What is the purpose of series reactors in power systems?

The purpose of series reactors in power systems is primarily to keep fault levels within the capacity of switchgear. Series reactors are inductive devices connected in series with transmission lines, and they serve to limit the short-circuit currents that can flow during a fault condition. By increasing the total impedance of the circuit, series reactors effectively reduce the magnitude of fault currents, making it easier for circuit breakers and other protective devices to operate within their rated limits. This protection is crucial for ensuring the safety and reliability of the power system, as excessive fault currents can lead to equipment damage and operational failures.

While other options may describe functions related to power systems, they do not accurately encapsulate the main role of series reactors. For instance, boosting voltage levels is typically achieved through transformers rather than reactors, increasing inductance is a characteristic rather than a primary function, and filtering harmonics is typically the job of specialized harmonic filters, not series reactors.