Evaluation and optimization of insulation status test for primary heating network

To accurately understand the insulation status of primary heating pipe network in the Chengyin District of Daqing City, its present insulation status has been tested through the enthalpy drop method. The field test results, with the data processing, are compared and analyzed, which reveals that there are weak links in the insulation structure of the primary heating pipe network in the Chengyin area. Before the insulation structure is optimized according to the field conditions, which provides a basis and reference for testing the insulation status of the heating pipe network, and has a guiding significance for evaluating and optimizing the insulation structure of pipe network.

The Degree of Polymerization in a Prediction Model of Insulating Paper and the Remaining Life of Power Transformers

The aging of power transformers causes several defects and damages in the insulating system, especially in the insulating paper. The degradation of the insulating paper generates dissolved gases in the insulating oil, which are measured by gas chromatography and used as an indicator of the insulation status. The state of the insulating paper can be identified based on the degree of polymerization (DP) measurement. In some cases, when the measurement of DP is difficult, estimating DP can be accomplished through gathering information about some of the testing parameters, such as the dissolved gases (DGA), breakdown voltage (BDV), oil interfacial tension (IF), oil acidity (ACI), moisture content (MC), oil color (OC), dielectric loss (Tan δ), and furans concentration specifically (2-furfuraldhyde (FA)). The statistical tools (correlation and multiple linear regression), based on 131 transformer samples, can be used to build a relation linking DP and one or more of the previous parameters to identify the insulating paper status and the percentage of remaining life of the transformer. The results indicated that it is difficult to build a mathematical model to relate between the DP and the testing variables, except with FA, where the trend of DP with FA is more obvious than with other variables. The empirical formula to compute DP based on the FA concentration was developed and gave promising results to compute DP and the remaining life of the power transformers.

Application and Design of Inspection Robot System Based on Multi-parameter Hierarchical Inspection of UHV Substation

In this paper, a new substation inspection robot system is introduced, to meet the application requirements of multi-parameter full-station automatic hierarchical inspection of the insulation status of power equipment in UHV ( Ultra-High Voltage ) substation. The system is designed to control the inspection of substation robots, including identifying the number of meters on the cabinet, measuring partial discharge, measuring temperature and humidity and so on . The system is divided into two parts. One part runs in the robot body ,which is called the body control system , and it contains web server, robot ground control system and database. The other part runs on external industrial computer, which is called station control service system. The function of the body control system is more specific, mainly for controlling its own motor driver, in order to complete its own motion. The station control service system achieves important logic control, including configuring inspection plan, visual recognition, robot walking path planning, and writing inspection results into the database.

Unsupervised Monitoring System for Predictive Maintenance of High Voltage Apparatus

The online monitoring of a high voltage apparatus is a crucial aspect for a predictive maintenance program. Partial discharges (PDs) phenomena affect the insulation system of an electrical machine and—in the long term—can lead to a breakdown, with a consequent, significant economic loss; wind turbines provide an excellent example. Embedded solutions are therefore required to monitor the insulation status. The paper presents an online system that adopts unsupervised methodologies for assessing the condition of the monitored machine in real time. The monitoring process does not rely on any prior knowledge about the apparatus; nonetheless, the method can identify the relevant drifts in the machine status. In addition, the system is specifically designed to run on low-cost embedded devices.