PDIV
The case the place the PDIV of the combined gasoline modifications with the stress underneath completely different mixing ratios and the case the place the PDIV of the combined gasoline modifications with the blending ratio underneath completely different pressures are proven in Figs. 5 and 6, respectively. Every experiment adopts the step-by-step voltage division technique, and the voltage is utilized slowly at a relentless velocity from 0 kV. After the voltage is steady, observe the sign of the oscilloscope. When the voltage is excessive, it can trigger the pin-board electrode to interrupt down. Right now, the breakdown voltage is recorded, the voltage regulator is self-protected, the voltage drops to zero, and it’s turned off. Then repeat the above operation for five exams, and take the typical of all check outcomes as the ultimate outcome underneath this situation.
PDIV with the blending ratio.
It may be seen from the determine that the PDIV worth of the gasoline will increase with the rise of the stress and the gasoline mixing ratio. The pure N2 has a PDIV worth of 5.9 kV at 0.1 MPa and seven.2 kV at 0.2 MPa, with a rise of 1.3 kV. The PDIV worth of the two% combined gasoline was 6.7 kV at 0.1 MPa and 10.1 kV at 0.2 MPa, with a rise of three.4 kV. The PDIV values of the combination of 4% and 6% combined gasoline elevated by 4 kV and 4.6 kV respectively on this altering stress. It may be concluded that the combined gasoline of the excessive mixing ratio will increase the PDIV worth sooner because the stress modifications.
The connection between the beginning voltage and the stress is fitted by the formulation
$$ U_{PDIV} = AP + B. $$
(1)
UPDIV is the PDIV worth, A is the slope reflecting the speed of change of PDIV worth with stress, and P is the stress. The PDIV worth of the combined gasoline reveals a constructive correlation with the stress. The bigger the worth of A, the extra apparent the PDIV worth of the combined gasoline is affected by the stress. The outcomes calculated after becoming are: A0% = 12.14; A2% = 32.43; A4% = 40; A6% = 46.86. From this, it may be concluded that the upper the blending ratio, the better the affect of the stress on the gasoline combination.
In Fig. 6, when 2% C6F12O is added, the PDIV worth of the gasoline will increase quickly. After including 4% C6F12O gasoline, the gasoline PDIV worth will increase slowly. And the upper the stress, the sooner the PDIV worth will increase. It may be concluded that the PDIV worth will enhance sooner after N2 is added with C6F12O underneath excessive stress, however as the blending ratio will increase the velocity turns into slower at a sure stress.
Desk 2 exhibits the ratio of the PDIV worth at completely different pressures of every group of combined gases to the PDIV worth of N2, reflecting the rise within the partial discharge beginning voltage of the combined gasoline obtained after the addition of C6F12O. It may be seen from the desk that because the stress and the blending ratio enhance, the ratio of the PDIV worth of every combined gasoline to the PDIV worth of N2 is larger. On the identical mixing ratio, because the stress will increase, the ratio of the PDIV worth of the combined gasoline to the PDIV worth of N2 progressively will increase. From Desk 2, the ratio of two% combined gasoline to pure N2 will increase from 1.14 occasions at 0.1 MPa to 1.40 occasions at 0.2 MPa with the rise of stress, on the identical time, when the blending ratio is 6%, the ratio of PDIV of the combined gasoline to PDIV of pure N2 will increase from 1.20 occasions of 0.1 MPa to 1.63 occasions of 0.2 MPa. So the combined gasoline of excessive combined ratio will increase the PDIV worth extra clearly with the rise of stress, which per the outcomes of the earlier linear. On the identical stress, because the combined ratio will increase, the ratio of the PDIV worth of the combined gasoline to the PDIV worth of N2 additionally progressively will increase. When the stress is 0.1 MPa and the blending ratio of the combined gasoline will increase from 2 to six%, the ratio of the PDIV worth of the combined gasoline to the PDIV worth of N2 is from 1.14 to 1.20, a rise of 5.3%; and when the stress is 0.2 MPa, the info modifications from 1.40 to 1.63, a rise of 16.4%. From this it may be concluded that the addition of C6F12O to N2 will end in a extra important enhance within the PDIV worth of the combined gasoline at larger stress.
In abstract, when the stress is larger than 0.16 MPa and the blending ratio is larger than 2%, the PDIV worth of the combined gasoline is elevated by 50% or extra in comparison with pure N2.
PDEV
On this experiment, the measurement outcomes of the partial discharge extinction voltage in response to the experimental process are proven in Figs. 7 and 8. The figures present the change of PDEV worth with stress underneath completely different mixing ratios and the change of PDEV worth with mixing ratio underneath completely different pressures.
PDEV with the blending ratio.
In Figs. 7 and 8, much like the change of gasoline PDIV worth, as the blending ratio and stress enhance, the gasoline PDEV worth progressively will increase. For pure N2, its PDEV worth is 5.8 kV at 0.1 MPa, and its PDEV worth is 6.9 kV at 0.2 MPa, a rise of 1.1 kV. For two% C6F12O, its PDEV worth is 6.2 kV at 0.1 MPa, and its PDEV worth is 9.2 kV at 0.2 MPa, a rise of three kV. When the blending ratio is 4%, the PDEV worth of the combined gasoline at 0.1 MPa is 6.4 kV, which isn’t considerably improved in comparison with the two% combined gasoline. When it reaches 0.2 MPa, it will increase to 10.3 kV and will increase by 3.9 kV. When the blending ratio reaches 6%, the PDEV worth of the combined gasoline is 7 kV at 0.1 MPa, which is a comparatively giant enhance in comparison with the ratio of two% and 4%. At 0.2 MPa, the PDEV worth of the combined gasoline is 10.6 kV, which will increase 3.6 kV. Due to this fact, the addition of C6F12O will increase the PDEV worth of N2, whereas the sensitivity to stress will increase barely.
In response to the formulation (2), linearly match every curve in Fig. 7 to review the linear relationship between the PDEV worth of varied combined gases and the stress.
$$ U_{PDEV} = A^{prime}P + B^{prime}, $$
(2)
the place UPDEV is the partial discharge quenching discharge voltage worth, and A′ is the slope. The values of A′ calculated for every curve are: A′0% = 11, A′2% = 30.71, A′4% = 36.71, A′6% = 37.71. The values of the 4 curves A′ are all constructive values, that’s, the PDEV voltage worth of every group of gases is positively correlated with the stress. After including C6F12O, the affect of stress on the PDEV worth of the combined gasoline will increase sharply, and the upper the blending ratio of the combined gasoline, the better the PDEV worth is affected by the stress. The PDEV worth of the combined gasoline with a mixing ratio of 4% and 6% is roughly the identical underneath the affect of stress.
From Fig. 8, including 2% C6F12O will enhance the PDEV worth of N2, and because the stress is elevated, the magnitude of the rise additionally will increase accordingly. Nevertheless, the PDEV worth of the combined gasoline with a mixing ratio of 4% relative to the combined gasoline of two% has not elevated a lot. At 0.14 MPa and 0.18 MPa, the PDEV values of the 2 combined gases are nearly equal. That’s, as the blending ratio continues to extend, the growing development of the PDEV worth of the combined gasoline progressively slows down.
Desk 3 lists the ratio of the PDEV worth of every group of combined gasoline to the PDEV worth of pure N2, additional displaying the partial discharge extinction voltage traits of the combined gasoline. Within the case the place the blending ratio is fixed, the ratio of the PDEV worth of the combined gasoline to the PDEV worth of N2 progressively will increase because the stress will increase. When the blending ratio is 2% and the stress is from 0.1 to 0.2 MPa, the ratio of the PDEV worth of the combined gasoline to the PDEV worth of N2 will increase from 1.07 to 1.33; At a mixing ratio of 6%, this worth elevated from 1.21 to 1.54. So the upper the blending ratio, the upper the ratio of the PDEV worth of the combined gasoline to the PDEV worth of N2. At a set stress, the rise of the blending ratio for the rise of the N2’s PDEV worth is as follows. At 0.1 MPa, the ratio of the PDEV worth of the combined gasoline to the PDEV worth of N2 modifications from 1.07 to 1.21 as the blending ratio will increase. At 0.2 MPa, the ratio of the PDEV worth of the combined gasoline to the PDEV worth of N2 will increase from 1.33 to 1.54 as the blending ratio will increase. It may be concluded that the upper the stress, the upper the ratio of the PDEV worth of the combined gasoline to the PDEV worth of pure N2, and the better the rise within the PDEV worth of the combined gasoline relative to the pure N2. The PDEV worth of 6% of the combined gasoline at 0.18 MPa and above can attain greater than 1.5 occasions of N2 underneath the identical circumstances.
Comparability of partial discharge voltage and breakdown voltage of combined gasoline
This part compares the partial discharge traits and breakdown traits of the gasoline. Tables 4 and 5 respectively checklist the ratio of partial discharge inception voltage and partial discharge extinction voltage to breakdown voltage of the combined gasoline underneath completely different mixing ratios and completely different stress circumstances.
Desk 4 exhibits that the ratio of the pure N2’s PDIV worth to the breakdown voltage worth is concentrated round 0.6 at 0.1–0.2 MPa, when the blending ratio is 2%, the ratio of the combined gasoline’s PDIV worth to the breakdown voltage is about 0.4 at 0.1–0.2 MPa, so the partial discharge voltage of the combined gasoline is already smaller than the breakdown voltage worth underneath the identical circumstances. When the blending ratio is 4% and 6%, the ratio of the combined gasoline’s PDIV worth to the breakdown voltage worth is about 0.34 at 0.1–0.2 MPa. It exhibits that underneath this mixing ratio situation, the partial discharge beginning voltage is nice smaller than the breakdown voltage. It may be concluded that when the pure N2 is partially discharged, the voltage worth could also be comparatively near the breakdown worth. After including C6F12O, the distinction between the partial discharge voltage and the breakdown voltage of the gasoline will increase considerably.
It may be seen from Desk 5 that the ratio of the pure N2’s PDEV worth to the corresponding breakdown voltage worth is 0.59 at 0.1–0.2 MPa, which is comparatively near the above-mentioned PDIV worth. When the blending ratio is 2%, the ratio of the combined gasoline’s PDEV worth to the breakdown voltage worth underneath the corresponding circumstances is about 0.35 at 0.1–0.2 MPa. When the blending ratio is 4% and 6%, this worth is 0.31 and 0.32 respectively. The addition of C6F12O combined gasoline can scale back the ratio of the pure N2’s partial discharge extinction voltage to the breakdown voltage underneath corresponding circumstances.
