| Vdc |
DC link voltage |
| M |
Modulation index |
| f |
Frequency |
| fs |
Switching frequency |
| f1 |
Fundamental frequency |
| Vref |
Reference Voltage |
| n |
Level inverter |
| SL |
Lower switch |
| SU |
Upper switch |
| C1, C2, C3 |
Capacitors |
| Vao, Vbo, Vco |
Pole voltages |
| Vab, Vbc, Vca |
Line-to-line voltages |
| Va, Vb, Vc |
Line voltages |
| Van, Vbn, Vcn |
Phase voltages |
| Vno |
Common mode voltage |
| Iga, Igb, Igc |
Gate currents |
| Ia, Ib, Ic |
Stator currents of induction motor |
| Id, Iq |
d- and q-axis stator currents |
| Irms |
RMS current |
| ω |
Angular speed |
| ωm |
Rotor speed of induction motor |
| ∅ |
Flux |
| ma |
Amplitude modulation ratio |
| mf |
Frequency modulation ratio |
| dv/dt |
Change in voltage |
| Ta, Tb, Tc |
Switching times |
| Ts |
Sampling time |
| P, O, N |
Switching states of three-level inverter |
| A00, A01, A02 |
Vertices of two-level space vector diagram |
| (α00, β00), (α01, β01), (α 02, β02) |
Co-ordinates of the vertices |
| (a0 b0 c0), (a1 b1 c1), (a2 b2 c2) |
Switching states of two-level inverter |
| R1, R2, R3 |
Triangular regions of three-level inverter |
| AooP |
Reference space vector |
| m1, m2 |
Duty cycles of reference voltage vector |
| V1 |
Fundamental voltage |
| Vcarrier |
Carrier voltage |
| (α, β) |
Direct and quadrature axis |
| Vd |
Reference voltage vector d-axis component |
| Vq |
Reference voltage vector q-axis component |
| V1, V2, V3, V4, V5, V6 |
Voltage vectors |
| T0 T1, T2 |
Switching times |
| α |
Reference angle |
| TL |
Load torque |
| d1, d2, d3 |
Duty cycles of nearest voltage vectors |
| θ |
Angle of reference vector with zero axis |
| V* |
Reference voltage vector |
| V′0, V′1, V′2 |
Voltage vectors of two-level inverter |
| V1,N, V2,N, V3,N |
Voltage vectors of N-level inverter |
| t′0, t′1, t′2 |
Switching times of two-level inverter |
| t1,N, t2,N, t3,N |
Switching times of N-level inverter |
| T |
Sampling time |
| A2, A3, A4 |
Regions of three-level inverter |
| X, Y |
Classification of voltage vectors |
| λ1, λ2, λ0 |
Three dimension array |
| N |
Level of inverter |
| Ta1, Ta2, Ta3 |
Switching devices |
| S |
Hexagon number |
| V7* |
Reference vector of seven-level inverter |
| Vd7* |
d-axis component of seven-level voltage vector |
| Vq7* |
q-axis component of seven-level voltage vector |
| V4* |
Reference vector of four-level inverter |
| Vd4* |
d-axis component of four-level voltage vector |
| Vq4* |
q-axis component of four-level voltage vector |
| V3* |
Reference vector of seven-level inverter |
| Vd3* |
d-axis component of three-level voltage vector |
| Vq3* |
q-axis component of three-level voltage vector |
| V2* |
Reference voltage vector of two-level inverter |
