Determining of Fault Locations with Hilbert – Huang Transformation on XLPE Cables between Land and Offshore Substations

Using of mathematical transformations and digital signal processing (DSP) methods of recorded voltage and currents in power systems in order to extract important informations about physical processes is already known. Higher resolution of measurements and massive introduction of PMU devices in the power systems allows appliance of DSP - based fault location methods in complex power networks. High availability of power systems is required in the modern societies. Fast fault location algorithms and consequent fast repairing of faults is necessary condition for high availability of power networks. Here is represented a numerical procedure for fault location and testing of method already introduced in scientific literature on complex configuration of power network consisting of XLPE underground submarine and land cables between land and offshore substation connecting large wind park with main power system

Power line fault location using the Complex Space-Phasor and Hilbert-Huang Transform

Fault location finding in power system is very important problem in power system monitoring. Moreover, demand for high grid availability are crucial for TSO's contracts. Many scientific papers are published on mentioned theme, along with efforts in transmission and distribution system operators about improving fault location accuracy. Recently, signal processing methods like Wavelets and Hilbert-Huang Transform are introduced in fault location procedure. In this paper, a new approach to power system fault signal processing is proposed. Three-phase fault voltages are converted to the vector of absolute values of its complex-space phasor. This vector represents fault travelling wave and it is further processed for fault location finding with Hilbert-Huang transform. The simulation results show that proposed method allows better accuracy in comparison to earlier procedures

Determining of Fault Locations with Hilbert – Huang Transformation on XLPE Cables between Land and Offshore Substations

Using of mathematical transformations and digital signal processing (DSP) methods of recorded voltage and currents in power systems in order to extract important informations about physical processes is already known. Higher resolution of measurements and massive introduction of PMU devices in the power systems allows appliance of DSP - based fault location methods in complex power networks. High availability of power systems is required in the modern societies. Fast fault location algorithms and consequent fast repairing of faults is necessary condition for high availability of power networks. Here is represented a numerical procedure for fault location and testing of method already introduced in scientific literature on complex configuration of power network consisting of XLPE underground submarine and land cables between land and offshore substation connecting large wind park with main power system

Impact of Characteristics of Block-Transformers on Inrush Currents and Voltage Distortions at the Connection Point of Wind Parks

In the procedure of connecting large wind parks (WP) to the external power grid, TSO's or DSO's request is that WPs in operation do not excessively affect the power quality in the connection point. In the process of determining WP operating procedures it is necessary to include switching operations in the WP main feeder. The transformers connected near the wind generator units are then energized and a transformer inrush current appears, followed usually by voltage distortions. Those currents may cause nuisance tripping of protection devices and power quality problems in the WP connection point. For illustration, the connection to a real power grid of a large WP with twelve generators and block transformers is simulated. Considered network short circuit power is comparable to typical parameters of the transmission or distribution medium-voltage networks. Simulated inrush currents depend on the characteristics of connected devices in the network. Results of our study can be useful for correct protection relay device setting and determining optimal WP exploitation procedures