METHOD OF DETERMINING COMPLEX VALUE OF TECHNICAL LOSSES OF FULL POWER IN POWER THREE-PHASE TWO-WINDING TRANSFORMERS USED IN URBAN AND INDUSTRIAL POWER SUPPLY SYSTEMS Russian patent published in 2024 - IPC G01R21/133 

FIELD: power supply systems.

SUBSTANCE: invention relates to power supply systems, in particular to a method of determining a complex value of technical losses of full power in power three-phase two-winding transformers. Based on the transformer nameplate data, the rated current in the high voltage (HV) winding is calculated, active, total and inductive resistance of windings of power three-phase double-winding transformer, active and inductive resistance of HV winding and reduced active and inductive resistance of dissipation of winding of low voltage (LV), rated current of idle run (IR) are calculated. Using the value of rated current of IR, the total active, total and inductive resistance of the magnetization branch and the scattering branch of the HV winding of the transformer are calculated. Further, knowing the values of active and inductive resistances of the dispersion branch of the HV winding, the active and inductive resistances of the magnetization branch are found. Using the measuring instruments installed in the input cell, the LV supply bus of the transformer substation (TS), to which the final consumer of electrical energy (load) is connected, for each of three phases and for each harmonic component, starting from 1st to 40th, values of active power consumed by the load connected to the transformer, current strength in the LV winding of the transformer and the load and voltage at the terminals of the LV winding of the power three-phase two-winding transformer and the load, active, total and reactive (inductive) resistances from 1st to 40th harmonic components of the load are calculated for each phase connected to the terminals of the low-voltage transformer winding. Given the transformation ratio, the reduced active, reactive and complex impedances are found for each harmonic component of the load of each phase connected to the terminals of the low-voltage transformer. Knowing the previously calculated parameters of the T-shaped equivalent circuit of the transformer phases, for each harmonic component of each phase conditionally constant coefficients are calculated A_{1 ν}, A_{2 ν}, A_{3 ν}, B_{1 ν}, B_{2 ν}, B_{3 ν}, C_{1 ν}, C_{2 ν}, C_{3 ν}, D_{1 ν}, D_{2 ν}, D_{3 ν}. Using their values, as well as the values of the reduced active, total and reactive resistances for each harmonic component of the load of each phase, complex values of total power losses in transformer phases are calculated for each νharmonic component. By summing them, the complex value of total losses of full power in each phase of the transformer is found taking into account additional losses from higher harmonic components. By adding complex values of total losses of full power, calculated for each phase, complex value of technical losses of full power in power three-phase two-winding transformer is calculated taking into account additional losses from higher harmonic components.

EFFECT: higher accuracy.

1 cl, 9 dwg