高导热绝缘漆的研制及其在低压电机上的应用

Preparation of High Thermal Conductive Insulating Varnish and Its Application in Low Voltage Motor

以不饱和聚酯改性环氧树脂为基体,采用硅烷偶联剂表面改性后的金刚石、碳化硅和氧化铝微粉为填料分别制备高导热绝缘漆,分析3种填料对绝缘漆的防沉淀性、导热系数、击穿电压和粘度的影响,采用3种改性填料复合制备了一种高导热绝缘漆,并在低压电机的整机上进行应用试验。结果表明:加入未改性填料的绝缘漆易产生沉淀现象,而加入硅烷偶联剂表面改性填料的绝缘漆储存稳定性好,不易沉淀;添加改性后的金刚石、碳化硅和氧化铝微粉填料后的绝缘漆,其导热系数随微粉含量的增加均有所提高、电气强度随微粉含量的增加而降低、粘度随微粉含量的增加而增大;3种改性填料复合使用制备的高导热绝缘漆导热系数可达0.432W/(m·K),粘度69 s,电气强度23.4 MV/m。电机温升同比下降7 K,电机效率提高0.97%。

Using epoxy resin modified by unsaturated polyester as matrix, using diamond, silicon carbide, and alumina powder modified by silane coupling agent as filler respectively, we prepared high thermal conductive insulating varnishes. The effect of three kinds of filler on the precipitation, coefficient of ther-mal conductivity, breakdown voltage, and viscosity of the insulating varnish were studied. By considering different factors comprehensively, we prepared a high thermal conductive insulating varnish using the mix-ture of three modified fillers as filler, and its application experiment in low voltage motor was conduct-ed. The results show that the insulating varnish containing unmodified filler would precipitate easily, and the insulating varnish containing modified powder would not precipitate easily and has good storage stabil-ity. With the increase of the filler content, the coefficient of thermal conductivity of the insulating var-nish containing modified diamond, silicon carbide, and alumina powder increases, the breakdown voltage reduces, and the viscosity increases. The thermal conductivity coefficient of the insulating varnish contain-ing the mixture of three modified fillers attains 0.432 W/（m·K）, the viscosity is 69 s, and the breakdown voltage is 23.4 MV/m. The temperature rise of motor decline 7 K compared to the past, and the motor ef-ficiency increases by 0.97%.