QVCO used for PLL Grid Voltage Reference

An essential issue in power electronics field is the limitation of power losses in the power supply grid. The distortions created by each consumer add up in the main network. The effect seen by customer is distorted mains voltage. The effects observed by the electric energy distribution operator consist in the increase of losses in the network (at the same active power, the supply current of the harmonic polluting consumer is higher than the supply current of the resistive consumer). For an efficient operation, the circuits used to compensate the over polluted grids need ideal reference signals. Starting from the idea of identifying a viable solution to this problem, this paper proposes a designing method and testing of a quadrature oscillator (QVCO) to provide the compensation circuit with the ideal necessary signal. The proposed circuit was designed and tested. The experimental results obtained during the QVCO testing show that the designed QVCO circuit provides a perfect reference sinusoidal signal, synchronous with the fundamental voltage of power supply network/grid.