Voltage transformer
The products are designed in strict accordance with IEC or ANSI standards, and the manufacturing steps meet the technological requirements
Model
Our Products
Dry-type PT transformers are hassle-free and low-maintenance, whilst oil-immersed PT transformers are built to last.
For indoor use, dry-type models are recommended; for outdoor use, the choice depends on the specific environment.
33/36kV oil immersed potential transformer
Oil immersed potential transformer MODEL:33-40.5 kV
22/24kV outdoor oil immersed potential transformer
Oil immersed potential transformer MODEL:20-24 kV
10/11kV outdoor oil immersed potential transformer
Oil immersed potential transformer MODEL:3.3-13.8 kV
33/36kV outdoor epoxy resin voltage transformer
Outdoor Dry type Voltage Transformer MODEL:33-40.5 kV
20/24kV outdoor epoxy resin potential transformer
Outdoor Dry type Potential Transformer MODEL:20-24 kV
10/11kV outdoor epoxy resin voltage transformer
Outdoor Dry type Voltage Transformer MODEL:3.3-13.8 kV
Overview
Key Strengths
A voltage transformer is a special type of transformer that operates on the principle of electromagnetic induction. It is primarily used to:
* Convert high voltage proportionally into a standard low voltage (typically 100 V or 100/3 V);
* Achieving electrical isolation to ensure the safety of measuring instruments, relay protection devices and operating personnel;
* Providing standardised signals for secondary equipment such as metering, protection, monitoring, synchronisation and waveform recording.
- High-precision measurement
- Wide-range adaptability
- Stable and reliable
- Multi-layered security
- Flexible installation
Advantages of Choosing Us
Why choose our products?
1
🏅Quality Assurance
Strict quality control, proven over time. Authorized certification, trustworthy.
2
✅Precise measurement
Every product undergoes individual inspection at the comprehensive testing station before leaving the factory to ensure consistent accuracy.
3
🌍Select
Complete range of sizes—everything you need in one place
Main Structure
A voltage transformer (PT) consists primarily of five
main components: the core, the primary winding,
the secondary winding, the insulation system,
the casing and accessories. These components work together
to achieve voltage transformation
- Iron Core — Magnetic Flux Path
- Primary winding — parallel voltage
- Secondary Winding — Inductive Output
- Insulation—A Safety Barrier
- Housing & Accessories
PT Core
Imported silicon steel sheet made of PT core, high quality insulation tape, high quality compression sponge, to ensure that resin shrinkage does not affect the performance of PT core, secondary use of high purity enameled wire.
Primary winding of PT
Mechanized winding secondary winding, all wire uses high purity copper enameled wire, each layer uses high quality insulating paper, to ensure that the layer withstand voltage qualified, to ensure the stability of partial discharge test.
Quick Q&A
Answers to some frequently asked questions about voltage transformers
Q1：Why must the secondary side of a PT not be short-circuited?
A:During normal operation, the secondary side is effectively open-circuited, with very high impedance. In the event of a short circuit, the inductive reactance disappears and the current surges (by a factor of tens), which can rapidly burn out the windings or cause an explosion. It is essential to fit a high-voltage fuse or miniature circuit breaker, and it is strictly forbidden to short-circuit the terminals.
Q2: Why is the secondary side of the PT earthed?
A:
* To prevent high voltage from entering the secondary circuit in the event of a primary insulation breakdown, thereby endangering personnel and equipment;
* To provide a reference potential for protective devices;
* Regulation: Grounding at a single point only (generally in the terminal box or protection panel) to avoid the formation of ground loops.”
Q3: Which type of PT should be selected for indoor switchgear?
A: Epoxy-encapsulated indoor dry-type PT (DZ/JDZX series, 6–35 kV).
* Oil-free, flame-retardant, maintenance-free
* Compact design, suitable for centre-mounted switchgear and ring main units
* The JDZX features a residual magnetic (open delta) winding, suitable for insulation monitoring
Q4: What type of PT is used for outdoor 10kV/35kV pole-mounted or open-air installations?
A: Outdoor dry-type (JDZW series) or outdoor oil-immersed.
Dry-type: Oil-free, maintenance-free, with silicone rubber for resistance to soiling flashovers (suitable for coastal and industrial areas)
Oil-immersed: Weather-resistant and proven, but requires periodic oil testing
Q5:What should I do if the PT emits an abnormal noise or the secondary voltage is abnormal?
A: Beware of ferromagnetic resonance!
In an ungrounded neutral system, the excitation inductance of the PT and the capacitance to earth may cause ferromagnetic resonance
* Symptoms: Abnormal rise or fluctuation in two-phase or three-phase voltage, humming noise from the PT, or blown fuses
* Measures: Install a primary-side anti-resonance device (linear resistor / non-linear component) or a microprocessor-based anti-resonance unit; select an anti-resonance PT
⭐We look forward to becoming your trusted electrical partner！