Hello,welcome to smartelecmfg
Contact us Merchants settle in
Recommend the best quality products to customers
Recommended Products
Data download More
Quality supplier More
industry news More
Three IEC International Standards for Electrical Relays Led by China Have Been Officially Released!
IEC 63522-6:2025 Electrical Relays – Tests and Measurements – Part 6: Contact Circuit Resistance (or Voltage Drop); IEC 63522-35:2025 Electrical Relays – Tests and Measurements – Part 35: Resistance to Cleaning Agents,IEC 63522-36:2025 Electrical Relays – Tests and Measurements – Part 36: Fire Hazard,Issuing Body: International Electrotechnical Commission (IEC)
2025/07/07
Protection Relay
Why Are GuoWei ZhiChuang’s Protective Relays So Popular Among Global Users?
GuoWei ZhiChuang’s protective relays have gained widespread popularity among global users due to their advantages in technological innovation, reliability, market adaptability, and policy support. Here is a detailed analysis:
2025/07/03
Generator Comprehensive Protection Relay Side View
Which Countries Globally Lack the Capability to Develop protection relays?
Based on search results, the global research and development (R&D) capabilities in the relay industry are unevenly distributed. Many countries still rely on imports or lack independent R&D capabilities for high-end relays (such as high-voltage, high-reliability, aerospace/military-grade relays). Below is an overview of countries or regions with limited or no capability to develop protective relays:
2025/06/25
Public Measurement and Control Device Side View
History of Global protection Relay
protection relays originated from simple fuses in the late 19th century. In 1901, the induction-type overcurrent relay was introduced, followed by ASEA (now ABB) launching the first time-delay overcurrent relay, TCB, in 1905, enabling graded protection. The current differential protection principle was proposed in 1908, and directional protection emerged in the 1910s.
2025/06/23
technical knowledge More
GWZC-9886 Generator Backup Protection Relay
Working principle, function, and setting calculation for the generator 100% stator earth fault protection.
Generator 100% stator earth fault protection overcomes traditional coverage limitations by combining two complementary methods. The third-harmonic voltage principle monitors the neutral-to-terminal voltage ratio to detect faults near the neutral, triggering when this ratio falls below a typical threshold of 0.3-0.5. Simultaneously, the low-frequency injection method introduces a 20Hz signal to measure insulation resistance across the entire winding, operating if resistance drops below pre-set thresholds (typically 1-5 kΩ). This dual approach ensures complete stator coverage without dead zones, provides high sensitivity for kΩ-range faults, and offers redundancy. Protection settings are derived from security margins applied to measured normal operating parameters, including harmonic voltage ratios and maximum unbalanced voltage, making it essential for large generator security.
2025/07/07
Line protection relay Side View
The working principle, function, and setting calculation of zero-sequence voltage protection.
Zero-sequence voltage protection is a vital protection scheme in power systems specifically designed for ground faults, particularly single-phase-to-ground faults. It is widely employed in systems with an ungrounded neutral, a neutral grounded via an arc-suppression coil (Petersen coil), or a low-resistance grounded neutral. The following provides a detailed explanation from three aspects: principle, function, and setting calculation.
2025/07/04
GWZC-9811 Line protection relay
Operating Principle, Function, and Setting Calculation of Instantaneous Overcurrent Protection
Instantaneous Overcurrent Protection (IOCP) is a protection scheme used in power systems to rapidly clear short-circuit faults. Its defining feature is zero intentional time delay (or minimal delay), with typical operating times of 20–50 ms, complying with IEC 60255-151 (Overcurrent Protection Standards) and IEEE C37.91 (Guide for Protection Relay Applications).
2025/07/03
GWZC-9000 Substation Automation Monitoring and Control System
What are the differences between the Modbus, 103, 104, and 61850 communication protocols?
Modbus, IEC 60870-5-103, IEC 60870-5-104, and IEC 61850 are widely used communication protocols in the fields of power systems and industrial automation. They exhibit significant differences in design objectives, architecture, data models, and application scenarios. Below is a detailed comparative analysis of them.
2025/07/03
home product email
live chat
my