One switch inverter - experience?

Question

Do somebody have experience with this one switch inverter?:

Here is a one switch inverter - but besides the one switch, it also has two parallel coupled reverse-blocking-switches closer to the output, that functions as active rectification - see the schematic at page 2:

A Synchronous Single Switch Inverter - Purdue School of:

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Quote: "... Four modes of operation were detected in creation of negative and positive polarity voltages. ... Not only did the bench test work, it lead to the discovery of several other circuits and controllers for high-power inverters with lower switching loss, higher voltage performance and lighter reconfigured circuits.

Therefore, as the number of high frequency switching devices is decreased, the efficiency is increased. For instance, a 90% efficient [H-bridge] converter becomes 97.2% efficient. ... CONCLUSION A new power inverter circuit was introduced that required only one high frequency switching transistor. The inverter used a synchronizing structure to change the voltage polarity on demand. Therefore, real time generation of infinite voltage levels was realized. The state space equations demonstrated a forth order system. ..."

The inverter could be used for solar micro-inverters:

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The inverter could also be used for:

brushless motor
step motor

The circuit is a "all-in-one". It could be used for (T1 and T2 refer to the iupui.edu article):

Positive DC, DV. T1 is used for active rectification. T2 is not used.

Negative DC, DV. T2 is used for active rectification. T1 is not used.
Any curve shape can be amplified with a signal from a suitable signal generator. (retangular, saw tooth, triangular...) T1 is used for positive curve parts - and T2 is used for negative curve parts.

Could it be used for a Class D audio amplifier with the right control circuit? Low enough distortion?

The circuit bear resemblance with a reversed SEPIC:

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Indiana University. (2012, October 17). New class of power inverter could mean cheaper, faster hybrid vehicles. ScienceDaily:

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Citat: "... Izadian's invention, the result of a creative reconfiguration of an electrical circuit during a laboratory experiment, would make inverters cheaper, lighter and therefore more efficient than current models. ... For example, unwanted harmonics are greatly reduced with Izadian's invention. ..."

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Additional reading:

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Active rectification (synchronous rectification):

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Glenn

Tim Williams · Accepted Answer

I'm sure there's a comment about liberals in there, somewhere...

Curious what Mr. (Dr.?) Aizadian thinks T1/T2 should be implemented with, if not "high speed switching transistors".

Tim

-- Seven Transistor Labs Electrical Engineering Consultation Website:

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piglet · Answer

Not me but *infinite* voltage sure sounds useful! I cannot take that paper seriously, fig 3 seems to show current in a  0.1uH inductor taking 20milli-secs to get to 75A. piglet

Jamie M · Answer

Hi, The high speed switch Q is probably PWM'ed to do that.  It looks like an interesting topology, if it is a new one that is cool, maybe will replace SEPIC? cheers, Jamie

piglet · Answer

Are those two inverse parallel transistors IGBTs? I have never used an IGBT but datasheets for them that I have seen show a body diode like a power mosfet. That would make the circuit as drawn useless as one or other of the two body diodes would always be in circuit.

I wonder whether the papers author meant to have a diode in series with each collector/drain and so then the IGBTs would only be switched at the low rate of output polarity changeover. That would tie in with his statement of one high speed switch. Or did he mean to have the two IGBTs series-opposed back to back i.e. emitter to emitter? Anyway that paper is not clearly written.

piglet

Glenn · Answer

They must be but besides the one switch, it also has two parallel coupled e.g. Reverse Blocking IGBT (RB-IGBT). (Or two serially connected Power MOSFETs. The Power MOSFETs must be connected so that their substrate diodes have opposite directions):

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Application Characteristics of an Experimental RB-IGBT (Reverse Blocking IGBT) Module:

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A High Efficiency Indirect Matrix Converter Utilizing RB-IGBTs:

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Glenn · Answer

They must be reverse blocking switches e.g. Reverse Blocking IGBT (RB-IGBT). (Or two serially connected Power MOSFETs. The Power MOSFETs must be connected so that their substrate diodes have opposite directions):

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Application Characteristics of an Experimental RB-IGBT (Reverse Blocking IGBT) Module:

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A High Efficiency Indirect Matrix Converter Utilizing RB-IGBTs:

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Glenn

Glenn · Answer

... I think you have a very good point there. But it might be that he meant that it was one non active rectification  switch. A half bridge uses two non active rectification switches. A full bridge uses four non active rectification switches. Glenn

Glenn · Answer

Please note that he writes "infinite voltage level" in the abstract.

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He made some graph axis blunder...

v=L*dI/dt

(0.000375 V) = (0.1E-6 H) * (75 A)/(0.02 sec)

So the axis label may be 10^-5 seconds?

Glenn

Glenn · Answer

Please note that he writes "infinite voltage level" in the abstract.

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He made some graph axis blunder...

v=L*dI/dt

(0.000375 V) = (0.1E-6 H) * (75 A)/(0.02 sec)

So the axis label may be 10^-5 seconds?

Glenn

Glenn · Answer

Definition:  Quote: "... * Active switch: Switch state is controlled exclusively by a third terminal (control terminal). * Passive switch: Switch state is controlled by the applied current and/or voltage at terminals 1 and 2. ... Single-quadrant switch: on-state i(t) and off-state v(t) are unipolar.  [e.g. diode-like, reverse blocking] ..." Better name: One active switch inverter. The two active rectification switches are passive switches. - A half bridge uses two active switches. A full bridge uses four active switches. Glenn

Tim Williams · Answer

Fine, but you'll have a hard time explaining how a back-to-back "passive switch" (diode) will be of benefit...

If the intent was to say that, "oh, well, you just need to tell it to be one or the other...", well pray tell, how do I convey that to the diode? Surely not with a third terminal? ;-)

Tim

One switch inverter - experience?

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