以一起220 k V主变压器保护装置发电压互感器(TV)异常告警为例,说明三次谐波超标是引起装置TV异常的原因之一。经过进一步分析得出,当TV中性点装有消谐器时,消谐器会产生电压并在TV零序开口三角上显现出三次谐波,进而引起主变压器保护...以一起220 k V主变压器保护装置发电压互感器(TV)异常告警为例,说明三次谐波超标是引起装置TV异常的原因之一。经过进一步分析得出,当TV中性点装有消谐器时,消谐器会产生电压并在TV零序开口三角上显现出三次谐波,进而引起主变压器保护装置发TV异常告警。针对该类异常告警提出了解决对策,以确保变电站内主设备安全稳定运行。展开更多
In the case of SV- or SH-wave oblique incidence,the reflection and refraction of the second-order bulk waves resulting from a plane boundary between two solid media are investigated and the mathematical expressions of...In the case of SV- or SH-wave oblique incidence,the reflection and refraction of the second-order bulk waves resulting from a plane boundary between two solid media are investigated and the mathematical expressions of them are given.It is shown that an SH-wave incidence is absolutely necessary to an overall knowledge of the relationship between the TOEs for isotropic solid.The importance of both contributions of the nonaccumulation waves and the effects of the boundary surface are indicated by numerical computation.展开更多
In the light of the theory of second-order potentials in nonlinear acoustics proposed by the author, this paper investigates the second-order harmonics resulting from an incident bulk wave in a solid with a plane boun...In the light of the theory of second-order potentials in nonlinear acoustics proposed by the author, this paper investigates the second-order harmonics resulting from an incident bulk wave in a solid with a plane boundary when the P, SV and SH waves are incident. It is shown that several bulk waves of the second-order harmonics occur in solid media besides second-order surface waves. Some of the waves are accumulated and some waves propagate in the direction parallel to the boundary surface. In order to obtain enough expressions for all the third-order elasticity constants, an SH-wave incidence is necessary in addition to the P and SV wave ones. It is pointed out that the contribution of the nonaccumulative waves and the waves resulting from the boundary surface are very important for measuring the nonlinear wave fields.展开更多
文摘以一起220 k V主变压器保护装置发电压互感器(TV)异常告警为例,说明三次谐波超标是引起装置TV异常的原因之一。经过进一步分析得出,当TV中性点装有消谐器时,消谐器会产生电压并在TV零序开口三角上显现出三次谐波,进而引起主变压器保护装置发TV异常告警。针对该类异常告警提出了解决对策,以确保变电站内主设备安全稳定运行。
基金Project supported by the National Natural Science Foundation of China
文摘In the case of SV- or SH-wave oblique incidence,the reflection and refraction of the second-order bulk waves resulting from a plane boundary between two solid media are investigated and the mathematical expressions of them are given.It is shown that an SH-wave incidence is absolutely necessary to an overall knowledge of the relationship between the TOEs for isotropic solid.The importance of both contributions of the nonaccumulation waves and the effects of the boundary surface are indicated by numerical computation.
基金Project Supported by the National Natural scierice Foundation of China
文摘In the light of the theory of second-order potentials in nonlinear acoustics proposed by the author, this paper investigates the second-order harmonics resulting from an incident bulk wave in a solid with a plane boundary when the P, SV and SH waves are incident. It is shown that several bulk waves of the second-order harmonics occur in solid media besides second-order surface waves. Some of the waves are accumulated and some waves propagate in the direction parallel to the boundary surface. In order to obtain enough expressions for all the third-order elasticity constants, an SH-wave incidence is necessary in addition to the P and SV wave ones. It is pointed out that the contribution of the nonaccumulative waves and the waves resulting from the boundary surface are very important for measuring the nonlinear wave fields.
