Integrating protection, measurement, and communication, the Generator Protection Relay Panel can realize the protection and control of various units, enabling unattended or minimally attended operation. It can achieve generator differential protection, rotor earth fault protection, stator earth fault protection, excitation protection, overcurrent protection, overvoltage protection, overload protection, backup protection, etc.

Transformer Protection Relay Panel is primarily used in automation systems for substations and distribution stations in power systems of 11kV, 33kV, 132kV and above. Its main function is to ensure that the transformer can promptly trip the faulty circuit in case of overload, short circuit, gas relay activation, and other abnormal operating conditions, thereby protecting the main transformer from damage and preventing the expansion of faults.

Feeder protection relays are a type of line protection relay and serve as critical devices in distribution systems for protecting power cables (feeders). They integrate multiple protection functions to achieve comprehensive, reliable, and selective protection. Below are the commonly used protection functions of feeder protection relays, along with their corresponding ANSI codes.

The working principle of the Transformer Differential Protection Relay is based on Kirchhoff's Current Law. This law states that the sum of currents entering a node is zero. Ideally, for a healthy (non-faulted) transformer, the current entering the primary winding should equal the current leaving the secondary winding (after accounting for the transformer's turns ratio and phase shift).

Capacitor Unbalance Voltage Protection is used to monitor the voltage distribution among individual units within a capacitor bank, particularly in series-connected banks. Its operating principle is based on Kirchhoff's Voltage Law and capacitor voltage division. Under normal operating conditions, the voltage across each unit in the bank is relatively balanced, resulting in a minimal unbalance voltage. When a capacitor unit fails (e.g., internal short circuit, open circuit, or performance degradation), the voltage distribution becomes unequal, generating a significant unbalance voltage.

Capacitor unbalanced current protection is a critical technology in power systems used to detect and protect against internal faults within capacitor banks. It operates by monitoring the changes in unbalanced current at the neutral point or bridge circuit of the capacitor bank, promptly isolating faults to prevent their escalation.

Our company supplies motor protection relays capable of integrating all the aforementioned functions. We provide comprehensive technical support and customized solutions. Please contact us for detailed product information and procurement inquiries.

Motor differential protection serves as the primary protection for internal short-circuit faults in medium-to-high capacity motors (typically above 2000 kW or 6 kV). Its operating principle is based on Kirchhoff's Current Law.

   In our previous session, we covered the working principle, function, and setting calculation of generator Underfrequency Protection. Today, we will discuss the working principle, function, and setting calculation of generator Underfrequency Protection, as detailed below: Generator Overfrequency Protection, internationally standardized under ANSI/IEEE C37.2 as code 81O, operates on the core principle of continuously monitoring the AC voltage frequency at the generator terminals or the point of interconnection.

Generator Underfrequency Protection, internationally standardized under ANSI/IEEE C37.2 as code 81, operates on a core principle of continuously monitoring the AC voltage frequency at the generator terminals or at the station auxiliary bus. Relationship between Frequency and Speed: For a synchronous generator, the output electrical frequency f is directly proportional to the rotor speed N and the number of pole pairs P (f = (P * N) / 120). Therefore, a decrease in system frequency directly indicates a decrease in the prime mover (turbine) speed, signifying that the mechanical input power is less than the electrical output power, putting the generator in a motoring condition.