Design of Nanosecond-Level Transient Electric Field Sensor and Its Application in HVDC Converter Station

In this letter, a nanosecond-level transient electric field (E-field) sensor based on a monopole electrically small rod antenna is proposed. The working principle and design process of the sensor are analyzed in detail while a finite-element simulation is carried out to verify the response characteristics of the sensor both in time and frequency domains, whose upper cut-off frequency can reach 680 MHz. For the purpose of assessing the actual detection capability of the sensor in HVDC converter stations, the sensor designed in this letter was used to detect the transient radiation E-field in the valve hall during the artificial short-circuit test in the Zhoushan +/- 200-kV five-terminal flexible dc transmission project. The measurement results of the transient E-field indicates that the sensor is able to respond instantaneously to the radiated E-field generated by the operation of the key power electronic equipment in the valve hall. It demonstrates that the designed sensor can be effectively applied in the scenario of the measurement of transient electromagnetic environment and noninvasive situational awareness technology for high-voltage devices in HVDC systems.