Development of poynting vector sensor

It is customary to use voltage and current transformers already present in the TPS system to determine power distribution in AC systems. As these components are normally only present at a limited number of locations, detailed recordings are hampered and have limited resolution. With the increasing interest in energy efficiency of power distribution in traction power supply systems, this is becoming a bottleneck in optimising railway systems. A new and innovative contactless sensor has been developed to determine the power transported over the catenary. This sensor determines the energy flow from the electrical and magnetic fields. Therefore the name Poynting Vector Sensor is adopted. The sensor measures the time derivatives of catenary current and voltage with a Rogowski-coil and a capacitive sensor, respectively. Current and voltage waveforms are restored by active integration at the receiving end of the signals. This approach takes full advantage of the excellent EMC properties of the Differentiating/Integrating (D/I) principle required for measurement in the harsh EM-environment typical for railway systems. The bandwidth of both voltage and current measurements ranges from power frequency to typically a few hundred kHz. The sensor can be mounted on an existing catenary pole, or alternatively on a separate catenary pole. The sensor can be applied on 15 kV/16.7 Hz systems as well as on 25 kV/50 Hz systems, for conventional and high speed lines. The sensor consists of an oval grounded screen containing the Rogowski-coil & monitoring system which can be fitted around the messenger wire. The grounded screen protects the sensor against over voltage in case of a lightning strike or a broken catenary, which might come in contact with the sensor. An active monitoring system is incorporated, allowing for a continuous remote check of proper functioning without the need of accessing the sensor itself. The mounting system also supports two capacitor plates for the voltage measurement. The design of the entire set-up is modular to facilitate easy mounting. This reduces the time needed for installation. Normally, one interdiction for either mounting or dismounting is sufficient