A simple formula for calculating the frequency-dependent resistance of a round wire

The high‐frequency phenomenon of copper clad aluminum wires which are lower the alternating current resistance than copper solid wires, and the application of copper clad aluminum wires to the electrical equipment

“…Therefore, AC resistance R CUac at radius r e in copper conductor is as follows 5 $$$$\begin{eqnarray} \hspace*{-12pt} {R_{CUac}} &=& {\rho _{cu}}/\pi {{\delta ^{\prime}}_{cu}}(2{r_e} - {{\delta ^{\prime}}_{cu}})\nonumber\\ &=& \frac{{{\rho _{cu}}}}{{\pi {\delta _{cu}}(1 - {e^{ - {r_e}/{\delta _{cu}}}})\left[ {2{r_e} - {\delta _{cu}}(1 - {e^{ - {r_e}/{\delta _{cu}}}})} \right]}}.$$…”

“…Therefore, AC resistance R CUac at radius r e in copper conductor is as follows. 5 𝑅 𝐶𝑈𝑎𝑐 = 𝜌 𝑐𝑢 ∕𝜋𝛿 ′ 𝑐𝑢 (2𝑟 𝑒 − 𝛿 ′ 𝑐𝑢 )…”

Modelling, Analysis, and Design of a Line-Start Permanent Magnet Synchronous Motor

“…However, a round cross-section is considered a reasonable choice for the sake of simplicity, and in double-cage SCIMs it is often employed for the external one dedicated to improve the start-up capability of the machine. The rotor bars equivalent resistances are dependent on rotor frequency f r , and their value is estimated as proposed in [21] for round bars. The A matrix relates the loop currents īr with the bar currents ībar .…”

The impact of lightning strike to multi‐blade on the lightning overvoltage and stresses of arresters in offshore wind farm

“…In order to study the travelling-wave properties of lightning current propagating in the blade correctly, the copper down conductor is divided into numerous segments according to Equation ( 2). Each segment of down conductor can be represented by a π-type R-L-C equivalent circuit, as shown in Figure 2, where the blade length l b is 75 m. The resistance R bi (i = 1, 2, 3…n) of each blade segment is calculated by [25]:…”

“…The resistance R bi ( i = 1, 2, 3… n ) of each blade segment is calculated by [25]: where Δ l b is the length of each blade segment, σ b is the copper material conductivity, r b is the radius of the copper down conductor and δ is the skin depth, given as: where μ b is the copper material relative permeability, μ 0 is the permeability of free space. The inductance L bi ( i = 1, 2, 3… n ) of each blade segment at high frequency is calculated as follows [26]: …”