I. Main Features of TC-3087(3U) Anti-Islanding Protection Device

1.1 The TC-3087(3U) device can be centrally grouped on panels or locally dispersed on high-voltage switchgear cabinets. Each bay functions independently, with devices connected only via a network for information sharing. This not only enhances system flexibility but also greatly improves reliability, as a failure in any single device affects only a local component.

1.2 The device utilizes a high-performance processor and high-resolution A/D converter, with 32-point sampling per cycle combined with measurement CTs, ensuring high accuracy of telemetry measurements.

1.3 The protection function is completely independent of the communication network; network failure does not affect normal protection operation.

1.4 The device adopts a fully sealed design along with carefully designed anti-interference components, significantly improving resistance to vibration and electromagnetic interference.

1.5 It features both hardware and software watchdog functions, enabling the system to achieve high measurement accuracy and strong anti-interference capability simultaneously.

1.6 User-friendly human-machine interface: The device uses a fully Chinese large-screen LCD display, with clear Chinese labels for trip reports, alarm reports, telemetry, teleindication, setting adjustments, etc., making it easy for users to operate and understand.

1.7 Communication is via a CAN port (Controller Area Network interface) or RS485 interface, characterized by: simple structure with only two external wires; high transmission speed up to 1Mbps; long transmission distance up to 10KM; CRC verification with corresponding error handling capability; non-destructive bus arbitration technology, providing high efficiency and anti-interference capability for station communication.

II. Brief Introduction of Main Functions

In addition to islanding trip and remote closing for islanding recovery functions, the TC-3087(3U) anti-islanding protection device continuously monitors bus voltage and measures current during system operation, with alarm functions for abnormal current and voltage. Settings include:

(1) Anti-islanding third harmonic voltage detection and discrimination (optional enable/disable)

(2) Stage 1 overvoltage trip (optional enable/disable)

(3) Stage 2 overvoltage trip (optional enable/disable)

(4) Stage 1 undervoltage trip (optional enable/disable, closing position discrimination lockout)

(5) Stage 2 undervoltage trip (optional enable/disable, closing position discrimination lockout)

(6) Voltage presence automatic closing (optional enable/disable)

(7) Stage 1 overfrequency trip (optional enable/disable)

(8) Stage 2 overfrequency trip (optional enable/disable)

(9) Stage 1 underfrequency trip (optional enable/disable, closing position discrimination lockout)

(10) Stage 2 underfrequency trip (optional enable/disable, closing position discrimination lockout)

(11) Overcurrent protection (optional enable/disable)

(12) Protection protection (optional enable/disable)

(13) Power variation protection (optional enable/disable)

(14) Frequency sudden change protection (optional enable/disable)

(15) Generator side reverse power instantaneous trip (optional)

(16) Rate of change of frequency protection and underfrequency lockout (optional)

(17) External interlocking trip for separation.

(18) Automatic closing function for electrical operation loss of voltage trip coil

(19) Measurement and control functions: U, I, P, Q, cosΦ, F (requires measurement current and voltage input)

(20) Optional automatic recovery closing function.

Normal operation mode of the clean power supply project system: One 10kV/400V distribution transformer supplies power normally while the clean power source is grid-connected. Control requirements are as follows:

(1) If the measured current exceeds the set limit (via parameter setting), the TC-3087-II anti-islanding protection device displays an alarm message on the LCD and can upload the alarm via communication.

(2) Real-time detection of three-phase voltage and current (measurement point) in the AC grid (AC380V, 50Hz) supply circuit to determine power flow direction and magnitude. If the system side has voltage greater than the voltage presence setting during initial power-up, the device automatically closes. Additionally, after an undervoltage trip, if the device remains powered, it can automatically perform voltage recovery closing.

(3) The device is configured with overvoltage protection trip, undervoltage protection trip, overfrequency protection trip, underfrequency protection trip, and instantaneous reverse power discrimination trip to prevent impacts on the system grid and equipment damage after islanding occurs.