Flexible DC Transmission Capacitor

Product Introduction

The Flexible DC Transmission Capacitor is a high-voltage, large-capacity power electronic capacitor designed for demanding DC-link applications. It is developed for flexible HVDC transmission systems, ultra-high-power frequency converters, and other high-power electrical equipment requiring stable DC energy storage and voltage buffering.

The capacitor offers a rated voltage range of 1200 to 5600V DC and a rated capacitance range of 1500 to 18000μF, providing multiple configuration options for different power conversion and transmission systems.

Its construction combines a rectangular austenitic stainless-steel enclosure with dry-type, low-density high-performance resin potting. The fixed installation structure incorporates lifting lugs and bolted fixing points, making the capacitor suitable for integration into large electrical assemblies and high-power equipment.

Product Highlights

High DC Voltage Capability

The capacitor is available with rated DC voltages from 1200V to 5600V. This broad voltage range allows the product to be considered for high-voltage DC-link circuits and power conversion equipment with different system voltage requirements.

Large Capacitance Range

Rated capacitance is available from 1500μF to 18000μF. The large-capacitance configuration provides substantial electrical energy storage capacity for high-power conversion systems.

Designed for Flexible HVDC Systems

Flexible HVDC transmission relies on power electronic conversion equipment to control and transfer electrical power. The DC-link capacitor is an important component in this architecture, helping provide energy buffering and DC voltage stabilization.

The Flexible DC Transmission Capacitor is designed specifically around the requirements of high-power DC transmission and conversion applications.

Suitable for Ultra-High-Power Frequency Converters

High-power frequency converter systems require DC-link components capable of handling demanding electrical operating conditions. The capacitor's high-voltage and large-capacitance specifications make it suitable for use in ultra-high-power converter equipment.

Long Expected Service Life

The expected lifespan reaches 100,000 hours, making the capacitor suitable for applications where long-term equipment operation and reduced maintenance frequency are important considerations.

Wide Operating Temperature Range

The specified operating temperature range is -40℃ to +70℃, allowing the capacitor to be applied in a variety of industrial environments when the complete system operates within the required conditions.

Stainless-Steel Housing

The capacitor uses a rectangular enclosure made of austenitic stainless steel. The rigid enclosure provides mechanical protection for the internal capacitor assembly and supports fixed installation in high-power electrical equipment.

Dry-Type Resin Potting

The product uses dry-type, low-density high-performance resin potting rather than a conventional liquid impregnation arrangement.

The resin potting process provides internal structural support and insulation protection while forming a compact and stable capacitor assembly.

Practical Fixed-Mounting Design

The capacitor is designed for fixed installation and incorporates lifting lugs and bolted capacitor fixing points. These features support handling, positioning, and secure mechanical fixation during equipment assembly.

Main Technical Specifications

DC-Link Application

In high-power conversion equipment, the DC link forms an important electrical connection between different stages of power conversion. Capacitors installed in this section can provide energy buffering and help maintain the stability of the DC bus.

The required capacitor specification depends on system voltage, capacitance requirements, operating temperature, converter architecture, and mechanical installation conditions.

With rated voltage options from 1200V to 5600V DC and capacitance from 1500μF to 18000μF, this capacitor provides a range of options for engineers designing high-power DC-link systems.

Flexible HVDC Transmission

Flexible HVDC systems are used for high-power electricity transmission and power network applications where controlled power conversion is required.

In these systems, DC-link capacitors work together with power semiconductor and converter equipment. A suitable capacitor helps support the electrical performance of the DC-link section and provides the required energy storage characteristics.

For HVDC projects, capacitor selection should consider the complete electrical system rather than capacitance alone. Rated voltage, capacitance, temperature conditions, installation structure, and expected service life should all be evaluated before specification confirmation.

Ultra-High-Power Frequency Conversion

Frequency converters used in large industrial and power applications can operate at substantial electrical power levels. Their DC-link sections require appropriately rated capacitors to support stable operation.

The combination of high DC voltage and large capacitance makes this product suitable for ultra-high-power frequency converter applications where higher-capacity DC-link components are required.

The available specifications also provide flexibility when adapting the capacitor to different converter designs and electrical system configurations.

Mechanical Construction

The rectangular housing is manufactured using austenitic stainless steel, providing a robust enclosure for the internal capacitor structure.

The fixed-mounting design includes lifting lugs for handling and bolted fixing points for mechanical installation. This arrangement is particularly practical for large capacitor assemblies that need to be securely mounted within electrical cabinets, converter systems, or other high-power equipment.

During system integration, the mounting position, supporting structure, clearances, connection arrangement, and mechanical load conditions should be evaluated according to the actual equipment design.

Resin Potting Structure

The capacitor uses a low-density high-performance resin potting process.

Dry-type resin potting provides mechanical support for internal components and contributes to the insulation structure of the capacitor. The low-density design is intended to provide the required internal protection while maintaining a practical product construction.

For high-voltage capacitors, the quality and consistency of the potting process are important considerations because the internal structure must remain stable throughout long-term operation.

Operating Temperature

The operating temperature specification is -40℃ to +70℃.

When applying the capacitor, system designers should evaluate the actual environmental temperature together with electrical loading, equipment ventilation, enclosure conditions, heat generation from nearby components, and installation location.

Maintaining the capacitor within its specified operating conditions is important for achieving the expected performance and service life.

Product Selection Guide

When selecting a DC-link capacitor for an HVDC or high-power converter project, the following parameters should be confirmed:

1. Rated DC Voltage

Determine the required DC-link voltage and select a capacitor with an appropriate rated voltage. The available range of 1200–5600V DC covers various high-voltage power electronic applications.

2. Required Capacitance

The required capacitance should be determined according to the converter topology, DC-link design, energy buffering requirements, and operating conditions.

The available 1500–18000μF range provides flexibility for different high-power system configurations.

3. Temperature Conditions

Confirm that the actual operating environment falls within the specified -40℃ to +70℃ range.

Thermal conditions should be evaluated at the equipment level, especially when multiple high-power components are installed within a confined enclosure.

4. Installation Requirements

The available rectangular housing, lifting lugs, and bolted fixing structure should be matched with the equipment's mechanical design.

Customers should confirm the installation arrangement and physical requirements before final specification.

5. Service Life Requirements

For HVDC transmission and industrial power conversion equipment, long operating periods can make component lifecycle an important selection factor. The capacitor has an expected lifespan of 100,000 hours, supporting applications that require long-term operation.

Typical Applications

The capacitor can be used in or considered for:

• Flexible HVDC transmission systems

• High-voltage DC-link circuits

• Ultra-high-power frequency converters

• Power electronic conversion equipment

• Industrial high-power electrical systems

• Grid-related power conversion equipment

• Rail transit power electronics

• Large-scale energy systems

• Specialized high-power electrical equipment

The final product selection should be based on the electrical, thermal, mechanical, and installation requirements of the target system.

Engineering and Manufacturing Capability

The production of high-voltage and large-capacitance capacitors requires coordinated control of product design, materials, manufacturing processes, testing, and quality management.

Wuxi Power Filtering Co., Ltd. was established following a shareholding reform in 1994 and has a long-standing focus on special capacitors, power electronic capacitors, power filtering equipment, reactive power compensation equipment, and related electrical solutions.

The company operates a production base in Tongling, Anhui Province, with a built-up area of approximately 20,000 square meters and registered capital of RMB 20 million.

Its technical team includes senior engineers and other experienced professionals, with an emphasis on research, engineering development, and technical talent cultivation.

The company has also established long-term cooperation with research institutions and universities, including the China Electric Power Research Institute, Southern Power Grid Electric Power Research Institute, Tsinghua University, Huazhong University of Science and Technology, and North China Electric Power University.

Industry Applications

The company's capacitor products and related electrical equipment have been developed for applications across multiple industries, including:

• Power systems

• Industrial and mining enterprises

• Rail transit

• Aerospace

• Specialized electrical equipment

• Energy and power conversion

• Smart grid applications

• Large-scale energy storage systems

Its product development activities cover power electronic capacitors, pulse capacitors, self-healing high-voltage power capacitors, power filtering devices, and shunt capacitor compensation installations.

Technical Development

The company is recognized as a National High-Tech Enterprise and a Wuxi City Specialized, Sophisticated, Innovative Enterprise. It operates a provincial-level Engineering Technology Research Center and a municipal-level Enterprise Technology Center.

Its technical development focuses on capacitor products and electrical equipment supporting green energy, smart grids, energy conservation, environmental protection, and large-scale energy storage.

Ordering Information

Before ordering, customers are recommended to confirm the following information:

• Required rated DC voltage

• Required rated capacitance

• Operating temperature

• Intended application

• DC-link system configuration

• Installation method

• Mechanical mounting requirements

• Expected operating conditions

• Quantity and project requirements

Technical specifications should be confirmed according to the actual application before production and delivery.

Product Summary

The Flexible DC Transmission Capacitor combines a 1200–5600V DC rated voltage range, 1500–18000μF capacitance range, 100,000-hour expected lifespan, -40℃ to +70℃ operating temperature, stainless-steel rectangular enclosure, fixed mounting structure, and dry-type high-performance resin potting. It is designed for flexible HVDC transmission, ultra-high-power frequency converters, and other demanding DC-link applications.

For technical specifications, project requirements, and capacitor selection support, customers can contact Wuxi Power Filtering Co., Ltd. for further product information.