Electrical apparatus and control system

In a system that receives power from an electric power grid, a variable frequency AC drive has an output connected to an AC electric motor, and an input connected to the power grid. The motor is in 1 connection with a load, and the AC drive includes an active converter having a predetermined maximum apparent power capacity. The converter is coupled to a controller programmed to regulate reactive power generation and consumption of the variable frequency AC drive so that the drive produces reactive power when the converter is utilizing less than its maximum apparent power capacity. This reactive power is fed to the power grid. A device monitors current and voltage in the power grid and calculates power factor, which is then used as a feedback to an external controller that generates a reactive power reference signal intended to control the system's power factor. The controller is programmed to respond to the signal, controlling power generation and consumption so that the combination of reactive power and real power does not result in apparent power exceeding the maximum capacity of the active converter and avoids generating reactive power that would result in a leading power factor for the system.