VFD Monitoring
Summary
Verivolt provides reliable sensing solutions for Variable Frequency Drive (VFD) monitoring and testing by offering high-bandwidth, low-noise, and fully isolated voltage and current sensors. Our sensors are engineered to meet the demanding requirements of VFD applications, ensuring accurate, safe, and stable performance in high-frequency and high-voltage environments.
Product in Use
The Challenge:
Voltage and Current Monitoring in VFD Systems
Variable Frequency Drives (VFDs) are widely used across various industries to optimize motor performance, enhance energy efficiency, and improve process control. VFDs are commonly found in manufacturing, HVAC systems, water and wastewater treatment, oil and gas, among many others. These applications often involve demanding electrical and environmental conditions, including high currents and voltages required to power motors. Additionally, such environments may expose equipment to high ambient temperatures, electrical noise from switching elements, and mechanical vibrations. Monitoring voltage and current in VFD applications is critical for performance verification, troubleshooting, and preventive maintenance.
Most modern VFDs have embedded sensors that measure current and voltage internally. These internal measurements are primarily used for control logic, protection mechanisms, and sometimes diagnostics. However, there are several good reasons to use independent current and voltage sensors to monitor the motor or load, even if the VFD already has built-in sensing, such as:
Accuracy and Signal Quality
Accurate Power Measurement
Advanced Analysis & Logging
Third-Party Compliance & Certification
Retrofit & Test Bench Applications
How do Verivolt’s Sensors Address these Challenges?
Conclusion
Characteristics | Importance in VFD Application |
High accuracy (0.1%) | Precise voltage and current measurement (<±0.1%) is critical for performance validation, efficiency analysis, and detecting unbalance or faults in motor control. |
High bandwidth (100 kHz to several MHz) | Required to accurately capture high-frequency PWM output waveforms from the VFD and detect fast transients or voltage overshoot. |
Galvanic isolation | Protects measurement systems and operators by electrically isolating the sensing system from high-power circuits; critical in industrial VFD environments. |
High CMRR (Common Mode Rejection Ratio) | Needed for accurate differential voltage measurements in noisy environments like motor drives. |
Low delay | Fast-reacting sensors are necessary for capturing real-time PWM signals used by VFDs. Low latency ensures accurate phase alignment between signals and responsiveness for control loops and dynamic testing. |
Wide temperature range | Allows reliable measurements in harsh industrial environments with high ambient temperatures, often near motors or inside enclosures. |
Compact Form Factor | Important for integration inside control cabinets or motor housings, where space is limited. |
Certification traceability (e.g., ISO 17025-calibrated) | Needed for test traceability and compliance in certification programs. |
