What is the purpose of the governor in an elevator system?

The purpose of the governor in an elevator system is to monitor the speed of the elevator car and activate safety brakes if the car moves at an unsafe speed. The governor serves as a vital safety device designed to ensure that the elevator operates within its specified speed limits. If the elevator exceeds these limits, the governor triggers the safety brakes to stop the car quickly and safely, thereby preventing accidents and maintaining passenger safety. This function is crucial for protecting users and ensuring the elevator's operation adheres to safety standards.

The other options, while related to elevator operation, do not represent the primary function of the governor. Energy efficiency management, weight limit control, and door operation regulation are handled by other systems and components within the elevator system, making the governor specifically focused on speed monitoring and safety.