The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Voltage deviations of dc-link capacitors are the main problem of multilevel diode-clamped converters (DCC). In this paper, a novel carrier-based voltage balance method is proposed to balance the dc-link capacitors of five-level DCCs. The proposed method is characterized by injecting proper zero-sequence voltages in the modulation signals of carrier-based modulators. The effects of the injected zero-sequence...
This paper decouples the floating capacitors voltage controlling and the neutral-point potential balancing of Seven-level Active Neutral-point-clamped (ANPC-7L) inverter by using the concept of average state, proposes a neutral-point potential balancing model based on zero-sequence voltage injection and derives the full controllable region of neutral-point potential. Based on this model, a testing-verification...
Traditional seven-level Active Neutral-point-clamped (ANPC-7L) converters suffer from the problems of dynamic voltage balancing in series switches and multi voltage levels jumping of phase output voltage during switching status transition. This paper presents a novel ANPC-7L topology with auxiliary commutating branches and elaborates on its commutating strategies. The presented topology and its commutating...
This paper introduces seven-level Active Neutral-point-clamped (ANPC-7L) inverter first. Then, the paper decouples the two problems of floating capacitors voltage controlling and neutral-point potential balancing by using the concept of average state, proposes a novel neutral-point potential balancing model based on zero-sequence voltage injection. After that, two neutral-point potential balancing...
This paper discusses the dead-time effect of dual bridge series resonant DC/DC converter (DBSRC). The phase-shift modulation is usually adopted in DBSRC. However, the phase-shift angle is usually small, and voltage polarity reversal (VPR) may occur in dead-time, which may deteriorate EMI/EMC and increase loss. This paper analyzes the commutation of DBSRC when VPR occurs and proposes a method to eliminate...
In order to solve the difficulty of measuring the speed and the position of maglev permanent magnet linear synchronous motor (PMLSM), a speed sensorless back electromotive force (EMF)-based sliding mode is proposed. And to overcome the drawback of the sliding mode technique called chattering phenomenon, a series of improvements are provided.
Five-level neutral point clamped H-bridge (NPCH) converter has been found practical application due to its low EMI and high output capacity. However, the unbalanced loss distribution of semiconductor devices in NPCH converter would limit the lifetime and the output capacity. In this paper, a five-level active neutral point clamped H-bridge (ANPCH) converter topology is studied, which is composed two...
According to the special structure and operation mechanism of the maglev permanent magnet linear synchronous motor (PMLSM), this paper established a theoretical mathematical model of electromagnetic thrust and levitation force of the motor in two-phase rotating reference frame and then realized the stability control of PMLSM with the simulation models under vector control (VC). Considering the large...
This paper proposes a novel PWM strategy for three-level active neutral-point-clamped (ANPC) converter, this strategy can balance the power losses of all semiconductors and eliminate the fluctuation in the neutral point voltage over full range of converter output voltage and for all load power factors of ANPC converter. The performance of this modulation approach and its benefits are verified through...
In order to eliminate the even order harmonic currents of the NPC rectifiers, the modified SVM (short for NP-SVM) is proposed in the past. However, when the NP-SVM is used in the multi-sampling system, there will be direct jumps between N and P which can result in narrower pulse width, higher dv/dt, even the destruction of devices, which is very undesirable. In this paper, the reasons of direct NP...
The linear induction motor (LIM) drives using conventional direct thrust control (DTC) schemes have drawbacks of large thrust ripples in low speed range and so on. In this paper, the thrust ripples of the DTC-based LEVI drives are theoretically analyzed. A novel switching scheme using synthesized voltage vector and magnitude modulation method is proposed to replace the conventional switching table...
The paper describes multi-level topologies contain two ways of paralleling inverters and multiple inverters. When inverters in parallel, it is important to restrain the circulating current effectively. It proposes a control strategy to eliminate circulating current and analyses the impact of parameters on the control system. When inverters in multiple, it is important to improve the output voltage...
It is well known that the minimum pulse width limitation must be considered to ensure the reliable operation of high power three-level neutral point clamped (NPC) converters equipped with GTOs or IGCTs, however the limitation has deleterious influence on neutral point voltage control. Based on the conventional realization of minimum pulse width limitation and its effect on the voltage balancing control...
The Specific Harmonic Elimination Pulse Width Modulation (SHEPWM) is used in a neutral-point-clamped converter. The SHEPWM is implemented in a DSP chip by software. Transient current between different PWM in open loop operation is small. Simulations of close loop control show that work of SHEPWM in dynamic process requires the voltage vector rotate steadily while the requirement on its length change...
Three phase three level neutral point clamped (NPC) rectifier is a popular topology for power converter front-ends to achieve controllable DC voltage. In this paper, its mathematical model is analyzed and a dual-loop control strategy is adopted to regulate both DC voltage and input power factor. Instead of space vector PWM, an improved multi-level carrier based PWM is presented. The control system...
This paper present a high power three-level NPC inverter with the Integrated Gate-Commutated Thyristor (IGCT) devices. The power circuit consisted of a 12-pulse diodes rectifier and three-level NPC inverter with IGCT. A valid SVPWM control strategy filled with a TMS320F2407 DSP controller is proposed to improve power quality, reduce total harmonic distortion and overcome the problem of the minimum...
This paper describes an implementation of a 3-phase voltage sourced regenerative rectifier under direct current control strategy. General mathematical model of the converter is first established. Based on the model, the principle of the direct current control strategy is presented, simulation results are given, and circuit operations in steady state are analyzed. Based on SVPWM, the analysis explains...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.