GAOHUI Heavy Duty MAO Power Supply (750V/100A) for Micro-arc Oxidation

Executive Summary
Engineered for the rigorous demands of plasma electrolytic oxidation (PEO) and ceramic coating processes, this GAOHUI 75kW unit is an industrial high frequency rectifier factory solution built specifically for the high-impedance, dynamic load of MAO plasma electrolytic oxidation. Unlike outdated silicon transformer units that struggle with arc suppression and voltage stability, this system delivers precise, pulsed DC output necessary for forming dense, wear-resistant ceramic layers on aluminum, magnesium, and titanium alloys. While standard models offer 0-800V adjustable output and current ratings from 5A to 100A, this heavy-duty configuration (750V/100A) maximizes coating throughput and surface uniformity for large-volume processing lines.
Part 1. Key Features and Engineering Highlights
This rectifier transitions beyond conventional thyristor control into true high-frequency switching topology, ensuring superior coating morphology and energy efficiency. Operating at lethal voltages (400–750 V DC), the unit prioritizes both operational safety and process repeatability. The IGBT inverter stage provides rapid pulse response essential for stabilizing the plasma discharge layer, preventing localized arcing that can burn workpiece edges. With a system efficiency exceeding 92% at full load, this unit significantly reduces operating costs compared to legacy linear supplies, while its compact air-cooled design eliminates the need for complex water-cooling infrastructure found in competitor units like the SY-P10600200.
Part 2. Technical Specifications
| Specification Parameter | Value / Range |
|—|—|
| Input Voltage (AC) | 380V ± 10% / 3-Phase 50Hz |
| Output Voltage (DC) | 0-750V (Continuously Adjustable) |
| Output Current (DC) | 0-100A (Rated Continuous Duty) |
| Output Power | 75kW |
| Efficiency | ≥ 92% (at rated load) |
| Pulse Frequency Control | 1-3000Hz (Adjustable via HMI) |
| Pulse Duty Cycle | 10% – 90% (Independent Adjustment) |
| Output Type | Direct Current (DC) with Pulse Modulation |
| Cooling Method | Forced Air Cooling (IP54 Standard) |
| Control Interface | RS485 Modbus RTU / Ethernet / 4-20mA |
| Protection Class | IP54 (Optional IP65 for Harsh Environments) |
Part 3. Advanced Built-in Protection Systems
Safety and longevity are paramount at these voltage levels. The cabinet integrates an interlocked enclosure door mechanism, ensuring access is impossible while bus bars are live. A hardware-based emergency stop circuit simultaneously cuts the IGBT gate drive signals and opens the main contactor, providing dual-redundant shutdown within microseconds. The system continuously monitors insulation resistance regarding ground chassis; any deviation beyond 10MΩ triggers an immediate fault state, halting the process to prevent electrolyte-induced short circuits. Thermal sensors on each IGBT module provide direct junction temperature feedback, derating output current automatically at 85°C to prevent semiconductor thermal runaway without abrupt process shutdown.
Part 4. Target Industrial Applications
This unit excels in high-throughput environments where continuous operation and coating consistency are mandatory. Primary applications include micro-arc oxidation of aluminum alloy for aerospace structural components, where 50-100μm thick ceramic layers are required for erosion resistance. For magnesium alloy ceramic coating in automotive lightweighting projects, the high voltage headroom (750V) effectively drives the oxide layer formation despite the substrate’s low melting point, avoiding the common “burn-through” defect seen at lower voltages. In titanium bio-compatible oxide applications, such as medical implant surface treatments, the precise current pulse control creates the anatase-rich porous structure critical for osseointegration, with the 1-3000Hz frequency range allowing operators to fine-tune discharge energy per pulse.
Part 5. Customization and Tailored Engineering Services
GAOHUI operates as a true IGBT rectifier manufacturer offering modular customization beyond standard catalog specifications. While this base model is configured for 750V/100A, the same platform supports a full range from 1V to 1000V and 1A to 100,000A, ensuring scalability from laboratory R&D tables to full production tank lines. For process engineers requiring deterministic batch control, we integrate an Ampere-Minute Integrator to automatically terminate the cycle once total charge reaches the layer thickness target. Multi-Stage Profile Control allows programming up to 100 steps of voltage, current, frequency, and duty ratio changes, enabling complex step-down regimes typical of advanced MAO sequences. Automatic Reverse Polarity modules are available for processes requiring bipolar pulsing to reduce electrode passivation. All units include Soft-Start ramping and digital Process Timer functions as standard. A custom current voltage rectifier solution can be delivered with your specific PLC protocol, whether it is Profibus, Ethernet/IP, or future-oriented IO-Link, ensuring seamless integration into your existing Line Control System. For a precise heavy-duty DC power supply price tailored to your exact tank dimensions and production volume targets, contact our engineering sales team with your substrate material, coating thickness requirement, and batch cycle time expectations.