Basler BE1-25 synchronous inspection relay principle and testing

Basler BE1-25 Simultaneous Inspection Relay: A Complete Guide to Principles, Testing, and Field Applications

System Overview and Application Positioning

The BE1-25 synchronous inspection relay launched by Basler Electric is a solid-state digital synchronous detection device specially designed to verify the synchronous conditions before the circuit breaker is closed. The relay measures the phase angle between the single-phase voltage on both sides of the line and bus to determine whether the closing permission condition is met, and ensures that the condition continues to meet the preset minimum time window before outputting the closing permission signal.

The typical application scenarios of BE1-25 in the power system include:

Generator grid connection: Verify synchronization conditions before connecting the generator in parallel with the power system

System segmented circuit breaker reclosing: restoring connection between two power system sections

Fast switching scheme supervision: occasions that require fast response and phase measurement circuits to quickly return

Compared with conventional synchronous detection relays, the core advantage of BE1-25 lies in its modular functional design - by selecting different voltage monitoring options, users can make the relay have the intelligent recognition ability of "voltage/no voltage/overvoltage" status of the line and bus, thus supporting various special operating modes such as "no voltage closing" and "dead bus closing", greatly expanding the scope of application of the equipment.

Core technical specifications

2.1 Simultaneous detection function

The synchronous detection function of BE1-25 is achieved by measuring the phase angle between the single-phase voltage of the line and the bus:

Phase angle setting range: 1~99 degrees (front panel dip switch, 1 degree step)

Phase angle measurement accuracy: ± 0.5 ° or ± 5% of the set value (whichever is greater), under the conditions of 50/60Hz rated frequency, 80-135V input voltage, and 25 ℃

Full temperature setting accuracy: ± 0.5 ° or ± 5% (whichever is greater), at rated frequency and input level

Delay setting: two selectable ranges

A6 option: 0.1~9.9 seconds (x 0.1 gear) or 1~99 seconds (x 1 gear)

A7 option: 1~99 cycles (based on bus frequency)

Timing accuracy (25 ℃): maximum 25ms or 5% set value (whichever is greater)

Full temperature zone timing accuracy: ± 10ms or ± 2% (whichever is greater)

2.2 Minimum voltage detection

The voltage sensing circuit of the synchronous detection circuit ensures reliable operation when the voltage is above 80V, and does not work when the voltage is below 20V. Due to individual differences in component characteristics, some units may start within the range of 45~55V. This feature ensures that the relay will not mistakenly send a closing permission signal when the system voltage drops significantly.

2.3 Output contacts and target indication

Rated output contact value:

Resistive load: 7A continuous at 120Vac; At 250Vdc, it can connect 30A (0.2s), carry continuous current of 7A, and disconnect 0.3A

Inductive load (L/R=0.04): Breaks 0.3A at 120Vac, 125Vdc, 250Vdc

The target indicator can be selected as internal excitation type or current excitation type (requiring at least 0.2A current in the output circuit). After September 2007, the target indicator has been upgraded from an electromagnetic flipping indicator to an electronic locking LED indicator - after a power outage, the locked target status automatically recovers after the power is restored, making it easy to trace faults.

Control panel and operating components

The front panel of BE1-25 integrates all operational control and status indicator components:

Phase Angle selector (00~99): Set the maximum allowed phase angle (degrees). Setting a value of 00 will prohibit simultaneous output.

TIME DELAY selector (00~99): Set the shortest duration of the same period condition. Setting a value of 00 will prohibit simultaneous output.

TIME DELAY multiplier switch: X 0.1 gear (0.1~9.9 seconds) or X 1 gear (1~99 seconds).

SYNC indicator light (red LED): When the synchronization condition continues to reach the TIME DELAY set value, it lights up and synchronizes with the SYNC output contact closure.

POWER indicator light: Indicates that the relay power supply is working properly.

Target reset switch: Manually reset the target indicator of the latch.

PUSH-TO-ENERGIZE test button (recessed, I and J): Press with a 1/8 inch diameter non-conductive thin rod, the I button closes the SYNC output contact and auxiliary SYNC output contact, and the J button closes (optional) the voltage monitoring output contact.

The core configuration component with voltage monitoring function is located on the right internal circuit board:

MODE switches No.1 (bus) and No.2 (line): Updip=NORMAL mode, Downdip=NOT-OV mode

Deliberation switches No.1~No.5: Configure the response logic of the voltage monitor

Detailed explanation of voltage monitoring function

The voltage monitoring function of BE1-25 is a key feature that distinguishes it from similar products. By selecting different sub options of Option 2 (2-A, 2-B, 2-C, 2-R, 2-T, 2-U, 2-V), the device can obtain intelligent judgment ability for the "voltage on/off/overvoltage" status of the input voltage.

4.1 MODE Switch - Define State Boundaries

NORMAL mode (dial up):

The low voltage threshold (set by DL/NOT OV control) is defined as "no voltage (DEAD)"

Above the high voltage threshold (set by LL/LB control) is defined as "live voltage"

Between the two is the uncertainty zone

NOT-OV mode (dial down):

Below the LIVE setting value is defined as' DEAD '(no pressure)

Between the LIVE setting value and NOT-OV setting value is defined as' LIVE '

Exceeding the NOT-OV setting value is defined as' Overvoltage '

Allow the circuit and busbar to operate in different modes, such as achieving functions such as "closing the generator circuit breaker to the dead busbar" or "prohibiting closing when the voltage is too high".

4.2 CONDITION Switch - Define Response Logic

The output conditions for configuring the voltage monitor with the ON (down) position of the five CONDITION switches are as follows:

Switch No.1 (NOT-OV enabled): When turned on, add a "non overvoltage" constraint on the LL-LB condition

Switch No.2 (LL-LB, Voltage Line/Voltage Bus): When turned on, immediately drives the voltage monitor output upon recognizing the LL-LB condition

Switch No.3 (DL-LB, no voltage line/voltage bus): When turned on, immediately drive SYNC or voltage monitoring output after identifying the condition

Switch No.4 (LL-DB, voltage line/non voltage bus): When turned on, immediately drive SYNC or voltage monitoring output after identifying the condition

Switch No.5 (DL-DB, no voltage line/no voltage bus): When turned on, immediately drive SYNC or voltage monitoring output after identifying the condition

4.3 Voltage difference monitoring (Δ V)

After selecting the voltage difference option (Option 2-A/B/C/R/T/U), BE1-25 can compare the voltage difference between the line and the bus, and prohibit synchronous output when the difference exceeds the set value, thereby reducing the system impact during closing.

Phasor Voltage Difference Detection (Option 2-R/T/U):

Calculate the vector difference between the line voltage and the bus voltage, and close the area as shown in Figure 1-2. Using the cosine theorem to calculate Δ V, the relationship is Δ V ²=VL ²+VB ² − 2 · VL · VB · cos θ. When VL is tangent to the Δ V circle, ΔV=VB·sinθ， Or θ=arcsin (Δ V/VB).

Average voltage difference detection (Option 2-A/B/C):

Detect the voltage difference of the effective value, independent of the phase angle, and the closed region is a constant Δ V boundary (Figure 1-3).

4.4 Scalable Phase Angle Window (Option 9)

In emergency situations, the phase angle window can be expanded by 2 or 3 times (determined by the position of the circuit board jumper) through external contact closure, for rapid load recovery after system failure. This option is not recommended for generator applications as excessive closing angles can generate excessive mechanical stress on the generator.

Installation and wiring points

5.1 Mechanical Installation

BE1-25 adopts the S1 standard chassis size and supports two installation methods: semi embedded or protruding. The grounding terminal at the rear of the chassis must be hard connected to the ground with a copper wire of not less than 12AWG. In multi device systems, it is recommended to lead each device separately to the grounding bus.

5.2 Wiring and connection plugs

The relay is connected to the chassis terminal through a removable connector plug (1 plug for a 10 terminal chassis, 2 plugs for a 20 terminal chassis). When unplugging, disconnect the normally open trip circuit first, short-circuit the normally closed circuit first, and then disconnect the power supply and induction circuit to ensure that the CT does not open circuit.

5.3 Contact induction configuration

BE1-25 provides two types of contact induction methods:

Isolated contact sensing (Options 1-5): The relay provides current monitoring from the internal to the external dry contacts, and no voltage should be applied externally.

Non isolated contact induction (Options 1-4): Monitor the external DC voltage source (voltage level should be the same as the relay power supply), apply voltage through contact closure to achieve signal input.

When using a T-type power supply (250Vdc or 240Vac), an external contact induction module (Figure 4-12) must be used.

5.4 Voltage Differential Resistance Module

When the mode/condition switching of the voltage monitor is controlled by external contacts (Option 2-C/U/V), a resistance module needs to be installed at the rear of the relay (Figure 4-11). When installing in a protruding manner, the module needs to be removed first, and the installation panel should be placed between the relay and the module before reinstalling.

5.5 EMI Suppression and Storage

It is recommended to parallel reverse diodes at both ends of the coil for EMI suppression in all applications where the output drive relay coil is in contact. For long-term storage (backup) equipment, it is recommended to power on and run for 30 minutes each year to extend the life of the internal aluminum electrolytic capacitor.

Complete process of on-site testing and calibration

6.1 Test Preparation

It is recommended to use a dedicated relay protection tester or build a testing circuit according to Figure 5-2 for testing equipment:

Dual voltage source that can independently adjust amplitude, frequency, and phase

timer

DC power supply (for output circuit and target testing)

6.2 Preliminary Setting

All contact induction inputs are open circuit

All CONDITION switches and MODE switches are turned off

Rotate all multi turn potentiometers counterclockwise to the minimum (Δ V controls clockwise to the maximum)

The input voltage of the line and bus is 95Vac, with a phase difference of 0 °

Apply relay power supply

6.3 Basic functional testing of synchronous detection

Step 1: Verification of Phase Angle Function

Set PHARE ANGLE as the target value and TIME DELAY as the minimum

Verify that the 'allow/prohibit' action is within the specification range

Observe that the PHASE ANGLE LED lights up during the delay period, and the SYNC LED flashes when the output contact is closed (the LED goes out after the input of the circuit is open in case of an open circuit in case of an open circuit in case of an open circuit in case of an open circuit in case of an open circuit in case of an open circuit in case of an

Step 2: Timing accuracy verification

Line and bus are in phase (0 ° phase difference)

Set TIME DELAY to 9.9 seconds (x 0.1 level) and 99 seconds (x 1 level) respectively

Start/stop timing by closing/opening the input of the 56b

Verify timing accuracy within specification range

Step 3: Low voltage suppression verification

Reduce the voltage of the line and bus to 80Vac, and the synchronous function should work normally (not suppressed)

Reduce the line voltage to 20Vac, and the synchronous function should be suppressed (the PHARE ANGLE LED should not light up)

Restore the line to 80Vac, reduce the busbar to 20Vac, and suppress the synchronous function

6.4 Voltage Monitoring Function Test (NORMAL Mode)

Adjust LB control to 80Vac threshold, DB/NOT OV control to 30Vac threshold, LL control to 80Vac threshold, DL/NOT OV control to 30Vac threshold

Set TIME DELAY to 99 seconds (to prevent interference from synchronous output testing)

Verify the output logic of each conditional switch combination in Table 2

6.5 Voltage Monitoring Function Test (NOT-OV Mode)

Adjust LB control to 80Vac threshold, DB/NOT OV control to 120Vac threshold, LL control to 80Vac threshold, DL/NOT OV control to 120Vac threshold

Verify the output logic of each conditional switch combination in Table 3

Additional constraint of 'non overvoltage' added when confirming switch No.1 ON

6.6 Voltage Difference (Δ V) and Extended Window Test

Verify that the synchronous output is enabled within the set range of Δ V, and suppress it when it exceeds the range

Verify the option to expand the phase angle window (if equipped) to increase the window by 2 or 3 times

Common troubleshooting guide

Troubleshooting direction

Check if the power terminal voltage meets the nominal value of the selected power option when the POWER indicator light is not on; DC input has no polarity requirement but must be within the specification range

SYNC output is not closed. Check if the input of the circuit breaker is closed (auxiliary contact signal of the circuit breaker); Is PHASE ANGLE set to 00 (inhibition); Is TIME DELAY set to 00 (inhibition); Is the line/bus voltage below the minimum detection threshold of 80V; Does the Δ V option exceed the set value

Check the positions of the MODE switch and CONDITION switch for abnormal voltage monitoring LED indication; Verify if LL/LB/DL/DB/NOT OV control potentiometer calibration is offset

The target indication does not maintain a current of at least 0.2A in the output circuit (current excitation type); Check if the target reset switch is stuck; Is the target state recovery function normal after power interruption

If the test button is invalid, a non-conductive thin rod with a diameter of no more than 1/8 inch must be used to press it (metal tools may cause short circuits); Check if the corresponding output relay is faulty

Check the contact induction module (Type T power supply) for abnormal communication with SCADA (if any); Does the isolated input mistakenly apply external voltage (which can cause damage)