Advanced control scheme for a single-phase PWM rectifier in traction applications

A Harmonic Voltage Injection Based DC-Link Imbalance Compensation Technique for Single-Phase Three-Level Neutral-Point-Clamped (NPC) Inverters

“…In contrast, the offset voltage injection method with the second-order harmonic component or the half-wave rectified can be adopted for smooth control. Furthermore, the proposed method could easily configure the controller using Equations (11), (12), and (22), and the PWM modulator described in Figure 6. However, the proposed method has limitations on the range of capacitor voltage difference given the effects of the voltage difference of the dc-link capacitor on the injection signal.…”

“…This voltage imbalance harms the stability of the system, and limits the switching operation of the power stage [8][9][10][11]. In order to mitigate the voltage imbalance, many strategies that are based on additional hardware configurations or control algorithms have been proposed, hardware configurations or control algorithms have been proposed, and have been successfully adapted in some applications [12][13][14][15][16][17][18][19][20][21][22][23][24][25]. In [12,13], additional circuits for dc-link balancing were proposed.…”

DC-Link Capacitor Voltage Imbalance Compensation Method Based Injecting Harmonic Voltage for Cascaded Multi-Module Neutral Point Clamped Inverter

“…This voltage imbalance is considered a system imperfection, which is caused by the difference in hardware components or switching operations of the NPC inverter [10,11]. Many strategies have been proposed to solve the capacitor voltage imbalance problem, and these strategies have achieved successful results [12][13][14][15][16][17][18][19][20][21][22][23][24][25].…”

“…This method can achieve voltage balance between the upper and lower capacitor but there is a problem with an increase in cost and system loss caused by the additional circuit. Several modulation techniques for single-phase three-level NPC inverters have been presented in References [14][15][16][17][18][19][20][21]. Among these modulation techniques, the carrier-based pulse width modulation (CB-PWM) method has been widely used due to its simplicity of appliance.…”

“…Among these modulation techniques, the carrier-based pulse width modulation (CB-PWM) method has been widely used due to its simplicity of appliance. In Reference [14], synthesizing the offset voltage method with zero-sequence component into a reference voltage was presented. The zero-sequence component 2 of 13 was calculated at every switching period based on the DC-link capacitor voltage and grid current.…”