DDG Series High-Current Generators: Design Principles and Technical Consideratio

The DDG Series High-Current Generator is a specialized apparatus engineered for rigorous electrical testing applications in power utilities, industrial plants, and mining facilities. Designed to deliver precision-controlled high-current outputs, this equipment supports critical tasks such as primary busbar protection calibration, current transformer (CT) ratio verification, circuit breaker testing, and thermal stability assessments. With its modular architecture (integrated or split configurations) and adaptive load management, the DDG Series addresses the evolving demands of modern power system diagnostics and maintenance.

Key Features

1.Dual-Range Current Monitoring
Equipped with two independent ammeters, the system ensures accurate measurement across varying current magnitudes (e.g., 500A to 20kA), enabling seamless transitions between low- and high-range testing scenarios.

2.Autotransformer-Based Current Regulation
A continuously adjustable autotransformer provides smooth current ramping (0–100% rated output), minimizing harmonic distortion and ensuring stable operation during dynamic load changes.

3.Robust Structural Design

Integrated Units (≤3kVA): Compact, single-body construction (e.g., 430×338×550mm for 500A) optimizes portability for field testing.

Split Units (≥4kVA): Separated power and control modules (e.g., 800×600×1100mm + 380×550×600mm for 20kA) reduce onsite installation complexity and enhance thermal management.

4.Operator-Centric Interface
Intuitive push-button controls, LED status indicators, and fail-safe interlocks streamline operation while adhering to IEC safety standards.

Technical Specifications

Performance Parameters

1.Duty Cycle: Designed for short-term operation (5-minute ON at full load). For intermittent use, limit ON-time to ≤2.5 minutes with ≥10-minute cooling intervals.

2.Input/Output Configuration:

 3.Efficiency: >92% across all models, achieved through low-loss silicon steel cores and forced-air cooling (for units >5kVA).

Design Considerations

1.Thermal Management
High-duty applications leverage copper windings with Class H insulation (180°C rating) and temperature relays to prevent overheating. Split-unit designs decouple heat-generating components (e.g., transformers) from control electronics.

2.Voltage Drop Compensation
Secondary output maintains 6V (±2%) under load, critical for replicating real-world fault conditions during CT saturation testing.

3.Scalability
Parallel operation of multiple units enables ultra-high current generation (e.g., combining two 10kA units for 20kA output), subject to phase synchronization protocols.

Typical Applications

1.Protective Relay Calibration: Simulate fault currents to validate trip thresholds of overcurrent relays (e.g., IDMTL curves).

2.Circuit Breaker Testing: Stress-test interrupting capacity and contact endurance under 10kA–20kA short-circuit conditions.

3.CT Ratio/Polarity Verification: Inject precise primary currents to assess secondary winding accuracy (IEC 60044-1 compliance).

4.Busbar/Cable Thermal Cycling: Evaluate conductor integrity during prolonged high-current exposure (1–4 hours).

Operational Guidelines

1.Pre-Test Preparation

Verify input voltage compatibility (200V/380V variants).

Ground all non-current-carrying metallic parts (IEEE 80).

2.Load Matching
Use Equation:  to avoid under/overloading. For example, a 6V/5000A unit requires

3.Safety Protocols

Deploy current-limiting reactors for inductive loads (e.g., motor testing).

Monitor harmonic distortion (<8% THD) using external analyzers for sensitive equipment.

The DDG Series High-Current Generator combines precision engineering with operational flexibility, making it indispensable for power system reliability programs. Its adaptive design—from compact 500A units to modular 20kA systems—ensures scalability across diverse testing environments. By adhering to the outlined technical parameters and safety practices, technicians can maximize equipment lifespan while achieving repeatable, accurate test outcomes.

GDZX is a manufacturer of power detection equipment, offering a diverse range of products with comprehensive models and providing professional technical support. Contact us at +86-27-6552607 or +86-17396104357.Website: http://en.gdzxdl.com/