【作者】 马献鸿；

【导师】 同向前；

【作者基本信息】 西安理工大学 ， 电力电子与电力传动， 2005， 硕士

【摘要】 基于正弦脉宽调制电压源逆变器(SPWM_VSI)结构的静止同步补偿器是一种新型无功补偿装置,它具有发出容性无功功率和吸收感性无功功率的双向补偿功能。本文研究了在平衡负荷和不平衡负荷条件下配网静止同步补偿器(DSTATCOM)的控制方法。首先,本文分析了DSTATCOM的工作原理,建立了控制角单变量控制、控制角与调制深度协调控制下的数学模型和控制系统结构,设计了DSP为核心的控制系统。 在理论分析的基础上,通过实验探讨了DSTATCOM的控制策略,比较了不同控制策略下DSTATCOM的动态性能。实验结果表明,采用控制角与调制深度相结合的双变量协调控制具有更好的动态性能。在经典PI控制中引入前馈环节,进一步提高了装置的响应速度。实验装置从输出容性(感性)额定无功功率切换到感性(容性)无功功率的调节时间不到两个工频周期。 本文探讨了在负荷不对称条件下的控制策略,提出了根据负序电压瞬时值调整PWM脉宽的负序电流补偿方法。该方法有效地补偿了负荷的负序电流,并且响应速度快。更多还原

【Abstract】 DSTATCOM based on voltage source converter is a new type of reactive power compensator, which can generate or draw reactive power from the power network. The main object of this paper is to deal with the control strategy of DSTATCOM used in distribution system under balanced loads and unbalanced loads. First, the principle of DSTATCOM is analyzed in detail. By theoretical analysis, the mathematic model based on the variables ( δ , λ ) is modeled, which reflects the characteristics of DSTATCOM. Then, on the basis of this model, the control way of SPWM-based DSTATCOM is investigated, and the dynamic performance of DSTATCOM with different control strategies is compared. The experimental results show that the co-control of control angle and modulation index has better dynamic characteristics. A forward link added to the classic PI controller improves dynamic response, and the regulating time of the tested device from the rated leading var (lagging var) to lagging var (leading var) is less than two cycles. Last, the control strategy of DSTATCOM under the unbalance loads is investigated. The compensation way with the instantaneous value of negative-sequence voltage to adjust the pulse width of balance compensation gains good characteristics, which can compensate negative-sequence current caused by loads effectively and quickly.更多还原