{"id":2410,"date":"2026-08-20T07:00:00","date_gmt":"2026-08-19T23:00:00","guid":{"rendered":"https:\/\/cnbygele.com\/blog\/calculate-reactive-power\/"},"modified":"2026-08-24T17:23:09","modified_gmt":"2026-08-24T09:23:09","slug":"calculate-reactive-power","status":"publish","type":"post","link":"https:\/\/cnbygele.com\/vi\/blog\/calculate-reactive-power\/","title":{"rendered":"T\u00ednh to\u00e1n C\u00f4ng su\u1ea5t Ph\u1ea3n kh\u00e1ng: C\u00f4ng th\u1ee9c, Ng\u00f5 v\u00e0o C\u00f4ng su\u1ea5t v\u00e0 Ki\u1ec3m tra Nh\u00e0 m\u00e1y"},"content":{"rendered":"<div class=\"b2b-article\">\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u1ebfn <strong>t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng<\/strong>, h\u00e3y kh\u1edbp c\u00f4ng th\u1ee9c v\u1edbi c\u00e1c s\u1ed1 \u0111o b\u1ea1n \u0111\u00e3 c\u00f3: d\u00f9ng Q = P \u00d7 tan(arccos(PF)) khi bi\u1ebft kilowatt v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t, ho\u1eb7c t\u00ednh c\u1ea1nh tam gi\u00e1c c\u00f2n thi\u1ebfu v\u1edbi Q = \u221a(S\u00b2 \u2212 P\u00b2) khi bi\u1ebft kilovolt-ampere v\u00e0 kilowatt. Trang n\u00e0y d\u1eabn d\u1eaft qua hai h\u01b0\u1edbng \u0111i \u0111\u00f3 c\u1ee7a nh\u00e0 m\u00e1y, ti\u1ebfp theo l\u00e0 c\u1ea1m b\u1eaby gi\u1eefa m\u1ed9t pha v\u00e0 ba pha, r\u1ed3i \u0111\u1ebfn vi\u1ec7c ph\u1ea3i l\u00e0m g\u00ec v\u1edbi con s\u1ed1 kvar.<\/p>\n<nav class=\"b2b-toc\" style=\"background:#f5f8fa;padding:16px 20px;border-radius:8px;margin:0 0 24px\">\n<h2 id=\"contents\" style=\"margin:42px 0 14px;scroll-margin-top:96px\">M\u1ee5c l\u1ee5c<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"#which-meter-inputs-you-need-before-any-formula\">C\u00e1c \u0110\u1ea7u V\u00e0o \u0110\u1ed3ng H\u1ed3 \u0110o N\u00e0o B\u1ea1n C\u1ea7n Tr\u01b0\u1edbc B\u1ea5t K\u1ef3 C\u00f4ng Th\u1ee9c N\u00e0o<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#calculate-q-from-kw-and-power-factor\">T\u00ednh Q t\u1eeb kW v\u00e0 H\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#calculate-q-from-kva-and-kw\">T\u00ednh Q t\u1eeb kVA v\u00e0 kW<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#single-phase-versus-three-phase-line-factors\">H\u1ec7 s\u1ed1 \u0111\u01b0\u1eddng d\u00e2y m\u1ed9t pha so v\u1edbi ba pha<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#mistakes-that-inflate-or-cancel-q-on-mixed-loads\">Nh\u1eefng l\u1ed7i l\u00e0m t\u0103ng ho\u1eb7c h\u1ee7y Q \u0111\u1ed1i v\u1edbi h\u00e0ng h\u1ed7n h\u1ee3p<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#after-you-have-q-choose-capacitor-q-or-an-svg-solution\">Sau Khi B\u1ea1n \u0110\u00e3 C\u00f3 Q: N\u00ean Ch\u1ecdn T\u1ee5 \u0110i\u1ec7n \u0394Q Hay Gi\u1ea3i Ph\u00e1p SVG<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#faqs\">C\u00e1c c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/a><\/li>\n<\/ul>\n<\/nav>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"which-meter-inputs-you-need-before-any-formula\">C\u00e1c \u0110\u1ea7u V\u00e0o \u0110\u1ed3ng H\u1ed3 \u0110o N\u00e0o B\u1ea1n C\u1ea7n Tr\u01b0\u1edbc B\u1ea5t K\u1ef3 C\u00f4ng Th\u1ee9c N\u00e0o<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Ch\u1ecdn c\u00f4ng th\u1ee9c t\u1eeb c\u00e1c c\u1ed9t tr\u00ean thi\u1ebft b\u1ecb ghi d\u1eef li\u1ec7u ho\u1eb7c h\u00f3a \u0111\u01a1n, kh\u00f4ng ph\u1ea3i t\u1eeb m\u1ed9t \u201cph\u01b0\u01a1ng tr\u00ecnh duy nh\u1ea5t\u201d \u0111\u01b0\u1ee3c ghi nh\u1edb.\u201d<\/p>\n<div class=\"b2b-table-scroll\" role=\"region\" aria-label=\"B\u1ea3ng d\u1eef li\u1ec7u c\u00f3 th\u1ec3 cu\u1ed9n\" tabindex=\"0\" style=\"width:100%;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px\">\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Nh\u1eefng g\u00ec b\u1ea1n \u0111\u00e3 c\u00f3<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">H\u1ecd c\u00f4ng th\u1ee9c c\u1ea7n s\u1eed d\u1ee5ng<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">\u0110i\u1ec1u b\u1ea1n \u0111ang c\u1ea7n gi\u1ea3i quy\u1ebft<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">C\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng P (kW) v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = P \u00d7 tan(arccos(PF))<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng hi\u1ec7n t\u1ea1i<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">C\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn S (kVA) v\u00e0 c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng P (kW)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = \u221a(S\u00b2 \u2212 P\u00b2)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng hi\u1ec7n t\u1ea1i<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">\u0110i\u1ec7n \u00e1p RMS, d\u00f2ng \u0111i\u1ec7n RMS v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t PF (ho\u1eb7c \u03c6)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = V I sin\u03c6 (1\u03c6) ho\u1eb7c \u221a3 U I sin\u03c6 (3\u03c6)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng hi\u1ec7n t\u1ea1i t\u1eeb c\u00e1c thi\u1ebft b\u1ecb \u0111i\u1ec7n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu ngu\u1ed3n \u0111i\u1ec7n ch\u1ee9a nhi\u1ec1u th\u00e0nh ph\u1ea7n h\u00e0i, h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t cos\u03c6 tr\u00ean nh\u00e3n m\u00e1y l\u00e0 m\u1ed9t gi\u00e1 tr\u1ecb thay th\u1ebf k\u00e9m hi\u1ec7u qu\u1ea3 cho Q \u0111o \u0111\u01b0\u1ee3c. H\u00e3y s\u1eed d\u1ee5ng \u0111\u1ed3ng h\u1ed3 \u0111o ch\u1ea5t l\u01b0\u1ee3ng \u0111i\u1ec7n n\u0103ng c\u00f3 kh\u1ea3 n\u0103ng hi\u1ec3n th\u1ecb tr\u1ef1c ti\u1ebfp tr\u1ecb s\u1ed1 kvar khi d\u1ea1ng s\u00f3ng kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t s\u00f3ng sin chu\u1ea9n.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u1ec3 bi\u1ebft \u00fd ngh\u0129a c\u1ee7a c\u00e1c c\u1ed9t P \/ Q \/ S, h\u00e3y xem <a href=\"https:\/\/cnbygele.com\/vi\/blog\/active-vs-reactive-power\/\">C\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng v\u00e0 c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng<\/a>. Trang n\u00e0y v\u1eabn \u1edf ph\u1ea7n s\u1ed1 h\u1ecdc.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Vi\u1ebft ranh gi\u1edbi v\u00e0o b\u1ea3ng t\u00ednh tr\u01b0\u1edbc c\u00e1c con s\u1ed1: t\u1ee7 ph\u00e2n ph\u1ed1i ch\u00ednh, thanh c\u00e1i MCC, ho\u1eb7c m\u1ed9t \u0111\u1ed9ng c\u01a1 l\u1edbn duy nh\u1ea5t. Vi\u1ec7c tr\u1ed9n l\u1eabn c\u00e1c ranh gi\u1edbi \u0111\u00f3 l\u00e0 nguy\u00ean nh\u00e2n khi\u1ebfn m\u1ed9t c\u00f4ng th\u1ee9c r\u00f5 r\u00e0ng t\u1ea1o ra m\u1ed9t gi\u00e1 tr\u1ecb kvar v\u00f4 d\u1ee5ng.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/08\/calc-q-featured.webp\" alt=\"B\u1ea3ng \u0111\u1ed3ng h\u1ed3 nh\u00e0 m\u00e1y \u0111\u1ec3 t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng t\u1eeb c\u00e1c ch\u1ec9 s\u1ed1 \u0111\u1ecdc \u0111\u01b0\u1ee3c\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"calculate-q-from-kw-and-power-factor\">T\u00ednh Q t\u1eeb kW v\u00e0 H\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Khi b\u1ed9 ghi d\u1eef li\u1ec7u \u0111\u00e3 in ra kilowatt v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t, h\u00e3y s\u1eed d\u1ee5ng \u0111\u01b0\u1eddng d\u1eabn tan.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">H\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t l\u00e0 c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng chia cho c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn. \u0110\u1ed1i v\u1edbi \u0111\u1ed9 d\u1ecbch pha h\u00ecnh sin, t\u1ef7 s\u1ed1 \u0111\u00f3 l\u00e0 cos \u03c6, do \u0111\u00f3 \u03c6 = arccos(PF) v\u00e0 Q = P \u00d7 tan \u03c6.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">T\u00ednh to\u00e1n theo ki\u1ec3u nh\u00e0 m\u00e1y: m\u1ed9t m\u1ea1ch c\u1ea5p \u0111\u1ed9ng c\u01a1 ti\u00eau th\u1ee5 56 kW v\u1edbi h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t l\u00e0 0,86. Khi \u0111\u00f3 \u03c6 = arccos(0,86), tan \u03c6 \u2248 0,59, v\u00e0 Q \u2248 56 \u00d7 0,59 \u2248 33 kvar.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Tuy\u1ebfn \u0111\u01b0\u1eddng t\u01b0\u01a1ng t\u1ef1 c\u0169ng c\u00f3 hi\u1ec7u l\u1ef1c cho c\u1ea3 m\u1ed9t thanh g\u00f3p n\u1ebfu P v\u00e0 PF l\u00e0 c\u00e1c gi\u00e1 tr\u1ecb thu\u1ed9c v\u1ec1 thanh g\u00f3p \u0111\u00f3, ch\u1ee9 kh\u00f4ng ph\u1ea3i c\u1ee7a m\u1ed9t nh\u00e3n th\u00f4ng s\u1ed1 \u0111\u1ed9ng c\u01a1 \u0111\u01a1n l\u1ebb trong khi c\u00e1c t\u1ea3i kh\u00e1c \u0111ang ho\u1ea1t \u0111\u1ed9ng.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">H\u00e3y ghi nh\u1edb quy \u0111\u1ecbnh v\u1ec1 d\u1ea5u. C\u00e1c t\u1ea3i c\u1ea3m kh\u00e1ng c\u00f3 \u0111\u1ed9 tr\u1ec5 nh\u1eadn c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng $Q$ d\u01b0\u01a1ng theo quy \u01b0\u1edbc th\u00f4ng th\u01b0\u1eddng c\u1ee7a nh\u00e0 m\u00e1y. D\u00f2ng \u0111i\u1ec7n dung d\u1eabn tr\u01b0\u1edbc s\u1ebd tr\u1eeb \u0111i.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu b\u1ea3n in duy nh\u1ea5t ch\u1ec9 c\u00f3 kilowatt v\u00e0 xu h\u01b0\u1edbng h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t (PF) t\u1eeb b\u1ea3n t\u1ed5ng k\u1ebft c\u00f4ng \u00edch c\u1ee7a th\u00e1ng tr\u01b0\u1edbc, h\u00e3y coi PF \u0111\u00f3 l\u00e0 m\u1ee9c trung b\u00ecnh h\u00e0ng th\u00e1ng, kh\u00f4ng ph\u1ea3i l\u00e0 \u1ea3nh ch\u1ee5p nhanh c\u1ee7a thi\u1ebft b\u1ecb c\u1ea5p ngu\u1ed3n \u0111\u1ec9nh. H\u00e3y t\u00ednh to\u00e1n l\u1ea1i b\u1eb1ng kho\u1ea3ng th\u1eddi gian \u0111\u01b0\u1ee3c ghi nh\u1eadt k\u00fd ph\u00f9 h\u1ee3p v\u1edbi quy\u1ebft \u0111\u1ecbnh m\u00e0 b\u1ea1n s\u1eafp \u0111\u01b0a ra.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/08\/calc-q-meter-path.webp\" alt=\"Ch\u1ec9 s\u1ed1 nh\u00e0 m\u00e1y \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 t\u00ednh to\u00e1n c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng t\u1eeb c\u00e1c \u0111\u1ea7u v\u00e0o c\u1ee7a c\u00f4ng t\u01a1\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"calculate-q-from-kva-and-kw\">T\u00ednh Q t\u1eeb kVA v\u00e0 kW<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Khi m\u00e1y bi\u1ebfn \u00e1p ho\u1eb7c b\u1ed9 l\u01b0u \u0111i\u1ec7n (UPS) \u0111\u01b0\u1ee3c \u0111\u1ecbnh m\u1ee9c theo kVA v\u00e0 \u0111\u1ed3ng h\u1ed3 \u0111o quy tr\u00ecnh hi\u1ec3n th\u1ecb kilowatt, h\u00e3y s\u1eed d\u1ee5ng tam gi\u00e1c c\u00f4ng su\u1ea5t.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">C\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn l\u00e0 c\u1ea1nh huy\u1ec1n. C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng l\u00e0 c\u1ea1nh g\u00f3c vu\u00f4ng c\u00f2n l\u1ea1i: Q = \u221a(S\u00b2 \u2212 P\u00b2), v\u1edbi \u0111i\u1ec1u ki\u1ec7n S \u2265 P.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">S\u1eed d\u1ee5ng c\u00f9ng m\u1ed9t ngu\u1ed3n c\u1ea5p: S = 65 kVA v\u00e0 P = 56 kW cho ta Q = \u221a(65\u00b2 \u2212 56\u00b2) \u2248 33 kvar. K\u1ebft qu\u1ea3 n\u00e0y kh\u1edbp v\u1edbi ph\u01b0\u01a1ng ph\u00e1p t\u00ednh theo h\u00e0m tan v\u00e0 l\u00e0 m\u1ed9t c\u00e1ch ki\u1ec3m tra ch\u00e9o h\u1eefu \u00edch.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu S nh\u1ecf h\u01a1n P tr\u00ean gi\u1ea5y, c\u00e1c \u0111\u1ea7u v\u00e0o kh\u00f4ng thu\u1ed9c v\u1ec1 c\u00f9ng m\u1ed9t ranh gi\u1edbi. H\u00e3y s\u1eeda \u0111i\u1ec3m \u0111o tr\u01b0\u1edbc khi \u0111\u1ed5 l\u1ed7i cho c\u00f4ng th\u1ee9c.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">M\u1ed9t b\u1ed9 ng\u1eafn <strong>C\u00f4ng th\u1ee9c c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng<\/strong> \u0111\u1eb7t th\u1ebf l\u00e0 \u0111\u1ee7: Q t\u1eeb sin \u03c6 khi b\u1ea1n c\u00f3 V v\u00e0 I, Q t\u1eeb tan \u03c6 khi b\u1ea1n c\u00f3 P v\u00e0 PF, Q t\u1eeb tam gi\u00e1c khi b\u1ea1n c\u00f3 S v\u00e0 P.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">C\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn tr\u00ean nh\u00e3n m\u00e1y UPS l\u00e0 m\u1ee9c tr\u1ea7n, kh\u00f4ng ph\u1ea3i l\u00e0 th\u00f4ng s\u1ed1 \u0111\u1ecdc t\u1ea3i li\u00ean t\u1ee5c. H\u00e3y gh\u00e9p n\u1ed1i n\u00f3 v\u1edbi c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng (kilowatt) \u0111\u00e3 \u0111o \u0111\u01b0\u1ee3c ch\u1ec9 khi UPS \u0111\u00f3 l\u00e0 ranh gi\u1edbi m\u00e0 b\u1ea1n \u0111\u1ecbnh hi\u1ec7u ch\u1ec9nh.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/08\/calc-q-triangle.webp\" alt=\"Tam gi\u00e1c c\u00f4ng su\u1ea5t li\u00ean quan \u0111\u1ebfn c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng, c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng v\u00e0 c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn \u0111\u1ec3 t\u00ednh Q\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"single-phase-versus-three-phase-line-factors\">H\u1ec7 s\u1ed1 \u0111\u01b0\u1eddng d\u00e2y m\u1ed9t pha so v\u1edbi ba pha<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">H\u1ec7 s\u1ed1 $\\sqrt{3}$ ba pha ch\u1ec9 xu\u1ea5t hi\u1ec7n khi b\u1ea1n t\u00ednh Q t\u1eeb \u0111i\u1ec7n \u00e1p d\u00e2y v\u00e0 d\u00f2ng \u0111i\u1ec7n d\u00e2y tr\u00ean m\u1ed9t m\u1ea1ch ba pha \u0111\u1ed1i x\u1ee9ng.<\/p>\n<div class=\"b2b-table-scroll\" role=\"region\" aria-label=\"B\u1ea3ng d\u1eef li\u1ec7u c\u00f3 th\u1ec3 cu\u1ed9n\" tabindex=\"0\" style=\"width:100%;max-width:100%;overflow-x:auto;-webkit-overflow-scrolling:touch;margin:0 0 18px\">\n<table style=\"width:100%;border-collapse:collapse\">\n<thead>\n<tr>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">M\u1ea1ch \u0111i\u1ec7n<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">D\u1ea1ng c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng (h\u00ecnh sin)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">M\u1ed9t pha (pha - trung t\u00ednh)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = V I sin \u03c6<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">M\u1ed9t pha (pha\u2013pha)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = U I sin \u03c6<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Ba pha c\u00e2n b\u1eb1ng (3 d\u00e2y ho\u1eb7c 3 d\u00e2y + N)<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Q = \u221a3 U I sin \u03c6<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p style=\"margin:0 0 16px;line-height:1.7\">U l\u00e0 \u0111i\u1ec7n \u00e1p d\u00e2y-d\u00e2y. V l\u00e0 \u0111i\u1ec7n \u00e1p d\u00e2y-trung t\u00ednh. I l\u00e0 d\u00f2ng \u0111i\u1ec7n d\u00e2y. \u03c6 l\u00e0 g\u00f3c pha gi\u1eefa \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n theo \u0111\u1ecbnh ngh\u0129a \u0111\u00f3.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Kh\u00f4ng nh\u00e2n k\u1ebft qu\u1ea3 V I sin\u03c6 m\u1ed9t pha v\u1edbi \u221a3 \u201c\u0111\u1ec3 t\u00ednh cho h\u1ec7 th\u1ed1ng ba pha\u201d. Thay v\u00e0o \u0111\u00f3, h\u00e3y b\u1eaft \u0111\u1ea7u t\u1eeb h\u00e0ng ba pha.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">D\u00f2ng \u0111i\u1ec7n \u0111\u1ecbnh m\u1ee9c tr\u00ean nh\u00e3n c\u1ee7a \u0111\u1ed9ng c\u01a1 ba pha l\u00e0 d\u00f2ng \u0111i\u1ec7n d\u00e2y. H\u00e3y gh\u00e9p n\u1ed1i n\u00f3 v\u1edbi \u0111i\u1ec7n \u00e1p d\u00e2y-v\u00e2y-d\u00e2y v\u00e0 h\u00e0ng ba pha, ho\u1eb7c s\u1eed d\u1ee5ng \u0111\u01b0\u1eddng d\u1eabn kW\/PF v\u00e0 b\u1ecf qua ho\u00e0n to\u00e0n V\u00b7I.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u1ed1i v\u1edbi m\u1ea1ch m\u1ed9t pha d\u00e2y-trung t\u00ednh d\u1ea1ng r\u00fat g\u1ecdn, Q b\u1eb1ng V nh\u00e2n I nh\u00e2n sin \u03c6. \u0110\u1ed1i v\u1edbi m\u1ea1ch ba pha \u0111\u1ed1i x\u1ee9ng, d\u1ea1ng d\u00e2y l\u00e0 Q b\u1eb1ng c\u0103n b\u1eadc ba c\u1ee7a ba nh\u00e2n U nh\u00e2n I nh\u00e2n sin \u03c6.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">M\u1ed9t th\u1ee3 l\u1eafp r\u00e1p t\u1ee7 \u0111i\u1ec7n sao ch\u00e9p c\u00f4ng th\u1ee9c b\u00e0i t\u1eadp m\u1ed9t pha sang b\u1ed9 c\u1ea5p ngu\u1ed3n ba pha m\u00e0 thi\u1ebfu \u0111i h\u1ec7 s\u1ed1 ba pha s\u1ebd t\u00ednh thi\u1ebfu c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng Q v\u00e0 ch\u1ecdn k\u00edch th\u01b0\u1edbc qu\u00e1 nh\u1ecf cho m\u1ecdi b\u1ed9 t\u1ee5 \u0111i\u1ec7n ti\u1ebfp theo.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/08\/calc-q-threephase.webp\" alt=\"Thi\u1ebft b\u1ecb \u0111\u00f3ng c\u1eaft ba pha trong ng\u1eef c\u1ea3nh c\u00e1c c\u00f4ng th\u1ee9c t\u00ednh Q d\u1ef1a tr\u00ean \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n \u0111\u01b0\u1eddng d\u00e2y\"><\/figure>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"mistakes-that-inflate-or-cancel-q-on-mixed-loads\">Nh\u1eefng l\u1ed7i l\u00e0m t\u0103ng ho\u1eb7c h\u1ee7y Q \u0111\u1ed1i v\u1edbi h\u00e0ng h\u1ed7n h\u1ee3p<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Ph\u00e9p \u0111\u1ea1i s\u1ed1 n\u00e0y kh\u00f4ng c\u00f2n \u0111\u00fang trong th\u1ef1c t\u1ebf khi c\u00e1c t\u1ea3i c\u00f3 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t kh\u00e1c nhau \u0111\u01b0\u1ee3c k\u1ebft h\u1ee3p theo c\u00e1ch sai l\u1ea7m.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">B\u1ea1n kh\u00f4ng th\u1ec3 c\u1ed9ng hai \u0111\u1ed9 l\u1edbn c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn v\u00e0 coi t\u1ed5ng \u0111\u00f3 l\u00e0 \u0111\u01b0\u1eddng d\u1eabn \u0111\u1ec3 t\u00ednh t\u1ed5ng Q. C\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng v\u00f4 h\u01b0\u1edbng m\u00e0 b\u1ea1n c\u00f3 th\u1ec3 ch\u1ed3ng ch\u1ea5t l\u00ean nhau khi c\u00e1c g\u00f3c kh\u00e1c nhau.<\/p>\n<blockquote>\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>T\u1eeb l\u0129nh v\u1ef1c:<\/strong> B\u1eadt <a href=\"https:\/\/electronics.stackexchange.com\/questions\/695160\/reactive-power-calculation-what-did-i-do-wrong\" rel=\"nofollow noopener\" target=\"_blank\">Electrical Engineering Stack Exchange<\/a>, c\u00e1c c\u00e2u tr\u1ea3 l\u1eddi \u0111\u1ec1u ch\u1ec9 ra c\u00f9ng m\u1ed9t b\u1eaby trong k\u1ef3 thi: vi\u1ec7c c\u1ed9ng c\u00e1c \u0111\u1ed9 l\u1edbn c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn s\u1ebd kh\u00f4ng \u0111\u01b0a b\u1ea1n \u0111i \u0111\u1ebfn \u0111\u00e2u, v\u00e0 Q d\u1eabn tr\u01b0\u1edbc s\u1ebd tri\u1ec7t ti\u00eau Q tr\u1ec5. H\u00e3y c\u1ed9ng c\u00e1c c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng v\u00e0 c\u00e1c c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng c\u00f3 d\u1ea5u, sau \u0111\u00f3 t\u00ednh l\u1ea1i \u0111\u1ed9 l\u1edbn c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn t\u1eeb tam gi\u00e1c c\u00f4ng su\u1ea5t n\u1ebfu b\u1ea1n c\u1ea7n t\u1ed5ng kilov\u00f4n-ampere.<\/p>\n<\/blockquote>\n<p style=\"margin:0 0 16px;line-height:1.7\">Chia kilowatt cho h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t s\u1ebd ra kilovolt-ampere, ch\u1ee9 kh\u00f4ng ph\u1ea3i kvar. N\u1ebfu b\u1ea1n c\u1ea7n Q sau b\u01b0\u1edbc \u0111\u00f3, v\u1eabn t\u00ednh \u221a(S\u00b2 \u2212 P\u00b2) ho\u1eb7c P \u00d7 tan(arccos(PF)).<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">T\u1ee5 \u0111i\u1ec7n Q kh\u00f4ng ph\u1ea3i l\u00e0 m\u1ed9t d\u1ea1ng v\u1eadt l\u00fd th\u1ee9 ba \u0111\u1eb7c bi\u1ec7t. \u0110\u1ed1i v\u1edbi m\u1ed9t nh\u00e1nh t\u1ee5 \u0111i\u1ec7n, Q = V I sin\u03c6 v\u1edbi d\u00f2ng \u0111i\u1ec7n v\u01b0\u1ee3t tr\u01b0\u1edbc, ho\u1eb7c Q = I\u00b2 Xc v\u1edbi \u0111i\u1ec7n kh\u00e1ng c\u1ee7a t\u1ee5 \u0111i\u1ec7n. C\u00e2u h\u1ecfi v\u1ec1 thi\u1ebft b\u1ecb th\u01b0\u1eddng l\u00e0 t\u1ee5 b\u00f9 cung c\u1ea5p bao nhi\u00eau kvar d\u1eabn tr\u01b0\u1edbc \u1edf \u0111i\u1ec7n \u00e1p \u0111\u1ecbnh m\u1ee9c, \u0111\u00f3 l\u00e0 th\u00f4ng s\u1ed1 kvar tr\u00ean b\u1ea3ng d\u1eef li\u1ec7u \u1edf m\u1ed9t \u0111i\u1ec7n \u00e1p \u0111\u00e3 \u0111\u1ecbnh.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"after-you-have-q-choose-capacitor-q-or-an-svg-solution\">Sau Khi B\u1ea1n \u0110\u00e3 C\u00f3 Q: N\u00ean Ch\u1ecdn T\u1ee5 \u0110i\u1ec7n \u0394Q Hay Gi\u1ea3i Ph\u00e1p SVG<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Present Q tr\u1ea3 l\u1eddi cho c\u00e2u h\u1ecfi \u201cranh gi\u1edbi n\u00e0y \u0111ang y\u00eau c\u1ea7u bao nhi\u00eau kvar ngay l\u00fac n\u00e0y?\u201d \u0110\u00e2y ch\u01b0a ph\u1ea3i l\u00e0 m\u1ed9t b\u1ea3ng kh\u1ed1i l\u01b0\u1ee3ng v\u1eadt t\u01b0 (bill of materials).<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu m\u1ee5c ti\u00eau l\u00e0 n\u00e2ng cao h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t tr\u1ec5 kh\u00e1 \u1ed5n \u0111\u1ecbnh, ph\u00e9p t\u00ednh ti\u1ebfp theo l\u00e0 hi\u1ec7u s\u1ed1 gi\u1eefa Q hi\u1ec7n t\u1ea1i v\u00e0 Q m\u1ee5c ti\u00eau. V\u1ea5n \u0111\u1ec1 $\\Delta Q$ \u0111\u00f3 \u0111\u01b0\u1ee3c \u0111\u1ec1 c\u1eadp trong <a href=\"https:\/\/cnbygele.com\/vi\/blog\/capacitor-bank-sizing-for-power-factor-correction\/\">t\u00ednh to\u00e1n dung l\u01b0\u1ee3ng t\u1ee5 b\u00f9 cho vi\u1ec7c n\u00e2ng cao h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t<\/a>, v\u00e0 c\u00e1c d\u00f2ng ph\u1ea7n c\u1ee9ng n\u1eb1m tr\u00ean <a href=\"https:\/\/cnbygele.com\/vi\/reactive-power-compensator\/\">b\u1ed9 b\u00f9 c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng<\/a> Trung t\u00e2m.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu Q dao \u0111\u1ed9ng c\u00f9ng v\u1edbi m\u00e1y h\u00e0n, c\u1ea7n c\u1ea9u ho\u1eb7c d\u00e2y chuy\u1ec1n m\u1ebb, m\u1ed9t d\u00e3y t\u1ee5 chuy\u1ec3n m\u1ea1ch c\u00f3 th\u1ec3 ph\u1ea3n h\u1ed3i qu\u00e1 ch\u1eadm. Khi \u0111\u00f3, cu\u1ed9c tr\u00f2 chuy\u1ec7n chuy\u1ec3n sang <a href=\"https:\/\/cnbygele.com\/vi\/product\/svg-static-var-generators\/\">M\u00e1y ph\u00e1t c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng t\u0129nh SVG<\/a>.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Trang s\u1ea3n ph\u1ea9m SVG li\u1ec7t k\u00ea th\u00f4ng s\u1ed1 ngu\u1ed3n \u0111i\u1ec7n 230\u2013690 V, th\u1eddi gian \u0111\u00e1p \u1ee9ng d\u01b0\u1edbi 10 ms, h\u1ec7 s\u1ed1 b\u00f9 tr\u00ean 95% v\u00e0 hi\u1ec7u su\u1ea5t tr\u00ean 97%. Nh\u1eefng con s\u1ed1 n\u00e0y m\u00f4 t\u1ea3 n\u1ed9i dung tr\u00ean trang s\u1ea3n ph\u1ea9m. Ch\u00fang kh\u00f4ng th\u1ec3 thay th\u1ebf cho vi\u1ec7c kh\u1ea3o s\u00e1t hi\u1ec7n tr\u01b0\u1eddng hay ph\u00e9p t\u00ednh Q n\u00eau tr\u00ean.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img decoding=\"async\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/08\/svg-path1-source.webp\" alt=\"Giao di\u1ec7n s\u1ea3n ph\u1ea9m b\u1ed9 b\u00f9 c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng t\u0129nh CNBYG SVG sau khi t\u00ednh to\u00e1n c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng\"><\/figure>\n<p style=\"margin:0 0 16px;line-height:1.7\">S\u1eed d\u1ee5ng s\u1ed1 kvar \u0111\u00e3 t\u00ednh \u0111\u1ec3 th\u00f4ng b\u00e1o ng\u1eafn g\u1ecdn cho nh\u00e0 cung c\u1ea5p. Kh\u00f4ng \u0111\u01b0\u1ee3c b\u1ecf qua b\u01b0\u1edbc ki\u1ec3m tra \u0111\u1ea7u v\u00e0o v\u00e0 y\u00eau c\u1ea7u k\u00edch th\u01b0\u1edbc t\u1ee7 ch\u1ec9 d\u1ef1a tr\u00ean m\u1ed9t nh\u00e3n \u0111\u1ed9ng c\u01a1 trong khi to\u00e0n b\u1ed9 ph\u1ea7n c\u00f2n l\u1ea1i c\u1ee7a thanh c\u00e1i b\u1ecb b\u1ecf qua. H\u00e3y t\u00ednh to\u00e1n l\u1ea1i t\u01b0\u01a1ng t\u1ef1 sau khi thay \u0111\u1ed5i quy tr\u00ecnh tr\u01b0\u1edbc khi b\u1ea5t k\u1ef3 ai ph\u00ea duy\u1ec7t \u0111\u01a1n \u0111\u1eb7t h\u00e0ng.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"faqs\">C\u00e1c c\u00e2u h\u1ecfi th\u01b0\u1eddng g\u1eb7p<\/h2>\n<h3 style=\"margin:28px 0 12px\">C\u00e1ch t\u00ecm c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u1ecdc xem b\u1ea1n \u0111\u00e3 tin t\u01b0\u1edfng c\u00e1i n\u00e0o trong s\u1ed1 P, S, PF, V v\u00e0 I \u1edf m\u1ed9t ranh gi\u1edbi. Sau \u0111\u00f3, h\u00e3y s\u1eed d\u1ee5ng h\u00e0ng t\u01b0\u01a1ng \u1ee9ng trong b\u1ea3ng \u0111\u1ea7u v\u00e0o \u1edf tr\u00ean.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">N\u1ebfu \u0111\u1ed3ng h\u1ed3 \u0111o \u0111\u00e3 hi\u1ec3n th\u1ecb kvar, h\u00e3y coi \u0111\u00f3 l\u00e0 ph\u00e9p \u0111o v\u00e0 ch\u1ec9 s\u1eed d\u1ee5ng c\u00e1c c\u00f4ng th\u1ee9c \u0111\u1ec3 \u0111\u1ed1i chi\u1ebfu.<\/p>\n<h3 style=\"margin:28px 0 12px\">C\u00f4ng th\u1ee9c n\u00e0o t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">C\u00e1c d\u1ea1ng bi\u1ec3u di\u1ec5n ph\u1ed5 bi\u1ebfn c\u1ee7a c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng l\u00e0 Q = P \u00d7 tan(arccos(PF)), Q = \u221a(S\u00b2 \u2212 P\u00b2), v\u00e0 Q = V I sin\u03c6 (v\u1edbi \u221a3 \u0111\u1ed1i v\u1edbi c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng \u0111\u01b0\u1eddng d\u00e2y ba pha \u0111\u1ed1i x\u1ee9ng).<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Ch\u00fang l\u00e0 c\u00f9ng m\u1ed9t tam gi\u00e1c c\u00f4ng su\u1ea5t \u0111\u01b0\u1ee3c vi\u1ebft cho c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng \u0111\u00e3 bi\u1ebft kh\u00e1c nhau.<\/p>\n<h3 style=\"margin:28px 0 12px\">C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng l\u00e0 g\u00ec?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u00e2y l\u00e0 th\u00e0nh ph\u1ea7n dao \u0111\u1ed9ng duy tr\u00ec t\u1eeb tr\u01b0\u1eddng ho\u1eb7c \u0111i\u1ec7n tr\u01b0\u1eddng v\u00e0 \u0111\u01b0\u1ee3c t\u00ednh b\u1eb1ng \u0111\u01a1n v\u1ecb var ho\u1eb7c kvar. \u0110\u1ec3 c\u00f3 s\u1ef1 so s\u00e1nh b\u1eb1ng ng\u00f4n ng\u1eef th\u00f4ng th\u01b0\u1eddng v\u1edbi watt v\u00e0 volt-ampere, h\u00e3y s\u1eed d\u1ee5ng <a href=\"https:\/\/cnbygele.com\/vi\/blog\/active-vs-reactive-power\/\">C\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng v\u00e0 c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng<\/a> b\u00e0i vi\u1ebft.<\/p>\n<h3 style=\"margin:28px 0 12px\">L\u00e0m th\u1ebf n\u00e0o \u0111\u1ec3 t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng c\u1ee7a m\u1ed9t t\u1ee5 \u0111i\u1ec7n?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u1ede \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n RMS \u0111\u00e3 bi\u1ebft v\u1edbi \u0111\u1ed9 l\u1ec7ch pha 90\u00b0, Q = V I. V\u1edbi \u0111i\u1ec7n kh\u00e1ng, Q = I\u00b2 Xc ho\u1eb7c Q = V\u00b2 \/ Xc \u0111\u1ed1i v\u1edbi m\u1ed9t t\u1ee5 \u0111i\u1ec7n l\u00fd t\u01b0\u1edfng.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">C\u00e1c bi\u1ec3n t\u00ean c\u1ee7a t\u1ee5 \u0111i\u1ec7n th\u01b0\u1eddng ghi ch\u1ec9 s\u1ed1 kvar \u1edf \u0111i\u1ec7n \u00e1p \u0111\u1ecbnh m\u1ee9c; h\u00e3y gi\u1ea3m \u0111\u1ecbnh m\u1ee9c n\u1ebfu \u0111i\u1ec7n \u00e1p thanh c\u00e1i th\u1ef1c t\u1ebf kh\u00e1c bi\u1ec7t.<\/p>\n<h3 style=\"margin:28px 0 12px\">C\u00f4ng th\u1ee9c t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng trong h\u1ec7 th\u1ed1ng 3 pha l\u00e0:\n\n$Q = \\sqrt{3} \\times V_L \\times I_L \\times \\sin(\\varphi)$\n\nHo\u1eb7c theo c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng ($P$) v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t ($\\cos\\varphi$):\n\n$Q = P \\times \\operatorname{tg}(\\varphi)$\n\nTrong \u0111\u00f3:\n* **$Q$**: C\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng (\u0111\u01a1n v\u1ecb: VAR, kVAR, ho\u1eb7c MVAR)\n* **$V_L$**: \u0110i\u1ec7n \u00e1p d\u00e2y (Line-to-Line voltage)\n* **$I_L$**: D\u00f2ng \u0111i\u1ec7n d\u00e2y (Line current)\n* **$\\varphi$**: G\u00f3c l\u1ec7ch pha gi\u1eefa \u0111i\u1ec7n \u00e1p v\u00e0 d\u00f2ng \u0111i\u1ec7n\n* **$\\sin(\\varphi)$**: H\u1ec7 s\u1ed1 ph\u1ea3n kh\u00e1ng<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">\u0110\u1ed1i v\u1edbi c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng \u0111\u01b0\u1eddng d\u00e2y ba pha c\u00e2n b\u1eb1ng, Q = \u221a3 \u00d7 U \u00d7 I \u00d7 sin\u03c6, v\u1edbi U l\u00e0 \u0111i\u1ec7n \u00e1p gi\u1eefa c\u00e1c d\u00e2y.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Nhi\u1ec1u nh\u00e0 m\u00e1y b\u1ecf qua b\u01b0\u1edbc n\u00e0y v\u00e0 t\u00ednh to\u00e1n Q t\u1eeb c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng ba pha (kW) v\u00e0 h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t (PF) thay v\u00e0o \u0111\u00f3.<\/p>\n<h3 style=\"margin:28px 0 12px\">T\u00f4i c\u00f3 th\u1ec3 c\u1ed9ng kVA c\u1ee7a hai t\u1ea3i \u0111\u1ec3 ra t\u1ed5ng Q kh\u00f4ng?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Kh\u00f4ng. C\u1ed9ng c\u00e1c c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng v\u00e0 c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng c\u00f3 d\u1ea5u. Ch\u1ec9 t\u00ednh l\u1ea1i c\u00f4ng su\u1ea5t bi\u1ec3u ki\u1ebfn t\u1eeb t\u1ed5ng khi b\u1ea1n c\u1ea7n |S|.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">T\u1ea3i h\u1ed7n h\u1ee3p g\u1ed3m c\u1ea3 c\u00f3 t\u00ednh c\u1ea3m kh\u00e1ng v\u00e0 dung kh\u00e1ng s\u1ebd b\u00f9 tr\u1eeb l\u1eabn nhau m\u1ed9t ph\u1ea7n trong c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng Q ngay c\u1ea3 khi m\u1ed7i gi\u00e1 tr\u1ecb |S| \u0111\u1ec1u c\u00f3 v\u1ebb l\u1edbn.<\/p>\n<h2 style=\"margin:42px 0 14px;scroll-margin-top:96px\" id=\"references\">T\u00e0i li\u1ec7u tham kh\u1ea3o<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/en.wikipedia.org\/wiki\/AC_power\" rel=\"nofollow noopener\" target=\"_blank\">Wikipedia \u2014 D\u00f2ng \u0111i\u1ec7n xoay chi\u1ec1u<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/www.omnicalculator.com\/physics\/power-factor\" rel=\"nofollow noopener\" target=\"_blank\">Omni Calculator \u2014 M\u00e1y t\u00ednh h\u1ec7 s\u1ed1 c\u00f4ng su\u1ea5t<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/electronics.stackexchange.com\/questions\/695160\/reactive-power-calculation-what-did-i-do-wrong\" rel=\"nofollow noopener\" target=\"_blank\">Electrical Engineering Stack Exchange \u2014 T\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng: t\u00f4i \u0111\u00e3 l\u00e0m sai \u1edf \u0111\u00e2u?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/electronics.stackexchange.com\/questions\/411869\/calculating-the-reactive-and-active-power\" rel=\"nofollow noopener\" target=\"_blank\">Electrical Engineering Stack Exchange \u2014 T\u00ednh to\u00e1n c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng v\u00e0 c\u00f4ng su\u1ea5t t\u00e1c d\u1ee5ng<\/a><\/li>\n<\/ul>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>\u0110\u1ec3 t\u00ednh c\u00f4ng su\u1ea5t ph\u1ea3n kh\u00e1ng, h\u00e3y s\u1eed d\u1ee5ng c\u00f4ng th\u1ee9c Q = P tan(arccos(PF)) ho\u1eb7c c\u0103n b\u1eadc hai c\u1ee7a tam gi\u00e1c c\u00f4ng su\u1ea5t t\u1eeb kVA v\u00e0 kW. Xem x\u00e9t c\u00e1c ng\u00f5 v\u00e0o c\u1ee7a c\u00f4ng t\u01a1, h\u1ec7 th\u1ed1ng 1 pha so v\u1edbi 3 pha, v\u00e0 c\u00e1c l\u1ed7i th\u01b0\u1eddng g\u1eb7p c\u1ee7a nh\u00e0 m\u00e1y.<\/p>","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_gspb_post_css":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-2410","post","type-post","status-publish","format-standard","hentry","category-blog"],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":7}},"acf":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/posts\/2410","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/comments?post=2410"}],"version-history":[{"count":1,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/posts\/2410\/revisions"}],"predecessor-version":[{"id":2528,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/posts\/2410\/revisions\/2528"}],"wp:attachment":[{"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/media?parent=2410"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/categories?post=2410"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnbygele.com\/vi\/wp-json\/wp\/v2\/tags?post=2410"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}