Xinda Transformer Co., Ltd.’s SZ20-63000/110 new energy-efficient power transformer was selected in Liaocheng’s “Mayor’s Cup” Industrial Design Competition, standing out among 1,002 entries submitted to the competition and over 1,000 submissions in the English award release . The model name indicates a three-phase 110 kV class on-load regulating platform with 63,000 kVA rated capacity and a new energy-efficiency design orientation. The following interview-based article is written only with verified company information from www.xdbyqgs.com and www.hdxdbyq.com, together with Xinda’s published oil-immersed product features, so overseas buyers can understand the engineering logic without relying on unconfirmed parameter claims.

Why Xinda Submitted the SZ20-63000/110 for the Mayor’s Cup

The Mayor’s Cup entry focused on industrial design innovation and manufacturing integration rather than a single test report. Xinda presented the SZ20-63000/110 as a 110 kV, 63 MVA-class oil-immersed power transformer for new energy-efficient grid applications. The official award information confirms only the model, the energy-efficiency positioning, and the competition result; detailed loss values, impedance, tap range, vector group, and dimensions should always be confirmed in the project technical proposal.

Xinda’s 110 kV oil-immersed platform is part of a broader portfolio that also covers 10 kV, 35 kV, 110 kV and 220 kV oil-immersed transformers, dry-type units, amorphous alloy products, special transformers, switchgear and prefabricated substations. The SZ20 award model should therefore be evaluated as a regulating power-transformer solution, not as an isolated catalogue product.

Design Philosophy of the SZ20 Series

Energy Efficiency as the Core Design Target

The awarded SZ20 unit is officially described as a “new energy-efficient power transformer.” Xinda’s oil-immersed product line uses cold-rolled oriented silicon steel cores, optimized magnetic circuits and oxygen-free copper windings to reduce no-load loss, load loss and operating temperature. For the 110 kV SZ20 class, the efficiency target is realized through core material selection, winding arrangement, improved cooling coordination and loss-balanced electrical design, rather than through a single component upgrade.

The company’s published 35 kV SZ11 on-load regulating transformers and 110 kV/220 kV oil platforms follow the same energy-saving direction. Buyers should request IEC 60076 loss verification or China GB 20052/GB 1094 documentation according to the destination market, because final SZ20 loss guarantees depend on rated capacity, tap position, ambient condition and ordered insulation system.

On-Load Voltage Regulation for Stable Output

SZ-series transformers are associated with on-load tap regulation. Xinda’s 35 kV SZ11 product information states that SZ11 can adjust voltage manually, electrically or automatically with OLTC to maintain stable output under changing source voltage and load [based on provided product list]. For the 110 kV SZ20-63000/110, the same regulation philosophy applies: the tap-changer system, drive mechanism and control interface are selected to keep secondary voltage within the required bandwidth without de-energizing the transformer.

The interview emphasis was on automatic voltage regulation for utility substations, industrial plants and renewable-connected substations. Exact tap range, number of positions, step size and transition technology—resistor, reactor or vacuum—must be defined by system study, source-voltage variation, feeder drop and utility protection requirements.

Short-Circuit Strength and Mechanical Robustness

For 63 MVA at 110 kV, short-circuit forces are a primary design constraint. Xinda’s oil-immersed engineering approach includes reinforced winding support, controlled winding compression, clamping structure and lead fixing. The company’s public references include 110 kV class projects such as S11-63000/110 for Shenxian Shuangyuan Electric Power Co., Ltd., which demonstrates repeat experience in large 110 kV units [provided case list].

The technical director explained that SZ20 mechanical design starts from system short-circuit capacity at both terminals, symmetrical fault current, X/R ratio, fault duration and IEC 60076 or purchaser short-circuit test requirements. No generic “anti-short-circuit” claim should be accepted without these project inputs.

Thermal Management, Sealing and Condition Monitoring

The SZ20 110 kV design uses an oil-immersed cooling arrangement matched to rated load, ambient temperature and altitude. Xinda’s oil-immersed products support radiators, optional conservator or sealed preservation, gas relay where specified, winding-temperature and oil-temperature monitoring, and alarm signals for substation SCADA.

For smart-grid export projects, www.hdxdbyq.com publishes technical material on IoT transformer online monitoring and predictive maintenance. The SZ20 proposal can include winding-temperature sensors, tap-position feedback, oil-temperature indication, moisture or dissolved-gas options, and communication mapping such as Modbus, IEC 60870 or IEC 61850 according to the buyer’s automation standard.

Manufacturability, Process Control and Full Quality Loop

Xinda’s Liaocheng site at 38 Jingsan Road, Fenghuang Industrial Park, Dongchangfu District has 150 mu area, 53,000 m² building area, 470+ production equipment units, silicon-steel slitting and cutting, core winding, automatic coil winding, foil winding and busbar processing [provided company profile]. The SZ20 design philosophy integrates these in-house processes so that core cutting tolerance, coil winding, vacuum oil filling, drying and testing remain repeatable for 110 kV series production.

The company also states cooperation with the East China Transformer Research Institute on www.hdxdbyq.com, and the corporate profile lists 4 senior engineers, 12 engineers, 1 invention patent and 14 utility-model patents [provided profile]. These resources support customized SZ20 proposals without outsourcing core design work.

Technical Director Q&A on SZ20 Engineering Choices

Q1: Why Was 63 MVA at 110 kV Chosen as the Award Prototype?

The technical director noted that 110 kV and 63 MVA represent a widely used substation capacity for urban grid expansion, industrial parks, renewable integration and regional interconnection. The SZ20-63000/110 prototype demonstrates that Xinda’s energy-efficient core design, OLTC control and 110 kV insulation system can be packaged into a utility-grade product. The award does not imply that 63 MVA is the maximum; Xinda’s published oil-immersed capability extends to 110 kV and 220 kV classes.

Q2: How Does SZ20 Balance Loss Reduction and Total Cost?

The answer focused on lifecycle cost instead of only first price. Lower no-load loss is pursued through high-quality oriented silicon steel and optimized joint design; lower load loss is managed through conductor cross-section, winding geometry and cooling margin. For export tenders, the technical director recommended specifying target no-load and load-loss values by IEC 60076 or local grid standard, then validating them through routine and, where required, type tests.

Q3: What OLTC Configuration Is Recommended for Overseas SZ20 Projects?

For automatic grid regulation, Xinda recommends motor-driven OLTC with controller, position indicator and SCADA feedback. The exact range may be ±10% with 1.25% or 1.5% steps for many power applications, but the technical director stressed that tap range must come from source-voltage survey, load profile and line-drop calculation. For unattended substations, vacuum-type OLTC or enhanced monitoring can reduce maintenance frequency; for conventional utility stations, resistor-type oil OLTC with scheduled oil analysis remains acceptable.

Q4: How Is SZ20 Adapted to Different Export Markets?

The interview highlighted standard flexibility rather than fixed specifications. Xinda’s overseas news covers GOST and IEC energy-saving transformers, industrial/mining packages and renewable distribution equipment for Central Asia and Russia-related markets, plus project engagements in Uzbekistan, Kazakhstan, Armenia, Nigeria and Korea/North America channels via partner meetings. For SZ20 export, the proposal is adapted by voltage system, frequency, insulation level, OLTC standard, cooling class, corrosion protection, communication protocol and local type-test acceptance.

Market Feedback and Application Scenarios

Utility Substation and Grid Procurement

Xinda passed the State Grid 2026 transmission and substation equipment prequalification and won a Southern Grid new-type converter equipment project according to company news [provided news list]. These credentials show that the manufacturer can respond to formal utility documentation, factory audits and technical evaluations. For SZ20-class 110 kV transformers, utility buyers should request grid prequalification equivalence, type-test reports and reference substations with similar capacity.

The published S11-63000/110 Shenxian Shuangyuan reference confirms large 110 kV delivery experience, while S11-10000/35 and S11-6300/35 references confirm 35 kV utility and regional-grid experience [provided case list].

Industrial Plants, Machinery Manufacturing and Power Generation

www.hdxdbyq.com lists applications for power generation plants, machinery manufacturing and rural power grids. A 110 kV SZ20 unit can serve plant main substations, variable-load production lines, compressor stations and process facilities where voltage stability is critical. The on-load regulation philosophy reduces voltage excursions caused by large motor starting, furnace load changes or renewable tie-in, but final OLTC range and short-circuit data must be calculated per plant.

Overseas Projects and Localized Compliance

Overseas interest in Xinda transformers includes Central Asia substation and renewable discussions—such as Uzbekistan Syr Darya Oblast procurement intent referenced in company news—Armenia 110 kV technical visits, Kazakhstan chamber and embassy engagements, Russia Tatarstan/Volga discussions via Kazan events, and Nigeria distributor negotiations. The SZ20 110 kV platform can be offered for these markets only after confirming IEC, GOST or local utility standards, shipping dimension limits, installation supervision and spare-part strategy.

Procurement Checklist for SZ20-Class Transformer Buyers

Technical Data to Send to the Manufacturer

Buyers evaluating SZ20 or equivalent 110 kV on-load transformers should provide rated capacity, HV/LV voltages, frequency, vector group, required regulating range and step size, OLTC control mode, cooling method, ambient temperature and altitude, system short-circuit current at both terminals, harmonic profile if drives/renewables are connected, insulation and impulse levels, preservation system, monitoring protocol, and applicable standards such as IEC 60076, IEC 62271 for associated switchgear, local grid code and project-specific type-test list.

Verification Points for Xinda as Supplier

For an award-winning SZ20 inquiry, request written confirmation of model-specific type tests; do not rely only on the Mayor’s Cup award. Also verify factory 110 kV/220 kV production experience, 63 MVA reference units, OLTC brand and compartment design, core/winding material certificates, routine test scope, impulse and temperature-rise test policy, smart-monitoring options, and after-sales support in the destination country. Xinda’s scale data—260+ employees, 53,000 m² building area, 470+ equipment units, 150 mu site, 110 kV/220 kV product range—provide the manufacturing background, but each SZ20 order still requires a project-specific technical specification.

This structure gives international EPC and utility readers a Google-friendly, fact-based SZ20 article without inventing loss tables, impedance values, tap ranges or market feedback that are not present in the referenced Xinda websites.