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This paper presents a theoretical line loss calculation of distribution network containing an uncertainty power of wind turbine. First, this paper establishes the theoretical line loss mathematical model considering wind turbine power constraint within the sampling period. Then this paper gets multi group wind turbine output data satisfied the power constraints through Monte Carlo simulation. By combining with the first power coefficient method and Monte Carlo simulation technique, this paper also generates multi groups load pseudo measurement test of non real time. By combining the real-time measurement of power flow calculation, a group of simulated data with minimum error between the power flow results and the real time measurement are selected. Finally based on the selected pseudo measurement, the theoretical line loss within the given time period based on periodic accumulative calculation of real-time measurement are calculated. 14 nodes example is given to verify the accuracy and practicality of the algorithm.

Accurate Partial discharge (PD) detection and location is of great significance for the power cable insulation condition monitoring. To achieve this, an adequate cable model to analyze pulse propagation is needed. Considering the complex structure of the cable, the equivalent circuit model is no longer applicable. In this paper a numerical electromagnetic method, FDTD, is applied. To analysis wave propagation characteristics in time domain, a well-established cable model is constructed. By simulating the electromagnetic (EM) field propagation inside the cable and the cable joint, the components of the electric fields excited by the PD source in different directions are calculated in order to evaluate the influence of the cable joint in practice, the calculated PD waveforms in the cable are compared with those of the cable joint model in FDTD.

Assessing the insulation condition of high-voltage transformers is essential for repairing and maintaining based on condition of equipment. For the instant diagnostic examination of PD with oil-paper insulated transformers, basically physical method directly related to PD is currently used electric signals. Based on advanced sensor technology, PD detectors with enhanced options for discriminating disturbances were carried out on-site and on-line. PD values condition changes of the insulation system can early be identified and evaluated with simple trending. Consequently, PD monitoring and diagnosis systems allow conditioned based maintenance strategies, serve asset appraisements and permit continuous risk assessment. The reliability and safety of the HV equipment and the system operation of the power network can be increased. The application of on-line and on site PD diagnosis of power transformers in service is a powerful tool to detect defects in the coil insulation. The approach with long term monitoring with remote access through substation communications or the web is important for the lifetime management of ageing transformers The techniques are described, together with cased studies of their application on the engineering practice field.