Sizes and formula symbols used
- Constants
- \(\mu _{\mathrm {0}}\)
- magnetic constant \(\mu _{\mathrm {0}}=1,256\,637\,062\cdot 10^{-6}\,\frac {\mathrm {Vs}}{\mathrm {Am}} \approx 4\pi \cdot 10^{-7}\,\frac {\mathrm {Vs}}{\mathrm {Am}}\)
- Units
- A
- Ampere - electric current
- H
- Henry - inductance \(\mathrm {H}=\frac {\mathrm {V}\cdot \mathrm {s}}{\mathrm {A}}=\frac {\mathrm {kg}\cdot \mathrm {m}^2}{\mathrm {s}^2\cdot \mathrm {A}^2}\)
- kg
- Kilogram - mass
- m
- Meter - length
- N
- Newton - force \(\mathrm {N}=\frac {\mathrm {kg}\cdot \mathrm {m}}{s^2}\)
- s
- Second - time
- T
- Tesla - magnetic flux density \(\mathrm {T}=\frac {\mathrm {V}\cdot \mathrm {s}}{\mathrm {m}^2}=\frac {\mathrm {kg}}{\mathrm {s}^2\cdot \mathrm {A}}\)
- V
- Volt - voltage \(\mathrm {V}=\frac {\mathrm {W}}{\mathrm {A}}=\frac {\mathrm {J}}{\mathrm {C}}=\frac {\mathrm {N}\cdot \mathrm {m}}{\mathrm {A}\cdot \mathrm {s}}=\frac {\mathrm {kg}\cdot \mathrm {m}^2}{\mathrm {s}^3\cdot \mathrm {A}}\)
- W
- Watt - active power \(\mathrm {W}=\frac {\mathrm {J}}{\mathrm {s}}=\mathrm {A}\cdot \mathrm {V}=\frac {\mathrm {kg}\cdot \mathrm {m}^2}{\mathrm {s}^3}\)
- Wb
- Weber - magnetic flux \(\mathrm {Wb}=\mathrm {V}\cdot \mathrm {s}=\frac {\mathrm {kg}\cdot \mathrm {m}^2}{\mathrm {s}^2\cdot \mathrm {A}}\)
- Symbols
- \(\omega _\mathrm {r}\)
- rotor angular frequency \(\frac {1}{\mathrm {s}}\)
- \(\omega _\mathrm {s}\)
- synchronous angular frequency of the supply network \(\frac {1}{\mathrm {s}}\)
- \(\vartheta \)
- pole angle of the synchronous machine \(\circ \)
- \(L_\mathrm {h}\)
- main inductance of a transformer
- \(L_\sigma \)
- leakage inductance of a transformer
- \(M_\mathrm {K}\)
- tipping moment (breakaway torque) of the induction motor Nm
- \(n\)
- rotational speed \(\frac {1}{\text {min}}\)
- \(p\)
- number of pole pairs
- \(s\)
- slip of the induction motor
- \(s_\mathrm {K}\)
- critical slip (breakaway slip) of the induction motor
- \(\delta \)
- penetration depth in the conductor due to the skin effect (skin depth) \(\mathrm {m}\)
- \(\rho _{\mathrm {R}}\)
- specific resistivity \(\frac {\Omega \cdot \mathrm {mm}^2}{\mathrm {m}}\)
- \(\varPhi \)
- magnetic flux Wb
- \(\varTheta \)
- magnetomotive force A
- \(A\)
- area \(\mathrm {m}^2\)
- \(B\)
- magnetic flux density T
- \(d\)
- distance in the magnetic core m
- \(F\)
- force N
- \(f\)
- frequency Hz
- \(H\)
- magnetic field strength \(\frac {\mathrm {A}}{\mathrm {m}}\)
- \(I\)
- electric current (steady) A
- \(\vec {J}\)
- current density \(\frac {\mathrm {A}}{\mathrm {m}^2}\)
- \(\ell \)
- length m
- \(\ell _{\mathrm {m}}\)
- mean magnetic path length of a coil m
- \(L\)
- inductance H
- \(M\)
- torque \(\mathrm {Nm}\)
- \(m\)
- mass kg
- \(N\)
- abstract count (e.g., number of turns of a coil) \(1\)
- \(P\)
- active power W
- \(R_{\mathrm {m}}\)
- magnetic reluctance \(\frac {\mathrm {A}}{\mathrm {V}\cdot \mathrm {s}}\)
- \(t\)
- time s
- \(U\)
- voltage (steady) V
- \(u\)
- voltage (time-varying) V
- \(v\)
- velocity \(\frac {\mathrm {m}}{\mathrm {s}}\)
- \(W\)
- work \(\mathrm {J}\)
- \(W\)
- energy J