r 1 = r 3 1 * r 12/(r 12+R23+r 3 1)，r 12 =(r 1r 2+r2r 3+r3r 1)/R3

R2 = r 12 * R23/(r 12+R23+r 3 1)，？ r23 =(r 1r 2+r2r 3+r3r 1)/r 1

R3 = R23 * r 3 1/(r 12+R23+r 3 1)，r 3 1 =(r 1r 2+r2r 3+r3r 1)/R2

The formula is as follows:

Orangutans put on briefs and compare the sum of the three products;

The orangutan took off his underwear, and the product ratio of both sides was three.

Star trigonometric transformation is a circuit transformation, which can be completed by Kirchhoff's law. The three phases of star circuit are: r 1, r2, R3; The three phases of the triangular circuit are R 12, R23 and R 13 respectively.

Kirchhoff's law is the basic law of voltage and current in the circuit, and it is the basis of analyzing and calculating complex circuits. It was put forward by German physicist G.R. Kirchhoff (1824 ~ 1887) in 1845. Kirchhoff's law includes Kirchhoff's current law (KCL) and Kirchhoff's voltage law (KVL).

Kirchhoff's law can be used to analyze DC circuits, AC circuits and nonlinear circuits containing electronic components.

References:

Kirchhoff Law-Baidu Encyclopedia