Sz9 on-Load-Tap-Changing Power Transformer of 35kv Oltc Distribution Transformer

Product Description

 

Product Description

SZ9 and SFZ9 Series Three-phase On-load-tap-changing

Power Transformer of 35kV
General
This kind of product is applied to power system of three-phase, 50Hz as well as 
35kV and below, it is the main transformer equipment of medium and small-sized 
transformer substation, supplies power distribution, power and illumination for 
the industry and agriculture.
The company introduces domestic and overseas advanced technique, adopts the 
latest material and optimizes design, which enables the product structure more 
reasonable, and greatly improves the product electric strength, mechanical 
strength and heat-sinking capability. S9 Series product has passed the shortcircuit test prepared by Wuhan High Voltage Research Institute and also the test 
prepared by National Center for quality Supervision & Test of Transformer.

The SZ9 series oil-immersed power transformer is a high-efficiency voltage regulating transformer designed for power transmission and distribution systems. Equipped with an On-Load Tap Changer (OLTC), the transformer can adjust voltage levels under load conditions without interrupting power supply, ensuring stable and reliable operation of the electrical network. It is widely used in substations, industrial plants, commercial facilities, mining projects, and utility power systems.

The SZ9 transformer is manufactured in accordance with IEC 60076, GB1094, and other international standards, providing excellent electrical performance, energy-saving operation, and long service life.  

Main Features

1. On-Load Voltage Regulation

The SZ9 transformer is equipped with a reliable on-load tap changer that allows voltage adjustment while the transformer remains energized. This feature helps maintain stable output voltage during load fluctuations and improves overall power quality.  

2. Energy-Saving Design

Advanced magnetic circuit optimization and high-quality cold-rolled grain-oriented silicon steel core significantly reduce no-load losses and no-load current. Compared with older transformer series, the SZ9 transformer provides improved energy efficiency and lower operating costs.  

3. High-Quality Winding Structure

The windings are manufactured using oxygen-free copper or high-conductivity aluminum conductors. Optimized coil design improves short-circuit withstand capability, mechanical strength, and thermal performance, ensuring reliable long-term operation.  

4. Excellent Cooling Performance

The transformer adopts an oil-immersed insulation and cooling system. Scientifically designed oil ducts allow efficient heat dissipation, reduce winding temperature rise, and extend insulation life.  

5. Low Noise and Stable Operation

The multi-step lap core structure minimizes magnetic flux leakage and vibration, effectively reducing operating noise while improving transformer efficiency and reliability.  

6. Robust Tank Construction

The transformer tank is manufactured using high-strength steel plates with anti-corrosion surface treatment. Corrugated or radiator-type cooling structures are available to meet different project requirements and environmental conditions.  

7. Safe and Reliable Performance


The SZ9 transformer can be equipped with comprehensive protection devices, including:
    •    Buchholz Relay
    •    Pressure Relief Valve
    •    Oil Level Indicator
    •    Oil Temperature Indicator
    •    Winding Temperature Monitoring System
    •    Gas Relay Protection

These protective devices enhance operational safety and reduce maintenance risks.  



Applications

The SZ9 oil-immersed transformer is widely used in:
    •    Utility Power Distribution Networks
    •    Urban and Rural Substations
    •    Industrial Manufacturing Plants
    •    Mining Projects
    •    Petrochemical Facilities
    •    Commercial Buildings
    •    Renewable Energy Power Stations
    •    Infrastructure Construction Projects


Conclusion

The SZ9 oil-immersed on-load tap changer transformer combines advanced voltage regulation technology, low-loss operation, strong overload capability, and dependable mechanical design. It is an ideal solution for modern power systems requiring continuous voltage stability, high efficiency, and long-term operational reliability. With customizable specifications and compliance with international standards, the SZ9 transformer is suitable for a wide range of power distribution and transmission applications worldwide.  

Structural Features
1.  Iron core
The iron core is made of high quality cold rolled silicon steel sheet, adopts the 
kinds of types like full-bias multi-step seam, no punched hole, winding iron core, 
etc., besides, both stainless steel stay plate and epoxy glass belt are for clamping 
it.
2.  Coil
High quality enameled wire that is made of oxygen free copper or paper wrapped flat copper wire is used as conductor, the coils is provided kinds of types such as 
drum type, spiral type, improved spiral type, continuous type and interleaved type.
3. Oil tank
The oil tank is of barrel type or shield type, the heat-sinking element is provided with corrugated plate or plated radiator.
The transformer has not been equipped with trolley, but there is a base that 
accords with national standard rail gauge welded at the bottom of box for your convenience.
4.  Safety protection device
According to national standard and users' requirements, the transformer may be
equipped with following safety protection devices: pressure relief valve, gas relay, 
signal thermometer, oil purifier, oil conservator, oil sampling valve, etc.

 

Detailed Photos

Product Parameters

   

SZ9 and SFZ9 series three-phase on-load-tap-changing power transformer of 35kV

SZ9 series three-phase on-load-tap-changing power transformer of 10kV

Certifications

 

 

 

 

Company Profile

Haocheng Group Co., Ltd. is located in Dongfeng Industrial Park, Liushi Wenzhou, which is famous production base of high and low voltage electrical appliances in China. Mainly research and develop power products, covering high and low voltage complete sets of equipment and cabinets, box-type substations and enclosures, power transformers, cable junction boxes, distribution boxes, meter boxes, circuit breakers, high power transmission and distribution products
such as low-voltage electrical accessories, power engineering installation,etc. 

A professional power equipment manufacturing enterprise integrating
research and development. The company strictly manages in accordance with the operating standards of the ISO9001, ISO1400, OHSAS18001 quality system. 

The company adheres to the corporate tenet of "scientific development, pursuit of excellence, customer first, service commitment", and takes the market as a guide.

Inherit and carry forward the exquisite craftsmanship with the business philosophy of seeking development through quality, efficiency through management, and scientific and technological innovation.

 

 

 

Workshop

 

  

SZ9 OLTC Transformer

Packaging & Shipping

 

OUR SERVICE:

1,Quick response in before sales period 

2,Excellent service in production time 

3,Reliable quality 

4,Long period quality waranty 
 

FAQ

 

1.Q: Are you manufacturer?
    A: Yes, we are manufacturer.

2.Q: Can I get guarantee of products?
    A: Yes, each product is 1 year quality warrantee under customer correct using the products

3.Q: How to buy it? What about the delivery?
    A: Please contact me by email or online, let me know your requirement, we will provide you professional solution. We have shipping agent can  choosing the cheapest and fastest delivery. FOB,CIF, C&F, FCA or EXW, each is available to us

4.Q: How can I pay you?
    A: T/T and L/C

5.Q: What about the production?
    A: Produce time is 2~4weeks  

6.Q: Could you offer some spare parts?
    A: Yes, no problem.

7.Q: Is the S9 transformer suitable for new projects?
   A: The S9 series is mainly recommended for replacement projects or markets with moderate energy-efficiency requirements.

8.Q: Can the transformer be customized?
   A: Yes, voltage, capacity, vector group, and standards can be customized.

9.Q: What standards do you follow?
   A: IEC, GB, or other international standards as required by customers.