Reliability-Oriented Assessment and Design Towards Energy system integration with offshore Renewables (ROADsTER)

未来的能源转换系统要求具有较高的可靠性和效率。这在海上风电中尤为重要，因为这些系统的位置越来越偏远，维护起来也越来越复杂和昂贵，而且海上风电在英国未来能源方案中的份额也越来越大。然而，在这些应用中，电源转换器是产生受控电力的关键使能器，许多研究证明，它是这些系统中最脆弱的部件之一，也是维护成本和停机时间的主要来源。为了提高海上风电场变流器的可靠性，建立风电场级变流器的可靠性模型并对其进行优化是至关重要的。这项工作的关键假设是，通过对海上风电场的功率变流器进行主动热管理，不仅包括单个变流器，还包括它们之间由于尾流效应而产生的相互作用，有可能提高系统的整体可靠性并对其进行主动管理。例如，通过智能降额组件（例如，开关）或转换器（涡轮机）的降额，其寿命消耗将减少，因此，通过适当的系统控制，将有可能将压力从压力较大的转换器转移到压力较小的转换器，并优化系统的整体可靠性并积极管理它。此外，有可能协调电力转换器的运行，以实现最佳维护计划，例如，通过增加更多转换器可以继续运行的可能性，直到下一次计划的预防性维护。因此，本项目提出了以下解决方案：(1)实时风电场级别评估和可靠性监测；(2)海上风电场电源变流器的主动可靠性增强和寿命管理。值得注意的是，由于尾流效应，风力涡轮机的运行是相互关联的，因此某台涡轮机的功率处理能力的降低并不一定意味着产生的总功率会减少，实际上它甚至可能会增加。因此，本课题在多目标优化问题中同时考虑可靠性和发电量的优化。

Future energy conversion systems are required to have high reliability and efficiency. This is particularly important in offshore wind due to the increasingly remote locations and complicated and costly maintenance for these systems, as well as the increasing share of offshore wind in UK's future energy scenarios. However, power converters which are the key enablers for producing a controlled electrical power in these applications, are proven by numerous studies to be one of the most fragile parts of these systems and a major source of maintenance cost and downtime. To improve the reliability of power converters in offshore wind farms, it is vital to be able to model the reliability of power converters at wind farm level and optimise it. This work's key hypothesis is that by active thermal management of power converters of an offshore wind farm, incorporating not only the individual converters but the interactions between them due to the wake effect, it is possible to improve the overall reliability of the system and manage it actively. For example, by intelligent derating of a component (e.g., a switch) or derating of a converter (turbine), its lifetime consumption will decrease, therefore by proper control of the system it will be possible to shift the stress from the more-stressed converter to the less-stressed ones and optimise the overall reliability of the system and manage it actively. Moreover, it would be possible to coordinate the operation of power converters for an optimal maintenance plan, for example, by increase the likelihood that more converters can continue their operation until the next planned preventive maintenance. This project therefore proposes solutions for (1) real-time wind farm level assessment and monitoring of reliability, and (2) active reliability enhancement and lifetime management of power converters in offshore wind farms. It is important to note that given the interlinked operation of wind turbines due to wake effect, a reduction in the power handling capability of a particular turbine does not necessarily mean that the overall power generated will decrease, and in fact it may even increase. Therefore, this project considers the optimisation of both reliability and power generation in a multi-objective optimisation problem.