New improved three‐phase hybrid multilevel inverter with reduced number of components

Abstract

A new three-phase hybrid multilevel inverter configuration is proposed. The proposed inverter is modular and consists of three single-phase H-bridge inverters, one three-phase H-bridge inverter and auxiliary modules for increasing the number of output voltage levels. The performance of the proposed inverter has been compared with some of the commonly used inverters within the literature in terms of the number of components, blocking voltage and overall losses. The proposed multilevel inverter has lower number of insulated-gate bipolar transistors and gate drivers and subsequently requires a relatively simple control strategy for generating the desired output voltage. Finally, the performance of the proposed inverter has been validated via a laboratory-scale prototype along with numerical simulation.

Modified Topology for Three-Phase Multilevel Inverters Based on a Developed H-Bridge Inverter

“…It is evident from the graph of Figure 3 and that of Figure 2 that the proposed topology together with references [19,22] requires the least quantity of driver circuits. [11] 6(n − 1) 6(n − 1) n − 7 n − 6 (16n + 6) Y2 [12] 6(n − 1) 6(n − 1) n + 3 n − 5 17n Y3 [13] ( [16] 3n + 3 3n + 3 n + 3 n − 6 (12n + 4) Y7 [18] 3(2n − 4) 3(2n − 4) n + 3 n − 5 (14n + 3) Y8 [19] 2(n + 2) 2(n + 2) -n − 3 3(2n + 4) + 6 Y9 [20] 3n + 3 3n + 3 n + 1 n − 3 12n Y10 [21] 3n + 3 3n + 3 n + 1 n − 6 3(4n − 1) Y11 [22] 2(n + 2) 2(n + 2) -n − 1 3(4n − 2) Y12 [23] 3n Variation of total component quantity (N TOTAL ) between the proposed topology and other aforementioned topologies of Table 3 is shown by Figure 4. Similar to the other abovementioned comparison parameters, the proposed topology requires the least quantity of components as against the other presented topologies.…”

“…Figure 2 shows the graph of comparison of IGBT quantity between the proposed topology and other presented topologies of Table 3 with respect to level count. As shown by the graph, the proposed topology together with two other references [19,22] requires the least number of IGBTs to generate the desired 7-levels. The number of IGBTs and diodes are equal in all topologies under review because of the use of unidirectional switches, however the diode clamped topology requires extra diodes for voltage clamping purposes.…”

“…Similar to the other abovementioned comparison parameters, the proposed topology requires the least quantity of components as against the other presented topologies. However, the graph of the proposed topology and reference [19] are same for Figure 4 because the difference in total component count is 1 as shown in Table 2. The maximum number of total component count is found in the three conventional topologies of CHB, NPC and FC where NPC and CHB have the highest and the least component count respectively.…”

“…A 7-levels minimum common-mode voltage converter is presented in [18], the structure of which is composed of one DC source, 10 switches and three capacitors for each phase. A new multilevel inverter structure presented by [19] is composed of one three-phase HB and three single-phase HB structures, to obtain increased multilevel functionality, an auxiliary three-phase HB structure is added to the basic unit, so the phase output voltages are not evenly distributed between positive and negative cycles. Without any auxiliary circuit, 18 switches and four DC sources are used to generate 7-levels having one negative voltage component.…”

17‐level inverter with low component count for open‐end induction motor drives

“…In high‐power applications, statutory limits on harmonic content necessitate high‐resolution voltage space‐vector (SV) generation, which is possible with inverters having more output voltage levels. However, topologies with higher number of levels often have prohibitively high component counts, and many techniques have been proposed to reduce the component count [10, 11].…”