微电网黑启动中考虑DG特性与线路投入顺序的串行恢复策略

制定合理的孤立微电网黑启动恢复策略对于加快微电网的恢复进程、减少事故损失具有重要意义。提出了一种适用于微电网黑启动的串行恢复策略。首先分析了分布式电源(Distributed Generation,DG)与大电网中传统火电机组所不同的特性,在此基础上建立了基于变异系数法的DG黑启动能力评估模型,并用于选取黑启动电源。然后以线路重要度和节点重要度作为网架重构的指标,建立了网架重构优化模型,并采用遗传算法进行求解。在求解出目标网架后,以单位时间内恢复发电量最大为目标,进一步确定线路的投入顺序。最后通过算例的分析及结果验证了所提方案的有效性。

Comparison of Characteristics of Periodic and Non-Periodic Defected Ground Structures

The filter characteristic of defected ground structure (DGS) is analyzed and the equivalent circuit of C-shaped DGS is extracted. The characteristics of non-periodic and periodic DGS with different dimensions are compared. Then the DGS is simulated and optimized with software, and the circuit board is manufactured and measured.The non-periodic structure is simple in structure and small in size and ripple compared with the periodic structure.Though the stop band of the non-periodic structure is narrow, it can meet the requirement of application. The C-shaped structure with two stop bands can select frequency in a special band.

DDS信号源在扫频测试中的应用

电子设计中经常碰到的问题是对待测电路（DUT）传输特性的测试．这里所说的传输特性包括增益和衰减、幅频特性、相位特性和时延特性等，而最常见的就是DUT的幅频特性。