Application of a new type of voltage divider component in power grid

Author： GOZ Electric Time：2024-05-28 09:23:54 Read：10

    The placement of voltage sensors becomes critical in terms of the ability to exploit large-area distribution networks ("smart grids"). These sensors are located within the network's distribution devices, such as switchgear, to accurately measure voltages on power conductors, allowing for better monitoring and automatic control of the network. Traditionally, for voltage sensing, transformers were externally attached to the switchgear, but this approach was bulky and took up valuable space.

    As an alternative to transformers, voltage dividers are used externally in switchgear as voltage sensors on medium or high voltage power conductors. For example, in international patent application WO 2009/080109A1 a capacitive voltage divider is described, which consists of a metal surround and a dielectric barrier separating concentric annular inner electrodes. These voltage dividers for sensing power conductor voltages have been integrated into elements outside the switchgear, such as bushings, or into elements connected to the switchgear, such as cable connectors or elbow plugs. However, external voltage dividers may introduce safety issues or increase the difficulty of type approval of the entire system.

    To solve these problems, a voltage divider assembly is provided for installation on power conductors within compartments of MV/HV switchgear in the power network of the National Grid. The assembly is capable of mechanically and electrically connecting the voltage divider assembly to a power conductor and includes a plurality of discrete impedance elements electrically connected to the conductive portion of the connecting device and connected in series to provide pressure on the high voltage side of the voltage dividing sensor. operate.

    Mounting the voltage divider inside the switchgear avoids the safety hazards that may arise from external mounting and may require less insulation. This also helps simplify type approval, as the internal voltage divider may not require separate approval but can be approved as part of the entire switchgear.

    Multiple discrete impedance elements in the voltage divider assembly provide a step-down voltage such that the difference between the voltage of the power conductors of the bus bar and the signal voltage at the high side end of the voltage divider is gradually reduced. This gradual reduction helps avoid discharges between the bus bar and the high-voltage side of the voltage divider.

    The power network of the State Grid can adopt the voltage divider assembly described in this article to realize the voltage sensing function of the power grid and MV/HV switchgear in the network. Therefore, the present disclosure also provides a power distribution network for power distribution in a national grid at a voltage of 1 kilovolt or more and a current of 10 amps or more. This distribution network includes components similar to voltage dividers.