JDZ11-15,20G Voltage Transformer
Panoramica del prodotto
Il trasformatore di tensione JDZ11-15,20G è un trasformatore di tensione a secco completamente incapsulato in resina epossidica, specificamente progettato per sistemi di alimentazione in corrente alternata per interni da 15 kV/20 kV (Um=24 kV). Appartiene alla serie potenziata di prodotti per media tensione da interno, caratterizzato da un design ad alta distanza di dispersione anti-inquinamento e anti-scarica. È adatto per media tensione switchgear, sottostazioni prefabbricate e unità a anello, fornendo funzioni di misurazione della tensione, misurazione dell'energia, protezione di relè e monitoraggio dell'isolamento per i sistemi di alimentazione. È ampiamente applicato nei sistemi di distribuzione da 15 kV/20 kV in imprese industriali e minerarie, edifici commerciali e parchi industriali.
Caratteristiche principali del prodotto
Isolamento e Prestazioni Elettriche
High Voltage Rating Compatibility: Designed specifically for 15 kV/20 kV systems with a rated maximum operating voltage of Um=24 kV. Capable of withstanding power-frequency and impulse withstand voltage tests corresponding to the applicable system voltage level. Insulation performance fully meets medium-voltage distribution system requirements.
Fully-Enclosed Epoxy Resin Cast Insulation: The entire body is formed by vacuum casting with epoxy resin, eliminating internal voids. Insulation performance is excellent, with partial discharge level ≤10 pC. Long-term operation presents no insulation aging risk, and the design is free from leakage and oil contamination, making it suitable for oil-free indoor distribution applications.
High Anti-Pollution-Flashover Performance: The high-voltage side employs a multi-layer shed-type insulation structure with significantly increased creepage distance, providing excellent anti-pollution-flashover capability. Suitable for polluted and humid environments, reducing the risk of surface flashover. The G-type is an enhanced anti-pollution-flashover version capable of withstanding more severe environmental conditions.
Wide Voltage Ratio Compatibility: Supports standard voltage ratios (e.g., 15/0.1 kV, 20/0.1 kV, 20/0.1/0.1 kV). Metering-class accuracy can reach Class 0.2; protection-class accuracy can be customized to Class 3P/6P. Meets requirements for metering, protection, and insulation monitoring applications.
Caratteristiche Strutturali e di Installazione
Fully-Enclosed Dry-Type Construction: The monolithic cast body has no exposed live parts, with protection class IP20. The oil-free design eliminates fire hazards. The compact, small-footprint structure is compatible with standard 15 kV/20 kV switchgear mounting dimensions.
Clear Secondary Terminals: Secondary terminals are protected by a transparent cover for clear identification and convenient wiring, preventing mis-connection and short circuits. Terminal layout conforms to secondary circuit wiring standards for switchgear interiors.
Flexible Mounting: The base metal mounting plate incorporates fixing holes for bolt-secured installation, supporting horizontal indoor cabinet mounting. The installation is mechanically robust with excellent vibration resistance, facilitating compact arrangement within switchgear panels.
Funzionalità di Operatività e Manutenzione
Maintenance-Free Operation: The dry, oil-free construction eliminates leakage and fire hazards. The epoxy resin cast body offers high mechanical strength with resistance to impact and aging, enabling maintenance-free long-term operation and reducing operational costs.
Wide Operating Temperature Range: Capable of operating in ambient temperatures from -30°C to +70°C. Epoxy resin performance remains stable across high and low temperatures with no risk of embrittlement or deformation, suitable for climatic conditions in various regions.
High-Reliability Design: The core is laminated with high-quality silicon steel sheets; windings are wound with enameled copper wire. Operating losses are low with minimal heat generation. The unit can withstand switching overvoltages and lightning impulse overvoltages, ensuring stable performance and reliable metering and protection signal output.
Parametri Tecnici (Specifiche Tipiche)
| Categoria Parametro | Parametro | Specifiche |
| Parametri elettrici | Tensione di sistema | 15 kV/20 kV AC (Um=24 kV) |
| Frequenza nominale | 50 Hz | |
| Tensione primaria nominale | 15 kV/20 kV | |
| Tensione secondaria nominale | 100 V (metering/protection), 100/3 V (insulation monitoring) | |
| Classe di precisione di misurazione | Classe 0,2 / 0,5 / 1 | |
| Classe di Protezione Accuratezza | Class 3P / 6P | |
| Tensione di tenuta alla frequenza di rete (terminale AT) | 50 kV / 1 min, no breakdown | |
| Tensione di tenuta all'impulso (picco) | 95 kV, no breakdown | |
| Livello di scarica parziale | ≤10 pC | |
| Resistenza di isolamento (HV verso LV e terra) | ≥1000 MΩ | |
| Parametri Strutturali e Materiali | Mezzo isolante | Colata completa in resina epossidica |
| Classe di protezione | IP20 | |
| Metodo di montaggio | Montaggio a bullone da interno di tipo a palo | |
| Classe Termica dell'Isolamento | Classe B (130°C) | |
| Parametri ambientali | Altitudine applicabile | ≤2000 m (personalizzazione per alta quota disponibile) |
| | Temperatura ambiente operativa | -30°C a +70°C | |
| Temperatura ambiente di stoccaggio | -40°C a +85°C | |
| Umidità Relativa | ≤95% (non condensante) | |
| Standard | Norma Nazionale | GB 1207 Voltage Transformers, GB/T 20840 series |
Ambito di applicazione
Applicable Voltage Level: 15 kV/20 kV (Um=24 kV) indoor AC power systems.
Applicazioni tipiche:
Misura di tensione, misurazione di energia e protezione di relè in quadri elettrici interni di media tensione e cabine di trasformazione prefabbricate;
15 kV/20 kV distribution systems in distribution substations, industrial and mining enterprises, commercial buildings, and industrial parks;
Acquisizione di segnali per il monitoraggio, il controllo e la protezione della tensione nei sistemi di automazione di potenza;
Distribution applications in polluted and humid environments; G-type for high anti-pollution-flashover requirements.
Functional Purpose: Proportionally steps down the high voltage of the power system to a standard low voltage (100 V), providing voltage signals for metering instruments, protective relays, and control equipment, while achieving electrical isolation between the primary and secondary systems. May also serve as a voltage signal source for insulation monitoring devices to detect system ground faults.
Condizioni di servizio
Condizioni di Servizio Normali
Altitude: ≤2000 m
Temperatura ambiente: da -30°C a +70°C, senza forti fluttuazioni di temperatura
Umidità relativa: ≤95% (non condensante)
Condizioni ambientali: Libero da gas corrosivi, mezzi infiammabili o esplosivi, vibrazioni e urti severi, e significativa polvere o nebbia salina
Mounting: Indoor post-type installation, away from direct sunlight, rain, and condensation
Condizioni di Servizio Speciali (Personalizzazione Richiesta)
Altitude exceeding 2000 m
Ambient temperature outside the range of -30°C to +70°C
Ambienti gravemente inquinati, nebbia salina o chimicamente corrosivi
Condizioni operative di alta vibrazione o alto impatto
Non-standard voltage ratios, accuracy classes, or mounting dimension requirements
Installazione e Manutenzione
Procedura di installazione
Pre-Installation Inspection: Inspect the voltage transformer for external damage — the cast body must be free from cracks, voids, and physical damage; terminal markings must be legible; all accessories must be present. Verify that the model, rating, voltage ratio, and accuracy class conform to the design specifications. For G-type units, confirm that the anti-pollution-flashover structure is intact.
Mechanical Mounting: Position the voltage transformer in its designated location within the switchgear cabinet and secure it via the base mounting holes with bolts. Ensure the installation is firm with no looseness or misalignment; the mounting surface must be level to avoid eccentric loading.
High-Voltage Side Wiring: Connect the high-voltage terminals in accordance with the design requirements, ensuring all connections are tight and have good contact. Maintain adequate safety clearance between high-voltage leads, earthed parts, and other live parts to prevent flashover.
Low-Voltage Side Wiring: Connect the low-voltage terminals according to their markings, with separate wiring for metering, protection, and insulation monitoring circuits. Verify all connections are correct. Short-circuiting the secondary circuit is strictly prohibited; the secondary circuit must be reliably earthed at a single point to prevent overvoltage.
Insulation Testing: After installation, measure the insulation resistance of the voltage transformer (HV to LV and ground; LV to ground) to confirm insulation performance meets requirements. Verify secondary circuit wiring for correctness, absence of short circuits, and absence of open circuits.
Linee guida per la manutenzione
Periodically inspect the external condition of the voltage transformer: the cast body must show no cracks, damage, or discharge marks; high-voltage terminals must show no looseness or oxidation; shed surfaces must show no accumulation of contamination. For G-type units, pay particular attention to the anti-pollution-flashover structure.
Periodically inspect high-voltage and low-voltage connections for tightness and absence of overheating or discoloration. Verify reliable earthing of the secondary circuit with no risk of short circuit or open circuit.
Periodically test insulation resistance and voltage ratio to confirm metering and protection accuracy meets requirements. Also verify that the insulation monitoring function is operating normally.
Clean dust and contamination from the voltage transformer surface. Prevent oil and corrosive substances from adhering to the unit. Keep the equipment dry and clean. Periodically clean shed surfaces to prevent flashover.
If abnormalities such as cracks, discharge, overheating, or out-of-tolerance voltage ratio are detected, de-energize the unit immediately for inspection. Replace the equipment if necessary. Operation of defective equipment is strictly prohibited.
Precauzioni
Short-circuiting the secondary winding is strictly prohibited. A secondary circuit short circuit during operation will generate excessive current, endangering equipment and personnel safety. During maintenance, the secondary circuit must be reliably open-circuited and earthed.
During installation, avoid impacts and collisions to the cast body and high-voltage terminal sheds to prevent epoxy resin cracking and insulation damage, which would compromise the equipment’s insulation performance and anti-pollution-flashover capability.
High-voltage side wiring must use dedicated insulated conductors and maintain adequate safety clearance from earthed parts and other live parts to prevent phase-to-phase or phase-to-ground flashover.
Equipment earthing must be reliable. The base earthing terminal must be securely connected to the cabinet earthing busbar to ensure proper equipment grounding.
During storage, keep the unit in a dry, well-ventilated, and cool environment, away from direct sunlight, high temperatures, humidity, and mechanical compression, to prevent aging and deformation of the cast body.
Installation, commissioning, and maintenance must be performed only by qualified electrical personnel in strict accordance with electrical safety operating procedures.
Configurazione di fornitura standard
| No. | Descrizione | Scopo |
|---|---|---|
| 1 | JDZ11-15,20G Voltage Transformer Body | Core device for voltage transformation, isolation, and signal acquisition |
| 2 | Bulloni e rondelle di montaggio | For mechanical securing of the voltage transformer |
| 3 | Coperchio protettivo trasparente del terminale secondario | Protects low-voltage terminals against mis-connection and short circuit |
| 4 | Manuale del prodotto | Installation, operation, and maintenance guide, including anti-pollution-flashover maintenance instructions |
| 5 | Certificato di Conformità del Prodotto e Rapporto di Prova di Fabbrica | Documentation of product quality and performance, including voltage ratio and error test data |
Standard e Certificazioni Applicabili
This product conforms to the following national standards: GB 1207 Voltage Transformers; GB/T 20840.1 Instrument Transformers — Part 1: General Requirements; GB/T 20840.3 Instrument Transformers — Part 3: Additional Requirements for Inductive Voltage Transformers. The product has passed type tests and its performance meets the operating requirements of 15 kV/20 kV indoor power systems.
Appendice: Disegno schematico del prodotto
