小型风力机电能质量评价指标及影响因素研究

Study on evaluation and influencing factors of power quality for small wind turbines

文章以一系列小型风力发电机为研究对象,拟采用以DH5902为主的数据采集分析系统对其电信号数据进行采集并依据IEC标准和国家标准计算其电能质量指标,研究预得到电能质量评价指标和其影响因素,为改善小型永磁风力发电机电能质量提供切实依据。研究表明:风力发电机低转速超负荷运行易引起电压波动和偏差、频率偏差和功率因数下降,然而转速过高易造成三相不平衡度增大,故在限制风机转速的同时优化负荷是提升电能质量的必要举措;再者,电能质量各指标受槽形和每极每相槽数影响较大,优化齿槽结构对提升发电机电能质量较为重要;此外,发电机绝缘老化和退磁使得气隙磁场谐波含量增大,会导致谐波畸变、电压偏差、频率偏差等多项电能质量指标恶化。

This study order a series of small wind turbines as the research object. The data acquisition and analysis system especially DH5902 is adopt to collected electrical data, and according to IEC standards and national standards the indexes of power quality are calculated. The study would give the evaluation indexes of power quality and its influencing factors, so that the practical basis can be provided for power quality improvement of small permanent magnet wind turbines. It has shown that the low speed or overload operation can lead to voltage fluctuation and deviation, frequency deviation and power factor drops. However, excessive speed operation also easily lead to three-phase imbalance.Therefore, limited speed and load is reasonably necessary for power quality optimization. Furthermore,the slotted profiles and the number of per pole per phase slots has large impact on each indexes of power quality, optimizing cogging structure is more important for improve generator power quality. In addition, the insulation ageing and demagnetization make the harmonic content of gap magnetic field increases, so that the wave distortion, the voltage deviation,the frequency deviation and a number of power quality indicators have worsened.