The reduction of reactive energy becomes necessary as a way for the efficient use of electrical energy, mainly in industrial activities. To reduce this undesired energy, it is necessary to correct the power factor, which results in an increase of the active energy of the electric system. Some loads, applied in the circuits of the company, generate harmonic currents, as for example the inverters of frequencies used in the electric motors, and the harmonics distort the voltage. These distortions, depending on the impedance, may result in resonance of the capacitors, with system inductances, and damage these capacitors, among other problems. To solve the resonance, detuning inductors are installed serially with the capacitors.