{"id":132,"date":"2026-08-22T02:34:28","date_gmt":"2026-08-21T18:34:28","guid":{"rendered":"https:\/\/q8bbzjnpm5.wpdns.site\/?p=132"},"modified":"2026-08-29T23:43:28","modified_gmt":"2026-08-29T15:43:28","slug":"sz11-10000kva-35-10-5kv-oil-immersed-transformer-outstanding-quality-the-choice-for-power","status":"publish","type":"post","link":"https:\/\/subian-electric.com\/fr\/news\/sz11-10000kva-35-10-5kv-oil-immersed-transformer-outstanding-quality-the-choice-for-power\/","title":{"rendered":"SZ11 \u2013 Transformateur immerg\u00e9 dans l'huile 10000KVA\/35\/10.5KV : Qualit\u00e9 exceptionnelle, le choix pour l'\u00e9nergie"},"content":{"rendered":"<p>Un directeur des op\u00e9rations d'une usine de transformation alimentaire en Afrique de l'Est se retrouve \u00e0 examiner le journal de tension de la semaine derni\u00e8re. En une journ\u00e9e, il a constat\u00e9 que le bus de 10,5 kV \u00e9tait tomb\u00e9 en dessous de 9,9 kV trois fois pendant la p\u00e9riode de broyage diurne. Il a \u00e9galement observ\u00e9 qu'il atteignait 11,2 kV pendant la nuit lorsque la charge de la ville \u00e9tait minimale. L'usine alimentaire dispose de son propre transformateur de 10 MV, mais l'approvisionnement de l'utilitaire n'est pas stable. Par cons\u00e9quent, il recherche un transformateur capable de g\u00e9rer une charge de 10 000 kVA et de maintenir la stabilit\u00e9 de la tension et envisage l'achat possible d'un transformateur immerg\u00e9 dans l'huile SZ11-10000kVA 35\/10,5 kV comme recommand\u00e9 par un entrepreneur.<\/p>\n<p>Ainsi, l'article d\u00e9crit les d\u00e9tails du transformateur immerg\u00e9 dans l'huile SZ11-10000kVA 35\/10,5 kV : ses avantages par rapport aux transformateurs moins chers, la signification de la qualit\u00e9 dans la production et l'exploitation, la fourchette de prix th\u00e9orique et les questions cl\u00e9s qui devraient \u00eatre pos\u00e9es par un client avis\u00e9 avant d'acheter un transformateur immerg\u00e9 dans l'huile de cette classe.<\/p>\n<blockquote><p>R\u00e9ponse courte : Le transformateur SZ11-10000kVA 35\/10,5 kV est un transformateur de puissance triphas\u00e9 rempli d'huile avec une puissance de 10 000 kVA (10 MVA), qui a une tension primaire de 35 kV et une tension secondaire de 10,5 kV et est \u00e9quip\u00e9 d'un changeur de prises sous charge pour l'ajustement de la tension sans interrompre l'alimentation. Selon la conception normale IEC 60076, les pertes \u00e0 vide peuvent \u00eatre d'environ 8 \u00e0 12 kW et les pertes pendant la charge d'environ 45 \u00e0 55 kW \u00e0 75 \u00b0C, avec une imp\u00e9dance d'environ 7 \u00e0 8% et une efficacit\u00e9 \u00e0 pleine charge sup\u00e9rieure \u00e0 99,2%.<\/p><\/blockquote>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-133\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Sz11-10000Kva-35-10-5Kv-Oil-Immersed-Transformer-Outstanding-Quality-The-Choice-For-Power.webp\" alt=\"Sz11 10000Kva 35 10 5Kv Oil Immersed Transformer Outstanding Quality The Choice For Power\" width=\"1448\" height=\"1086\" \/><\/p>\n<hr \/>\n<h2 id=\"what-is\">Qu'est-ce que le transformateur SZ11-10000kVA ?<\/h2>\n<p>Le transformateur SZ11-10000kVA 35\/10,5 kV est un transformateur de 10 MVA con\u00e7u selon la s\u00e9rie SZ11 de Chine et test\u00e9 selon la norme IEC 60076. La lettre \u201c Z \u201d dans SZ11 l'identifie comme un transformateur avec changeur de prises sous charge et le num\u00e9ro \u201c 11 \u201d repr\u00e9sente la s\u00e9rie modernis\u00e9e dans GB\/T 6451. Un transformateur de 10 MVA peut r\u00e9pondre aux besoins d'une usine industrielle moyenne, d'un \u00e9tablissement hospitalier dans une seule usine, d'un terminal de manutention de marchandises portuaires et d'une municipalit\u00e9 et est un choix populaire lorsqu'il s'agit de passer des commandes de transformateurs de 35 kV.<\/p>\n<p>Le transformateur SZ11-10000 se distingue du transformateur S11-10000 en ce qu'il est \u00e9quip\u00e9 d'un changeur de prises. Une telle caract\u00e9ristique permet d'utiliser la r\u00e9gulation sous prise du transformateur, ce qui l'aide \u00e0 ajuster le rapport dans le processus de son fonctionnement. L'importance d'un tel attribut est \u00e9vidente car, pour ceux consommant de grandes quantit\u00e9s d'\u00e9nergie, m\u00eame une br\u00e8ve chute de tension peut endommager leur \u00e9quipement. L'apparition d'un moteur d\u00e9marrant quelque part ou d'un d\u00e9faut dans les conducteurs peut faire chuter la tension du busbar de 5 \u00e0 8% en quelques secondes, affectant directement la sortie du transformateur.<\/p>\n<p>La tension primaire de 35 kV est une autre caract\u00e9ristique distinctive de ce transformateur. De nombreux clients d\u00e9cident d'utiliser ce transformateur en raison de la n\u00e9cessit\u00e9 de passer aux transformateurs de 35 kV apr\u00e8s avoir pris connaissance des transformateurs de 11 kV ou 20 kV et \u00e9galement en raison du fait que leurs lignes de transmission fonctionnent \u00e0 ce niveau de tension. Le poids de ce transformateur peut \u00eatre d'environ 22-28 tonnes m\u00e9triques, ce qui permet d'atteindre une logistique et une installation faciles.<\/p>\n<h2 id=\"quality\">Ce que signifie \u201cQualit\u00e9 Exceptionnelle\u201d en Pratique<\/h2>\n<p>La qualit\u00e9 d'un transformateur ne peut pas \u00eatre consid\u00e9r\u00e9e comme un aspect unique. Au contraire, c'est un ensemble de d\u00e9cisions qui peuvent \u00eatre retrac\u00e9es dans le produit final et dans le certificat de test. Certains signes exceptionnellement importants de bonne qualit\u00e9 pour un transformateur de 10 MVA incluraient les \u00e9l\u00e9ments suivants.<\/p>\n<ul>\n<li>Qualit\u00e9 de l'acier utilis\u00e9 pour le noyau et la m\u00e9thodologie de empilement de l'acier. On s'attend \u00e0 ce que de l'acier CRGO de haute qualit\u00e9 de grades autour de 27ZH100-30ZH120 avec des joints en pas de lap soit utilis\u00e9. Son utilisation d\u00e9finira la perte \u00e0 vide ainsi que le niveau de bruit qui sera produit. Dans un bon atelier, les valeurs r\u00e9elles seront conformes aux caract\u00e9ristiques de conception sans marges suppl\u00e9mentaires introduites en raison de la surdimension.<\/li>\n<li>Cuivre contre aluminium pour les enroulements. Tout d'abord, il faut comprendre : le cuivre est d\u00e9finitivement plus cher, mais il vous fera certainement \u00e9conomiser sur les pertes de charge en plus d'augmenter la r\u00e9sistance aux courts-circuits. La majorit\u00e9 des transformateurs SZ11-10000 devraient avoir des enroulements en cuivre. Pour en \u00eatre s\u00fbr, il est judicieux de demander une confirmation \u00e9crite.<\/li>\n<li>Qualit\u00e9 de l'isolation. Elle devrait impliquer un enroulement en papier, des barri\u00e8res en carton impr\u00e9gn\u00e9es d'huile et un contr\u00f4le de la teneur en humidit\u00e9. Il convient de mentionner que l'humidit\u00e9 est n\u00e9faste pour l'isolation car chaque doublement de l'eau dans le papier r\u00e9duit la dur\u00e9e de vie de l'isolation de presque moiti\u00e9.<\/li>\n<li>S\u00e9chage sous vide et remplissage d'huile. La proc\u00e9dure appropri\u00e9e pour r\u00e9aliser le processus de s\u00e9chage sous vide doit \u00eatre suivie afin d'\u00e9liminer l'humidit\u00e9 du transformateur avant le remplissage d'huile. Malheureusement, les acheteurs trouvent tr\u00e8s difficile de contr\u00f4ler la qualit\u00e9 de cette \u00e9tape de production.<\/li>\n<li>Ensemble complet d'accessoires. Le relais Buchholz, le dispositif de d\u00e9charge de pression, les indicateurs de temp\u00e9rature d'huile et d'enroulement, le manom\u00e8tre de niveau d'huile et le respirateur en gel de silice sont tous n\u00e9cessaires \u00e0 un transformateur pour son fonctionnement normal. \u00c9tant des points qui peuvent potentiellement \u00e9chouer, tous les accessoires mentionn\u00e9s doivent \u00eatre fournis par des fabricants de qualit\u00e9.<\/li>\n<\/ul>\n<p>La qualit\u00e9 se manifeste \u00e9galement par la coh\u00e9rence. La preuve en serait la mise en \u0153uvre efficace de syst\u00e8mes de gestion de la qualit\u00e9, tels que l'ISO 9001, et la capacit\u00e9 \u00e0 fournir des enregistrements des tests effectu\u00e9s en relation avec les unit\u00e9s exp\u00e9di\u00e9es.<\/p>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-134\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Core-Design-and-Key-Components.webp\" alt=\"Conception du Noyau et Composants Cl\u00e9s\" width=\"1448\" height=\"1086\" \/><\/p>\n<h2 id=\"design\">Conception du Noyau et Composants Cl\u00e9s<\/h2>\n<p>Un transformateur SZ11-10000 kVA est un transformateur de type conservateur immerg\u00e9 dans l'huile pr\u00e9sentant :<\/p>\n<ul>\n<li>Noyau : compos\u00e9 d'un noyau \u00e0 trois jambes en acier au silicium CRGO. Les joints entre chaque noyau sont r\u00e9alis\u00e9s en pas de lap, ce qui aide \u00e0 limiter les pertes \u00e0 vide ainsi que le bruit.<br \/>\nEnroulements HV : se composent d'enroulements de 35 kV en cuivre constitu\u00e9s de types de disques continus. Il est construit selon le niveau d'impulsion acceptable et le niveau de surtension de commutation selon les normes IEC 60076-3. La r\u00e9sistance \u00e0 l'impulsion doit \u00eatre de 170 kVp pour le c\u00f4t\u00e9 haute tension.<\/li>\n<li>Enroulements LV : se composent d'enroulements de type couche et h\u00e9lice pour 10,5 kV. La taille des enroulements est r\u00e9alis\u00e9e en fonction des forces de court-circuit mentionn\u00e9es dans la norme IEC 60076-5.<\/li>\n<li>Changeur de prises sous charge : un r\u00e9gulateur \u00e0 moteur rempli d'huile plac\u00e9 du c\u00f4t\u00e9 haute tension avec la capacit\u00e9 de contr\u00f4le \u00e0 distance et local. La r\u00e9gulation ne d\u00e9passe normalement pas \u00b18 \u00d7 1,25 %.<\/li>\n<li>R\u00e9servoir et conservateur : le r\u00e9servoir est en acier soud\u00e9 et contient des conservateurs \u00e9quip\u00e9s de respirateurs en gel de silice, de points d'\u00e9chantillonnage d'huile par thermosiphon, et de crochets de levage con\u00e7us pour un poids total d'environ 25t.<\/li>\n<li>Refroidissement : ONAN comme de base ; ONAF peut \u00eatre utilis\u00e9 comme option pour augmenter la capacit\u00e9 thermique d'au moins 25% pour des surcharges courtes.<\/li>\n<\/ul>\n<p>Les bushing haute tension de 35 kV peuvent \u00eatre utilis\u00e9s soit en porcelaine, soit en polym\u00e8re composite et peuvent \u00eatre des connexions de bo\u00eete de c\u00e2ble ou de barre omnibus. Le relais Buchholz est situ\u00e9 entre le r\u00e9servoir et le conservateur, et c'est le syst\u00e8me de protection principal contre les d\u00e9fauts internes.<\/p>\n<h2 id=\"specs\">Sp\u00e9cifications techniques en un coup d'\u0153il<\/h2>\n<table>\n<thead>\n<tr>\n<th>Param\u00e8tre<\/th>\n<th>Valeur typique<\/th>\n<th>R\u00e9f\u00e9rence<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Puissance nominale<\/td>\n<td>10 000 kVA<\/td>\n<td>\u00c9valuation continue<\/td>\n<\/tr>\n<tr>\n<td>Rapport de tension<\/td>\n<td>35 \u00b1 8 \u00d7 1.25% \/ 10,5 kV<\/td>\n<td>R\u00e8gles de prise IEC 60076-1<\/td>\n<\/tr>\n<tr>\n<td>Fr\u00e9quence<\/td>\n<td>50 Hz (option 60 Hz)<\/td>\n<td>\u2014<\/td>\n<\/tr>\n<tr>\n<td>Groupe vectoriel<\/td>\n<td>YNd11<\/td>\n<td>Arrangement commun 35\/10,5 kV<\/td>\n<\/tr>\n<tr>\n<td>Imp\u00e9dance<\/td>\n<td>7.5\u20138%<\/td>\n<td>IEC 60076-5<\/td>\n<\/tr>\n<tr>\n<td>Pertes \u00e0 vide<\/td>\n<td>8\u201312 kW<\/td>\n<td>Niveau S11 GB\/T 6451<\/td>\n<\/tr>\n<tr>\n<td>Pertes en charge<\/td>\n<td>45\u201355 kW<\/td>\n<td>\u00c0 75\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>Courant \u00e0 vide<\/td>\n<td>0.6\u20130.9%<\/td>\n<td>\u2014<\/td>\n<\/tr>\n<tr>\n<td>R\u00e9sistance \u00e0 l'impulsion HV<\/td>\n<td>170 kVp<\/td>\n<td>IEC 60076-3, LI<\/td>\n<\/tr>\n<tr>\n<td>\u00c9l\u00e9vation de temp\u00e9rature<\/td>\n<td>Enroulement moyen 65K<\/td>\n<td>Ambiance \u00e0 40\u00b0C<\/td>\n<\/tr>\n<tr>\n<td>M\u00e9thode de refroidissement<\/td>\n<td>ONAN \/ ONAF<\/td>\n<td>IEC 60076-2<\/td>\n<\/tr>\n<tr>\n<td>Poids total<\/td>\n<td>~22\u201328 tonnes m\u00e9triques<\/td>\n<td>Y compris l'huile<\/td>\n<\/tr>\n<tr>\n<td>Normes de conception<\/td>\n<td>S\u00e9rie IEC 60076, GB\/T 6451<\/td>\n<td>Efficacit\u00e9 \u00e9galement GB 20052<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Les pertes en termes mon\u00e9taires peuvent \u00eatre quantifi\u00e9es : un transformateur de 10 MVA, ayant une perte \u00e0 vide de 10 kW et une perte en charge de 50 kW, et fonctionnant pendant environ 8 000 heures avec un facteur de charge moyen de 60%, perdra, au total, environ 290 MWh en un an. Les co\u00fbts associ\u00e9s \u00e0 ces pertes en cuivre \u00e0 un tarif de $0,08 par kWh sont \u00e9quivalents \u00e0 environ $23 000 par an \u2014 ce qui signifie en m\u00eame temps qu'avec la diff\u00e9rence de 10% dans le niveau des pertes entre deux offres alternatives, les d\u00e9penses s'\u00e9l\u00e8veront \u00e0 presque $2 300 par an ou plus de $50 000 en 25 ans. La capitalisation des pertes doit toujours \u00eatre impliqu\u00e9e dans les discussions.<\/p>\n<table>\n<thead>\n<tr>\n<th>Classe de perte<\/th>\n<th>Perte \u00e0 vide (P0)<\/th>\n<th>Load loss (Pk)<\/th>\n<th>Relative first cost<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>S9 (legacy)<\/td>\n<td>~14 kW<\/td>\n<td>~58 kW<\/td>\n<td>R\u00e9f\u00e9rence<\/td>\n<\/tr>\n<tr>\n<td>S11<\/td>\n<td>~10 kW<\/td>\n<td>~50 kW<\/td>\n<td>+10\u201315%<\/td>\n<\/tr>\n<tr>\n<td>S13<\/td>\n<td>~8 kW<\/td>\n<td>~48 kW<\/td>\n<td>+20\u201330%<\/td>\n<\/tr>\n<tr>\n<td>Amorphous (SBH15)<\/td>\n<td>~4 kW<\/td>\n<td>~48 kW<\/td>\n<td>+35\u201355%<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>At the rate of $0.08 for every kWh consumed, each kW of loss when the machine is not under load generates a profit of $700 a year in its continuous usage, meaning the difference between S9 and S11 is worth about $2,800 a year.<\/p>\n<h2 id=\"compare\">SZ11-10000 vs. Fixed-Ratio and Dry-Type Units<\/h2>\n<table>\n<thead>\n<tr>\n<th>Option<\/th>\n<th>R\u00e9gulation de la tension<\/th>\n<th>Loss profile<\/th>\n<th>Maintenance<\/th>\n<th>Typical price (FOB)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>S11-10000, off-circuit taps<\/td>\n<td>None during operation<\/td>\n<td>Same as SZ11<\/td>\n<td>Simple<\/td>\n<td>$22,000\u2013$38,000<\/td>\n<\/tr>\n<tr>\n<td>SZ11-10000, on-load<\/td>\n<td>Continuous \u00b18 \u00d7 1.25%<\/td>\n<td>Same as S11<\/td>\n<td>OLTC oil\/contacts<\/td>\n<td>$28,000\u2013$48,000<\/td>\n<\/tr>\n<tr>\n<td>S13-10000, off-circuit<\/td>\n<td>None during operation<\/td>\n<td>~20% lower no-load loss<\/td>\n<td>Simple<\/td>\n<td>$26,000\u2013$44,000<\/td>\n<\/tr>\n<tr>\n<td>Dry-type 10MVA (rare)<\/td>\n<td>Depends<\/td>\n<td>Higher load loss typical<\/td>\n<td>Faible<\/td>\n<td>$60,000\u2013$100,000<\/td>\n<\/tr>\n<tr>\n<td>Amorphous core 10MVA<\/td>\n<td>Off-circuit typically<\/td>\n<td>~60\u201370% lower no-load loss<\/td>\n<td>Simple<\/td>\n<td>$38,000\u2013$65,000<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>While dry-type transformers are a good option indoors in cases where flammable liquids are banned, with ratings of 10 MVA and 35 kV, they become large, costly, and inefficient during operation. For a substation that is located outdoors and is properly contained, oil-filled units are the normal choice. The main choice to be made is whether to go for fixed-ratio or variable-ratio transformers: if the utility supply is stable (the voltage does not change more than \u00b12.5%) and the load is steady, it would be more cost-effective to buy S11 or S13 transformers. If one is operating in an environment with weak grids or with varying load patterns, then SZ11&#8217;s regulating properties will make the difference between uninterrupted production and constant breakdowns.<\/p>\n<h2 id=\"apps\">Who Uses a 10MVA Transformer<\/h2>\n<ul>\n<li>Mining and processing plants: Crushers, mills, and flotation circuits work under heavy and fluctuating loads. The SZ11, rated at 10 MVA, keeps the bus voltage stable.<\/li>\n<li>Food and beverage industry: Freezing and packaging lines are sensitive to voltage changes, hence any undervoltage would be costly.<\/li>\n<li>Ports and terminals: Gantry cranes and refrigerated containers lead to sudden changes in the load.<\/li>\n<li>Hospitals and educational institutions: Backup switching and high-reliability loads are well provided before starting generators.<\/li>\n<li>Municipal water and waste treatment: Pump stations with large motors both generate and suffer from voltage dips.<\/li>\n<li>Renewable microgrids: Energy storage with solar generation, which is dynamic, requires regulating voltage characteristics at the coupling point.<\/li>\n<\/ul>\n<p>In all the above cases, the transformer is usually the single most expensive piece of equipment installed in the electrical system and is expected to last more than 25 years with normal maintenance. That is why the choice of specifications, the level of losses, and the manufacturer should be taken seriously and be given more attention than any switches on the same project.<\/p>\n<h2 id=\"brands\">Brand Landscape and Price Ranges<\/h2>\n<table>\n<thead>\n<tr>\n<th>Marque<\/th>\n<th>Origine<\/th>\n<th>Typical price (USD, FOB)<\/th>\n<th>Positioning<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>ABB<\/td>\n<td>Switzerland\/Global<\/td>\n<td>$52,000\u2013$78,000<\/td>\n<td>Premium engineering and service<\/td>\n<\/tr>\n<tr>\n<td>Siemens Energy<\/td>\n<td>Germany\/Global<\/td>\n<td>$50,000\u2013$75,000<\/td>\n<td>Utility-grade reliability<\/td>\n<\/tr>\n<tr>\n<td>Hitachi Energy<\/td>\n<td>Japan\/Global<\/td>\n<td>$55,000\u2013$82,000<\/td>\n<td>High-spec, longer lead times<\/td>\n<\/tr>\n<tr>\n<td>Schneider Electric<\/td>\n<td>France\/Global<\/td>\n<td>$48,000\u2013$72,000<\/td>\n<td>Broad distribution portfolio<\/td>\n<\/tr>\n<tr>\n<td>Toshiba \/ Hyundai<\/td>\n<td>Japan\/Korea<\/td>\n<td>$46,000\u2013$68,000<\/td>\n<td>Industrial-grade build quality<\/td>\n<\/tr>\n<tr>\n<td>Jiangsu Subian Electric Power<\/td>\n<td>Chine<\/td>\n<td>$28,000\u2013$48,000<\/td>\n<td>IEC-certified, export-focused value<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>European and Japanese manufacturers excel in every aspect including engineering sophistication, after-sales service, and long-term proven reliability. In light of the prices commanded in these countries, many organizations view the additional costs (sometimes up to 60% higher) as the necessary expense to procure other equipment from abroad. This difference in performance is decreasing as the CRGO steel and testing equipment are used by the factories located in China.<\/p>\n<p>One such company is Jiangsu Subian Electric Power, a Chinese transformer manufacturer. Its SZ11-10000kVA 35\/10.5kV transformers are built according to IEC 60076 standards and subjected to numerous tests including ratio, vector group, and impedance. Subian operates in Asia, Africa, the Middle East, and South America and is capable of fulfilling its promises of compliance with all deadlines and production quality standards.See <a href=\"https:\/\/subian-electric.com\/fr\/\">subian-electric.com<\/a> for the product catalog.<\/p>\n<h2 id=\"select\">Selection Checklist for Power Users<\/h2>\n<ul>\n<li>Size your unit based on actual demand, not installed load. Carry out either a load study or refer to historical peak values with a 15-20% additional margin in order to avoid the increased losses due to an oversized transformer, which will be inflation for the rest of its life.<\/li>\n<li>Establish the loss percentage considering the tariff. If power costs are high, pay for the efficiency at the outset \u2013 you will have your money back in 3-7 years.<\/li>\n<li>Make sure what is the tap range based on the voltage supply profile. Get in touch with the utility for a voltage log, and only after that fix either \u00b18 \u00d7 1.25% or a narrower range.<\/li>\n<li>Choose the brand of OLTC. MR or ABB OLTCs are the benchmarks, but a Chinese OLTC can save you considerably; in this case, check the operational results of the apparatus and availability of spare parts in your region.<\/li>\n<li>Indicate cooling truthfully. If you plan to run your unit above 100% on a regular basis, you should prefer ONAF cooling.<\/li>\n<li>Check site accessibility. Make sure to confirm both crane capacity and truck access for a unit of approximately 22-28 tons in weight and 3.5-4.5 m in length.<\/li>\n<li>Negotiate the extra parts and test report package. It is better to include Buchholz relay, breathers, gaskets, and whole factory acceptance testing in the contract.<\/li>\n<\/ul>\n<p style=\"text-align: center;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-135\" src=\"https:\/\/subian-electric.com\/wp-content\/uploads\/2026\/08\/Factory-Quality-Assurance-and-Testing.webp\" alt=\"Factory Quality Assurance and Testing\" width=\"1448\" height=\"1086\" \/><\/p>\n<h2 id=\"quality-assurance\">Factory Quality Assurance and Testing<\/h2>\n<p>A top-notch 10MVA power transformer rolls out of a factory that is much more than just component manufacturing. Check for the following aspects:<\/p>\n<ul>\n<li>ISO 9001 quality system and third-party inspections required by the purchaser for export projects at major production milestones.<\/li>\n<li>Testing of each unit as per IEC 60076-1, namely, winding resistance, turns ratio, vector group, short-circuit impedance and power losses, and insulation resistance.<\/li>\n<li>Testing reports before the production of each transformer family, such as temperature rise tests, lightning impulse tests, and short-circuit tests performed on similar types of transformers.<\/li>\n<li>Measuring tools\u2019 reliability.<\/li>\n<\/ul>\n<p>Commissioning at the site means further quality check.<\/p>\n<table>\n<thead>\n<tr>\n<th>Test stage<\/th>\n<th>Typical items<\/th>\n<th>Norme r\u00e9gissant<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>Factory routine tests<\/td>\n<td>Ratio, vector group, impedance, no-load and load loss, insulation resistance, dielectric tests<\/td>\n<td>IEC 60076-1<\/td>\n<\/tr>\n<tr>\n<td>Factory type tests<\/td>\n<td>Temperature rise, lightning impulse, short-circuit withstand<\/td>\n<td>IEC 60076-2\/3\/5<\/td>\n<\/tr>\n<tr>\n<td>Oil certification<\/td>\n<td>Breakdown voltage, water content, acidity, tan delta<\/td>\n<td>IEC 60296<\/td>\n<\/tr>\n<tr>\n<td>Site commissioning<\/td>\n<td>Megger, oil dielectric, OLTC full-range exercise, baseline DGA<\/td>\n<td>IEC 60422<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>Prior to energization, the contractor must confirm insulation resistance (generally &gt; 1,000 M\u03a9 for 35 kV class winding at 20 \u00b0C), verify oil dielectric strength according to IEC 60296 (\u2265 50 kV\/2.5 mm for fresh oil), operate the OLTC over its entire range of motion, and take the commissioning DGA sample in order to have a reference for the unit&#8217;s lifetime.<\/p>\n<h2 id=\"faq\">Questions Fr\u00e9quemment Pos\u00e9es<\/h2>\n<h3>How much does a 10MVA 35\/10.5kV transformer cost?<\/h3>\n<p>A feasible budget should range from $28,000 to $48,000 for the SZ11-10000 made in China and from $48,000 to $82,000 for the same equipment of European or Japanese brands, not including freight costs, insurance, installation costs, and civil costs. The loss level, brand of OLTC, accessories, and the copper prices contribute to variations in the price and should be quoted based on a written specification instead of the nominal rating.<\/p>\n<h3>Is an on-load tap changer worth the extra cost on a 10MVA unit?<\/h3>\n<p>In general, that is true, but only if your supply is not constant. The cost difference between a fixed ratio unit and its variable counterpart is approximately $6,000\u2013$12,000; however, one undervoltage incident could lead to losses for the factory equal to many times that amount due to lost production. If everything is stable and you have a flat load, there is no need to go for this option and you should buy a standard unit instead.<\/p>\n<h3>What is the typical lifespan of this transformer?<\/h3>\n<p>If the 10 MVA oil-immersed transformer is well maintained, a life span of 25 to 35 years is possible. Insulation aging follows the Arrhenius principle regarding temperature \u2014 6 degrees K above the temperature of the windings doubles or halves the insulation life. Therefore, observe the load conditions described in the guidelines of IEC 60076-7 and check on the oil quality by performing annual DGA tests.<\/p>\n<h3>Can a 50Hz unit be used on a 60Hz network?<\/h3>\n<p>A new design is necessary. Flux density is frequency dependent; supplying a design designed for 50Hz for a 60Hz application changes its magnetizing current and can lead to overexcitation issues. Ensure that proper frequency is specified correctly from the beginning in the documentation, as it greatly influences the design of a core and tap range verification.<\/p>\n<h3>How often should oil be tested?<\/h3>\n<p>The IEC 60422 standards dictate that yearly testing is needed for any facility working under normal operating circumstances. The yearly assessment should include DGA (dissolved gas analysis), dielectric strength tests, water content, acidity, and tan delta according to IEC 60599. If there are any marked changes in gas key ratios, begin monthly sampling until there is a clear trend.<\/p>\n<h2 id=\"references\">R\u00e9f\u00e9rences<\/h2>\n<ul>\n<li><a href=\"https:\/\/webstore.iec.ch\/publication\/637\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-1: Power transformers \u2013 General<\/a> \u2014 Rating, temperature rise, and tapping requirements for all power transformers.<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/publication\/640\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-3: Insulation levels, dielectric tests and external clearances in air<\/a> \u2014 Defines the 170 kVp impulse level for 35kV class windings.<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/publication\/643\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60076-5: Ability to withstand short circuit<\/a> \u2014 Short-circuit design and testing requirements.<\/li>\n<li><a href=\"https:\/\/webstore.iec.ch\/publication\/6047\" rel=\"nofollow noopener\" target=\"_blank\">IEC 60422: Mineral insulating oils in electrical equipment \u2013 Supervision and maintenance guidance<\/a> \u2014 Oil testing and maintenance schedules.<\/li>\n<li><a href=\"https:\/\/standards.ieee.org\/ieee\/c57.104\/7462\/\" rel=\"nofollow noopener\" target=\"_blank\">IEEE C57.104: Guide for the Interpretation of Gases Generated in Oil-Immersed Transformers<\/a> \u2014 DGA interpretation reference.<\/li>\n<li><a href=\"https:\/\/www.siemens-energy.com\/global\/en\/offerings\/transformers.html\" rel=\"nofollow noopener\" target=\"_blank\">Siemens Energy transformers<\/a> \u2014 Product family reference for large power transformers.<\/li>\n<li><a href=\"https:\/\/subian-electric.com\/fr\/\" rel=\"nofollow\">Jiangsu Subian Electric Power official site<\/a> \u2014 IEC-certified transformer manufacturer, product and certification information.<\/li>\n<\/ul>\n<h2 id=\"conclusion\">Conclusion<\/h2>\n<p>The SZ11-10000kVA 35\/10.5kV oil-immersed transformer is a major financial success of every energy consumer; specifications made today will define operation costs and dependability for the next quarter of a century. On-load voltage regulation addresses actual voltage quality issues within fragile grid markets, while loss capitalization makes it possible to maintain proper economical return.<\/p>\n<p>Main facts:<\/p>\n<ul>\n<li>Do budget $28,000\u2013$48,000 FOB for a Chinese model; if getting a premium brand, budget even more.<\/li>\n<li>Compare bids for TCO with your specific tariff, not just initial price.<\/li>\n<li>Do ensure you have copper winding and the brand of OLTC secured in your contract, along with copper winding and core steel quality.<\/li>\n<li>Do from now on plan to conduct yearly oil testing and DGA.<\/li>\n<\/ul>\n<p>If you are shortlisting suppliers for a 10MVA 35\/10.5kV project, <strong>Jiangsu Subian Electric Power<\/strong> supplies IEC 60076-certified SZ11 units with competitive pricing and export experience. Browse the range and request factory test documentation at <a href=\"https:\/\/subian-electric.com\/fr\/\">subian-electric.com<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"<p>An operations director at a food processing factory in East Africa finds himself looking over last week\u2019s voltage log. In one day he saw the 10.5 kV bus dip below 9.9 kV three times during the daytime grinding period. He also saw it get up to 11.2 kV overnight when the load from the town [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":133,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[77],"tags":[],"class_list":["post-132","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"blocksy_meta":[],"acf":[],"_links":{"self":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/132","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/comments?post=132"}],"version-history":[{"count":2,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/132\/revisions"}],"predecessor-version":[{"id":11081,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/posts\/132\/revisions\/11081"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/media\/133"}],"wp:attachment":[{"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/media?parent=132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/categories?post=132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/subian-electric.com\/fr\/wp-json\/wp\/v2\/tags?post=132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}