III. PARAMETRICAL EXPERIMENTAL INVESTIGATION
OF DYNAMIC PROPERTIES OF SELECTED DIODES
The experimental measurements required construction of testing circuit, which enabled to change the power circuit parameters just to reach the conditions in practical application (supply voltage, switching frequency, and load current). This led us to construct a testing device, whose construction is realized as circuit with variable topology whereby primary requirement was to gain exact emulation of different soft – switching techniques and consecutive interpretation of generated switching loss [5] [6].
For the purposes of experimental verification we have focused namely on these devices:
Note: parameters are valid for 25 ºC.
It can be seen that we have focused on the structures, whose current and voltage ratings are according to the possibilities as closest as possible. Investigation of dynamic behavior was done with the use of well-known circuit, which is shown on fig. 3. This circuit is generally known as testing configuration for investigation of dynamics of the power diodes as well as of the power transistors. Due to fact, that our aim is comparison of today's top class devices, we have utilized IPW60R070C6 as power transistor.
Several measurements were realized under parameters, by which the diode turn - off losses are dependent on (switching frequency, supply voltage, load
current). In order to evaluate measured results we have used discrete forms of equation. The measured data were
processed in the table editor and consequently evaluated.
The turn-off losses are generated during reverse recovery
time of the diode, whereby this interval is :
tRR = tA + tB
whereby for the power loss calculation the next equation is valid:
T – time
- period of computed action iP
– time function of device’s current uP
– time function of device’s voltage
Most of data that are available from oscilloscope for calculation are in discrete form, so then it is necessary to use equations in discrete version (4), instead of (3).
where
TZ1 – is sequence of sample at the begin of process
(turn – on/off, stabilized conductivity/non-conductivity of device)
TZ2 – is sequence of sample at the end of process
(turn – on/off, stabilize conductivity/non-conductivity of device)
IP[n] – i-sample of current through device UP[n] – i-sample of device’s voltage
T – sampling time
Thereby it is possible to calculate the element of energy which is being absorbed by diode during time - interval trr. Consequently there is need to use an equation to determine the value of total losses:
Pon T1 Won
Based on such analysis it is possible to select most suitable diode for the application with given circuit parameters (load current, switching frequency, etc...
IV. EVALUATION OF THE DYNAMIC BEHAVIOUR
As was mentioned, the experimental investigation was
done during change of parameters which are influencing
diode´s dynamic properties in the highest amount.These
were:
- diode current IF(AV) - 5 A
- diode reverse voltage UR - from 50 V up to 300 V
- switching frequency fSW - from 50 kHz up to 300 kHz
The evaluation of switching losses is done through 3-D
graphical interpretation.
III PARAMETRICAL ทดลองสอบสวนของDYNAMIC การวัดการทดลองต้องก่อสร้างของวงจรการทดสอบที่ใช้ในการเปลี่ยนพารามิเตอร์วงจรไฟฟ้าเพียงที่จะไปถึงเงื่อนไขในการใช้งานจริง นี้นำเราไปสู่การสร้างอุปกรณ์ทดสอบที่มีการก่อสร้างเป็นที่ตระหนักถึงความเป็นวงจรที่มีโครงสร้างตัวแปรโดยความต้องการหลักคือเพื่อให้ได้รับการแข่งขันที่แน่นอนของอ่อนที่แตกต่างกัน- เปลี่ยนเทคนิคและการตีความติดต่อกันสร้างความสูญเสียเปลี่ยน สำหรับวัตถุประสงค์ของ การตรวจสอบการทดลองเราได้มุ่งเน้นคือบนอุปกรณ์เหล่านี้หมายเหตุองศาเซลเซียสจะเห็นได้ว่าเราได้มุ่งเน้นไปที่โครงสร้างที่มีในปัจจุบันและการจัดอันดับแรงดันไฟฟ้าที่เป็นไปตามความเป็นไปได้เป็นที่ใกล้เคียงที่สุดที่เป็นไปได้ การสืบสวนของพฤติกรรมแบบไดนามิกได้ทำกับการใช้งานของวงจรที่รู้จักกันดีซึ่งจะแสดงในรูป 3. เนื่องจากความเป็นจริงที่จุดมุ่งหมายของเราคือการเปรียบเทียบของอุปกรณ์ที่ชั้นบนสุดของวันนี้เราได้นำมาใช้ วัดหลายคนตระหนักภายใต้พารามิเตอร์โดยที่ไดโอดเปิด ( ) เพื่อประเมินผลการวัดที่เราได้ใช้รูปแบบของสมการที่ไม่ต่อเนื่อง III. PARAMETRICAL EXPERIMENTAL INVESTIGATION
OF DYNAMIC PROPERTIES OF SELECTED DIODES
The experimental measurements required construction of testing circuit, which enabled to change the power circuit parameters just to reach the conditions in practical application (supply voltage, switching frequency, and load current). This led us to construct a testing device, whose construction is realized as circuit with variable topology whereby primary requirement was to gain exact emulation of different soft – switching techniques and consecutive interpretation of generated switching loss [5] [6].
For the purposes of experimental verification we have focused namely on these devices:
Note: parameters are valid for 25 ºC.
It can be seen that we have focused on the structures, whose current and voltage ratings are according to the possibilities as closest as possible. Investigation of dynamic behavior was done with the use of well-known circuit, which is shown on fig. 3. This circuit is generally known as testing configuration for investigation of dynamics of the power diodes as well as of the power transistors. Due to fact, that our aim is comparison of today's top class devices, we have utilized IPW60R070C6 as power transistor.
Several measurements were realized under parameters, by which the diode turn - off losses are dependent on (switching frequency, supply voltage, load
current). In order to evaluate measured results we have used discrete forms of equation. The measured data were
processed in the table editor and consequently evaluated.
The turn-off losses are generated during reverse recovery
time of the diode, whereby this interval is :
tRR = tA + tB
whereby for the power loss calculation the next equation is valid:
T – time
- period of computed action iP
– time function of device’s current uP
– time function of device’s voltage
Most of data that are available from oscilloscope for calculation are in discrete form, so then it is necessary to use equations in discrete version (4), instead of (3).
where
TZ1 – is sequence of sample at the begin of process
(turn – on/off, stabilized conductivity/non-conductivity of device)
TZ2 – is sequence of sample at the end of process
(turn – on/off, stabilize conductivity/non-conductivity of device)
IP[n] – i-sample of current through device UP[n] – i-sample of device’s voltage
T – sampling time
Thereby it is possible to calculate the element of energy which is being absorbed by diode during time - interval trr. Consequently there is need to use an equation to determine the value of total losses:
Pon T1 Won
Based on such analysis it is possible to select most suitable diode for the application with given circuit parameters (load current, switching frequency, etc...
IV. EVALUATION OF THE DYNAMIC BEHAVIOUR
As was mentioned, the experimental investigation was
done during change of parameters which are influencing
diode´s dynamic properties in the highest amount.These
were:
- diode current IF(AV) - 5 A
- diode reverse voltage UR - from 50 V up to 300 V
- switching frequency fSW - from 50 kHz up to 300 kHz
The evaluation of switching losses is done through 3-D
graphical interpretation.
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