Voltage transformer JDZ10-10

Model Meaning: J: Represents "Voltage Transformer"
D: stands for "single-phase"
· Z: stands for "cast" or "resin cast" insulation (Cast-resin Insulation)
10: Design serial number, representing that it belongs to the 10th series design.
-10: Rated voltage level, indicating that it is suitable for 10kV power system.
main function and role
A voltage transformer (PT or VT) is essentially a special transformer whose core functions are:
1. Voltage conversion: convert high voltage (such as 10kV) into standard low voltage (usually 100V or 100/3V) in proportion to facilitate measurement and protection equipment access.
2. Electrical isolation: the high voltage circuit and low voltage measurement, protection circuit for electrical isolation, to ensure personal and equipment safety.
3. Provide signals for instrumentation and relay protection devices:
· Measurement: Provide voltage signals for voltmeters, energy meters (watt-hour meters), power meters, power factor meters, etc.
· Protection: Provide voltage signals for relay protection devices (such as overvoltage, low voltage, grounding protection, etc.).
Main technical parameters and characteristics: rated voltage ratio 10/0.1 kV or 10/& radic;3 / 0.1/& radic;3 kV This is the most important parameter, which means that when the rated voltage on the primary side is 10kV, the output voltage on the secondary side is 100V. The latter ratio is often used where phase voltages are required.
Accuracy grade/precision grade 0.2, 0.5, 1,3, 3P, 6P and other different precisions are used in different occasions: grade 0.2: used for precision metering (e.g. gateway watt-hour meter) grade 0.5: used for general metering (e.g. user watt-hour meter) grade 1/grade 3: used for measuring instruments (e.g. voltmeter) grade 3P/6P: used for protection circuit (p represents protection)
Rated output/capacity has different values corresponding to different accuracy levels, for example: 0.5 level: 50 VA 1 level: 80 VA 3 level: 200 VA 3P level: 150 VA this indicates the maximum power that can be output from the secondary side of the transformer under the corresponding accuracy.
The limit output of about 400 VA refers to the maximum output capacity of the transformer that can meet the thermal performance requirements, but the accuracy cannot be guaranteed at this time.
Insulation level semi-insulation (or non-full insulation) power frequency withstand voltage: 42/30 kV (primary to secondary/ground; Secondary to ground) lightning impulse withstand voltage: 75 kV note: "semi-insulation" means that the end (n end) of its primary winding cannot withstand the same voltage to ground as the head end (a end).
Insulation mode Epoxy resin vacuum casting This is the core feature of JDZ series. The epoxy resin mixture for the winding is cast into a solid in a vacuum environment. Advantages include: • Moisture-proof, mildew-proof, anti-salt spray, stable performance • High mechanical strength, maintenance-free • Small local discharge capacity, high reliability
The installation method is usually fixed by screws in the front of the board, and the base has mounting holes.
Operating conditions for indoor use. Not suitable for installation outdoors or in humid, corrosive gas environment.
Weight of about 10-15 kg (specific slightly different due to manufacturers)
Structural features: 1. Primary winding: high-voltage winding, usually only one or a few turns, with a rated voltage of 10kV. The primary terminals are usually labeled A (head end) and N (end end).
2. Secondary winding: low-voltage winding with more turns and rated output voltage of 100V. The secondary terminals are usually labeled a (head end) and n (end end).
3. Insulator: The entire winding system is cast into a solid whole by high-quality epoxy resin, forming a "pagoda" or "drum-shaped" appearance. This not only provides insulation, but also serves as mechanical protection and heat dissipation.
4. Iron core: made of high-quality silicon steel sheet, used to form a magnetic circuit, located inside the pouring body.
5. Base: usually made of steel plate or aluminum alloy, with mounting holes for easy fixing.
Connection mode and application
JDZ10-10 is a single-phase voltage transformer, and the common wiring modes in 10kV system are:
1. Single use:
Used to measure line voltage (AB, BC, CA), connected between two phases of a system (e. g. A and B phases).
· Used for single-phase voltage monitoring of generators, transformers and other equipment.
2. V/v wiring (combination of two):
· This is the most common way. Two JDZ10-10 transformers are used, and the primary side is connected to AB and BC phases respectively.
The secondary side can output three line voltages (Uab, Ubc, Uca = Uab-Ubc) for measuring instruments and relay protection. This wiring saves equipment, but does not measure phase voltage and insulation to ground.
3. Y/yn wiring (three combinations):
Three JDZ10-10 transformers are used, the primary side is connected to a star shape (Y shape), and the neutral point must be reliably grounded.
The secondary side is also connected into a star shape, which can output line voltage and phase voltage. This wiring can be used both for measurement and for insulation monitoring (with voltage relays).
Important note: Since the JDZ10-10 is a semi-insulating structure, in any connection mode, the N terminal of the primary winding must be reliably grounded! If it is not grounded, when a single-phase ground fault occurs in the system, a high voltage will appear at the N terminal to the ground, which may cause the transformer insulation breakdown damage.