Woodward ESDR4 Current Differential Protection Relay

Differential protection configuration: After enabling differential protection, modify the triggering value, delay time, hysteresis of the trip characteristics, set parameters for surge and overexcitation suppression, and display harmonics.

debugging

Prerequisite: Connect the equipment according to the wiring diagram, connect a 24Vdc power supply, set parameters, and activate the display mode.

Secondary value testing: Using three-phase testing equipment to test the threshold, single phase testing systems may produce mismatched measurement values due to phase matching system elimination.

One time value debugging: Remove all testing equipment before testing to ensure that the current transformer is not open circuited, configure the system to allow for the most precise current regulation, test connection correctness, perform cyclic exchange testing, and retest after correct connection.

Appendix

Size: Display the external dimensions and installation hole positions of ESDR 4T.

Technical data: including technical parameters such as measured current, frequency, accuracy, power consumption, environmental conditions, digital inputs, relay outputs, protection functions, terminal and housing protection.

Parameter List: lists all parameters and their setting ranges and default values during the configuration process.

Service options: Provide product service options, including return for repair, packaging requirements, return authorization number, replacement parts, and ways to contact Woodward.

Characteristics of Protection Function

Differential current monitoring

Two level monitoring: the first level is a warning, which displays text and activates relay contacts when the threshold is exceeded; The second level is for tripping, which can monitor adjustable tripping characteristics (Id<IN) and a fixed threshold of 100% rated current (Id>IN), and the tripping delay can be independently set.

Has a 2% hysteresis characteristic to prevent frequent signal movements near the threshold.

Selective protection

It only operates when there is a fault within the protection zone, and does not trigger faults outside the zone. Accurate protection is achieved by measuring the current difference on both sides.

Surge and overexcitation suppression

Using digital Fourier transform (DFT) to detect 2nd (surge) and 5th (overexcitation) harmonics, enabling electrical suppression function can prevent false tripping, and action margin (10% -50%) needs to be set.

Technical parameter characteristics

Measurement and Accuracy

Supports 6 current inputs, measurement frequency 40-70Hz, accuracy Class 1, linear measurement range up to 5 × I N.

The secondary side of the current transformer supports 1A or 5A, with a rated short-time current (1s) of 100 × I N (1A) or 30 × I N (5A).

Power supply and power consumption

The power supply is 24Vdc (± 25%), with a maximum inherent power consumption of 6W, and supports wide temperature operation (operating temperature -20~70 ℃).

Output capability

4 relay outputs, contact material AgCdO, supporting resistive and inductive loads:

Resistive load: 2A@250Vac The 2A@24Vdc Wait.

Sensory load: 1A@250Vac The 0.36A@125Vdc Wait.

Configuration and operational characteristics

Flexible parameter settings

Configurable transformer vector group (such as Yd5, Dd0, etc.), rated current, CT ratio, voltage ratio and other parameters to adapt to different devices.

The tripping characteristic curve can be adjusted, including the braking current threshold (X12), differential current threshold (Y1/Y2), and delay time.

Human Computer Interaction and Display

The front panel is equipped with an LC display screen (two lines of 16 characters) and LED indicator lights (brake current, differential current, monitoring status, alarm), which display real-time measurement values and fault information.

Support switching between display mode and configuration mode through buttons (message scrolling, selection, numerical adjustment, etc.), easy to operate.

Relay function can be customized

Relays 1-2 and 4 can be configured for operating current (N.O.) or idle current (N.C.) mode, while relay 3 is fixed as a "ready to run" signal and supports automatic/manual fault confirmation.

Safety and protection features

electrostatic protection

Electronic components are sensitive to static electricity, and during operation, body static electricity must be released to avoid contact with plastic and other materials. Disassembling circuit boards must follow anti-static regulations.

Electrical safety design

Measure input electrical isolation to prevent interference; The power supply and input/output terminals support overload protection, and the terminal wiring specifications are clear (2.5mm ² or 4mm ²).

Sealing and Certification

The protection level of the front panel is IP42 (standard) or IP54 (with gasket), and the rear is IP21. It has passed CE and UL certification and is suitable for ordinary places and ship environments (GL certification).

Application scenario characteristics

Applicable object: Designed specifically for block connections of generators, motors, and transformers, forming protection zone boundaries and accurately detecting faults within the zone.