Generator-Transformer Differential Protection Relay Product Introduction:

          The ​GWZC-9887 Generator-Transformer Differential Protection Relay​ is designed for differential protection of small to medium-sized generator-transformer units with capacities up to ​10MW. It provides ​high-speed fault detection, ​selective tripping, and ​secure operation​ for generator and transformer windings. Suitable for ​hydropower plants, ​industrial power systems, and ​distributed generation facilities, this relay can be ​panel-mounted in centralized protection panels​ or ​deployed in decentralized switchgear cabinets​ near the protected equipment. Its compact design ensures reliable performance in diverse installation environments while maintaining compliance with industry protection standards.

Generator-Transformer Differential Protection Relay Product functions（ANSI）：

1.Instantaneous Differential Protection (ANSI 87H)
2.Percentage Differential Protection (ANSI 87)
3.Differential Current Alarm (ANSI 87A)
4.CT Open-Circuit Detection (ANSI 87B)
5.Main Tank Buchholz Alarm (ANSI 71M)
6.Main Tank Buchholz Trip (ANSI 71M)
7.OLTC Buchholz Alarm (ANSI 71T)
8.OLTC Buchholz Trip (ANSI 71T)
9.Temperature Rise Alarm (ANSI 38)
​10.Overtemperature Trip (ANSI 49)
​11.High Oil Level Alarm (ANSI 71O)
12.Low Oil Level Alarm (ANSI 71O)
​13.Pressure Relief Device (ANSI 63PR)
​14.Thermal/Hydraulic Fault (ANSI 27/81U)
​15.Excitation System Fault (ANSI 40)

Electrical Specifications​

​Power Supply:​​

● AC: 85-264V, 47-63Hz (≤15% THD)
● DC: 100-370V (≤5% ripple)

​Rated AC Parameters:​​

● Voltage: 100V/√3 or 100V
● Current: 5A/1A
● Frequency: 50Hz

​Overload Capacity:​​

● Current Circuit: 2×In continuous | 10×In (10s) | 40×In (1s)
● Voltage Circuit: 1.5×Un continuous

​Power Consumption:​​

● Supply: <10W (static), ≤15W (trip)
● Current Circuit: ≤1VA/phase (5A) / ≤0.5VA/phase (1A)
● Voltage Circuit: ≤0.5VA/phase

​Digital Output:​​

● Dry contact (8A@250VAC / 30VDC)
● Dielectric: 4kVAC (coil-contact), 1kVAC (open contact)
● Operating Time: 5ms (typ) / 8ms (max)
● Mechanical Life: 100k operations

​Protection Performance​

​Operating Range:​​

● Voltage: 0.5-120V (phase)
● Current: 0.02-20×In
● Zero-Seq Current: 0.05-20A
● Frequency: 35-65Hz | Delay: 0-100s

​Accuracy:​​

● Voltage/Current: ±2.5% or ±0.1V/±0.05A (whichever greater)
● Frequency: ±0.01Hz
● Settings: ±2.5%

​Trip Time:​​

● Instantaneous: ≤35ms (≥1.2× setting)
● Time-Delayed: ≤1% of setting or 35ms

​Measurement & Monitoring​

​Range:​​

● Voltage: 0.5-120V | Current: 0.02-1.2×In

​Accuracy:​​

● V/I: ±0.2% | Frequency: ±0.01Hz | Other: 0.5%
● Time Sync: ≤2ms | SOE: ≤1ms

​Event Recording:​​

● 128 protection trips/operations
● 32 self-tests/fault waveforms (COMTRADE)

​Environmental & Mechanical​

​Operating Temp:​​

● Standard: -10°C to +55°C
● Extended: -40°C to +70°C*

​Storage Temp:​​ -40°C to +80°C
​Humidity:​​ 5-90% RH (non-condensing)
​Pressure:​​ 60-110 kPa
​Compliance:​​

● IEC 60255-21 (vibration/shock)
● IEC 61000-6 (EMC)