摘要
春季雨季土壤湿度高,土壤电阻率降低,系统接地电阻变小;夏秋季高温干旱,土壤电阻率升高;冬季温度太低形成冻土层,土壤电阻率急速增加,系统接地电阻变大。建立了配电网终端农场的电网模型,研究不同气候环境下,接地电阻的变化对具体农业用户电能质量的影响。计算表明,当接地电阻变大时,农场电压幅值、有效视在功率变化量超过允许范围,电压总谐波畸变率、HRUh_(vs d,CP99)、THDU_(vs d,CP99)超过限值范围,极端气候时会更严重。当湿度增加、接地电阻变小时,农户电压会发生电压暂降,波形会随湿度变化而波动。
In spring and rainy season,the soil humidity is high,so the soil resistivity decreases and the system grounding resistance decreases.The high temperature and dry weather in summer and autumn lead to the increase of soil resistivity.In winter,the rather low temperature causes the formation of a frozen soil layer,resulting in the rapidly increment of soil resistivity,and the larger system grounding resistance.The power grid model of distribution network terminal farm is established in this paper to study the influence of the change of grounding resistance on the power quality of agricultural power grid under different climatic environments.The calculation shows that when the grounding resistance becomes larger,the farm voltage amplitude and effective apparent power change exceed the allowable range,and the total harmonic distortion rate,HRU_(h vs d,CP99),THD U_(vs d,CP99),exceed the limit range,which will be more serious in extreme weather.When the humidity increases and the grounding resistance decreases,the household voltage will undergo a voltage sag,and the waveform will fluctuate with the humidity change.
作者
熊志伟
林寿英
兰建容
XIONG Zhiwei;LIN Shouying;LAN Jianrong(College of Mechanical and Electrical Engineering,Fujian Agriculture and Forestry University,Fuzhou 350001,China)
出处
《电工技术》
2023年第17期217-220,共4页
Electric Engineering
基金
福建省教育厅中青年教师教育科研项目“乡村电网升级和乡村电气化关键问题解决方案的研究”(编号KLA19044A)。
