HDMV Series Frequency Converters

1. Project Background
The high-voltage motor system at Shaanxi Yangxian Yuhu Chemical Co., Ltd. had been operating with liquid-resistance soft starters for more than a decade. As the existing equipment aged, several pain points became evident:
The liquid-resistance cabinets were bulky and occupied excessive floor space.
Their complex design demanded frequent maintenance of electrolytes, electrodes, and mechanical parts, resulting in significant O&M workload and high costs.
Startup performance was limited—low accuracy and the inability to support frequent restarts within short intervals—constraining production scheduling flexibility. The customer urgently required a high-efficiency, low-maintenance, and intelligent high-voltage soft-start solution.

2. Hengda's Solution：
 Having reliably used Hengda’s excitation systems for more than a decade, the customer had full confidence in our product quality and service support. Based on this established trust, the customer directly selected the HDGR solid-state soft starter cabinet for this critical upgrade. 
The solution delivered transformative results:
Lower O&M Costs & Space Optimization: The fully solid-state, modular design occupies significantly less space than the former liquid-resistance cabinet. Eliminating the need for electrolytes and mechanical upkeep, the maintenance frequency and costs were drastically reduced, achieving truly “low-maintenance or maintenance-free” operation.
Improved Startup Performance & Productivity: Leveraging high-precision thyristor control technology (as HDGR is solid-state), the system ensures smooth starting, completely eliminating mechanical and electrical shock during startup. It also supports rapid, repetitive starts and stops, significantly increasing the operational efficiency of the production process. The system's integration enables remote monitoring and condition diagnostics, further aligning with the customer's requirements for a digitalized and intelligent factory upgrade.

3. Client Feedback
The Operations and Maintenance (O&M) Department spoke highly of the benefits of the HDGR's minimal maintenance needs and high starting accuracy. They reported that the new equipment's performance stability and reliability significantly exceeded expectations, effectively guaranteeing the full life-cycle operation of critical assets. This retrofit not only addressed the client's core O&M pain points but also—via advanced solid-state technology—achieved a dual enhancement in production efficiency and reliability in a critical industrial segment.

● Customer Challenge
The original temperature control system for Hubei Sanning Group's synthesis reactor relied on analog, non-microprocessor-based circuitry (using resistors and capacitors) to adjust the thyristor firing angle. This caused significant three-phase output imbalance. The resulting uneven heating of three-phase resistor elements led to frequent filament cracking, breakage, and short circuits, repeatedly forcing production line stoppages.

● Our Solution
Since 1997, we have supplied the first-generation WDTJ AC voltage and power regulation cabinet to address this issue. By implementing high-performance industrial control chips and digital synchronous phase-shifting technology, we entirely replaced the unstable analog control, achieving precise digital regulation of the firing angle.

● Long-Term Results
After the upgrade, the system immediately delivered accurate three-phase voltage triggering and stable output current. This completely eliminated unplanned downtime caused by three-phase imbalance at Hubei Sanning Group, ensuring continuous production.

● Built on this long-term trust and proven operational performance,Hubei Sanning Group has since adopted nearly 20 sets of our latest WDTJ AC voltage and power regulation cabinet across five newly built chemical plants. All WDTJ cabinets have been maintaining precise control and stable operation, consistently supporting the development of Hubei Sanning Group's chemical industry.

● Customer Challenges
Hubei Sanning Chemical’s electrostatic precipitator (ESP) system had been operating for years with increasing failures and declining dust collection efficiency. Key issues included:
-Failure to reach target high-voltage levels
-Poor voltage control accuracy
-Inability to effectively limit discharge spark frequency
These shortcomings not only risked non-compliance with environmental standards but also undermined production stability.

● Our Solution
We delivered a customized WGT-series high-voltage control power supply featuring:
-Highly precise voltage regulation and improved step-up characteristics
-Microprocessor-controlled monitoring and limitation of spark rate (sparks per minute)

● Results Achieved
-Operating voltage increased by 10%, significantly improving dust removal efficiency
-Stable and accurate voltage output with tightly controlled sparking
-Markedly improved system reliability and reduced failure rate
-The system has now operated flawlessly for three years, earning consistent positive feedback from the custome