A new neutral active grounded compensation system based on dual inverters is developed to solve some problems existing in passive arc-suppression coils

for example

active component and harmonic of grounded fault current are not compensated so that residual current is not limited within the standard range

and arc grounding overvoltage is easy to occur. The system is composed of a measurement and control system and a compensation system. When the distribution network is in normal operation

the fundamental and active component of grounded fault current is to be measured and then calculated out through asymmetric voltage method and constant frequency injection method. When single-phase earthing fault occurs

zero-sequence current at neutral point is detected then its harmonic is calculated out. And the compensation system is quickly switched on to output compensation current. The compensation system is mainly composed of dual inverters

which are used to compensate fundamental

active component and harmonic of grounded fault current

so as to realize the full compensation and the zero residual current and to improve safety level of equipment and power supply reliability of distribution network. The computer simulations and inverter’s tests on the system verify its feasibility and effectiveness.