Three Phase Step Voltage Regulator - Distribution Voltage Stabilizer
The Three Phase Step Voltage Regulator is a high-reliability, automatic on-load tap changing device engineered to maintain stable voltage levels in medium-voltage distribution systems. Featuring premium copper windings, advanced low-loss silicon steel cores, and a fast-response motorized tap changer, it delivers precise voltage correction with excellent accuracy and minimal waveform distortion. The intelligent digital AVR controller continuously monitors three-phase parameters and automatically adjusts taps in real time to compensate for load variations and grid fluctuations. Designed for demanding outdoor environments, it offers robust overload capacity, low power losses, comprehensive protection systems, and remote monitoring capabilities. This regulator effectively improves voltage profile, reduces energy losses, and enhances the overall stability and efficiency of distribution networks.
- Primary Voltage Ratings 11 kV / 22 kV / 33 kV
- Secondary Voltage Ratings --
- H.V. Tap Range --
- Type Voltage Regulator
- BIL 11kV - 200kV
- Standards IEC 60076, IEC 60137, ASTM D202
- Application residential, commercial, industrial voltage stabilization
- Power Rating --
- Certificate UL, CESI, IEEE
- Cooling Method ONAN/ ONAF
- Opeartion --
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
Three Phase Step Voltage Regulator - Distribution Voltage Stabilizer
Three Phase Step Voltage Regulator Parameter
| Parameter | Specification |
| Rated Capacity | 250 kVA – 3000 kVA |
| Rated Voltage | 11 kV / 22 kV / 33 kV |
| Regulation Range | ±15% ~ ±25% |
| Number of Steps | 32 steps |
| Step Voltage | 0.75% per step |
| Response Time | ≤ 1.0 second |
| Cooling Method | ONAN / ONAF |
| Ambient Temperature | -40°C to +55°C |
Customization Optional
Three Phase Step Voltage Regulator - Distribution Voltage Stabilizer
The Three Phase Step Voltage Regulator provides extensive customization to perfectly align with different distribution network requirements and environmental conditions. Customers can choose rated capacity from 250kVA to 3000kVA, primary voltage from 6kV to 36kV, and regulation range up to ±30%. The control system supports multiple communication protocols such as IEC 61850, DNP3, Modbus, and 4G/GSM for full remote monitoring and smart grid integration. We also offer enhanced cooling systems (ONAF), stainless steel tanks for coastal or highly corrosive areas, and heavy overload designs capable of 200% loading for extended durations.
Further customization includes low-noise models for urban installations, harmonic filtering modules, automatic bypass switches, programmable voltage profiles with time-based scheduling, and integration with renewable energy sources or energy storage systems. Enclosure configurations range from compact pole-mounted to pad-mounted or fully substation-integrated designs with advanced animal guards, seismic reinforcement, and anti-corrosion treatments. These tailor-made options enable utilities and project developers to achieve optimal voltage stability, reduced line losses, and maximum system reliability according to their specific operational needs.
Packing and Shipping
Three Phase Step Voltage Regulator - Distribution Voltage Stabilizer
The Three Phase Step Voltage Regulator undergoes professional heavy-duty packaging to ensure safe arrival even after long-distance transportation. The unit is firmly anchored to a reinforced steel skid with anti-vibration rubber mounts and multiple high-tensile steel strapping bands. All high-voltage bushings, radiators, and the control cabinet are individually protected with custom wooden frames and high-density foam padding. The complete assembly is wrapped in multi-layer waterproof and anti-static film with sufficient desiccant packets. A sturdy, ISPM 15 fumigated wooden crate or steel-reinforced open frame provides full protection, equipped with shock indicators and tilt sensors for complete transit monitoring.
We offer flexible and secure shipping solutions tailored to project schedules and locations. For international shipments, sea freight in 20ft or 40ft flat-rack or open-top containers with professional lashing and blocking ensures safe and cost-effective delivery, typically taking 25–65 days. Air freight is available for urgent spare parts or emergency replacements. Domestic and regional shipments utilize specialized low-bed trailers with hydraulic cranes and GPS tracking for oversized loads.
Comprehensive export documentation is prepared in advance, including commercial invoices, detailed packing lists, certificates of origin, factory test reports, and installation manuals to facilitate smooth customs clearance. We adopt sustainable logistics practices by using recyclable materials and optimizing container loading to reduce carbon footprint. Customers receive a secure online tracking portal with real-time GPS updates and dedicated logistics coordinator support.
Upon arrival at the project site, we provide optional professional supervision for unloading, oil level verification, and initial inspection. For large-scale projects, we support consolidated multi-unit shipments and phased delivery scheduling to minimize on-site storage requirements and logistics costs. This meticulous packing and shipping process guarantees that every Three Phase Step Voltage Regulator arrives in perfect condition, ready for efficient installation and operation.
We offer flexible and secure shipping solutions tailored to project schedules and locations. For international shipments, sea freight in 20ft or 40ft flat-rack or open-top containers with professional lashing and blocking ensures safe and cost-effective delivery, typically taking 25–65 days. Air freight is available for urgent spare parts or emergency replacements. Domestic and regional shipments utilize specialized low-bed trailers with hydraulic cranes and GPS tracking for oversized loads.
Comprehensive export documentation is prepared in advance, including commercial invoices, detailed packing lists, certificates of origin, factory test reports, and installation manuals to facilitate smooth customs clearance. We adopt sustainable logistics practices by using recyclable materials and optimizing container loading to reduce carbon footprint. Customers receive a secure online tracking portal with real-time GPS updates and dedicated logistics coordinator support.
Upon arrival at the project site, we provide optional professional supervision for unloading, oil level verification, and initial inspection. For large-scale projects, we support consolidated multi-unit shipments and phased delivery scheduling to minimize on-site storage requirements and logistics costs. This meticulous packing and shipping process guarantees that every Three Phase Step Voltage Regulator arrives in perfect condition, ready for efficient installation and operation.
32
32 years of industry experience
Manufacturer Test
Three Phase Step Voltage Regulator - Distribution Voltage Stabilizer
Progress Test
Early manufacturing progress testing for the Three Phase Step Voltage Regulator includes core material validation through Epstein frame and watt-loss testing to confirm superior magnetic performance. Copper winding resistance, insulation resistance, and inter-turn withstand voltage tests are performed before assembly. The motorized on-load tap changer mechanism undergoes rigorous mechanical endurance cycling exceeding 20,000 operations to ensure smooth and reliable switching. Tank welding quality is inspected using helium leak detection and radiographic examination. Initial control system calibration verifies voltage sensing accuracy, protection thresholds, and communication modules. These early-stage tests, supported by full digital traceability, establish strong mechanical and electrical foundations. Oil processing, degassing, and vacuum filling are strictly monitored for optimal dielectric strength. The automatic regulation algorithm is simulated under wide input voltage and load variations to verify accuracy and response time.
Design Tests
All transformer will be test after finished the production, test items as below:
♦ Insulation Power Factor
♦ Ratio, Polarity, and Phase Relation
♦ Winding Resistance
♦ Impulse Tests
♦ On load Loss Test
♦ No Load Loss Test
♦ Transformer Turns Ratio/TTR (All Tap Voltages)
♦ Impedance Voltage & Load Loss (Rated Voltage)
♦ Polarity, 1-Ph / Phase Relation, 3-Ph (Rated Voltage)
♦ Excitation & No-Load Loss (Rated Voltage)
♦ Applied Voltage
♦ Induced Voltage
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Factory Acceptance Test
Factory Acceptance Testing for the Three Phase Step Voltage Regulator begins with precise ratio, polarity, and impedance verification across all tap positions. No-load loss and excitation current measurements confirm core efficiency. Full-range automatic regulation tests verify output voltage stability and step precision under different load conditions. All protection functions (over/under voltage, overload, short-circuit, phase imbalance) are activated and validated for correct operation. Control system calibration, display accuracy, alarm functions, and remote communication protocols are thoroughly tested. These essential electrical and functional tests are documented with detailed waveforms and data sheets. On-load tap changer endurance cycling under load confirms long-term mechanical and electrical reliability. Harmonic distortion, power factor, and regulation response time are measured under various load types.
Routine Test - Transformer Turns Ratio/TTR (All Tap Voltages)
Purpose of Testing
The purpose of the transformer turns ratio (TTR) test is to confirm whether the voltage ratio between each tap of the transformer meets the design requirements and ensure that the transformer winding is connected correctly. By measuring the voltage ratio of each tap, it is possible to detect whether there is a fault or deviation in the transformer winding.
Testing Equipment
TTR tester: such as Doble, Megger, Omicron and other brands of transformer winding ratio tester.
Voltage source: usually AC 10 V to 30 V , used to test different voltages for each tap.
Temperature and humidity meter: used to record environmental conditions during the test to ensure test accuracy.
Current probe: used to measure the load current of the winding and ensure the accuracy of the test results.
Voltage source: usually AC 10 V to 30 V , used to test different voltages for each tap.
Temperature and humidity meter: used to record environmental conditions during the test to ensure test accuracy.
Current probe: used to measure the load current of the winding and ensure the accuracy of the test results.
Pre-Test Preparation
Disconnect all transformer tap-changers from the power supply and ensure that all equipment is properly grounded and discharged.
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Test Progress
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Measure and Record
Start the test and record the following parameters:
The voltage ratio between the windings
Deviation of the measured value from the rated ratio
The voltage ratio between the windings
Deviation of the measured value from the rated ratio
Temperature Correction
If necessary, perform temperature correction on the measured turns ratio data (especially when testing at higher or lower temperatures). Generally, the standard reference temperature for temperature correction is 20°C.
Repeat Testing (if necessary)
Test the transformer's windings of different voltage levels (high voltage, medium voltage, and low voltage) separately to ensure that the turns ratios of all windings are normal.
Evaluation Criteria (Reference)
Turns ratio error ≤ 0.5% (pass)
0.5% < Turns ratio error ≤ 1% (caution)
Turns ratio error > 1% (further inspection or corrective action required)
0.5% < Turns ratio error ≤ 1% (caution)
Turns ratio error > 1% (further inspection or corrective action required)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
Extensively deployed in utility distribution networks, renewable energy integration points, and mixed residential-industrial areas, providing reliable three-phase automatic voltage regulation to improve power quality, reduce losses, and enhance overall system efficiency.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
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What is a Transformer?A transformer is an electrical device used to change the voltage of alternating current (AC). It works on the principle of electromagnetic induction, converting high-voltage current into low-voltage current or low-voltage current into high-voltage current. Transformers are widely used in power transmission, distribution systems, and various electronic devices.
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What are the main uses of a transformer?The main use of a transformer is voltage conversion. Transformers are used in power transmission systems to help transfer electricity from power plants to consumers. In addition, transformers are also used in electronic devices such as chargers, televisions, power adapters, etc., to adjust the voltage to meet the requirements of different devices.
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Do you have UL listed?Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.
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