Voltage-Sensor-Less Synchronization to Unbalanced Grids by Frequency-Adaptive Virtual Flux Estimation
Voltage-Sensor-Less Synchronization to Unbalanced Grids by Frequency-Adaptive Virtual Flux Estimation
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DOI：
10.1109/tie.2011.2168793
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发表时间：
2012-07
影响因子：
7.7
通讯作者：
J. Suul;A. Luna;P. Rodríguez;T. Undeland
中科院分区：
文献类型：
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作者：
J. Suul;A. Luna;P. Rodríguez;T. Undeland
针对无电压传感器电网同步和电压源换流器控制问题，提出了一种简单的固有频率自适应虚拟磁链（VF）估计方法。频率自适应特性是通过使用二阶广义积分器配置为正交信号发生器（SOGI-QSG）与电网频率作为一个显式的输入变量。它还示出了如何可以利用SOGI-QSGs的基础上的VF估计的属性，以实现一个简单而有效的同步技术，集成频率自适应带通滤波，VF估计，和对称分量序列分离成一个操作。这种新方法避免了VF估计和序列分离的级联延迟，并且由于其基于两个并行的SOGI-QSG而被标记为基于双SOGI-VF（DSOGI-VF）估计。DSOGI-VF估计的属性和性能进行了分析，比较传统的配置的VF估计和序列分离，表明它是一个更简单的结构与改进的动态响应。实际上，实现了与基于电压测量的电网同步类似的响应时间。所提出的DSOGI-VF估计方法的操作和性能已经通过实验室实验在小规模转换器设置中进行了验证。
This paper proposes a simple method for inherently frequency-adaptive virtual flux (VF) estimation intended for voltage-sensor-less grid synchronization and control of voltage source converters. The frequency-adaptive characteristics are obtained by using a second-order generalized integrator configured as a quadrature signal generator (SOGI-QSG) with the grid frequency as an explicit input variable. It is also shown how the properties of VF estimation based on SOGI-QSGs can be utilized to achieve a simple and effective synchronization technique that integrates frequency-adaptive bandpass filtering, VF estimation, and symmetrical component sequence separation into one operation. This new method avoids cascaded delays of VF estimation and sequence separation and is labeled as dual SOGI-based VF (DSOGI-VF) estimation since it is based on two parallel SOGI-QSGs. The properties and performance of the DSOGI-VF estimation are analyzed in comparison to conventional configurations of VF estimation and sequence separation, demonstrating that it is a simpler structure with improved dynamic response. In fact, similar response time as for grid synchronization based on voltage measurements is achieved. The operation and performance of the proposed DSOGI-VF estimation method have been verified by laboratory experiments in a small-scale converter setup.