenomenon 2: Voltage establishment → attenuation → re establishment (periodic)

If the external remote control voltage regulator resistor (R50) has been installed, short-circuit terminals 6-7; If stable, permanently short-circuit

If it is unstable, replace the regulator and try again

Fault phenomenon 3: Voltage too high and uncontrollable

Immediately disconnect the excitation shutdown switch (to prevent overexcitation from damaging the equipment)

Check if the E1 tap matches the generator voltage

Check if the wiring of the detection circuit is correct

Perform the Operational Test in Section 4-3, build a test circuit using an isolation transformer and a light bulb, and verify the basic function of the regulator

Fault phenomenon 4: Voltage oscillation/traveling block

Check if the engine speed is stable

Perform stability tuning process (Chapter 5, Section 3)

Replace the regulator to eliminate internal faults

Fault phenomenon 5: Poor adjustment accuracy

If it is XR2002F, check if the frequency compensation has malfunctioned due to a decrease in speed

Ensure that the voltmeter is connected to the same position as the regulator detection

Waveform distortion may cause deviation between the RMS meter and the average voltage detection value of the regulator. It is recommended to use a rectifier instrument for calibration

Preventive maintenance and spare parts management

The regulator is a solid-state electronic device, and maintenance focuses on:

Regular cleaning: prevent the accumulation of dust and moisture

Terminal fastening: All connecting terminals should maintain reliable contact

It is strictly prohibited to use a megohmmeter or voltage tester to perform insulation testing on the regulator, otherwise it may damage the semiconductor devices

The most critical components in the spare parts list are the circuit board assembly (XR2002 is 9 1394 01 100, XR2002F is 9 1394 01 101) and the 500 Ω/25W power resistor (R50). It is recommended to keep at least one circuit board on site to shorten the downtime caused by faults.