Midpoint potential compensation balance control method based on virtual space vector pulse‐width modulation for NPC three‐level inverter

Abstract

The neural‐point‐clamped (NPC) three‐level inverters exhibit a midpoint potential unbalance problem. With the analysis on the midpoint potential fluctuation, its voltage vectors are discussed, and the mathematical model of the midpoint current in each sector is established. Based on virtual space vector pulse‐width modulation (VSPWM) calculated in the gh coordinate, a balance control method is proposed to compensate the midpoint potential. The virtual medium vector and voltage adjustment factor are introduced. Different positive and negative short vectors are distributed to different adjustable parameters to improve the influence of short vectors on the midpoint potential. The experimental results show that the proposed method balances the midpoint potential effectively, and VSVPWM with the gh coordinate can reduce the complexity of the calculation.

A review on technological aspects of different PWM techniques and its comparison based on different performance parameters

“…From Figure 1B, it can be observed that along the line AB the fundamental is zero. But out of different combination of (α 1 ,α 2 ) leading to zero fundamental, points (A) and (B) perform best as the tripplen order harmonics cancels out at those points and along all the other point on the line AB results into inferior harmonic performance.If suppose the value of fundamental is denoted by a constant k, then the fourier series expansion for two switching angles of the fundamental can be represented as shown in Equation (5).…”

“…[55][56][57][58] The equal division of null state are made by addition of a proper common-mode signal to the SPWM. 5,59,60 At Section 4 of the paper, a complete description of space vector PWM technique has been presented. From this sub-section of the paper readers will have a clear idea about the comprehensive relationship between the carrier based PWM and the SVPWM.…”

“…The difference in SVPWM and SPWM lies in the fact that in SVPWM the null states (0 4 7) are divided equally in a sub‐cycle duration 55–58 . The equal division of null state are made by addition of a proper common‐mode signal to the SPWM 5,59,60 …”

A hybrid space vector modulation for the near‐zero common‐mode voltage and common‐mode current mitigation in diode‐clamped multilevel‐inverter‐fed induction motor drive

“…The reduced switching loss PWM method have been addressed to CMV attenuation under condition of DC link voltage balance, their applications are limited only to specific power converter systems. 21 In Reference 27, the virtual SVM control method is used for neutral point clamped (NPC) three‐level inverter to balance the midpoint potential compensation. Recently, three‐level PWM schemes have been continuously developed to improve certain inverter characteristics such as switching loss, modulation range, or common mode mitigation 28–30 .…”

Direct torque control scheme for a five‐level multipoint clamped inverter fed induction motor drive using fractional‐order PI controller

“…In MPC topology, less number of components are required over other conventional MLI topologies. [5][6][7] The NPC and MPC topologies are different only when the output voltage levels are more than three. The input DC voltage steps are obtained either by isolated DC voltage sources or single DC voltage source splits it into voltage steps by using a capacitor bank.…”