Abstract
The present paper proposes a direct space vector modulation and novel balance algorithm for easy software application of three-level converters which operate in three-phase. In the case of the conventional space vector modulation, to get the on-state times of the switches, the dwell times of the three nearest stationary vectors, which are obtained after sector and region selection algorithms, should be rearranged. These processes, therefore, contain diverse conditional statements and complicated calculations such as inverse trigonometric functions and square roots. However, the burden of the software application of the proposed algorithm is greatly reduced by not using the sector selection algorithm, the region selection algorithm, and the on-state time allocation process as the proposed modulation can directly control the switch on-state time. In a three-level topology, it is required to balance top and bottom capacitor voltages because the DC-link voltage is composed of two capacitor voltages; the unbalanced voltage of each DC-link capacitor causes the overvoltage of the switching devices. Thus, the DC-link voltage balancing algorithm is proposed, and it is also very simple and effective without additional circuits because it controls the switch on-state time directly as well. The 5-kW prototype proved the validity of the proposed algorithm with its feasibility.
Highlights
For three-phase control, space vector modulation (SVM) control is commonly used [1,2]
A seven-segment switching sequence is used for the three-level converter which operates in three-phase after direct space vector modulation (DSVM)
This paper proposes a direct space vector modulation and a novel DC-link voltage balance algorithm for easy software application of three-level converters which operate in three-phase
Summary
For three-phase control, space vector modulation (SVM) control is commonly used [1,2]. The current controller in the d–q frame gives the angle of desired vector and magnitude to SVM algorithm; the d–q frame is often used to regulate the reactive power and active power [4,5]. The proposed algorithm and DC-link voltage balancing algorithm were validated through the T-type topology which represents the three-level converter. The proposed direct space vector modulation (DSVM) controls the switch on-state time directly without complicated calculations such as sector and region selection algorithms and on-state time allocation procedure on the software. The DC-link voltage comes into a balanced state by controlling the neutral-point-current, so the concerns about overvoltage on switching devices are reduced. The experimental results of the 5-kW T-type topology prototype are provided to verify the validity of the proposed algorithm with its feasibility
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
