The invention relates to a 
pilot frequency heavy-current multifunctional grounding parameter testing 
system based on a variable frequency power supply, belonging to a testing device of a grounding parameter of a 
transformer substation ground network. The 
system mainly comprises a variable frequency 
power supply unit and a boosting 
transformer unit, wherein the variable frequency 
power supply unit is formed by connecting two pushoff amplification 
type variable frequency power supplies in parallel, and the rated input 
voltage of each variable frequency power supply adopts a 380V+ / -10 percent and 50Hz three-phase 
alternating current, and outputs continuous and adjustable sine 
waves between 0V and 350V; and output frequency is continuous and adjustable between 20Hz and 30Hz; the boosting 
transformer unit consists of a boosting transformer, a primary coil of the boosting transformer is connected with two output ends of the variable frequency 
power supply unit, and a secondary coil of the boosting transformer is connected with the ground network of the transformer substation; and the rated volume of the boosting transformer is 15kVA, the output 
voltage is 200V, 400V, 600V, 800B or 1,000V, and the preset frequency is 20-300Hz. The 
system has the characteristics of strong 
ant-jamming capacity and high measurement accuracy.