1. Basic Industry Overview
The DC high voltage generator, commonly known as DC HV tester, is a portable core device for power preventive tests. Manufactured in accordance with DL/T848.1-2004 standard, it is widely applied in power grids, power plants, industrial and mining enterprises to conduct DC withstand voltage tests and leakage current measurement on zinc oxide arresters, power cables, transformers and generators.
Products fall into two categories: integrated type (40–120kV) and split type (200kV and above). The integrated version is lightweight for distribution network field tests, while the split type provides sufficient insulation clearance for tests on substation and large electrical equipment.
2. Core Technologies & Product Features
- Adopts high-frequency PWM + IGBT voltage multiplier circuit with closed-loop voltage feedback, output ripple factor ≤1% for smooth voltage regulation. Equipped with one-touch 75%UDC1mA function specially for arrester testing.
- Voltage multiplier cylinder made of epoxy fiberglass with air insulation (no oil leakage) and foldable support structure for high stability. Overvoltage protection via dial coding for intuitive setting.
- Powered by single-phase AC 220V/50Hz for intermittent operation, with a maximum continuous test duration of 30 minutes. It supports charging large-capacity cables with 1.5 times rated current.
- Mandatory safety rules: Operators must hold high-voltage operation certificates; single-point grounding is required throughout the test. Large-capacity test samples shall be discharged slowly via current-limiting discharge rod. For 200kV and above high voltage, floating potential exists; personnel are prohibited from physical contact with each other during testing.
3. Main Application Scenarios
- Zinc oxide arrester testing: Measure 1mA reference voltage and leakage current under 0.75 times reference voltage to judge valve plate aging and dampness.
- DC withstand voltage test for oil-paper cables: Identify insulation damage by analyzing leakage current variation.
- Withstand voltage test for transformer and generator windings during handover or overhaul.
- Insulation leakage detection of high-voltage bushings, transformers and switchgears.
4. Complete Accessories & Maintenance Specifications
Standard package includes control box, voltage multiplier cylinder, discharge rod, shielded microammeter, special grounding wire, spare parts and technical documents. The equipment shall be stored in dry environment without condensation. Voltage and current accuracy shall be calibrated by metering institutions annually to ensure valid and compliant test data.
5. Brief Comparison with New Models in Recent Years
Traditional MOEORW models adopt fully manual mechanical operation without data storage or wireless transmission. New models launched in the past five years upgrade to SiC components and dual closed-loop voltage stabilization with better precision and lower ripple. They add intelligent functions including touch-screen automatic testing, data storage, Bluetooth report export and real-time grounding monitoring.
In terms of model selection, grassroots power supply stations and small factories widely adopt MOEORW for its cost-effectiveness and easy maintenance. Provincial/municipal maintenance departments, new energy enterprises and third-party testing institutions prefer new intelligent models.
6. Industry Development Trends
- Lightweight design: New materials reduce overall weight; modular voltage multiplier cylinders realize multi-scenario compatibility with one unit.
- Digitalization: Automatic test data archiving and online traceability to meet smart grid management requirements.
- Expanded application scenarios: Additional withstand voltage testing for high-voltage components of photovoltaic, energy storage and new energy vehicles.
- Optimized safety protection: Add active protection functions such as grounding self-inspection and high-voltage distance induction.
