The restriction of load power, two-valued regulation characteristic, and interference of several loads are observed in power supply systems with a limited capacity of voltage sources. In this paper, the definition of ...The restriction of load power, two-valued regulation characteristic, and interference of several loads are observed in power supply systems with a limited capacity of voltage sources. In this paper, the definition of regime in an invariant form through different parameters, of changes of transformation ratio and voltage load is grounded for these circuits with two loads. The approach for interpretation of changes or ＂kinematics＂ of load regime is presented by using the conformal and hyperbolic plane. To simplify the task and reveal the basic moments of influence of the limited source power, the static regulation characteristics and idealized models of voltage converters are considered. Geometrical interpretation of a simplified model of multichannel power supply system allows basing the definition of operating regime parameters. Results can be useful for electric circuit theory education and for voltage coordinated control of given loads. Non-Euclidean geometry is a new mathematical apparatus in the electric circuit theory, adequately interprets ＂kinematics＂ of circuit, and provides a validation for the introduction and definition of the proposed concepts. From the methodological point, the presented approach is applied for a long time in other scientific domains, as mechanics and biology.展开更多
When the line impedance is considered in the microgrid, the accuracy of load sharing will decrease. In this paper, the impact of line impedance on the accuracy of load sharing is analyzed. A robust droop control for a...When the line impedance is considered in the microgrid, the accuracy of load sharing will decrease. In this paper, the impact of line impedance on the accuracy of load sharing is analyzed. A robust droop control for a highvoltage microgrid is proposed based on the signal detection on the high-voltage side of the coupling transformer. For a high-voltage microgrid, the equivalent impedance of coupling transformer connecting distributed generator with the grid is usually the dominate factor. Compared with the conventional droop control strategy, the proposed control method in this paper detects the feedback signal from the high-voltage side of the coupling transformer. The impact of line impedance on the load sharing accuracy can be mitigated significantly. The proposed droop control only changes the detection point of the feedback signal, thus it is easy to be implemented. The PSCAD/EMTDC simulation results show the effectiveness of the proposed robust droop control concept in load sharing and voltage regulation with highly accuracy.展开更多
电力用户负荷种类的多样化造成变压器电压波动超出允许范围,严重影响电力系统的供电质量,因此提出基于奇异值分解的配电变压器有载自动调压方法。基于奇异值分解技术提取配电变压器分接头间的电压信号,使用比例积分微分(Proportion Inte...电力用户负荷种类的多样化造成变压器电压波动超出允许范围,严重影响电力系统的供电质量,因此提出基于奇异值分解的配电变压器有载自动调压方法。基于奇异值分解技术提取配电变压器分接头间的电压信号,使用比例积分微分(Proportion Integral Differential,PID)控制算法根据分接头间电压和额定电压范围之间的偏差输出控制信号,控制触发分接开关的导通与关断,实现配电变压器的有载自动调压。实验结果表明,设计方法可以通过控制分接开关位置维持电压的平稳,且不会对负载产生不利影响。展开更多
文摘The restriction of load power, two-valued regulation characteristic, and interference of several loads are observed in power supply systems with a limited capacity of voltage sources. In this paper, the definition of regime in an invariant form through different parameters, of changes of transformation ratio and voltage load is grounded for these circuits with two loads. The approach for interpretation of changes or ＂kinematics＂ of load regime is presented by using the conformal and hyperbolic plane. To simplify the task and reveal the basic moments of influence of the limited source power, the static regulation characteristics and idealized models of voltage converters are considered. Geometrical interpretation of a simplified model of multichannel power supply system allows basing the definition of operating regime parameters. Results can be useful for electric circuit theory education and for voltage coordinated control of given loads. Non-Euclidean geometry is a new mathematical apparatus in the electric circuit theory, adequately interprets ＂kinematics＂ of circuit, and provides a validation for the introduction and definition of the proposed concepts. From the methodological point, the presented approach is applied for a long time in other scientific domains, as mechanics and biology.
基金supported by the National Natural Science Foundation of China(No.51207048)the National High Technology Research and Development of China(No.2014AA052601)Higher National Excellent Doctoral Dissertation of Special Funds(No.201441)
文摘When the line impedance is considered in the microgrid, the accuracy of load sharing will decrease. In this paper, the impact of line impedance on the accuracy of load sharing is analyzed. A robust droop control for a highvoltage microgrid is proposed based on the signal detection on the high-voltage side of the coupling transformer. For a high-voltage microgrid, the equivalent impedance of coupling transformer connecting distributed generator with the grid is usually the dominate factor. Compared with the conventional droop control strategy, the proposed control method in this paper detects the feedback signal from the high-voltage side of the coupling transformer. The impact of line impedance on the load sharing accuracy can be mitigated significantly. The proposed droop control only changes the detection point of the feedback signal, thus it is easy to be implemented. The PSCAD/EMTDC simulation results show the effectiveness of the proposed robust droop control concept in load sharing and voltage regulation with highly accuracy.
文摘电力用户负荷种类的多样化造成变压器电压波动超出允许范围,严重影响电力系统的供电质量,因此提出基于奇异值分解的配电变压器有载自动调压方法。基于奇异值分解技术提取配电变压器分接头间的电压信号,使用比例积分微分(Proportion Integral Differential,PID)控制算法根据分接头间电压和额定电压范围之间的偏差输出控制信号,控制触发分接开关的导通与关断,实现配电变压器的有载自动调压。实验结果表明,设计方法可以通过控制分接开关位置维持电压的平稳,且不会对负载产生不利影响。
