±500 kV同塔双回线路杆塔空气间隙操作冲击放电特性试验研究

在海拔2 100 m和50 m地区对±500 kV同塔双回线路杆塔空气间隙的操作冲击放电特性进行试验研究,在实验条件下,获得了上、下层间隙的50%放电电压曲线,验证了下横担的存在对上层空气间隙的操作冲击放电特性无明显影响。基于两种海拔高度试验结果对比,提出了海拔2 100 m及以下地区的海拔校正方法和校正系数,进而给出了当操作过电压标幺值取1.6时,不同海拔高度下所要求的杆塔上、下层空气间隙的最小允许距离。成果已用于指导溪洛渡右岸电站送电广东±500 kV同塔双回直流输电工程的外绝缘设计。     

±660kV直流输电带电作业安全距离的试验研究

宁东-山东±660kV直流输电示范工程是世界首条±660kV电压等级直流输电工程,结合工程实际,在详细介绍试验条件的基础上,对各种工况下的带电作业安全距离进行试验研究,并根据不同作业位置安全距离的放电特性,结合线路相地过电压倍数,计算得到海拔2000m以下地区±660kV直流输电线路带电作业最小安全距离和最小组合间隙。...     

Experimental Studies on Impulse Flashover Characteristics of Tower Head Air Gaps of±1 000 kV DC Transmission Lines and

The ± 1000 kV DC transmission line represents a new voltage level. In order to guarantee the design reliability and rationality, the air clearance selection is very important and needs to be researched...     

云南—广东特高压直流输电线路孤岛运行方式下过电压水平及其影响因素(英文)

Overvoltage is one of the key factors influencing whether Yunnan-Guangdong UHVDC Project can be operated in Islanded Mode or not.Based on the on-site test parameters of primary equipments and the actual control and protection system of the project,this paper performs calculations of the overvoltage level in islanded operation models.The influence of BLOCK process and load retard speed of Yunnan-Guangdong UHVDC on the overvoltage level in islanded mode is also studied.The results show that it is an important measure for suppressing the overvoltage level to switch off the converter transformer after ac filters have been switched off.The maximum per unit switching overvoltage is 1.71(reference value is 449 kV) under various fault conditions.The maximum transient overvoltage is 1.66(reference value is 318 kV),but its duration is short.The maximum transient recovery voltage across AC filter/capacitor bank circuit breakers is less than 1 300 kV.The arrester’s absorption energy in the case of a bipolar BLOCK can be greatly reduced with the protection logic modified with respect to decreasing current characteristic,which was compared with the protection logic of direct load retard.It is favorable for the reduction of both,overvoltage and arrester’s absorption energy,to lower the force retard speed in the case of bipolar ESOF command.     

向家坝—上海±800kV特高压直流输电工程中直流电压分压器故障分析(英文)

Transient DC voltage measurement error has been observed several times ever since Xiangjiaba-Shanghai ±800 kV UHVDC project started its commercial operation.The measurement error causes considerable disturbances to the AC networks.By analyzing the time frequency record,simulating faults at different positions of the divider,and testing the gas in voltage dividers,the fault is located and then is proved to be some partial discharges inside DC voltage dividers.The reason of the internal flashes and the solution to the problem is also discussed in this paper.The conclusion is that instead of N2,SF6 should be used for the internal insulation of high voltage DC voltage dividers.     

±800kV 直流系统用棒形支柱瓷芯复合绝缘子研究

介绍了机械固定用±800kV棒形支柱瓷芯复合绝缘子的设计、计算、制造、试验等试制情况。根据产品的使用特点,对高温硫化硅橡胶伞套材料配方进行了改进与完善;采用"ANSYS"三维有限元对金属附件进行了分析论证;对水泥胶合剂和硅橡胶与瓷芯棒用粘接剂进行了一系列的摸索研究;通过对绝缘子的电场分布计算,优化了绝缘子的整体结构设计和均压环配置;同时,进行了特高压输电系统用支柱绝缘子的结构抗震稳定性计算。试验结果表明,产品通过了所要求的23项定型试验。     

±800 kV直流系统用耐污型户外棒形支柱瓷绝缘子研究

介绍了±800 kV直流系统用耐污型户外棒形支柱瓷绝缘子的设计、试制情况。根据产品特点进行了优化设计:每柱绝缘子由六节元件通过螺栓连接组成;每节元件由瓷件组成,金属附件由高强度水泥胶合剂胶装而成;伞形采用大小伞交替、伞下无棱形式。对特高压系统用支柱绝缘子的结构抗震稳定性进行了计算,结果表明,可满足九度地震烈度地区。     

高压直流换流站阀厅双层屏蔽巡视走道应用研究

目的  为了减小高压直流换流站阀厅占地面积并降低投资成本,提出了一种适用于高压直流换流站阀厅的双层屏蔽巡视走道方案。 方法  在借鉴1100kV昌吉—古泉特高压直流输电工程首次应用双层屏蔽巡视走道的成功经验,以及国内科研单位开展的试验结果基础上,针对阀厅内不同巡视走道方案开展经济性对比,验证本方案的经济性。 结果  结果证明文章提出的双层屏蔽巡视走道方案具备一定的优势。 结论  文章提出的一种高压直流换流站阀厅采用双层屏蔽巡视走道的具体实施方案,并在某工程的阀厅中得以成功应用,具备推广价值。     

δ±01含量法在生产实际中的应用

探讨在原煤可选性评定过程中 ,遇到特殊煤质的原煤 ,不能单凭所求得的± 0 1含量的数值进行其可选性的评定 ,而应该具体问题具体分析 ,并借助经验公式进行验证 ,修正初始评定结果 ,从而实现其可选性的准确定位。