针对电力系统不对称负荷日益多样性的状况,将瞬时无功功率理论应用于提高功率因数和补偿三相不平衡的静止无功功率补偿装置(Static Var Compensator)控制之中,提出了一种基于新算法的SVC补偿控制方法。该算法以对称分量法为理论支撑,通...针对电力系统不对称负荷日益多样性的状况,将瞬时无功功率理论应用于提高功率因数和补偿三相不平衡的静止无功功率补偿装置(Static Var Compensator)控制之中,提出了一种基于新算法的SVC补偿控制方法。该算法以对称分量法为理论支撑,通过对负荷电流进行基波有功分量和无功分量的解耦,利用分离出的无功电流计算理想补偿导纳,简化了传统的不对称补偿算法。采用Matlab/Simulink对所提出的控制算法进行仿真建模,建立对晶闸管相控电抗器(TCR)并联电容型SVC的控制,仿真结果证明了所提方法的正确性和可行性。展开更多
近年来,由于电能质量引发的纠纷和电网事故呈上升趋势,而公共连接点(point of common coupling,PCC)的电压不平衡是由该点所连接的所有不对称负荷共同作用产生的,因此明确计算公共连接点所有不对称负荷分别在该点引起的电压不平衡度,对...近年来,由于电能质量引发的纠纷和电网事故呈上升趋势,而公共连接点(point of common coupling,PCC)的电压不平衡是由该点所连接的所有不对称负荷共同作用产生的,因此明确计算公共连接点所有不对称负荷分别在该点引起的电压不平衡度,对于明确各自的责任,解决供用电双方的矛盾,具有重要意义。提出了根据不对称负荷的电流不平衡度计算该不对称负荷在公共连接点引起的电压不平衡度的方法,基于LabVIEW环境编制了相应的计算程序,并在PSCAD搭建了不同的仿真模型,模拟在各种电压等级下连接不同负荷的情况,验证了所提方法的正确性和合理性。展开更多
According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. Acco...According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. According to the model, the stresses of three tunnels and single tunnel are calculated and compared to analyze the distribution characteristics, where the stresses are influenced by controlling factors of clear distance, covering depth and inclination angle of ground surface. The results show that, in general, the bias distribution is more serious. Therefore, it is significant to settle down the load model of three shallow tunnels so as to determine the measure of reinforcement and design the structure of support. The model and results can be used as a theoretical basis in designation and further research of the three shallow tunnels.展开更多
文摘针对电力系统不对称负荷日益多样性的状况,将瞬时无功功率理论应用于提高功率因数和补偿三相不平衡的静止无功功率补偿装置(Static Var Compensator)控制之中,提出了一种基于新算法的SVC补偿控制方法。该算法以对称分量法为理论支撑,通过对负荷电流进行基波有功分量和无功分量的解耦,利用分离出的无功电流计算理想补偿导纳,简化了传统的不对称补偿算法。采用Matlab/Simulink对所提出的控制算法进行仿真建模,建立对晶闸管相控电抗器(TCR)并联电容型SVC的控制,仿真结果证明了所提方法的正确性和可行性。
文摘近年来,由于电能质量引发的纠纷和电网事故呈上升趋势,而公共连接点(point of common coupling,PCC)的电压不平衡是由该点所连接的所有不对称负荷共同作用产生的,因此明确计算公共连接点所有不对称负荷分别在该点引起的电压不平衡度,对于明确各自的责任,解决供用电双方的矛盾,具有重要意义。提出了根据不对称负荷的电流不平衡度计算该不对称负荷在公共连接点引起的电压不平衡度的方法,基于LabVIEW环境编制了相应的计算程序,并在PSCAD搭建了不同的仿真模型,模拟在各种电压等级下连接不同负荷的情况,验证了所提方法的正确性和合理性。
基金Projects(2013CB036004, 2011CB013800) supported by the National Basic Research Program of ChinaProject(51178468, 50908234) supported by the National Natural Science Foundation of ChinaProject(2011G103-B) supported by the Science and Technology Development of Railway in China
文摘According to the interaction of three shallow tunnels with large section, the analytical solution to rock pressure has been derived and discussed. The load model is given when the bilateral tunnels are excavated. According to the model, the stresses of three tunnels and single tunnel are calculated and compared to analyze the distribution characteristics, where the stresses are influenced by controlling factors of clear distance, covering depth and inclination angle of ground surface. The results show that, in general, the bias distribution is more serious. Therefore, it is significant to settle down the load model of three shallow tunnels so as to determine the measure of reinforcement and design the structure of support. The model and results can be used as a theoretical basis in designation and further research of the three shallow tunnels.
