直流输电系统电阻器热时间常数及过负荷保护的研究

Research on Thermal Time Constant and Overload Protection ofResistors in DC Transmission Systems

直流输电系统电阻器可能在电网中过负荷运行,为保证电阻器能安全可靠运行,必须对其热特性及过负荷保护进行研究。首先通过理论计算得到了电阻器在各种工况(长期、短时、断续)下运行的热特性,然后结合试验数据和计算结果给出了电阻器综合散热系数与热时间常数,最后结合理论计算和实际试验结果,提出了适合于电阻器的过负荷保护方案,为电阻器的设计与过负荷保护提供了依据。

Resistors in DC power transmission system may be overloaded in the power grid.In order to ensure the safe and reliable operation of resistors,it is necessary to study the thermal characteristics and overload protection.Firstly,the thermal characteristics of the resistor under various working conditions(long-term,short-term and intermittent)were obtained by theoretical calculation.Then,combined with the test data and calculation results,the comprehensive heat dissipation coefficient and thermal time constant of the resistor were given.Finally,combining the theoretical calculation and practical test results,a suitable overload protection scheme for resistors was proposed,which provided a basis for the design and over-load protection of resistors.