{"id":2556,"date":"2026-07-15T09:00:00","date_gmt":"2026-07-15T01:00:00","guid":{"rendered":"https:\/\/cnbygele.com\/?p=2556"},"modified":"2026-08-24T18:10:19","modified_gmt":"2026-08-24T10:10:19","slug":"marine-shipbuilding-power-quality-welding-shore-power","status":"publish","type":"post","link":"https:\/\/cnbygele.com\/th\/blog\/marine-shipbuilding-power-quality-welding-shore-power\/","title":{"rendered":"\u0e04\u0e38\u0e13\u0e20\u0e32\u0e1e\u0e44\u0e1f\u0e1f\u0e49\u0e32\u0e2a\u0e33\u0e2b\u0e23\u0e31\u0e1a\u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d\u0e40\u0e23\u0e37\u0e2d\u0e40\u0e14\u0e34\u0e19\u0e17\u0e30\u0e40\u0e25: \u0e01\u0e32\u0e23\u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21, \u0e0a\u0e32\u0e22\u0e1d\u0e31\u0e48\u0e07, APF \u0e41\u0e25\u0e30 SVG"},"content":{"rendered":"<p style=\"margin:0 0 16px;line-height:1.7\"><strong>Marine shipbuilding power quality<\/strong> is rarely a single-number problem. A modern shipyard combines intermittent welding loads, variable-frequency drives on cranes and pumps, temporary dockside supply, and shore-power interfaces that can change source stiffness from one operating mode to the next. Engineers therefore need a measured view of harmonics, reactive power, and voltage fluctuation before selecting APF\/AHF, SVG, or a coordinated system.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">This guide explains how to investigate shipyard disturbances, separate harmonic from reactive-power symptoms, and prepare an RFQ that supports a defensible equipment decision at the point of common coupling (PCC).<\/p>\n<nav class=\"b2b-toc\" style=\"background:#f5f8fa;padding:16px 20px;border-radius:8px;margin:0 0 24px\">\n<h2 style=\"margin:42px 0 14px\">\u0e2a\u0e32\u0e23\u0e1a\u0e31\u0e0d<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"#part-1-why-do-welding-and-converter-loads-make-marine-shipbuilding-power-quality-harder\">Part 1. Why do welding and converter loads make marine shipbuilding power quality harder?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-2-what-should-a-shipyard-measure-before-selecting-mitigation\">Part 2. What should a shipyard measure before selecting mitigation?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-3-how-should-the-results-separate-harmonic-reactive-and-voltage-fluctuation-problems\">Part 3. How should the results separate harmonic, reactive, and voltage-fluctuation problems?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-4-when-does-apf-svg-or-a-combined-approach-fit\">Part 4. When does APF, SVG, or a combined approach fit?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-5-why-must-shore-power-and-generator-operation-be-assessed-separately\">Part 5. Why must shore power and generator operation be assessed separately?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-6-where-should-equipment-and-cts-be-located-in-a-shipyard-distribution-system\">Part 6. Where should equipment and CTs be located in a shipyard distribution system?<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"#part-7-what-should-a-marine-power-quality-rfq-include-and-when-is-cnbyg-not-a-fit\">Part 7. What should a marine power-quality RFQ include, and when is CNBYG not a fit?<\/a><\/li>\n<\/ul>\n<\/nav>\n<p style=\"margin:0 0 16px;line-height:1.7\">For the wider application context, see the CNBYG <a href=\"https:\/\/cnbygele.com\/th\/solutions\/marine-shipbuilding\/\">Marine &amp; Shipbuilding solution<\/a>.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_.webp\" alt=\"Series reactor equipment for shipyard power quality panels\" class=\"wp-image-1369\" srcset=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_.webp 800w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-300x300.webp 300w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-150x150.webp 150w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-768x768.webp 768w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-500x500.webp 500w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-600x600.webp 600w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/7.CKSG_-100x100.webp 100w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption>Shipyard power quality panels often combine reactors, filters, and compensation equipment after a site study.<\/figcaption><\/figure>\n<h2 style=\"margin:42px 0 14px\" id=\"part-1-why-do-welding-and-converter-loads-make-marine-shipbuilding-power-quality-harder\">Part 1. Why do welding and converter loads make marine shipbuilding power quality harder?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Shipyards and repair yards share several nonlinear and fast-changing loads:<\/p>\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\">\u0e1b\u0e23\u0e30\u0e40\u0e20\u0e17\u0e02\u0e2d\u0e07\u0e20\u0e32\u0e23\u0e30\u0e07\u0e32\u0e19<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Electrical behavior<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Typical shipyard symptom<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Arc and resistance welding<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Intermittent high current pulses<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Voltage dips, flicker, harmonic current<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Portable welding on vessels<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Single-phase or uneven duty cycles<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Phase unbalance and neutral stress<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Crane and pump VFDs<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Rectifier front ends and fast torque changes<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Harmonics plus reactive-power swings<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Shore-power converters<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Controlled power electronics at the interface<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Distortion and control interaction with the yard bus<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Temporary generator supply<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Different source impedance than shore feed<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Changed THD and voltage response for the same load<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">Welding behavior in industrial plants is well documented as a source of voltage fluctuation. EPRI guidance treats welders among the large variable loads that can produce measurable flicker when duty cycles repeat quickly. In shipbuilding, that effect is amplified because welding may occur across multiple bays, alongside moving cranes, and while the yard switches between shore feed and temporary generation.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">For a related automotive-plant view of welding harmonics, see the <a href=\"https:\/\/cnbygele.com\/th\/blog\/welding-robot-harmonic-profile-mitigation\/\">welding robot harmonic profile guide<\/a>. Marine projects differ because the supply mode, outdoor exposure, and shore interface add constraints that a land-based weld shop may not face.<\/p>\n<h2 style=\"margin:42px 0 14px\" id=\"part-2-what-should-a-shipyard-measure-before-selecting-mitigation\">Part 2. What should a shipyard measure before selecting mitigation?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Do not size APF or SVG from nameplate load alone. Start by defining the PCC and the operating modes that matter to the project.<\/p>\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\">\u0e01\u0e32\u0e23\u0e27\u0e31\u0e14<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Why it matters in shipyards<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Voltage trend and dips<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Shows whether flicker or stiff-source limits are exceeded<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Current harmonics and TDD<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Supports APF\/AHF planning at the PCC<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">THDv at the bus<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Shows whether current distortion is affecting voltage quality<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Power factor and kvar swing<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Determines whether SVG is relevant<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Phase unbalance and neutral current<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Important for mixed single-phase welding and 3P4W feeders<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Pst \/ Plt flicker<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Captures repetitive voltage movement from welding cycles<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Source mode: shore vs generator<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">A shipboard study found materially different distortion under shore and generator supply for the same welding load<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">Use a power quality analyzer during real production, not only during idle inspection. Capture representative welding activity, crane moves, pump starts, and any shore-power transfer sequences that operators actually use.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Engineers commonly reference <a href=\"https:\/\/standards.ieee.org\/ieee\/519\/10677\/\" rel=\"nofollow noopener\" target=\"_blank\">\u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19 IEEE Std 519-2022<\/a> when comparing measured distortion with planning targets at the PCC. IEEE 519 applies to steady-state distortion at the defined interface; it does not replace a shipyard-specific source-impedance study.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_.webp\" alt=\"Reactor component for marine and shipbuilding compensation systems\" class=\"wp-image-1368\" srcset=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_.webp 800w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-300x300.webp 300w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-150x150.webp 150w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-768x768.webp 768w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-500x500.webp 500w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-600x600.webp 600w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/6.CKSG_-100x100.webp 100w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption>Reactor and compensation components should be selected only after harmonic and resonance review.<\/figcaption><\/figure>\n<h2 style=\"margin:42px 0 14px\" id=\"part-3-how-should-the-results-separate-harmonic-reactive-and-voltage-fluctuation-problems\">Part 3. How should the results separate harmonic, reactive, and voltage-fluctuation problems?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">The most common shipyard mistake is treating every low power factor reading as a capacitor problem, or every voltage dip as a need for more kvar. The three disturbance families should be diagnosed separately.<\/p>\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\">Dominant symptom<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Likely primary issue<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">First engineering response<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">High current harmonics \/ high TDD<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Nonlinear load current<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Evaluate APF\/AHF at the measured bus<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Fast reactive-power swings \/ low PF<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Dynamic var demand<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Evaluate SVG or engineered var support<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Repetitive voltage dips with acceptable harmonics<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Flicker \/ source stiffness<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Study duty cycle, feeder impedance, and fast var support<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Capacitor overheating or nuisance trips<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Resonance or harmonic overstress<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Stop adding capacitance until spectrum and detuning are reviewed<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">For reactive-power fundamentals in industrial systems, see the <a href=\"https:\/\/cnbygele.com\/th\/blog\/reactive-power-compensation-guide-for-industrial-plants\/\">reactive power compensation guide for industrial plants<\/a>.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\"><strong>\u0e2a\u0e33\u0e04\u0e31\u0e0d:<\/strong> A conventional capacitor bank is not a default answer for welding-heavy shipyards. Forum discussions around welding and capacitor applications repeatedly raise concerns about ripple-current heating and resonance when nonlinear loads are present (Source: CR4 forum discovery F3; not used as technical proof). Use capacitors only after harmonic and detuning review, not as a substitute for measurement.<\/p>\n<h2 style=\"margin:42px 0 14px\" id=\"part-4-when-does-apf-svg-or-a-combined-approach-fit\">Part 4. When does APF, SVG, or a combined approach fit?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">APF\/AHF and SVG solve different problems. The selection should follow the measured dominant disturbance.<\/p>\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\">Primary finding<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Preferred mitigation<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">Reason<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">High harmonic current \/ high TDD<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\"><a href=\"https:\/\/cnbygele.com\/th\/product\/ahf-active-harmonic-filter-harmonic-control\/\">AHF \/ APF Active Harmonic Filter<\/a><\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Injects compensating harmonic current in real time<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Fast reactive-power swings \/ low PF<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\"><a href=\"https:\/\/cnbygele.com\/th\/product\/svg-static-var-generators\/\">\u0e40\u0e04\u0e23\u0e37\u0e48\u0e2d\u0e07\u0e01\u0e33\u0e40\u0e19\u0e34\u0e14\u0e44\u0e1f\u0e1f\u0e49\u0e32\u0e01\u0e23\u0e30\u0e41\u0e2a\u0e2a\u0e25\u0e31\u0e1a\u0e41\u0e1a\u0e1a\u0e2a\u0e16\u0e34\u0e15 SVG<\/a><\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Provides dynamic kvar compensation<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Harmonics plus reactive-power swings<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">APF + SVG or integrated power quality system<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Separates harmonic and var control<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Capacitor resonance risk<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Engineering study before adding capacitance<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Avoids amplifying harmonic voltage<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">CNBYG positions APF for harmonic-current mitigation and SVG for dynamic reactive compensation on the <a href=\"https:\/\/cnbygele.com\/th\/solutions\/marine-shipbuilding\/\">Marine &amp; Shipbuilding solution<\/a> page. That product-fit statement is not a guarantee of a numeric THD, PF, or approval outcome. Final selection still requires site measurements, CT placement review, and protection coordination.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">For APF selection basics, see the <a href=\"https:\/\/cnbygele.com\/th\/blog\/active-harmonic-filter-ahf-selection-guide\/\">AHF selection guide<\/a>. For combined product-line context, see the <a href=\"https:\/\/cnbygele.com\/th\/power-quality-system\/\">\u0e23\u0e30\u0e1a\u0e1a\u0e04\u0e38\u0e13\u0e20\u0e32\u0e1e\u0e44\u0e1f\u0e1f\u0e49\u0e32<\/a> \u0e2b\u0e19\u0e49\u0e32.<\/p>\n<h2 style=\"margin:42px 0 14px\" id=\"part-5-why-must-shore-power-and-generator-operation-be-assessed-separately\">Part 5. Why must shore power and generator operation be assessed separately?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Shore-power projects are not only cable-and-breaker exercises. <a href=\"https:\/\/standards.ieee.org\/ieee\/80005-1\/5835\/\" rel=\"nofollow noopener\" target=\"_blank\">IEEE\/IEC 80005-1<\/a> covers high-voltage shore connection systems including interface equipment, converters, control, monitoring, interlocking, and power management. Local owner requirements may add conditions beyond the standard.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">From a power-quality standpoint, the critical point is that the source condition can change the measured response. A published shipboard welding study compared shore supply and finite generator supply and found different measured distortion outcomes for the same welding machine. That does not create a universal sizing rule, but it does justify separate measurement logs for:<\/p>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\">Normal shore-connected production<\/li>\n<li style=\"margin:0 0 8px\">Generator-backed outage or cold-ironing scenarios<\/li>\n<li style=\"margin:0 0 8px\">Transfer sequences between sources<\/li>\n<li style=\"margin:0 0 8px\">Reduced-load maintenance windows<\/li>\n<\/ul>\n<p style=\"margin:0 0 16px;line-height:1.7\">Treat shore power as an interface and control-system assessment, not only a kvar problem.<\/p>\n<h2 style=\"margin:42px 0 14px\" id=\"part-6-where-should-equipment-and-cts-be-located-in-a-shipyard-distribution-system\">Part 6. Where should equipment and CTs be located in a shipyard distribution system?<\/h2>\n<p style=\"margin:0 0 16px;line-height:1.7\">Most shipyard projects place mitigation at one of three levels:<\/p>\n<ol style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\">The feeder serving the welding bay or dock workstation<\/li>\n<li style=\"margin:0 0 8px\">The yard main low-voltage switchboard<\/li>\n<li style=\"margin:0 0 8px\">The PCC where utility or shore-supply limits are evaluated<\/li>\n<\/ol>\n<p style=\"margin:0 0 16px;line-height:1.7\">The correct location depends on where the disturbance is created, which equipment is sensitive, and whether the project must also meet an upstream limit. CT polarity, protection grading, enclosure access, ventilation, and service clearance matter as much as kVA rating.<\/p>\n<p style=\"margin:0 0 16px;line-height:1.7\">Commissioning should include step-load tests under real welding and crane activity. A device that appears stable at no-load can still underperform when multiple nonlinear loads overlap.<\/p>\n<h2 style=\"margin:42px 0 14px\" id=\"part-7-what-should-a-marine-power-quality-rfq-include-and-when-is-cnbyg-not-a-fit\">Part 7. What should a marine power-quality RFQ include, and when is CNBYG not a fit?<\/h2>\n<h3 style=\"margin:28px 0 12px\">\u0e1c\u0e39\u0e49\u0e0b\u0e37\u0e49\u0e2d\u0e04\u0e27\u0e23\u0e08\u0e31\u0e14\u0e2b\u0e32<\/h3>\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\">\u0e02\u0e49\u0e2d\u0e21\u0e39\u0e25 RFQ<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">\u0e17\u0e33\u0e44\u0e21\u0e08\u0e36\u0e07\u0e2a\u0e33\u0e04\u0e31\u0e0d<\/th>\n<th style=\"border:1px solid #d9e1e8;padding:9px 12px;background:#f5f8fa;text-align:left\">\u0e02\u0e49\u0e2d\u0e1c\u0e34\u0e14\u0e1e\u0e25\u0e32\u0e14\u0e17\u0e31\u0e48\u0e27\u0e44\u0e1b<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Single-line diagram<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Defines PCC, feeders, and existing compensation<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Sending only a load list<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">PCC and measurement points<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Anchors IEEE 519-style comparisons<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Measuring only at the welding machine<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Harmonic spectrum and trend files<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Supports APF order and rating review<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Using a one-minute snapshot<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Shore vs generator operating modes<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Changes source stiffness and distortion<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Assuming one setting fits all modes<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Transformer \/ generator data<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Needed for impedance and flicker context<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Omitting temporary supply details<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Existing capacitors, reactors, filters<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Reveals resonance and retrofit constraints<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Hiding legacy PF equipment<\/td>\n<\/tr>\n<tr>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">\u0e15\u0e33\u0e41\u0e2b\u0e19\u0e48\u0e07\u0e02\u0e2d\u0e07\u0e0b\u0e35\u0e17\u0e35\u0e41\u0e25\u0e30\u0e02\u0e49\u0e2d\u0e08\u0e33\u0e01\u0e31\u0e14\u0e02\u0e2d\u0e07\u0e15\u0e39\u0e49<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Drives installability and protection<\/td>\n<td style=\"border:1px solid #d9e1e8;padding:9px 12px\">Leaving CT direction to the field crew<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p style=\"margin:0 0 16px;line-height:1.7\">CNBYG can review measured data and discuss APF, SVG, or coordinated options through the <a href=\"https:\/\/cnbygele.com\/th\/contact-us\/\">\u0e2b\u0e19\u0e49\u0e32\u0e15\u0e34\u0e14\u0e15\u0e48\u0e2d\u0e40\u0e23\u0e32<\/a>.<\/p>\n<h3 style=\"margin:28px 0 12px\">\u0e08\u0e31\u0e14\u0e1e\u0e2d\u0e14\u0e35\u0e02\u0e2d\u0e1a\u0e40\u0e02\u0e15<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">This article supports shipyards, repair yards, and shore-power integrators that can provide measurements or arrange a study. It is not a substitute for marine-classification approval, shore-connection protection review, generator sizing, or model-specific engineering sign-off. Do not recommend capacitor-only, APF-only, or SVG-only equipment before the disturbance type and operating mode are confirmed.<\/p>\n<figure style=\"margin:26px 0;text-align:center\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" style=\"max-width:640px;width:100%;height:auto;display:block;margin:0 auto;border-radius:8px\" src=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_.webp\" alt=\"Three-phase reactor for shipyard harmonic and compensation studies\" class=\"wp-image-1367\" srcset=\"https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_.webp 800w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-300x300.webp 300w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-150x150.webp 150w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-768x768.webp 768w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-500x500.webp 500w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-600x600.webp 600w, https:\/\/cnbygele.com\/wp-content\/uploads\/2026\/04\/5.CKSG_-100x100.webp 100w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><figcaption>Reactor and compensation components require harmonic and resonance review before shipyard deployment.<\/figcaption><\/figure>\n<h2 style=\"margin:42px 0 14px\">\u0e04\u0e33\u0e16\u0e32\u0e21\u0e17\u0e35\u0e48\u0e1e\u0e1a\u0e1a\u0e48\u0e2d\u0e22<\/h2>\n<h3 style=\"margin:28px 0 12px\">What is marine shipbuilding power quality?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">It is the set of voltage, current, harmonic, flicker, and power-factor conditions created by shipyard welding, drives, cranes, and shore or generator supply.<\/p>\n<h3 style=\"margin:28px 0 12px\">Do welding machines always require an active harmonic filter?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. APF is justified when measurements show excessive harmonic current, TDD, voltage distortion, or related equipment stress.<\/p>\n<h3 style=\"margin:28px 0 12px\">Can an SVG correct every shipyard power-quality problem?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. SVG addresses reactive power and dynamic var support. It does not replace APF where harmonic-current mitigation is the dominant need.<\/p>\n<h3 style=\"margin:28px 0 12px\">Are capacitor banks suitable for fast welding loads?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Not by default. Capacitors require harmonic and detuning review because welding and VFD loads can create resonance or overstress risk.<\/p>\n<h3 style=\"margin:28px 0 12px\">Should shore power and generator modes use the same settings?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Not necessarily. Measure each mode separately because source stiffness and distortion can change.<\/p>\n<h3 style=\"margin:28px 0 12px\">Where should a shipyard define the PCC?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">At the electrical interface where planning limits, utility requirements, or owner targets are evaluated\u2014often the main yard switchboard or shore connection point.<\/p>\n<h3 style=\"margin:28px 0 12px\">What data is needed to size APF or SVG equipment?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">Provide voltage, wiring, load inventory, harmonic logs, PF\/kvar trends, flicker data, existing compensation details, and enclosure constraints.<\/p>\n<h3 style=\"margin:28px 0 12px\">Do marine standards automatically certify the proposed equipment?<\/h3>\n<p style=\"margin:0 0 16px;line-height:1.7\">No. Standards such as IEEE\/IEC 80005-1 define system scope and interface requirements; equipment still needs project-specific engineering review.<\/p>\n<h2 style=\"margin:42px 0 14px\">\u0e40\u0e2d\u0e01\u0e2a\u0e32\u0e23\u0e2d\u0e49\u0e32\u0e07\u0e2d\u0e34\u0e07<\/h2>\n<ul style=\"margin:0 0 18px 1.2em;line-height:1.7\">\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/standards.ieee.org\/ieee\/519\/10677\/\" rel=\"nofollow noopener\" target=\"_blank\">\u0e21\u0e32\u0e15\u0e23\u0e10\u0e32\u0e19 IEEE Std 519-2022<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/standards.ieee.org\/ieee\/80005-1\/5835\/\" rel=\"nofollow noopener\" target=\"_blank\">IEEE\/IEC 80005-1<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/restservice.epri.com\/publicdownload\/000000000001020280\/0\/Product\" rel=\"nofollow noopener\" target=\"_blank\">EPRI flicker guidance for industrial customers<\/a><\/li>\n<li style=\"margin:0 0 8px\"><a href=\"https:\/\/doi.org\/10.21279\/1454-864x-18-i2-006\" rel=\"nofollow noopener\" target=\"_blank\">Shipboard THD evaluation under shore and generator supply<\/a><\/li>\n<\/ul>","protected":false},"excerpt":{"rendered":"<p>\u0e40\u0e23\u0e35\u0e22\u0e19\u0e23\u0e39\u0e49\u0e27\u0e34\u0e18\u0e35\u0e17\u0e35\u0e48\u0e01\u0e32\u0e23\u0e40\u0e0a\u0e37\u0e48\u0e2d\u0e21\u0e43\u0e19\u0e2d\u0e39\u0e48\u0e15\u0e48\u0e2d\u0e40\u0e23\u0e37\u0e2d \u0e1e\u0e25\u0e31\u0e07\u0e07\u0e32\u0e19\u0e08\u0e32\u0e01\u0e1d\u0e31\u0e48\u0e07 (shore power) \u0e44\u0e14\u0e23\u0e1f\u0e4c \u0e41\u0e25\u0e30\u0e40\u0e04\u0e23\u0e19 \u0e2a\u0e48\u0e07\u0e1c\u0e25\u0e15\u0e48\u0e2d\u0e04\u0e38\u0e13\u0e20\u0e32\u0e1e\u0e44\u0e1f\u0e1f\u0e49\u0e32\u0e43\u0e19\u0e01\u0e32\u0e23\u0e15\u0e48\u0e2d\u0e40\u0e23\u0e37\u0e2d \u0e41\u0e25\u0e30\u0e0a\u0e48\u0e27\u0e07\u0e40\u0e27\u0e25\u0e32\u0e17\u0e35\u0e48\u0e01\u0e32\u0e23\u0e25\u0e14\u0e2a\u0e31\u0e0d\u0e0d\u0e32\u0e13\u0e23\u0e1a\u0e01\u0e27\u0e19\u0e14\u0e49\u0e27\u0e22 APF \u0e2b\u0e23\u0e37\u0e2d SVG \u0e40\u0e2b\u0e21\u0e32\u0e30\u0e2a\u0e21\u0e01\u0e31\u0e1a\u0e43\u0e1a\u0e02\u0e2d\u0e43\u0e1a\u0e40\u0e2a\u0e19\u0e2d\u0e23\u0e32\u0e04\u0e32 (RFQ) \u0e2a\u0e33\u0e2b\u0e23\u0e31\u0e1a\u0e1c\u0e39\u0e49\u0e0b\u0e37\u0e49\u0e2d.<\/p>","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_gspb_post_css":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-2556","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\/th\/wp-json\/wp\/v2\/posts\/2556","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/comments?post=2556"}],"version-history":[{"count":1,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/posts\/2556\/revisions"}],"predecessor-version":[{"id":2615,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/posts\/2556\/revisions\/2615"}],"wp:attachment":[{"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/media?parent=2556"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/categories?post=2556"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnbygele.com\/th\/wp-json\/wp\/v2\/tags?post=2556"}],"curies":[{"name":"\u0e14\u0e35\u0e21\u0e32\u0e01","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}