Description
- The System Separation Protection (78) Device is a new-generation product independently developed and manufactured by our company. It is suitable for substations or interconnections operating with small power sources connected to medium- and low-voltage grids.
- In the event of a grid fault, the device can quickly and reliably disconnect the small power sources from the grid to ensure the restoration of power supply from the main source and guarantee the safe and stable operation of the grid system.
- It features functions such as low-frequency disconnection, low-voltage disconnection, over-frequency disconnection, busbar overvoltage disconnection, zero-sequence overvoltage disconnection, and loss-of-synchronism disconnection.
Product Functions (ANSI)
- Frequency relay｜81
- Undervoltage relay｜27
- Overvoltage relay ｜59
- System separation relay ｜78
- Neutral overvoltage relay｜59N
- Instantaneous Overcurrent｜50
- Time Delayed Overcurrent｜51
Communication Mode
- Optional: RS-485, CAN bus, Ethernet, IEC 60870-5-103 (IEC-103)
Main Functional Specifications
- Protection Response Time (including output relay response time): The average response time error is no more than 35 ms.
- Precision Operating Range: The minimum precision current is 0.08 In, and the maximum precision current is 20 In.
- Setting Accuracy: The current setting error is within ±2.5% for current values above 1.00 A; the voltage setting error shall not exceed ±3%.
- Measurement Accuracy: Current (I) and Voltage (U) meet Class 0.2 accuracy; Active power (P) and Reactive power (Q) meet Class 0.5 accuracy.
- Remote Signal Resolution: ≤ 2 ms.
Event Logging, Fault Recording
- The recorded events include protective action events and device malfunctions;
- Record the type of protection trip, the time of the trip, and the operating parameters at the time of the trip;
- The fault recording data includes: the time of the protection operation, the type of protection operation, and the rms values before and after the recording was initiated;
- Data length of the fault recording: 2 cycles before the fault and 4 cycles after the fault;
- The SOE can retain 48 sets of data after a power loss, and the fault report can retain 16 sets of data after a power loss.
Monitoring Features
- This device measures analog parameters including current, voltage and frequency.
- It acquires digital signals such as status data from circuit breakers, energy storage systems, disconnectors and remote/local control switches, and supports disconnector control functions.
Setting Table
| No. | Definition | Display | Setting Range | Default Value | Main Program | Remarks |
|---|---|---|---|---|---|---|
| 1 | Control Word 1 | 0000～FFFF | 0000 to FFFF | 0x0000 | – | – |
| 2 | Control Word 2 | 0000～FFFF | 0000 to FFFF | 0x0000 | – | – |
| 3 | Control Word 3 | 0000～FFFF | 0000 to FFFF | 0x0000 | – | – |
| 4 | Low Frequency Start-up Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 5 | Low Frequency Stage 1 Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 6 | Low Frequency Stage 2 Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 7 | Over Frequency Stage 1 Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 8 | Over Frequency Stage 2 Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 9 | Under Voltage Start-up Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 10 | Under Voltage Stage 1 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 11 | Under Voltage Stage 2 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 12 | Over Voltage Stage 1 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 13 | Over Voltage Stage 2 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 1.00 s | – | – |
| 14 | Over Current Stage 1 Delay | 0～120.00s | 0 to 120.00 s | 1.00 s | – | – |
| 15 | Over Current Stage 2 Delay | 0～120.00s | 0 to 120.00 s | 1.00 s | – | – |
| 16 | Over Current Stage 3 Delay | 0～120.00s | 0 to 120.00 s | 1.00 s | – | – |
| 17 | Zero Voltage Stage 1 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 5.00 s | – | – |
| 18 | Zero Voltage Stage 2 Protection Delay | 0.1～120.00s | 0.1 to 120.00 s | 5.00 s | – | – |
| 19 | Reserved | 0.1～120.00s | 0.1 to 120.00 s | 5.00 s | – | – |
| 20 | Reserved | 0.1～120.00s | 0.1 to 120.00 s | 5.00 s | – | – |
| 21 | Low Frequency Start-up Setting Value | 45.00～50.00Hz | 45.00 to 50.00 Hz | 49.50 Hz | – | – |
| 22 | Low Frequency Stage 1 Protection Setting Value | 45.00～50.00Hz | 45.00 to 50.00 Hz | 49.00 Hz | – | – |
| 23 | Low Frequency Stage 2 Protection Setting Value | 45.00～50.00Hz | 45.00 to 50.00 Hz | 48.50 Hz | – | – |
| 24 | Over Frequency Stage 1 Protection Setting Value | 50.00～55.00Hz | 50.00 to 55.00 Hz | 51.00 Hz | – | – |
| 25 | Over Frequency Stage 2 Protection Setting Value | 50.00～55.00Hz | 50.00 to 55.00 Hz | 52.00 Hz | – | – |
| 26 | Frequency Change Rate (Blocking Setting Value), df/dt2 | 0.00Hz/s～20.00Hz/s | 0.00 Hz/s to 20.00 Hz/s | 1.00 Hz/s | – |
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Outline and Installation Dimensions
FAQ
Q：In what types of projects are system separation protection devices primarily used?
A:System separation protection devices are primarily used in power generation projects, such as hydroelectric, thermal, and photovoltaic power plants. In the event of a fault on the generation side, these devices immediately isolate the faulty section to ensure the safety of the power grid.
Q：Where are system separation protection devices typically installed?
A:System separation protection devices are typically installed in parallel and are mainly located in the secondary distribution rooms of substations; however, they may sometimes be installed on high-voltage switchgear for grid connection depending on specific requirements.
xiao zhang –
This separation relay monitors grid voltage & frequency deviation, rapidly splits small power sources from main grid during system fault. Flexible threshold setup and multi communication for distributed PV, wind and captive power plants.
Jack –
Event records are stored reliably even after a complete power loss.