High Power Density Converter for HEV

8/3/2019 High Power Density Converter for HEV

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High Power Density

Converterfor

HEV

Presented by:-


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IEEE Paper

High Power Density 3-level Converter with

Switched Capacitors aimed for HEV byMitsuaki Hirakawa, Masao Nagano, YasutoWatanabe, Keigo Andoh, Somei Nakatomi,Satoshi Hashino and Toshihisa Shimizu


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Enlightened Area

HEV

Boost converter

3-level DC/DC converter with SC

Experimental results

Reduction of emission noise

conclusion


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Introduction to HEV Hybrid Electrical Vehicle (HEV)

combines an ICE propulsionsystem with an electricalpropulsion system.

Types are Series

Parallel

Power-split

Performance basically dependsupon the progress of battery.


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Power requirement for HEV

To match the driving performance of conventionalgasoline-powered vehicles, the electrical power systemsof HEV need to be supplied with 50KW from batteries.

To achieve this amount of power densities boost

converter is used as an intermediate between thebatteries and the inverter which is connected to thedriving motor.


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Boost converter Drive the output with required higher voltage than

that of available.

Achieved through proper switching ofswitches(typically semiconductor switches likeIGBT) and filtration with passive elements likeinductor and capacitor.

Boost converter has drawbacks of cost, size,weight.


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For electrical power system of HEV required highpower densities which is achieved with singleinductor chopper circuit, an interleaved circuit, aninterleaved circuit with loose-coupled inductors.

Compensation for reduction in inductor volume issoft switching method.

DC magnetic flux is reduced with an interleavedcircuit with close-coupled inductor (CCIconverter).

Switched capacitor is another way to reduce thesize of inductor


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3-level DC/DC converter with SC

The neutral point of C1 andC2 is connected to thetotem-pole arm.

It is a bidirectional DC/DCconverter with switchedcapacitor which is requiredfor the use in HEV.


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Ripple current analysis

=(2 )( 1)

2

D < 0.5 or < 2D > 0.5 or > 2

=( 2)

2


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Ripple current feature of an auxiliary inductor

It has a consistency in its input current featurecompared to CCI converter


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Effective current of output capacitor

Maximum effective current of output capacitor is higherfor SC converter


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Passive components

Input ripple current and flux density kept constant


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The wattage loss of the capacitor is estimated bymultiplying the ERS in each frequency component andadding them.


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The previous table is constructed by considering thecooling capability of 10KW/m2 .

From comparison the weight of main passive

components of SC converter is 44% of interleavedconverter and 64% of CCI converter. And also thevolume of main passive components is 43% ofinterleaved converter and 54% of CCI converter.


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Experimental results


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Maximum achievable output

power is 42KW and at 20KWmaximum efficiency isachieved with boost ratio of1.25

The rate of switching loss islarger than compare to the

two phase interleavedconverter and CCIconverter.


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The inductor current has anAC component whosefrequency is twice the

switching frequency

Comparing with theamplitude of ripple currentwith the table, it has ahigher value.


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When the input is higher than 180V, as given in table,output power go on increase.

At these condition maximum output power of 60KW isachieved. And also 26.8KW/liter of maximum powerdensity was achieved with efficiency exceeding 97.5 forboost ratio of 1.7.


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Emission noise

Caused due to long electrical cable connectedbetween power source and converter inputterminal.

Direct impact on all sorts of devices for controland communication.

modified


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References

All references of the above paper Google

Wikipedia


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Documents

High Power Density Converter for HEV