The classification of reverse power relays is mainly based on their operating principles, which can be summarized into three main types: amplitude comparison type, phase comparison type and cosφ type. Each type of relay has its unique working mechanism to adapt to different grid protection needs. For example, the amplitude comparison type determines the power grid status by comparing the amplitude difference of current or voltage; the phase comparison type works based on the difference in current or voltage phase; and the cosφ type relay performs its protection function based on changes in power factor. .
In the field of generator reverse power protection, the debugging of these relays is particularly important, because the stable output of the generator has a direct impact on the balance of the power grid. In the process of debugging reverse power relays, technicians face many challenges. First, the accuracy of the test equipment is extremely high, which requires the test equipment to accurately output power frequency currents, and the test instruments must be able to accurately reflect these tiny currents and their Phase change, the phase error is controlled within 0.2°. In addition, the test of the relay's sensitive angle and operating characteristics is also a key part of the debugging process. The accuracy of the sensitive angle needs to be controlled within ±1°, and the measurement of the operating current needs to accurately reflect the reverse power operating status of the generator. This is important for The accuracy and reliability of test methods have put forward higher requirements.
In the test of the relay operating characteristics, special emphasis is placed on measuring the relay's operating current at a specific phase point to ensure accurate response under the generator's reverse power operating state. This is very different from the general test method of directional relays. In addition, the return coefficient of the relay is another important indicator for evaluating its performance. Its value should not be greater than 0.7 to ensure that the relay can avoid malfunctioning when unnecessary. Finally, other test projects of reverse power relays also need to follow certain standards and methods to ensure the stability and safety of the entire power grid system.