Experiment Verification of Surge Voltage Reduction
by Zero Voltage Switching Indirect Matrix Converter◎Toshifumi Hinata, Jun-ichi Itoh
Department of Electrical Engineering, Nagaoka University of Technology

1. Introduction
Recently, indirect matrix converters (IMC) which uses nolarge energy storage components have been actively studied
because it has a smaller size than conventional converters.
Zero current switching method for the rectifier stage(1)(R-ZCS) is generally used. R-ZCS often intercepts the DC linkcurrent pathway. In high power converters, the wiring in DC(a) R-ZCS method.

link parts contains of large parasitic impedance and therefore
large surge voltage will be appeared for the use of R-ZCS.
This paper evaluates a zero voltage switching method for theinverter stage(2) (I-ZVS) of suppression for the surge voltage
with experimental results.

2. Generation mode of surge voltage
To avoid the surge voltage, the current of the parasitic(b) I-ZVS method.
Fig.1. Current pathway transitions of IMC.

inductance, i.e. DC link current, should be continuous current.
Using R-ZCS operation, the input current of the inverter
becomes discontinuous. The DC link current cannot be
commutated to other device at the switching point of theinverter. That is, the surge voltage occurs. On the other hands,in the I-ZVS operation, the DC link current keeps continuous
state. The DC link current achieves commutation to the otherswitch in the rectifier. Then, the surge voltage is suppressed.

(a) R-ZCS method.

Figure 1 shows one of example of current path transitions ofthe IMC. In Fig. 1(a), when the current path-1 changes to thepath-2, the DC link current drops to zero because the current
path of the DC link wiring is intercepted. Therefore, a large
surge voltage occurs at Sup. On the other hand, in Fig. 1(b), theDC link current continues flowing in DC link because the DC(b) I-ZVS method.
Fig.2. Experimental results.

link current commutates from Ssp to Stp. As a result, I-ZVS cansuppress a surge voltage. This method can protect theswitching devices and is suitable for high power converters
and/or multi-drive systems due to large parasitic inductance.

3. Experimental results
Figure 2 shows the experimental results to evaluate the effectof surge voltage reduction by I-ZVS. In this experiment, theoutput power is adjusted by Rout. Low input voltage is applied
Fig.3. Surge voltage vs. Output power (Experimental result).

due to keeping the voltage rating 600 V of power devices. In
R-ZCS given in figure 2(a), the large surge voltage occurs at
Sup when the switch is turned off. The maximum voltage for
R-ZCS is 515 V. On the other hand, the maximum voltage for
I-ZVS is 322 V and decreased approximately 37 % of surgeinductive energy in the DC link wiring inductance is increased.
By applying I-ZVS, a higher power converter can uses asmaller size snubber circuit and achieves high reliability at thesame time.

voltage in comparison with the R-ZCS.
Figure 3 shows the relationship between the maximum
voltage and the output power. The surge voltage of the R-ZCS
is increased according to the output power increase because

(1)
(2)

References
B. Wang, G. Venkataramanan: Power Electronics Specialists
Conference 2006 (2006)
J. Itoh, T. Hinata, K. Kato, D. Ichimura: The 35th Annual Conferenceof the IEEE Industrial Electronics Society, pp.4511-4516 (2009)