{'fraction_non_alphanumeric': 0.015138772077375946, 'fraction_numerical': 0.00336417157275021, 'mean_word_length': 5.01010101010101, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Use of Petri Nets to Model the Maintenance of Wind Turbines

With large expansion plans for the offshore wind turbine industry, there has never been a greater need for effective operations and maintenance. The two main problems with the current operations and maintenance of an offshore wind turbine are the cost and availability. In this work, a simulation model has been produced of the maintenance process for a wind turbine with the aim of developing a procedure that can be used to optimise the process. This initial model considers three types of maintenance—periodic, conditional and corrective—and also considers the weather in order to determine the accessibility of the turbine. Petri nets have been designed to simulate each type of maintenance and weather conditions. It has been found that Petri nets are a very good method to model the maintenance process because of their dynamic modelling and adaptability and their ability to test optimisation techniques. Because of their versatility, Petri net models are developed for both system hardware and the maintenance processes, and these are combined in an efficient and concise manner. Copyright © 2014 John Wiley & Sons, Ltd.