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Capacitor, Induction generator, Inrush current, Power factor, Reactive power, Reactor

1. ์„œ ๋ก 

์ฒญ์ •ํ•œ ์—๋„ˆ์ง€์— ๋Œ€ํ•œ ๋†’์€ ๊ด€์‹ฌ์€ ์žฌ์ƒ์—๋„ˆ์ง€์˜ ๋ณด๊ธ‰ ํ™•๋Œ€๋กœ ์ด์–ด์ง€๊ณ  ์žˆ๋‹ค. ์žฌ์ƒ์—๋„ˆ์ง€ ์ค‘์—์„œ ์—ญ์‚ฌ๊ฐ€ ์˜ค๋ž˜๋˜์—ˆ๊ณ , ์—๋„ˆ์ง€ ๋ณ€ํ™˜ํšจ์œจ์ด ๋†’์œผ๋ฉฐ ๊ธฐ์ˆ ๋ ฅ์ด ์ž˜ ๊ฒ€์ฆ๋œ ๊ฒƒ์ด ๋ฐ”๋กœ ์ˆ˜๋ ฅ์—๋„ˆ์ง€์ด๋‹ค[1]. ์ด ์ˆ˜๋ ฅ์—๋„ˆ์ง€๋Š” ์ถœ๋ ฅ์— ๋”ฐ๋ผ ๋Œ€์ˆ˜๋ ฅ, ์ค‘์ˆ˜๋ ฅ, ์†Œ์ˆ˜๋ ฅ, ๋งˆ์ดํฌ๋กœ ๋ฐ ํ”ผ์ฝ” ์ˆ˜๋ ฅ์œผ๋กœ ๋ถ„๋ฅ˜ํ•˜๊ณ  ์žˆ๋‹ค[1,2,3]. ์šฐ๋ฆฌ๋‚˜๋ผ์˜ ๊ฒฝ์šฐ ์ค‘ยท๋Œ€ ์ˆ˜๋ ฅ์€ ์ด๋ฏธ ๊ฐœ๋ฐœ์ด ๊ฑฐ์˜ ์™„๋ฃŒ๋˜์—ˆ์ง€๋งŒ, ์†Œ์ˆ˜๋ ฅ ๋˜๋Š” ๋งˆ์ดํฌ๋กœ๊ธ‰์— ํ•ด๋‹นํ•˜๋Š” ์ˆ˜๋ ฅ์—๋„ˆ์ง€๋Š” ๊ฐœ๋ฐœ ์ž ์žฌ๋ ฅ์„ ๊ฐ–๊ณ  ์žˆ๋‹ค.

์ˆ˜๋ ฅ์—๋„ˆ์ง€๋Š” ์ˆ˜์ฐจ์— ์˜ํ•ด ๋งŒ๋“ค์–ด์ง„ ์šด๋™์—๋„ˆ์ง€๋ฅผ ๋ฐœ์ „๊ธฐ๋ฅผ ๊ฑฐ์ณ ์ „๊ธฐ์—๋„ˆ์ง€๋กœ ๋ณ€ํ™˜์‹œ์ผœ ์ˆ˜์šฉ๊ฐ€์— ํ•„์š”ํ•œ ์ „๋ ฅ์„ ๋ณด๋‚ด๋Š” ๊ฒƒ์ด๋‹ค. ์ด ์ „๊ธฐ์—๋„ˆ์ง€ ๋ฐœ์ƒ์— ์‚ฌ์šฉ๋˜๋Š” ๋ฐœ์ „๊ธฐ๋กœ๋Š” ๋™๊ธฐ๋ฐœ์ „๊ธฐ์™€ ์œ ๋„๋ฐœ์ „๊ธฐ๊ฐ€ ์‚ฌ์šฉ๋œ๋‹ค[2,3]. ๋ฐœ์ „์ถœ๋ ฅ์ด ํฐ ๊ฒฝ์šฐ์—๋Š” ๋™๊ธฐ๋ฐœ์ „๊ธฐ๋ฅผ ์ฃผ๋กœ ์‚ฌ์šฉํ•˜์ง€๋งŒ, ๋ฐœ์ „์ถœ๋ ฅ์ด ํฌ์ง€ ์•Š๋Š” ์†Œ๊ทœ๋ชจ ๋ฐœ์ „์†Œ์—์„œ๋Š” ์ดˆ๊ธฐ ํˆฌ์ž๋น„, ์œ ์ง€๊ด€๋ฆฌ ๋“ฑ์„ ๊ณ ๋ คํ•˜์—ฌ ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๋งŽ์ด ์ ์šฉํ•˜๊ณ  ์žˆ๋‹ค. ์œ ๋„๋ฐœ์ „๊ธฐ๋Š” ๋™๊ธฐ๋ฐœ์ „๊ธฐ์™€ ๋‹ฌ๋ฆฌ ๊ณ„ํ†ต ์—ฐ๊ณ„์‹œ ๋Œ์ž…์ „๋ฅ˜์— ์˜ํ•œ ์ „์••๊ฐ•ํ•˜๊ฐ€ ๋ฌธ์ œ๊ฐ€ ๋œ๋‹ค. ๊ทธ๋ž˜์„œ ๋ฐœ์ „์ถœ๋ ฅ์ด ๋†’์€ ์†Œ์ˆ˜๋ ฅ๋ฐœ์ „์†Œ์—์„œ๋Š” ๋ฆฌ์•กํ„ฐ ๊ธฐ๋™์ด๋‚˜ ์†Œํ”„ํŠธ ๊ธฐ๋™๋ฒ•์„ ์ ์šฉํ•˜์—ฌ ๋Œ์ž…์ „๋ฅ˜์— ์˜ํ•œ ์ „์••๊ฐ•ํ•˜๋ฅผ ์ค„์ด๊ณ  ์žˆ๋‹ค[4,5,6]. ๊ทธ๋Ÿฌ๋‚˜ ๋งˆ์ดํฌ๋กœ ๋˜๋Š” ํ”ผํฌ ์šฉ๋Ÿ‰ ํ•ด๋‹นํ•˜๋Š” ๋ฐœ์ „์†Œ์—์„œ๋Š” ์ง์ž… ๊ธฐ๋™์„ ๋งŽ์ด ์‚ฌ์šฉํ•˜๊ณ  ์žˆ๋‹ค.

์œ ๋„๋ฐœ์ „๊ธฐ๋Š” ํšŒ์ „์ž๊ณ„๋ฅผ ์ง€์†์ ์œผ๋กœ ์œ ์ง€ํ•˜๋Š”๋ฐ ํ•„์š”ํ•œ ๋ฌดํšจ์ „๋ ฅ์„ ์ž์ฒด์ ์œผ๋กœ ๋งŒ๋“ค์ง€ ๋ชปํ•˜๋ฏ€๋กœ ๊ณ„ํ†ต์—์„œ ๊ณต๊ธ‰๋ฐ›์•„์•ผ ํ•œ๋‹ค[2,4~9]. ๊ทธ๋ž˜์„œ ๊ณ„ํ†ต์—์„œ ๋ณด๋ฉด ์—ญ๋ฅ ์ด ๋‚ฎ์•„์ง„๋‹ค. ๊ทธ๋ž˜์„œ ๋ฐœ์ „๊ธฐ์—์„œ ๋ถ€์กฑํ•œ ์—ญ๋ฅ ์„ ๋ณด์ƒํ•  ํ•„์š”๊ฐ€ ์žˆ๋‹ค. ์ด๊ฐ™์ด ๋‚ฎ์€ ์—ญ๋ฅ ์„ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด ์œ ๋„๋ฐœ์ „๊ธฐ์— ์ปคํŒจ์‹œํ„ฐ๋ฅผ ๋‹ฌ์•„ ๋ถ€์กฑํ•œ ๋ฌดํšจ์ „๋ ฅ์„ ๋ณด์ƒํ•˜๋Š”๋ฐ ๊ณ ์กฐํŒŒ์˜ ์ €๊ฐ๊ณผ ์ปคํŒจ์‹œํ„ฐ ํˆฌ์ž…์‹œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜ ์–ต์ œ๋ฅผ ์œ„ํ•ด ์ปคํŒจ์‹œํ„ฐ์— ์ถ”๊ฐ€๋กœ ๋ฆฌ์•กํ„ฐ๋ฅผ ์—ฐ๊ฒฐํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ์žˆ๋‹ค[5,9,10]. ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•˜๋Š” ๊ฒฝ์šฐ ์œ ๋„๋ฐœ์ „๊ธฐ ๋Œ์ž…์ „๋ฅ˜์™€ ์ „์••์˜ ๋ณ€ํ™”์— ์–ด๋–ค ์˜ํ–ฅ์„ ๋ฏธ์น˜๋Š”์ง€์— ๋Œ€ํ•œ ๋ถ„์„์ด ํ•„์š”ํ•˜๋‹ค.

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ๋งˆ์ดํฌ๋กœ๊ธ‰ ์ €์•• ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ๋‚ฎ์€ ์—ญ๋ฅ ์„ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด ์ปคํŒจ์‹œํ„ฐ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ์™€ ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ ๊ทธ๋ฆฌ๊ณ  ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•ด์„œ ์‚ฌ์šฉํ•  ๋•Œ ๊ณ„ํ†ต์— ๋ฏธ์น˜๋Š” ๋Œ์ž…์ „๋ฅ˜์™€ ์ „์••๊ฐ•ํ•˜ ๊ทธ๋ฆฌ๊ณ  ์—ญ๋ฅ  ๋ณด์ƒ์— ๋Œ€ํ•ด ๋ถ„์„ํ•˜์˜€๋‹ค.

2. ๊ณ„ํ†ต ๊ตฌ์„ฑ ๋ฐ ๋ฌดํšจ์ „๋ ฅ ๋ณด์ƒ

๊ทธ๋ฆผ 1์€ ์ˆ˜์ฐจ๋ฐœ์ „๊ธฐ๋ฅผ ํ†ตํ•ด ์ƒ์‚ฐ๋œ ์ „๋ ฅ์ด ๋ณ€์••๊ธฐ๋ฅผ ๊ฑฐ์ณ ๋ฐฐ์ „์„ ๋กœ์— ์—ฐ๊ฒฐ๋˜๋Š” ๋‹จ์ƒ ๋“ฑ๊ฐ€ํšŒ๋กœ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค. ์œ ๋„๋ฐœ์ „๊ธฐ์™€ ๋ณ€์••๊ธฐ 2์ฐจ ์‚ฌ์ด์—๋Š” ์—ญ๋ฅ  ๋ณด์ƒ์— ํ•„์š”ํ•œ ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ๊ฐ€ ๋ถ€์ฐฉ๋˜์–ด ์žˆ๋‹ค.

๊ทธ๋ฆผ 1. ์ˆ˜์ฐจ๋ฐœ์ „๊ธฐ - ๋ฐฐ์ „์„ ๋กœ ์—ฐ๊ฒฐ๋„

Fig. 1. Water turbine generator - Distribution line connection diagram

../../Resources/kiee/KIEEP.2022.71.1.35/fig1.png

์œ ๋„๋ฐœ์ „๊ธฐ๋Š” ์œ ๋„์„ฑ ๋ถ€ํ•˜๋กœ ํšŒ์ „์ž๊ณ„๋ฅผ ๊ณ„์† ์œ ์ง€ํ•˜๊ธฐ ์œ„ํ•ด ๋ฌดํšจ์ „๋ ฅ์„ ๊ณ„์†ํ•ด์„œ ๊ณต๊ธ‰๋ฐ›์•„์•ผ ํ•œ๋‹ค. ์ด ๋ฌดํšจ์ „๋ ฅ์€ ์ „์›์œผ๋กœ๋ถ€ํ„ฐ ๊ณต๊ธ‰๋ฐ›์•„์•ผ ํ•˜๋ฏ€๋กœ ๊ณ„ํ†ต์—์„œ์˜ ์—ญ๋ฅ ์ด ๋‚ฎ๋‹ค[ ]. ๋‚ฎ์•„์ง„ ์—ญ๋ฅ ์„ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•ด์„œ ๋ณด์ƒํ•˜์—ฌ์•ผ ํ•œ๋‹ค. ์—ญ๋ฅ  ๋ณด์ƒ์„ ์œ„ํ•ด ์œ ๋„๋ฐœ์ „๊ธฐ 2์ฐจ์— ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ์˜ ์šฉ๋Ÿ‰์€ ๋‹ค์Œ ์‹ (1) ๊ฐ™์ด ๊ตฌํ•œ๋‹ค.

(1)
Qc=P(tanฮธ1โˆ’tanฮธ2)

์—ฌ๊ธฐ์„œ P ๋Š” ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์œ ํšจ์ „๋ ฅ์ด๊ณ , ฮธ1 ๋Š” ๋ณด์ƒ ์ „์˜ ์—ญ๋ฅ ๊ฐ์ด๋ฉฐ, ฮธ2๋Š” ๋ณด์ƒ ํ›„์˜ ์—ญ๋ฅ ๊ฐ์ด๋‹ค.

์ผ๋ฐ˜์ ์œผ๋กœ ์ „๋ ฅํšŒ์‚ฌ์—์„œ๋Š” ๋ณ€์••๊ธฐ ์šฉ๋Ÿ‰์— ๋”ฐ๋ผ ์ปคํŒจ์‹œํ„ฐ์˜ ์šฉ๋Ÿ‰์€ 3~5% ์ •๋„๋กœ ์„ค์น˜ํ•˜๋Š” ๊ฒƒ์„ ๊ถŒ์žฅํ•˜๊ณ  ์žˆ๋‹ค[9,10].

์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์—ญ๋ฅ  ๋ณด์ƒ์„ ์œ„ํ•ด ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜์™€ ๋น„์„ ํ˜• ๋ถ€ํ•˜์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๊ณ ์กฐํŒŒ ์ „๋ฅ˜ ์ €๊ฐ์„ ์œ„ํ•ด ์ปคํŒจ์‹œํ„ฐ์— ์ง๋ ฌ๋กœ ๋ฆฌ์•กํ„ฐ๋ฅผ ๋ถ€์ฐฉํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ์žˆ๋‹ค. ์ด๋•Œ ์„ค์น˜ํ•˜๋Š” ๋ฆฌ์•กํ„ฐ๋Š” ์ปคํŒจ์‹œํ„ฐ์˜ ์šฉ๋Ÿ‰๊ณผ ์ „์••์— ๋”ฐ๋ผ ํฌ๊ธฐ๋ฅผ ๋‹ค๋ฅด๊ฒŒ ์ ์šฉํ•˜๊ณ  ์žˆ๋‹ค[9,10]. ์ ์šฉํ•˜๋Š” ๋ฆฌ์•กํ„ฐ์˜ ํฌ๊ธฐ๋Š” ๋ณดํ†ต ์ปคํŒจ์‹œํ„ฐ์˜ 6% ํฌ๊ธฐ์— ํ•ด๋‹นํ•˜๋Š” ์šฉ๋Ÿ‰์„ ์‚ฌ์šฉํ•˜๊ณ  ์žˆ๋‹ค[9,10]. ๋ฆฌ์•กํ„ฐ๋ฅผ ํฌํ•จํ•˜๋Š” ๊ฒฝ์šฐ ๋ฌดํšจ์ „๋ ฅ์˜ ํฌ๊ธฐ๋Š” ๋ฆฌ์•กํ„ฐ์˜ ์šฉ๋Ÿ‰์„ ๊ณ ๋ คํ•˜์—ฌ ๋‹ค์Œ ์‹ (2)์™€ ๊ฐ™์ด ๊ตฌํ•œ๋‹ค.

(2)
Qโ€ฒc=Qc+QL

์—ฌ๊ธฐ์„œ QL ์€ ๋ฆฌ์•กํ„ฐ ์šฉ๋Ÿ‰์„ ๋‚˜ํƒ€๋‚ธ๋‹ค. ๋ฆฌ์•กํ„ฐ๋ฅผ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ ๋ฆฌ์•กํ„ฐ์˜ ์ „๋ ฅ์€ 0 ์œผ๋กœ ๊ฐ„์ฃผํ•˜๋ฉด ๋œ๋‹ค.

์ปคํŒจ์‹œํ„ฐ๋ฅผ ๋ถ€์ฐฉํ•œ ์ดํ›„ ๊ฐœ์„ ๋œ ์—ญ๋ฅ ์€ ๋‹ค์Œ ์‹ (3)๊ณผ ๊ฐ™์ด ๊ตฌํ•˜๋ฉด ๋œ๋‹ค. ์ปคํŒจ์‹œํ„ฐ๊ฐ€ ์ถ”๊ฐ€๋˜๋ฉด ๋ถ„๋ชจ๋Š” ์ž‘์•„์ง€๋ฏ€๋กœ ์—ญ๋ฅ ์€ ํ–ฅ์ƒ๋œ๋‹ค.

(3)
pfโ€ฒ=PโˆšP2+(Q1โˆ’Qโ€ฒc)2=PโˆšP2+Q22

์—ฌ๊ธฐ์„œ Q1 ๋Š” ์—ญ๋ฅ  ๋ณด์ƒ ์ „์˜ ๋ฐœ์ „๊ธฐ์˜ ๋ฌดํšจ์ „๋ ฅ์ด๊ณ , Q2 ๋Š” ์—ญ๋ฅ  ๋ณด์ƒ ํ›„์˜ ๋ฌดํšจ์ „๋ ฅ์ด๋‹ค.

ํšŒ์ „์ž๊ณ„๋ฅผ ๋งŒ๋“œ๋Š”๋ฐ ํ•„์š”ํ•œ ๋ฌดํšจ์ „๋ ฅ์€ ์žํ™”์ „๋ฅ˜์™€ ๊ด€๊ณ„๊ฐ€ ์žˆ๋‹ค[4,7,8]. ์žํ™”์ „๋ฅ˜ Im์€ ๋‹ค์Œ ์‹ (4)์™€ ๊ฐ™์ด ๊ณ ์ •์ž ์ „๋ฅ˜ Is ์™€ ์—ญ๋ฅ ์˜ ๊ณฑ์œผ๋กœ ํ‘œํ˜„ํ•  ์ˆ˜ ์žˆ๋‹ค[4].

(4)
Im=Issinฮธ=Isร—โˆš1โˆ’cosฮธ2=Isร—โˆš1โˆ’pf2

์—ญ๋ฅ ์ด ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝ์šฐ ๋ฐœ์ „๊ธฐ์— ํ•„์š”ํ•œ ์žํ™”์ „๋ฅ˜๋Š” ๊ฐ์†Œํ•˜๊ฒŒ ๋˜๋ฏ€๋กœ ๋ฌดํšจ์ „๋ ฅ์˜ ํฌ๊ธฐ๋„ ์ค„์–ด๋“ค๊ฒŒ ๋œ๋‹ค.

๋ฆฌ์•กํ„ฐ์˜ ํŒŒ๋ผ๋ฏธํ„ฐ ์‚ฐ์ถœ์‹œ ์ ์šฉํ•˜๋Š” ์ „์••์˜ ํฌ๊ธฐ VL ์€ ์ปคํŒจ์‹œํ„ฐ์— ์ ์šฉํ•˜๋Š” ์ „์••์— 6%์— ํ•ด๋‹นํ•˜๋Š” ํฌ๊ธฐ๋ฅผ ์ ์šฉํ•˜๋ฉด ๋œ๋‹ค[5]. ์ด๋•Œ ์„ ์ •ํ•˜๋Š” 6%๋Š” ๊ณ ์กฐํŒŒ์— ์˜ํ•œ ๊ณต์ง„์„ ํ”ผํ•˜๊ธฐ ์œ„ํ•œ ๋ฒ”์œ„์˜ ๊ฐ’์ด๋‹ค.

(5)
VL=6

์—ฌ๊ธฐ์„œ Vc ๋Š” ์ปคํŒจ์‹œํ„ฐ์˜ ์ƒ์ „์••์ด๋‹ค.

์—ญ๋ฅ  ๋ณด์ƒ์„ ์œ„ํ•ด ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ์˜ ํŒŒ๋ผ๋ฏธํ„ฐ๋Š” ๋‹ค์Œ๊ณผ ๊ฐ™์ด ๊ตฌํ•˜๋ฉด ๋œ๋‹ค.

(6)
C=Qc2ฯ€fร—V2c
(7)
L=QL2ฯ€fร—V2L

3. ์‹œ๋ฎฌ๋ ˆ์ด์…˜ ๋ฐ ๋ถ„์„

๊ทธ๋ฆผ 1๊ณผ ๊ฐ™์ด ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ๋ฌดํšจ์ „๋ ฅ์„ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด ์„ค์น˜ํ•œ ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ์˜ ์ถ”๊ฐ€๋กœ ๋ฐœ์ƒํ•˜๋Š” ๋ฌธ์ œ๋ฅผ ๋ถ„์„ํ•˜๊ธฐ ์œ„ํ•ด ์ ์šฉํ•œ ์ €์•• 3์ƒ ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์‚ฌ์–‘์€ ํ‘œ 1๊ณผ ๊ฐ™๋‹ค.

ํ‘œ 1 ์œ ๋„ ๋ฐœ์ „๊ธฐ์˜ ์‚ฌ์–‘

Table 1 Induction generator specification

Item

Value

Voltage

380V

Capacity

50ใŽพ

Pole pair

4

Efficiency

97%

Power factor

0.77

๋ฐœ์ „๊ธฐ์—์„œ ๋ฐœ์ƒํ•œ ์ „๋ ฅ์„ ๊ณ„ํ†ต์œผ๋กœ ๋ณด๋‚ผ ๋•Œ ์ •ํ™•ํ•˜๊ฒŒ ์•Œ๊ณ  ์žˆ์–ด์•ผ ํ•˜๋Š” ๊ฒƒ ์ค‘ ํ•˜๋‚˜๊ฐ€ ๋ฐ”๋กœ ์—ญ๋ฅ ์ด๋‹ค. ์ด๋Š” ๋ฐฐ์ „๊ณ„ํ†ต์—์„œ ์š”๊ตฌํ•˜๋Š” ์—ญ๋ฅ ์„ ์œ ์ง€ํ•  ์ˆ˜ ์žˆ๋„๋ก ์„ค์น˜ํ•ด์•ผ ํ•  ์ฝ˜๋ด์„œ์˜ ํฌ๊ธฐ๋ฅผ ๊ณ„์‚ฐํ•˜๊ธฐ ์œ„ํ•œ ์ „์ œ ์กฐ๊ฑด์ด๋‹ค. ์œ ๋„๋ฐœ์ „๊ธฐ์™€ ๋ฐฐ์ „์„ ๋กœ๋ฅผ ์—ฐ๊ฒฐํ•˜๋Š” ๋ณ€์••๊ธฐ๋Š” ๋ฐœ์ „๊ธฐ์˜ ์šฉ๋Ÿ‰๋ณด๋‹ค 3๋ฐฐ ์ด์ƒ์˜ ํฌ๊ธฐ๋ฅผ ๊ฐ€์ง„ 150kVA๋ฅผ ์ ์šฉํ•˜์˜€๋‹ค. ์ด๋•Œ ์ „๋ ฅํšŒ์‚ฌ์˜ ๊ถŒ๊ณ ์— ๋”ฐ๋ผ ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ๋Š” ๋ณ€์••๊ธฐ ์šฉ๋Ÿ‰์˜ 5%์— ํ•ด๋‹นํ•˜๋Š” 7.5kVA์˜ ์šฉ๋Ÿ‰์„ ์„ค์น˜ํ•˜๋ฉด ๋œ๋‹ค.

์—ญ๋ฅ  ๋ณด์ƒ์„ ์œ„ํ•ด ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ๊ฐ€ ์ผ์ • ๋ฒ”์œ„๋ฅผ ๋„˜๋Š” ๊ฒฝ์šฐ ์ž๊ธฐ ์—ฌ์ž ํ˜„์ƒ์˜ ๋ฐœ์ƒ์œผ๋กœ ๋ฐœ์ „๊ธฐ์˜ ๊ถŒ์„  ์ ˆ์—ฐ์„ ์†์ƒ์‹œํ‚ฌ ์ˆ˜ ์žˆ์œผ๋ฏ€๋กœ ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์žํ™”์ „๋ฅ˜๋ณด๋‹ค ๋‚ฎ๋„๋ก ์„ ์ •ํ•˜๊ณ  ์žˆ๋‹ค[5,7]. ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ๋‚ฎ์€ 77% ์—ญ๋ฅ ์„ 95% ์ •๋„๋กœ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด ์ปคํŒจ์‹œํ„ฐ๋งŒ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ๋Š” ์•ฝ 20kVA ํฌ๊ธฐ๋ฅผ ์ถœ๋ ฅ๋‹จ์— ์„ค์น˜ํ•˜๋ฉด ๋ฐœ์ „๊ธฐ์— ํ•„์š”ํ•œ ๋ฌดํšจ์ „๋ ฅ์„ ์ œ๊ณตํ•  ์ˆ˜ ์žˆ๋‹ค. ๊ทธ๋Ÿฌ๋‚˜ ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•˜๋Š” ๊ฒฝ์šฐ ์‹ (2)์™€ ๊ฐ™์ด ์ปคํŒจ์‹œํ„ฐ์˜ ์šฉ๋Ÿ‰์€ ์ด๋ณด๋‹ค ์•ฝ๊ฐ„ ๋†’๊ฒŒ ์„ค์ •ํ•˜์—ฌ์•ผ ํ•œ๋‹ค. ๋ฌดํšจ์ „๋ ฅ์„ 20kVA์— ๊ฐ€๊น๊ฒŒ ์„ค์ •ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ์ปคํŒจ์‹œํ„ฐ์˜ ์šฉ๋Ÿ‰์— ์•ฝ 6%๊ฐ€ ๋˜๋„๋ก ๋ฆฌ์•กํ„ฐ๋ฅผ ํฌํ•จํ•˜๋Š” ๊ฒฝ์šฐ ์ปคํŒจ์‹œํ„ฐ๋Š” 21.3kVA๋กœ ์กฐ์ •ํ•˜๋ฉด ๋œ๋‹ค. ์ด๋•Œ ๋ฆฌ์•กํ„ฐ๋Š” 1.278kVA๊ฐ€ ๋œ๋‹ค. ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ์˜ ๊ฐ ํŒŒ๋ผ๋ฏธํ„ฐ๋Š” ์‹ (6)๋ฐ (7)๋กœ ๊ตฌํ•  ์ˆ˜ ์žˆ๋‹ค.

๋ณธ ์—ฐ๊ตฌ์—์„œ๋Š” ํ‘œ 1์— ์ œ์‹œ๋œ ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๊ทธ๋ฆผ 1๊ณผ ๊ฐ™์€ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•˜์—ฌ ์šด์ „ํ•  ๋•Œ ์ปคํŒจ์‹œํ„ฐ๋ฅผ ๋ถ€์ฐฉํ•˜์ง€ ์•Š์€ ๊ฒฝ์šฐ, ์ปคํŒจ์‹œํ„ฐ๋งŒ ๋ถ€์ฐฉํ•˜๋Š” ๊ฒฝ์šฐ ๊ทธ๋ฆฌ๊ณ  ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ๋ฅผ ํ•จ๊ป˜ ๋ถ€์ฐฉํ•˜๋Š” ๊ฒฝ์šฐ์˜ ํŠน์„ฑ ๋ณ€ํ™”๋ฅผ ์ „์ž๊ณ„ ๊ณผ๋„ํ•ด์„ ํ”„๋กœ๊ทธ๋žจ์œผ๋กœ ๋ถ„์„ํ•˜์˜€๋‹ค[11].

์šฐ์„  ์ฒซ ๋ฒˆ์งธ๋กœ ์œ ๋„๋ฐœ์ „๊ธฐ์— ์—ญ๋ฅ  ๋ณด์ƒ ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์‚ฌ์šฉํ•˜์ง€ ์•Š๋Š” ๊ฒฝ์šฐ ๋Œ์ž…์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ๋ณ€ํ™”๋ฅผ ๋ชจ์˜ํ•˜์˜€๋‹ค. ์œ ๋„๋ฐœ์ „๊ธฐ๋Š” ์ •์ง€์ƒํƒœ์—์„œ ๊ธฐ๋™ํ•˜์—ฌ ์†๋„๋ฅผ ์ฆ๊ฐ€ํ•œ ๋‹ค์Œ ๋™๊ธฐ์†๋„์—์„œ ๊ณ„ํ†ต์— ํˆฌ์ž…ํ•ด์„œ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 2. ์ปคํŒจ์‹œํ„ฐ๋ฅผ ๋ถ€์ฐฉํ•˜์ง€ ์•Š์„ ๋•Œ ์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ 

Fig. 2. Current, voltage drop, power and power factor w/o capacitor

../../Resources/kiee/KIEEP.2022.71.1.35/fig2.png

Fig. 2(a)์™€ ๊ฐ™์ด ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜๋Š” ์ •๊ฒฉ ์šด์ „์ „๋ฅ˜(76.67A)์˜ 7๋ฐฐ์—์„œ 8.7๋ฐฐ์— ํ•ด๋‹นํ•˜๋ฉฐ, ์ด๋•Œ ์ˆœ๊ฐ„์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ์ „์••๊ฐ•ํ•˜๋Š” Fig. 2(b)์™€ ๊ฐ™์ด 12.2% ์ •๋„์ด๊ณ , ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„์—๋„ ์•ฝ 1V ์ •๋„์˜ ์ „์••๊ฐ•ํ•˜๊ฐ€ ๋ฐœ์ƒํ•˜๊ณ  ์žˆ๋‹ค. ์ €์••์ธก(LV)์—์„œ ๋ฐœ์ƒํ•œ 10%๋ฅผ ์ดˆ๊ณผํ•˜๋Š” ์ „์••๊ฐ•ํ•˜๋Š” 10% ์ดํ•˜๊ฐ€ ๋˜๋„๋ก ๋ณ€์••๊ธฐ์˜ ์šฉ๋Ÿ‰์„ ๋†’์ด๊ฑฐ๋‚˜ ๋Œ์ž…์ „๋ฅ˜์˜ ์ €๊ฐ ๋“ฑ์˜ ๊ธฐ๋™ ๋ฐฉ๋ฒ•์˜ ๊ฐœ์„ ์ด ํ•„์š”ํ•  ์ˆ˜ ์žˆ๋‹ค[12]. ๊ณ ์••์ธก(HV)์˜ ์ „์••๊ฐ•ํ•˜๋Š” Fig. 2(c)์™€ ๊ฐ™์ด ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ๋‚˜ํƒ€๋‚˜๋„ ์ „์••๊ฐ•ํ•˜๋Š” ๋ฐฐ์ „์„ ๋กœ 22.9ใŽธ์—์„œ ๋ณผ ๋•Œ 60V ์ •๋„๋กœ ์•„์ฃผ ๋‚ฎ์•„ 0.3%์˜ ์ „์••๊ฐ•ํ•˜๋กœ ๋ฐฐ์ „์„ ๋กœ์— ๋ฌธ์ œ๊ฐ€ ๋ฐœ์ƒํ•  ์ •๋„๋Š” ์•„๋‹ˆ๋‹ค. ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„ ์ „์••์€ ๊ณ„ํ†ต ์—ฐ๊ฒฐ ์ „๊ณผ ๊ฑฐ์˜ ์ฐจ์ด๊ฐ€ ๋‚˜์ง€ ์•Š๋Š”๋‹ค. Fig. 2(d)๋Š” ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๋™๊ธฐ์†๋„์—์„œ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ์œ ํšจ์ „๋ ฅ(โ—‹), ๋ฌดํšจ์ „๋ ฅ(โ–ก), ํ”ผ์ƒ์ „๋ ฅ(โ–ณ) ๋ฐ ์—ญ๋ฅ (ร—)์˜ ํฌ๊ธฐ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์œผ๋กœ์„œ ์œ ํšจ์ „๋ ฅ์€ โ€“38.92ใŽพ๋กœ ๋ฐœ์ „๊ธฐ์—์„œ ์ƒ์‚ฐ๋œ ์ „๋ ฅ์ด ๊ณ„ํ†ต์œผ๋กœ ์—ญ์œผ๋กœ ๊ณต๊ธ‰๋จ์„ ์˜๋ฏธํ•˜๊ณ , 32.247kVAR์€ ๋ฌดํšจ์ „๋ ฅ์˜ ํฌ๊ธฐ๋กœ ์œ ๋„๋ฐœ์ „๊ธฐ์— ํ•„์š”ํ•œ ์šฉ๋Ÿ‰์œผ๋กœ ์ „์›์ธก์—์„œ ๋ฐœ์ „๊ธฐ๋กœ ๊ณต๊ธ‰๋˜์–ด์•ผ ํ•จ์„ ์˜๋ฏธํ•œ๋‹ค. ์ด๋•Œ์˜ ์—ญ๋ฅ ์€ 0.77์ด๋‹ค.

๋‘ ๋ฒˆ์งธ๋Š” ์œ ๋„๋ฐœ์ „๊ธฐ์— ์—ญ๋ฅ  ๋ณด์ƒ ์ปคํŒจ์‹œํ„ฐ๋งŒ์„ ์„ค์น˜ํ•œ ๊ฒฝ์šฐ์˜ ๋Œ์ž…์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ๋ณ€ํ™”๋ฅผ ๋ชจ์˜ํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 3. ์ปคํŒจ์‹œํ„ฐ๋ฅผ ๋ถ€์ฐฉํ•  ๋•Œ ์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ 

Fig. 3. Current, voltage drop, power and power factor with capacitor

../../Resources/kiee/KIEEP.2022.71.1.35/fig3.png

Fig. 3(a)์™€ ๊ฐ™์ด ๊ณ„ํ†ต ์—ฐ๊ณ„์‹œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜๋Š” ์ •๊ฒฉ ์šด์ „์ „๋ฅ˜(64.295A)์˜ 7๋ฐฐ์—์„œ 8.7๋ฐฐ์— ํ•ด๋‹นํ•˜๋ฉฐ, ์ด๋•Œ ์ˆœ๊ฐ„์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ์ „์••์ƒ์Šน์€ ํˆฌ์ž… ์ „๊ณผ ๋น„๊ตํ•ด ์•ฝ 30V์— ๊ฐ€๊นŒ์šด ์ „์••์ด ์ˆœ๊ฐ„์ ์œผ๋กœ ๋ฐœ์ƒํ•œ๋‹ค. ์ˆœ๊ฐ„์ ์ธ ์ „์••์ƒ์Šน ํ›„ ๋ฐœ์ƒํ•˜๋Š” ์ „์••๊ฐ•ํ•˜๋Š” Fig. 3(b)์™€ ๊ฐ™์ด 11.4% ์ •๋„์ด๊ณ , ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„์—๋Š” ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒƒ์— ๋น„ํ•ด ์•ฝ 1V ์ •๋„์˜ ์ „์••์ƒ์Šน์ด ์ผ์–ด๋‚œ๋‹ค. ์ €์••(LV)์ธก์—์„œ ์ „์••๊ฐ•ํ•˜๊ฐ€ 10%๋ฅผ ์ดˆ๊ณผํ•˜๊ธฐ ๋•Œ๋ฌธ์— ์ด ์ „์••๊ฐ•ํ•˜๋ฅผ 10% ์ดํ•˜๊ฐ€ ๋˜๋„๋ก ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๋ณ€์••๊ธฐ์˜ ์šฉ๋Ÿ‰์„ ๋†’์ด๊ฑฐ๋‚˜ ๋Œ์ž…์ „๋ฅ˜์˜ ์ €๊ฐ ๋“ฑ์˜ ๊ธฐ๋™ ๋ฐฉ๋ฒ•์˜ ๊ฐœ์„ ์ด ํ•„์š”ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ๋ฐœ์ƒํ•˜๋Š” ์‹œ์ ์—์„œ ์ˆœ๊ฐ„์ ์œผ๋กœ ์ „์••์ƒ์Šน์ด ๋ฐœ์ƒํ•˜๊ณ  ์žˆ๋‹ค. ๊ณ ์••(HV)์ธก์˜ ์ „์••๊ฐ•ํ•˜๋Š” Fig. 3(c)์™€ ๊ฐ™์ด ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ๋‚˜ํƒ€๋‚˜๋„ ์ „์••๊ฐ•ํ•˜๋Š” ๋ฐฐ์ „์„ ๋กœ 22.9ใŽธ์—์„œ ๋ณผ ๋•Œ ์•ฝ 60V ์ดํ•˜๋กœ 0.3%์˜ ๋‚ฎ์•„ ์ „์••๊ฐ•ํ•˜์œจ๋กœ ๋ฐฐ์ „์„ ๋กœ์— ๋ฏธ์น˜๋Š” ์˜ํ–ฅ์€ ๋ฏธ๋ฏธํ•œ ํŽธ์ด๋‹ค. ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„ ์ „์••์€ ๊ณ„ํ†ต ์—ฐ๊ฒฐํ•˜๊ธฐ ์ „๋ณด๋‹ค ์•ฝ 1V์˜ ์ „์••์ด ์ƒ์Šนํ•˜์˜€๋‹ค. Fig. 3(d)๋Š” ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๋™๊ธฐ์†๋„์—์„œ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ์œ ํšจ์ „๋ ฅ, ๋ฌดํšจ์ „๋ ฅ, ํ”ผ์ƒ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ํฌ๊ธฐ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์œผ๋กœ์„œ ์œ ํšจ์ „๋ ฅ์€ โ€“38.89ใŽพ๋กœ ๋ฐœ์ „๊ธฐ์—์„œ ์ƒ์‚ฐ๋œ ์ „๋ ฅ์ด ๊ณ„ํ†ต์œผ๋กœ ๊ณต๊ธ‰๋จ์„ ์˜๋ฏธํ•˜๊ณ , ์—ญ๋ฅ  ๋ณด์ƒ ์ „์— ๋ฐœ์ „๊ธฐ์— ํ•„์š”ํ•œ ๋ฌดํšจ์ „๋ ฅ 32.247kVAR์—์„œ 13.056kVAR๋กœ ์•ฝ 19.191kVAR๊ฐ€ ์ค„์–ด๋“  ๊ฒƒ์„ ์•Œ ์ˆ˜ ์žˆ๋‹ค. ์ด๋Š” ๊ณ„ํ†ต์—์„œ ๋ฐœ์ „๊ธฐ์— ๊ณต๊ธ‰ํ•ด์•ผ ํ•˜๋Š” ๋ฌดํšจ์ „๋ ฅ์ด ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์—ฐ๊ฒฐํ•˜์—ฌ ๋ณด์ƒํ•˜์˜€๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ๋”ฐ๋ผ์„œ ์—ญ๋ฅ ์€ 0.77์—์„œ 0.948๋กœ ํ–ฅ์ƒ๋˜์—ˆ๋‹ค.

์„ธ ๋ฒˆ์งธ๋กœ ์œ ๋„๋ฐœ์ „๊ธฐ์— ์—ญ๋ฅ  ๋ณด์ƒ ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ ์‚ฌ์šฉํ•˜๋Š” ๊ฒฝ์šฐ ๋Œ์ž…์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ๋ณ€ํ™”๋ฅผ ๋ชจ์˜ํ•˜์˜€๋‹ค. ๋ฆฌ์•กํ„ฐ์˜ ์ถ”๊ฐ€๋กœ ์ปคํŒจ์‹œํ„ฐ ์šฉ๋Ÿ‰์€ ๋‘ ๋ฒˆ์งธ ๋ณด๋‹ค ์•ฝ๊ฐ„ ๋†’๊ฒŒ ์„ค์ •ํ•˜์˜€๋‹ค.

๊ทธ๋ฆผ 4. ์ปคํŒจ์‹œํ„ฐ์™€ ๋ฆฌ์•กํ„ฐ์‹œ ์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜ ๋ฐ ์ „๋ ฅ๊ณผ ์—ญ๋ฅ 

Fig. 4. Current, voltage drop, power and power factor with capacitor & reactor

../../Resources/kiee/KIEEP.2022.71.1.35/fig4.png

Fig. 4(a)์™€ ๊ฐ™์ด ๊ณ„ํ†ต ์—ฐ๊ณ„์‹œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜๋Š” ์ •๊ฒฉ ์šด์ „์ „๋ฅ˜(63A)์˜ 8.6๋ฐฐ์—์„œ 10.7๋ฐฐ์— ํ•ด๋‹นํ•˜๋ฉฐ, ์ด๋•Œ ์ˆœ๊ฐ„์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ๋ณ€์••๊ธฐ 2์ฐจ์—์„œ์˜ ์ „์••๊ฐ•ํ•˜๋Š” Fig. 4(b)์™€ ๊ฐ™์ด 11.6% ์ •๋„์ด๊ณ , ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„์—๋Š” ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒƒ์— ๋น„ํ•ด ์•ฝ 1V ์ •๋„์˜ ์ „์••์ƒ์Šน์ด ์ผ์–ด๋‚œ๋‹ค. ๋ณ€์••๊ธฐ 2์ฐจ(LV)์—์„œ ๋ฐœ์ƒํ•œ 10%๋ฅผ ์ดˆ๊ณผํ•˜๋Š” ์ „์••๊ฐ•ํ•˜๋Š” 10% ์ดํ•˜๊ฐ€ ๋˜๋„๋ก ๋ณ€์••๊ธฐ์˜ ์šฉ๋Ÿ‰์„ ๋†’์ด๊ฑฐ๋‚˜ ๋Œ์ž…์ „๋ฅ˜๋ฅผ ์ค„์ด๊ธฐ ์œ„ํ•œ ๊ธฐ๋™ ๋ฐฉ๋ฒ•์˜ ๊ฐœ์„ ์ด ํ•„์š”ํ•  ์ˆ˜ ์žˆ๋‹ค. ๋ฆฌ์•กํ„ฐ์˜ ์ถ”๊ฐ€๋กœ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•˜๋Š” ๊ฒฝ์šฐ ๋Œ์ž…์ „๋ฅ˜์— ์˜ํ•ด ๋ณ€์••๊ธฐ 2์ฐจ์— ์ˆœ๊ฐ„์ ์œผ๋กœ ๋ฐœ์ƒํ•˜๋Š” ์ „์••์ƒ์Šน์€ ๋งค์šฐ ์ค„์–ด๋“  ๊ฒƒ์„ ํ™•์ธํ•˜์˜€๋‹ค. ๊ณ ์••์ธก(HV)์˜ ์ „์••๊ฐ•ํ•˜๋Š” Fig. 4(c)์™€ ๊ฐ™์ด ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ๋‚˜ํƒ€๋‚˜๋„ ์ „์••๊ฐ•ํ•˜๋Š” ๋ฐฐ์ „์„ ๋กœ 22.9ใŽธ์—์„œ ๋ณผ ๋•Œ ์•ฝ 60V๋กœ ์•„์ฃผ ๋‚ฎ์•„ ์ „์••๊ฐ•ํ•˜์— ๋Œ€ํ•œ ๋ฌธ์ œ๋กœ ๋ณด๊ธฐ ์–ด๋ ต๋‹ค. ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์ œ๊ฑฐ๋œ ์ดํ›„ ์ „์••์€ ๊ณ„ํ†ต ์—ฐ๊ฒฐํ•˜๊ธฐ ์ „๋ณด๋‹ค ์•ฝ 1V์˜ ์ „์••์ด ์ƒ์Šนํ•˜์˜€๋‹ค. Fig. 4(d)๋Š” ์œ ๋„๋ฐœ์ „๊ธฐ๋ฅผ ๋™๊ธฐ์†๋„์—์„œ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ์œ ํšจ์ „๋ ฅ, ๋ฌดํšจ์ „๋ ฅ, ํ”ผ์ƒ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ํฌ๊ธฐ๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์œผ๋กœ์„œ ์œ ํšจ์ „๋ ฅ์˜ ํฌ๊ธฐ๋Š” โ€“38.89ใŽพ๋กœ ๋ฐœ์ „๊ธฐ์—์„œ ์ƒ์‚ฐ๋œ ์ „๋ ฅ์ด ๊ณ„ํ†ต์œผ๋กœ ๊ณต๊ธ‰๋จ์„ ์˜๋ฏธํ•˜๊ณ , ์—ญ๋ฅ  ๋ณด์ƒ ์ „์— ๋ฐœ์ „๊ธฐ์— ํ•„์š”ํ•œ 32.247kVAR์˜ ๋ฌดํšจ์ „๋ ฅ์ด ๊ณ„ํ†ต์ธก์—์„œ๋Š” 11.724kVAR๋งŒ ๋ฐœ์ „๊ธฐ๋กœ ๋ณด๋‚ด๋ฉด ๋˜๋ฏ€๋กœ ์•ฝ 20.523kVAR์˜ ๋ฌดํšจ์ „๋ ฅ๊ณต๊ธ‰์ด ๊ณ„ํ†ต์—์„œ๋Š” ์ค„์–ด๋“  ๊ฒƒ์ด๋‹ค. ์ด๋Š” ๊ณ„ํ†ต์—์„œ ๋ฐœ์ „๊ธฐ์— ๊ณต๊ธ‰ํ•˜๋Š” ๋ฌดํšจ์ „๋ ฅ์ด ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์—ฐ๊ฒฐํ•˜์—ฌ ๋ณด์™„ํ•˜์˜€๊ธฐ ๋•Œ๋ฌธ์ด๋‹ค. ๋”ฐ๋ผ์„œ ์—ญ๋ฅ ์€ 0.77์—์„œ 0.957๋กœ ํ–ฅ์ƒ๋˜์—ˆ๋‹ค.

๋‹ค์Œ ํ‘œ 2๋Š” ์—ญ๋ฅ  ๋ณด์ƒ ์ปคํŒจ์‹œํ„ฐ ์„ค์น˜ ์ „ํ›„ ์ „๋ฅ˜, ์ „์••๊ฐ•ํ•˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ๋ณ€ํ™”๋ฅผ ๋‚˜ํƒ€๋‚ธ ๊ฒƒ์ด๋‹ค.

ํ‘œ 2 ์ปคํŒจ์‹œํ„ฐ ์„ค์น˜ ์ „ํ›„ ์ „๋ฅ˜, ์ „๋ ฅ ๋ฐ ์—ญ๋ฅ ์˜ ๋ณ€ํ™”

Table 2 Changes in current, power and pf before and after capacitor installation

๊ตฌ๋ถ„

์šด์ „์ „๋ฅ˜

(A)

๋Œ์ž…์ „๋ฅ˜

(pu)

์œ ํšจ์ „๋ ฅ

(ใŽพ)

๋ฌดํšจ์ „๋ ฅ

(kVAR)

ํ”ผ์ƒ์ „๋ ฅ

(kVA)

์—ญ๋ฅ 

๋ฏธ์„ค์น˜

76.67

6.9~8.7

38.92

32.25

50.54

0.77

์ปคํŒจ์‹œํ„ฐ๋งŒ ์„ค์น˜

64.29

8.7~

10.6

38.90

13.06

41.03

0.948

์ปคํŒจ์‹œํ„ฐ+๋ฆฌ์•กํ„ฐ ์„ค์น˜

63

8.7~10.7

38.90

11.72

40.62

0.957

ํ‘œ 2์—์„œ ์•Œ ์ˆ˜ ์žˆ๋“ฏ์ด ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ ์œ ๋ฌด์— ๊ด€๋ จ ์—†์ด ๋ฐœ์ „๊ธฐ์—์„œ ๋ฐœ์ƒํ•˜์—ฌ ๊ณ„ํ†ต์— ํ˜๋Ÿฌ ๋“ค์–ด๊ฐ€๋Š” ์œ ํšจ์ „๋ ฅ์˜ ํฌ๊ธฐ๋Š” ์ผ์ •ํ•˜๋‹ค.

์ปคํŒจ์‹œํ„ฐ์˜ ์„ค์น˜ ์ „ํ›„ ์šด์ „๋ณ€ํ™”์—์„œ ๋‹ค์Œ๊ณผ ๊ฐ™์€ ๊ฒฐ๊ณผ๋ฅผ ์–ป์—ˆ๋‹ค.

1. ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒƒ์— ๋น„ํ•ด ๋ฐœ์ „๊ธฐ์— ํ๋ฅด๋Š” ์šด์ „์ „๋ฅ˜๋Š” ์ค„์–ด๋“ค์—ˆ๋‹ค.

2. ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ๊ฐ€ ์„ค์น˜ํ•˜์ง€ ์•Š๋Š” ๊ฒƒ์— ๋น„ํ•ด ๋Œ์ž…์ „๋ฅ˜๋Š” ๋” ๋†’๊ฒŒ ๋‚˜ํƒ€๋‚˜๋ฏ€๋กœ ์ด๋ฅผ ์ค„์ผ ์ˆ˜ ์žˆ๋Š” ์ €๊ฐ ๋Œ€์ฑ…์ด ํ•„์š”ํ•˜๋‹ค.

3. ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์„ค์น˜ํ•˜์—ฌ ์—ญ๋ฅ ์„ ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฝ์šฐ ๊ณ„ํ†ต์—์„œ ๋ฐœ์ „๊ธฐ์— ๊ณต๊ธ‰ํ•˜์—ฌ์•ผ ํ•  ๋ฌดํšจ์ „๋ ฅ์€ ๊ฐ์†Œํ•œ๋‹ค.

4. ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•˜๋Š” ๊ฒฝ์šฐ ๊ณ„ํ†ต์— ์—ฐ๊ฒฐํ•  ๋•Œ ์ˆœ๊ฐ„์ ์ธ ์ „์••์ƒ์Šน์„ ์–ต์ œํ•˜๊ณ , ๊ณ„ํ†ต์—์„œ ๊ณต๊ธ‰ํ•˜๋Š” ๋ฌดํšจ์ „๋ ฅ์„ ์ค„์—ฌ ์—ญ๋ฅ ์„ ์•ฝ๊ฐ„ ์ƒ์Šน์‹œํ‚ค๋Š” ํšจ๊ณผ๋ฅผ ๊ฐ€์ง€๊ณ  ์žˆ๋‹ค.

4. ๊ฒฐ ๋ก 

์œ ๋„๋ฐœ์ „๊ธฐ๋Š” ์œ ๋„์„ฑ ๋ถ€ํ•˜๋กœ์„œ ํšŒ์ „์ž๊ณ„๋ฅผ ์œ ์ง€ํ•˜๊ธฐ ์œ„ํ•ด์„œ๋Š” ๋ฌดํšจ์ „๋ ฅ์ด ๊ณ„์†ํ•ด์„œ ๊ณต๊ธ‰๋˜์–ด์•ผ ํ•œ๋‹ค. ์œ ๋„๋ฐœ์ „๊ธฐ ์ž์ฒด๋กœ๋Š” ๋ฌดํšจ์ „๋ ฅ์ด ๋งŒ๋“ค์–ด์ง€์ง€ ์•Š์œผ๋ฏ€๋กœ ์ „์›์ธก์—์„œ ๊ณต๊ธ‰ํ•ด์•ผ ํ•˜๋ฏ€๋กœ ์ „์›์ธก์—์„œ ๋ณด๋ฉด ์—ญ๋ฅ ์ด ๋–จ์–ด์ง„๋‹ค. ์ด ๋–จ์–ด์ง„ ์—ญ๋ฅ ์„ ๋ณด์ƒํ•˜๊ธฐ ์œ„ํ•ด ๋ฐœ์ „๊ธฐ ๋‹จ์ž์— ์ปคํŒจ์‹œํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•˜์—ฌ ๋‚ฎ์•„์ง„ ์—ญ๋ฅ ์„ ์ „๋ ฅํšŒ์‚ฌ์—์„œ ์š”๊ตฌํ•˜๋Š” ์ˆ˜์ค€์œผ๋กœ ์œ ์ง€ํ•˜๊ณ  ์žˆ๋‹ค.

์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์šด์ „์—์„œ ๋‚ฎ์•„์ง„ ์—ญ๋ฅ  ๋ณด์ƒ์„ ์œ„ํ•ด ์„ค์น˜ํ•˜๋Š” ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์ถ”๊ฐ€ํ•˜์—ฌ ์ปคํŒจ์‹œํ„ฐ ํˆฌ์ž…์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜ ์ €๊ฐ๊ณผ ๊ณ ์กฐํŒŒ๋ฅผ ์ค„์ด๊ณ ์ž ์„ค์น˜ํ•˜๋Š” ๊ฒƒ์˜ ํ•ด์„ ๊ฒฐ๊ณผ ์—ญ๋ฅ  ๋ณด์ƒ์—๋Š” ๋„์›€์ด ๋˜๋‚˜, ๋ฐœ์ „๊ธฐ ๊ณ„ํ†ต ํˆฌ์ž…์—์„œ ๋ฐœ์ƒํ•˜๋Š” ๋Œ์ž…์ „๋ฅ˜๊ฐ€ ์˜คํžˆ๋ ค ๋” ์ฆ๊ฐ€ํ•˜๋Š” ๊ฒฐ๊ณผ๋ฅผ ๋‚ณ์„ ์ˆ˜ ์žˆ์œผ๋ฏ€๋กœ ๋ณ„๋„์˜ ๋Œ์ž…์ „๋ฅ˜ ์ €๊ฐ ๋Œ€์ฑ…์ด ํ•„์š”ํ•œ ๊ฒƒ์œผ๋กœ ํŒ๋‹จ๋œ๋‹ค. ์ปคํŒจ์‹œํ„ฐ๋งŒ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ๋ณด๋‹ค ์ปคํŒจ์‹œํ„ฐ์— ๋ฆฌ์•กํ„ฐ๋ฅผ ์„ค์น˜ํ•˜๋Š” ๊ฒฝ์šฐ ๋Œ์ž…์ „๋ฅ˜ ๋ฐœ์ƒ์‹œ ์ˆœ๊ฐ„์ ์ธ ์ „์••์ƒ์Šน์„ ๋‚ฎ์ถ”๋Š” ํšจ๊ณผ๊ฐ€ ์žˆ์Œ๋„ ํ™•์ธํ•˜์˜€๋‹ค.

๋ณธ ์—ฐ๊ตฌ ๊ฒฐ๊ณผ๋Š” ํ–ฅํ›„ ์ €์•• ์œ ๋„๋ฐœ์ „๊ธฐ์˜ ์—ญ๋ฅ  ๋ณด์ƒ๊ณผ ์ง์ž… ๊ธฐ๋™๋ฒ•์˜ ๊ฒ€ํ† ์— ๋„์›€์ด ๋  ๊ฒƒ์ด๋‹ค.

References

1 
2018, New & Renewable Energy Report, MOKE & KEMCOGoogle Search
2 
Jong-Gyeum Kim, 2014.6, A Comparison of the Operating Characteristics of the Synchronous Generator and Induction Generator Applied to the Small Hydroelectric Power Plant, KIEE, Vol. 63p, No. 2, pp. 55-60DOI
3 
2006, Environmentally Friendly Small Hydro Resource Research and Utilization Technology Plan, MOKEGoogle Search
4 
Jong-Gyeum Kim, 2015.9, A Study on the Variation of Power Factor by Connection of the Induction Generator to the Distribution Line, KIEE, Vol. 64p, No. 3, pp. 159-163DOI
5 
Jong-Gyeum Kim, 2017.3, Operating Analysis of Power Factor Compensation Condenser and Series Reactor in the Induction Generator, KIEE, Vol. 66, No. 3, pp. 593-598DOI
6 
Jong-Gyeum Kim, 2016.1, Soft Start-up Characteristics Analysis of Squirrel Cage Induction Generator, KIEE, Vol. 65, No. 1, pp. 103-107DOI
7 
M. Godoy Simoes, Felix A. Farret, 2004, Renewable Energy Systems-Design and Analysis with Induction Generators, CRC PressGoogle Search
8 
S. Chapman, 2005, Electric Machinery Fundamentals, 4th ed. New York, NY: McGraw-Hill EducationGoogle Search
9 
Ji-Yeon. Im, et al., 2015, A Study on the role and performance characteristic of the condense of induction generator at hydro power, KIEE summer conference, pp. 1509-1510Google Search
10 
2006.11, Samhwa Condenser Technical ReportDOI
11 
H.W. Dommel., 1986, Electromagnetic Transients Program. Reference Manual(EMTP Theory Book), BPA, PortlandGoogle Search
12 
1993, IEEE Recommended Practice for Electric Power Distribution for Industrial Plants, IEEE Std. 141-1993 (Revision of IEEE Std. 141-1986)Google Search

์ €์ž์†Œ๊ฐœ

๊น€์ข…๊ฒธ(Jong-Gyeum Kim)
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Jongโ€‘Gyeum Kim received his B.S degree in Electrical Engineering from Dong-A University, Busan, Korea, in 1984, and M.S, and Ph.D degrees in Electrical Engineering from Chungnam National University in 1991 and 1996 respectively. Between 2013 and 2014, he was visiting professor at Wisconsin-madison University, Wisconsin, USA. He has been working at Gangneung-Wonju National University since 1996. His research interest is the design and implementation of Energy Conversion System and Power Quality. Fellow member of the KIEE