High-voltage capacitors for three-level converters
High-voltage Film capacitor for three-level converter
Three-Level Converter is massively used in the field of power electronics multilevel converter technology, the core action is to reduce voltage steps and harmonics through multilevel output, so as to improve power efficiency and performance. Electrolytic capacitors are used for the power ripple coming out from this 3 level topology. Film capacitors are used for handling the current ripple coming out a the switching frequency. The following is a detailed analysis of its key application areas and technical characteristics:
Typical Applications of film capacitors
1. New energy power generation system
Photovoltaic inverters: Three-level topologies (such as NPC, T-type) can reduce switching losses, improve conversion efficiency (>98%), while reducing output harmonics and simplifying filter design.
Wind power converters: In medium and high voltage scenarios, the three-level structure reduces the voltage stress of the device, ADAPTS to the direct-driven permanent magnet generator, and improves grid compatibility.
2. Industrial variable frequency drive
Motor controls: Used for high-power motor (such as water pump, compressor), reduce dv/dt insulation damage to the motor, reduce electromagnetic interference (EMI), extend equipment life.
Medium and high voltage frequency converters: In the mining and metallurgical industries, the three-level module realizes 6kV/10kV high voltage output, replacing the traditional two-level scheme, and the efficiency is increased by 3-5%.
3.Rail Traction and Automotive
Traction converters: Three-level inverters are used in high-speed rail/subway to reduce harmonic current and reduce pollution to the grid, such as NPC three-level technology is used in some models of Japan's Shinkansen.
On-board charger (OBC) : Use SiC devices with three-level topology to achieve high power density (>3kW/L) and support 800V high voltage platform fast charging.
4.Power systems and energy storage
STATCOM/SVG: The three-level structure improves the dynamic reactive power compensation accuracy, and the response time is less than 10ms, which is suitable for the grid connection of new energy stations.
Energy storage converter (PCS) : bidirectional three-level design supports efficient charge and discharge, flat efficiency curve, efficiency >97% in the 30%-100% load range.
AC filter capacitor
