METHOD FOR COMBINED PROTECTION OF ALTERNATING CURRENT MACHINES AGAINST INTER-WINDING FAULTS IN STATOR WINDING Russian patent published in 2021 - IPC H02K11/00 H02H7/08 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, to devices for relaying protection of alternating current machines from inter-winding faults (IWF) in the stator winding. According to the proposed method, the formation of a control action on the shutdown of the machine is carried out with a decrease in the IWF coefficient relative to the operation setpoint. The actual value of the IWF coefficient function is corrected by calculating the damaged generator model and calculating the IWF coefficient in emergency mode. Compliance with the balance of the equations of equilibrium of e.m.f and the voltage drop at the terminals of the machine is monitored, and if the error threshold is exceeded, a signal is generated that blocks the protection operation. There is parallel simulation of the operation of the machine with the calculation of the compared values, which are taken as reference values in the process of operation. The adaptive properties of the algorithm are manifested in automatic adjustment during the actual determination of the IWF coefficient, using both physically measured parameters of the machine and indirect ones obtained through simulation, as a result, it is possible to identify damage up to one winding. The principle of combined protection is detuned from external unbalanced modes and in combination with the well-known method for transverse differential protection of the generator has high sensitivity and reliability of operation, and makes it possible to determine the place of damage and the quantitative value of the damage.

EFFECT: increasing sensitivity of protection against inter-winding faults in the stator winding and expanding the field of application due to the possibility of using it in AC machines with an unsplit stator winding.

1 cl, 1 dwg