Adenomyosis and hysteromyoma are common gynecological diseases in clinic, which can occur in adolescent women and perimenopausal women. Especially, women aged between 30 and 50 years old are high-risk groups. In gener...Adenomyosis and hysteromyoma are common gynecological diseases in clinic, which can occur in adolescent women and perimenopausal women. Especially, women aged between 30 and 50 years old are high-risk groups. In general, the clinical symptoms of patients with adenomyosis are mainly manifested as increased menstrual flow, prolonged menstrual period, and increased dysmenorrhea. At present, the disease of uterine glands is also one of the important causes of female infertility. The clinical manifestations of hysteromyoma are very similar to those of uterine gland diseases, especially when ultrasonic examination is performed. It is easy to be confused. In this study, the imaging characteristics of adenomyosis and hysteromyoma in ultrasonic examination were analyzed in depth and the differential value of ultrasonic examination was summarized.展开更多
The DC bias will lead to maloperation of the second harmonic restraint when entering the power system,which causes the failure of transformer differential protection.Therefore,this paper explores the impact of DC bias...The DC bias will lead to maloperation of the second harmonic restraint when entering the power system,which causes the failure of transformer differential protection.Therefore,this paper explores the impact of DC bias on differential protection and proposes a DC bias detection algorithm based on harmonic components.Firstly,the theoretical mechanism by which DC bias causes transformer differential protection failure is analyzed,exploring the influence of different magnitudes of DC bias and different fault types on differential protection.Subsequently,under the conditions of DC bias or inrush current,this study simulated the root mean square(RMs)value and phase angle characteristics of the second harmonic of transformer differential current,and established a DC bias detection algorithm using two criteria:RMS value identification and phase angle identification.When the algorithm detects DC bias,it will block the second harmonic restraint to ensure the normal operation of differential protection during internal transformer faults.The proposed method is validated through simulations using typical protection failure scenarios,demonstrating its effectiveness in resolving the refusal issue of transformer differential protection under DC bias conditions.展开更多
文摘Adenomyosis and hysteromyoma are common gynecological diseases in clinic, which can occur in adolescent women and perimenopausal women. Especially, women aged between 30 and 50 years old are high-risk groups. In general, the clinical symptoms of patients with adenomyosis are mainly manifested as increased menstrual flow, prolonged menstrual period, and increased dysmenorrhea. At present, the disease of uterine glands is also one of the important causes of female infertility. The clinical manifestations of hysteromyoma are very similar to those of uterine gland diseases, especially when ultrasonic examination is performed. It is easy to be confused. In this study, the imaging characteristics of adenomyosis and hysteromyoma in ultrasonic examination were analyzed in depth and the differential value of ultrasonic examination was summarized.
基金supported in part by the National Natural Science Foundation of China(No.51977173)Northwest Branch of State Grid Corporation of China(SGNW0000DKJS2310091).
文摘The DC bias will lead to maloperation of the second harmonic restraint when entering the power system,which causes the failure of transformer differential protection.Therefore,this paper explores the impact of DC bias on differential protection and proposes a DC bias detection algorithm based on harmonic components.Firstly,the theoretical mechanism by which DC bias causes transformer differential protection failure is analyzed,exploring the influence of different magnitudes of DC bias and different fault types on differential protection.Subsequently,under the conditions of DC bias or inrush current,this study simulated the root mean square(RMs)value and phase angle characteristics of the second harmonic of transformer differential current,and established a DC bias detection algorithm using two criteria:RMS value identification and phase angle identification.When the algorithm detects DC bias,it will block the second harmonic restraint to ensure the normal operation of differential protection during internal transformer faults.The proposed method is validated through simulations using typical protection failure scenarios,demonstrating its effectiveness in resolving the refusal issue of transformer differential protection under DC bias conditions.
