Wuhan, China – September 17, 2025 – The KDYDJ-6kVA/100kV Cascaded AC Withstand Voltage Test System from Wuhan Kaidi Zhengda Electric Co., Ltd. has emerged as a key solution for high-voltage insulation testing in power systems, combining advanced performance, compact design, and exceptional portability. Designed as a companion to lightweight high-voltage test transformers, this system delivers reliable, high-efficiency testing capabilities for a wide range of electrical equipment in both field and laboratory environments.
The KDYDJ-6kVA/100kV system utilizes a cascaded transformer configuration to generate high test voltages efficiently. In a two-stage setup, the first transformer (Stage I) has its high-voltage winding grounded at the X terminal, while the A terminal serves dual purposes: it outputs the first stage’s high voltage and simultaneously supplies power to the low-voltage primary winding of the second transformer (Stage II). The X terminal of the second transformer is then connected to the A terminal of the first, allowing the A terminal of the second stage to deliver a voltage equal to the sum of both stages (U1 + U2). By connecting two 50kV/3kVA units in series, the system achieves a total output of 100kV, effectively doubling the voltage while maintaining manageable unit sizes.
High Voltage Capability:
The cascaded approach enables the system to easily achieve test voltages of 100kV and above—levels that would be extremely difficult and costly to reach with a single-unit transformer due to size, weight, and manufacturing complexity.
Compact and Lightweight:
Through modular, split-body design, the KDYDJ-6kVA/100kV system significantly reduces the physical footprint and weight per component. Each transformer unit weighs approximately 52kg, with the control cabinet adding only 18kg. This makes transportation and on-site assembly feasible even in remote or constrained environments.
High Portability and Flexibility:
The system can be disassembled into individual modules, allowing for flexible configuration based on test requirements. Users can increase or decrease the number of cascaded units—for example, three 50kV units can be stacked to achieve 150kV—offering unmatched adaptability compared to fixed, monolithic designs.
Cost-Effective for High Voltage Applications:
By using standardized, mass-producible transformer units, the cascaded system offers a more economical solution for high-voltage testing. It avoids the prohibitively high costs associated with manufacturing large single-unit transformers.
Efficiency and Capacity Utilization:
While the overall rated capacity of the cascaded system is slightly less than the arithmetic sum of individual units (due to cumulative excitation current and magnetic coupling losses), the efficiency remains high enough to meet practical testing demands. The total output capacity is approximately calculated as: Total Capacity ≈ Unit Capacity × Number of Units × Utilization Factor.
The KDYDJ-6kVA/100kV system is widely used in the following scenarios:
Factory and Type Tests: Conducting mandatory withstand voltage tests on high-voltage equipment such as switchgear, transformers, current and voltage transformers, power cables, insulators, and surge arresters to ensure compliance with international standards like GB/T 16927.1 and IEC 60060-1.
Preventive Maintenance Testing: Utilities, substations, and industrial facilities use the system for periodic on-site testing of in-service equipment to detect insulation degradation caused by aging, moisture, contamination, or mechanical damage—helping prevent unexpected outages and failures.
Commissioning and Handover Tests: Verifying the integrity of newly installed equipment or transmission lines after transportation and installation, ensuring no insulation damage occurred during handling.
Research and Development: Supporting scientific institutions in evaluating new insulation materials, cable accessories, and novel electrical designs under controlled high-voltage conditions.
The Wuhan Kaidi Zhengda Electric Co., Ltd KDYDJ-6kVA/100kV Cascaded AC Withstand Voltage Test System resolves the long-standing conflict between high-voltage output requirements and equipment portability. Compared to traditional single-body test transformers, it offers superior flexibility, economic efficiency, and mobility—especially in high-voltage field applications. With its robust performance, user-friendly design, and modular scalability, the KDYDJ system has become an indispensable tool for modern power system testing, setting a new benchmark for on-site insulation diagnostics in the global electrical industry.
Oversea Sales Manager
