Automatic Oil Immersed Single Phase Step Voltage Regulator 250kVA 6.6kV 7.2kV11kV for Distribution Network Voltage Stabilization
250kVA automatic oil immersed single phase step voltage regulator for 6.6kV/7.2kV/11kV distribution networks. Features automatic voltage regulation, oil immersed cooling, and protection against overvoltage/undervoltage/overcurrent. Ideal for stabilizing voltage in utility, industrial, and rural electrification applications.
Automatic oil immersed voltage regulator 250kVA
,Single phase step voltage regulator 6.6kV
,Distribution network voltage stabilizer 11kV
Automatic Oil Immersed Single Phase Step Voltage Regulator 250kVA 6.6kV 7.2kV 11kV for Distribution Network Voltage Stabilization
Product Overview
The 250kVA Automatic Oil Immersed Single Phase Step Voltage Regulator is designed for medium-voltage distribution networks where voltage fluctuations can affect the reliability of downstream electrical equipment. Available for 6.6kV, 7.2kV, and 11kV systems, it automatically adjusts the output voltage through step-by-step tap regulation.
Unlike a conventional distribution transformer, the voltage regulator is primarily designed to stabilize an existing voltage level rather than simply change the voltage to another level. It is suitable for distribution feeders with frequent voltage variations, long transmission distances, changing loads, or unstable grid conditions.
The oil immersed design provides effective insulation and heat dissipation for continuous outdoor operation, making the unit suitable for utility distribution networks, rural electrification, industrial feeders, agricultural power systems, and other medium-voltage applications.
Key Selling Points
Automatic Step Voltage Regulation
The regulator continuously monitors the system voltage and automatically changes the tap position to compensate for voltage fluctuations and maintain the required output voltage.
250kVA Medium Voltage Capacity
The 250kVA rating provides a practical solution for medium-capacity distribution networks, rural feeders, industrial loads, and commercial power systems.
Multiple Voltage Configurations
Designed for 6.6kV, 7.2kV, and 11kV medium-voltage systems, with the final voltage configuration customized according to the local distribution network.
Oil Immersed Insulation and Cooling
The oil immersed structure provides reliable insulation and efficient heat dissipation, supporting stable long-term operation in outdoor distribution environments.
Improved Voltage Stability
Helps compensate for voltage drops and fluctuations caused by long feeders, changing loads, insufficient grid capacity, and other distribution network conditions.
Technical Specifications

| Specification | Value |
|---|---|
| Product Type | Automatic Single Phase Step Voltage Regulator |
| Rated Capacity | 250kVA |
| Phase | Single Phase |
| Rated Voltage | 6.6kV / 7.2kV / 11kV |
| Frequency | 50/60Hz |
| Regulation Type | Automatic Step Regulation |
| Voltage Regulation Range | Customized |
| Number of Taps | Customized |
| Control Mode | Automatic / Manual |
| Cooling Method | Oil Immersed |
| Installation | Outdoor |
| Insulation Level | Customized |
| Rated Current | Customized |
| Protection | Customized |
| Applicable Standard | IEC / IEEE |
| Application | Distribution Network / Rural Grid / Industrial Feeder |
Power Solution for Distribution Network Voltage Stabilization
Voltage instability is common on distribution feeders with long line distances, changing loads, limited transformer capacity, or weak grid conditions. When the voltage at the end of a feeder becomes too low or fluctuates significantly, motors, pumps, lighting systems, control equipment, and other electrical loads may not operate efficiently.
The HENTG 250kVA oil immersed single phase voltage regulator can be installed on the medium-voltage distribution line to automatically compensate for these voltage variations.
Common Challenges
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Voltage drops on long distribution feeders
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Frequent voltage fluctuations during peak demand
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Large changes in agricultural or industrial loads
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Remote areas located far from substations
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Weak distribution networks with limited voltage regulation capability
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Existing feeders requiring voltage improvement without complete reconstruction
Our Solution
The voltage regulator continuously measures the actual line voltage and automatically selects the appropriate tap position.
When the input voltage decreases, the regulator can increase the regulated voltage within its designed range. When the voltage rises, it can reduce the voltage accordingly. This automatic adjustment helps maintain a more stable voltage for downstream loads.
Typical applications include:
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Medium-voltage distribution networks
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Rural electrification projects
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Agricultural irrigation systems
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Industrial distribution feeders
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Commercial power networks
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Remote communities
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Utility grid voltage stabilization
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Long-distance MV feeders
FAQs
What is the difference between a step voltage regulator and a distribution transformer?
A distribution transformer mainly changes voltage from one level to another, such as 11kV to 400V. A step voltage regulator is primarily used to adjust and stabilize an existing voltage level. For example, an 11kV distribution feeder can use a voltage regulator to compensate for voltage fluctuations while continuing to operate at the medium-voltage level.
How does the 250kVA voltage regulator control the voltage?
The regulator monitors the line voltage through its control system. When the voltage moves outside the preset range, the control system commands the tap-changing mechanism to select another tap position. This increases or decreases the regulated voltage step by step until the voltage returns toward the desired range.
Can the regulator be used on 6.6kV, 7.2kV, and 11kV networks?
Yes. The regulator can be designed for different medium-voltage systems, including 6.6kV, 7.2kV, and 11kV. The insulation level, tap range, number of steps, and control parameters should be confirmed according to the specific grid requirements.
Why use an oil immersed design for this voltage regulator?
Oil provides both electrical insulation and heat dissipation. This makes the oil immersed configuration suitable for continuous outdoor operation and medium-voltage distribution applications where reliable thermal performance and insulation are important.
How do I select the correct regulation range?
The required regulation range should be determined from the actual voltage fluctuation of the distribution feeder. For example, if the feeder frequently experiences significant voltage drops during peak load periods, the regulator needs sufficient adjustment range to compensate for those variations. HENTG can recommend the appropriate configuration based on measured minimum and maximum line voltage.


Who We Are & What We Do
Hunan HENTG Power Electric Technology Co., Ltd. is a transformer and power equipment manufacturer with more than 15 years of manufacturing experience. HENTG operates its own production and R&D facilities and supplies distribution transformers, oil immersed transformers, dry type transformers, voltage regulators, pole mounted transformers, pad mounted transformers, compact substations, and renewable energy power equipment.
Our products are manufactured under ISO 9001 and ISO 14001 management systems and can be designed according to IEC, IEEE, and other international standards. We support customized voltage configurations, OEM/ODM production, factory inspection, testing, and technical coordination for utility, industrial, commercial, agricultural, and rural electrification projects.
Call to Action
Need a 250kVA automatic oil immersed voltage regulator for a 6.6kV, 7.2kV, or 11kV distribution network? Send us your system voltage, voltage fluctuation range, load capacity, and installation conditions for a suitable configuration and quotation.
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