8/18/2019 Patents Abstracts

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Patents abstracts

ABSTRACTBi-directional switches for use with neutral point

clamped PWM inverters have utilized clamping

switches which are operated alternately with main

power switches in the inverter to periodically connectan output terminal of the inverter to a neutral voltage.

However, a delay period is typically interposed between turn-off of a main power switch and turn-on of

the clamping switch to minimize the possibility of a

potentially destructive shoot-through condition. This

delay adversely affects the quality of the power developed by the inverter and leads to an undesired increase

in the size of snubber circuits coupled across the power

switches. In order to overcome these problems, a bi

directional switch according to the present invention

includes circuitry for providing a high impedance path

in series circuits including the main power switches and

the clamping switch so that shoot-through currents are

blocked even when one of the main power switches and

the clamping switch are simultaneously on. The delays

between turn-off of a main power switch and turn-on of

the clamping switch can thereby be reduced’ or elimi

nated, thereby resulting in improved quality of the out

put power of the inverter and a reduction in the size of

snubber circuits used therein.

A high poWer motor drive converter includes: a ?ve level

4,117,364 9/1978

Baker .................................... .. 318/230

lgg’gd tlfpcbolléput 20W?” conl'ergion sgge in‘ihédlng

three4,137,570 1/1979 Baker ...................................... .. 363/43 P as? n ges avmg SW1“: 65 an

C011,? 6 m a Wye

471677775 9/1979 Baker et aL 363/42 con?guration through a converter neutral point,

each NPC

472107826 7/198O Baker ______ __ 307/254 phase bridge receiving poWer on a respective direct

current

4,270,163 5 /1981 Baker _ ____ __ 363/43 bus; three isolated split series-connected DC capacitor

banks

4,855,893 8/1989 KratZ ..................................... .. 363/136 each coupled in parallel

to a respective one of the three NPC

4,881,159 11/1989 HoltZ et al. ............................. .. 363/58 phase bridges; and a

Controller for selecting switch positions

479617129 10/1990 Shekhawat ~~~~ ~~ 363/40 With active control of neutral voltages. The

controller is5,060,129 10/1991 Maruyama ' ' ' ' ' ' ' ' ' ' ' ' " 363/41 adapted to select sWitch positions using feedforWard sine

5’155’675 10/1992 Maruyama et a1‘ 363/98 trian le modulation With third harmonic in'ection

Zero5,274,542 12/1993 Tanaka et al. 363/96 g . . . d d. . dll . ’. .

573557297 10/1994 Kawabata et aL ' sequence 1n]ect1on, an /or iscontmuous mo u at1on 1n]ec

5,361,196 11/1994 Tanamachi et al. .................... .. 363/41 “on

Multilevel voltage arrangement having a transformer and ag ' TECHNOLOGY 5 L power converter or inverter comprising one or more common

’ ' ' DC links connectable to a poWer source, said arrangement

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21 A 1' N '2 13/331 051 comprising one ?rst set of H bridges being connected to said

( ) pp 0 ’ common DC link, Wherein each of said H bridges comprises

(22) Filed: Dec_ 20, 2011 With at least tWo nodes connected to the ends of Wirings at

the

primary side of a transfer, Wherein control means are con?g

(30) Foreign Application Priority Data ured for controlling H bridges so as to achieve

a multilevel

voltage signal between the ?rst node and the second node ofDec. 22, 2010 (ES) ............................. .. ES201001600 Said H bridges~