南京欧陆电气EV510系列高性能矢量变频器产品及现场应用案例

Frequency Converter Interference Analysis and Solutions by Nanjing Oulu Electric

During operation, the thyristors inside frequency converters switch at high speeds, generating continuous interference currents accompanied by significant electromagnetic radiation and harmonic pollution. This can disrupt other electrical equipment, cause monitoring/control systems to malfunction, compromise power system stability, and even lead to self-induced speed regulation failures in the converters themselves.

To better serve our customers across industries, Nanjing Oulu Electric summarizes common interference issues and solutions based on recent field experience:

Three Types of Frequency Converter Interference

1. Internal Interference (Converter as Source)

• Cause:
  The main circuit (rectifier + inverter) uses nonlinear power electronic components that generate high-order harmonics during high-speed switching.

• Effects:

• Contaminates power supply with harmonics

• Causes overvoltage/overcurrent in connected equipment2. External Interference (Converter as Victim)

• Vulnerable Components:
  Low-energy control circuits (analog signals, communication lines) are susceptible to external EMI.

• Typical Symptoms:

• Erratic speed commands

• False fault alarms (e.g., overcurrent triggers)

3. Cross-Interference (Converter Affecting Others)

• Motor System Manifestations:

• Sudden stops

• Unstable speed fluctuations

• Torque pulsations

Upcoming Solutions (Preview)

Our next technical bulletin will detail countermeasures including:

• Hardware: EMI filters, shielded cables, proper grounding

• Software: Carrier frequency adjustment, slew rate control

• Installation: Layout optimization, separation of power/signal lines

For immediate assistance, contact our service team:
☎ 159-5163-6558