Debugging and Testing of Basler BE1-700 Relay

VT Ratio: Set the Phase VT Ratio and Aux VT Ratio (if using auxiliary voltage) on the Sensing Transformers page. VT Connection can be selected as 3W (three-phase three wire), 4W (three-phase four wire), or single-phase (AN/BN/CN/AB/BC/CA). The 27/59 Pickup Mode allows for the selection of PN (phase neutral) or PP (phase phase), which affects the calculation benchmark for overvoltage/undervoltage protection.

Example of core protection function setting

BE1-700 provides rich voltage/frequency protection, with each function having independent enable/disable, setting, delay, and logical connections. The following illustrates the tuning approach using commonly used functions as examples.

5.1 Overvoltage protection (59P)

Used to prevent system overvoltage from damaging equipment. One of Three (action upon overvoltage of any phase), Two of Three, or Three of Three modes can be set. The setting value is in volts (PN or PP, depending on 27/59 Mode). For example, assuming Pickup=120V (approximately 173% for the 69.3V benchmark), with a delay of 500ms and a fixed time limit. Connect the Trip output of this component to the physical output OUT1 in BEST logic Plus to drive the trip.

5.2 Under voltage protection (27P)

Similar to overvoltage, but operates when the voltage drops. Voltage Inhibit value can be set to avoid brief voltage drops during startup (such as motor startup). For example, suppose Pickup=60V (approximately 86.6%), with a delay of 2 seconds.

5.3 Negative sequence overvoltage (47)

Negative sequence voltage reflects three-phase imbalance and can be used to detect phase loss or asymmetric faults. The setting value is expressed as the phase neutral voltage, but in actual testing, the single-phase injection voltage is three times the setting value (because V2=Va/3 for single-phase input). For example, assuming Pickup=10V (corresponding to a single-phase test voltage of 30V), with a delay of 1 second.

5.4 Overexcitation (24) - V/Hz protection

Used for over excitation protection of transformers or generators. V/Hz reference needs to be set (i.e. rated V/Hz=√ 3 × Vnom/Fnom). Reverse time limit (optional index 0.5, 1, 2) or fixed time limit can be selected, and alarm level can be set. For example, if the transformer manufacturer allows 2 hours for 105% V/Hz and 10 minutes for 120% V/Hz, the inverse time curve (M-1) ² can be set, and the time dial can be selected according to the curve. Chapter 35 of the manual provides the complete curve family.

5.5 Frequency Protection (81)

Overfrequency or underfrequency can be set, and the source can be selected from phase voltage or auxiliary voltage. Used for load shedding or islanding detection. The setting accuracy is ± 0.01Hz, and the minimum delay is 0 (instantaneous).

5.6 Simultaneous testing (25)

Compare the amplitude, frequency, and phase angle of the phase voltage with the auxiliary voltage, and output a signal to allow closing. Angle compensation needs to be set (if PT wiring causes inherent phase shift). The voltage difference, slip frequency, and slip angle are all independently set.

5.7 Other auxiliary functions

Virtual switch (43): A logical switch that can be operated on software or a panel, used for switching on/off protection or changing the operating mode.

Logic Timer (62): Provides multiple timing modes (delayed on/off, monostable, oscillation, integration, etc.) for complex logic coordination.

Recloser (79): Automatic reclosing up to 4 times, in conjunction with circuit breaker status and external locking.

Circuit breaker control (101): Simulate the opening and closing buttons of the circuit breaker, which can be operated locally/remotely.

Programmable Logic Plus Settings

The strength of BE1-700 lies in its fully programmable logic. BEST logicPlus uses a graphical drag and drop method to connect protective components, inputs, outputs, timers, gate circuits, and more. The default logic is overvoltage/undervoltage trip (Trip of 59P-1 and 27P-1 is connected to OUT1 through OR gate). To lead the Pickup signal of 59P-1 to OUT2 as an alarm, simply connect the Pickup output of 59P-1 to the input of OUT2. Each output can have custom labels (such as' overvoltage alarm '), which will appear in the fault report and SOE.

After modifying the logic, it must be 'Save' and 'Upload Logic to Device' to take effect. Note that logical changes will not be automatically saved to the file, and the. bst4 settings file needs to be manually saved.

On site testing and verification (emphasis)

During acceptance or regular calibration, it is necessary to verify the measurement accuracy, action value, and delay of the relay. Chapters 37-47 of the manual provide detailed testing steps covering various functions. The following summarizes general principles and key testing methods.

7.1 Test Preparation

Use BESTCOMSPlus to read and save the current settings to prevent changes during testing.

Clear all targets and alarms (press Reset on the Targets and Alarms screens).

For each test, temporary configuration logic is used to output the corresponding Trip and Pickup to idle output contacts (such as OUT2 for Pickup and OUT1 for Trip) for easy monitoring with a multimeter or timer.