Design of an omnidirectional PD UHF antenna for substation inspection robot considering installation circumstance

The omnidirectional antenna mounted on the substation inspection robot is an important device for PD detection in substation. In addition to the requirements such as wide operating frequency band, directional pattern covering detecting area and large gain, this antenna must also consider the requirements of practical application circumstance. On the one hand, the fact that antenna is operated on a mobile robot gives the requirements about the size and weight of the antenna. On the other hand, type selecting and parameters adjusting of antenna must consider the effects on antenna performance caused by the metallic environment of installation position. This paper designed and optimized a dual polarized planar antenna with the inverted-cone structure based on the requirements of PD detecting omnidirectional antenna in substation. In the bottom half of the antenna, cross - orthogonal trapezoidal plates are used to build up the inverted-cone structure to achieve the “up-warp” in the antenna E-plane radiation pattern, and the size of the bottom of the antenna is reduced by using a bottom circular plate with the outward-dipping edge. It can receive the PD electromagnetic wave signal sensitively, which meets the design requirements of the installation circumstance on inspection robot and PD detection in the entire substation.