Voltage and Current Sensing for EV Charging Systems
Summary
Verivolt offers voltage and current sensors used in several EV charger architectures. These sensors provide the precision, speed, isolation, and support for higher voltage required by the newest and upcoming EV charging system generations.
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?
Verivolt sensors used in this application field present the following characteristics.
Recommended Verivolt Sensors for VFD Application
Voltage Measurement
- IsoBlock V-4C: (up to 300 KHz – custom) A 4-channel, differential-input, high-bandwidth isolated voltage suitable for capturing line-to-line voltages with ranges from 2V up to 1500V. The IsoBlock V-4C sensor is ideal to monitor the VFD output phases with up to 0.1% accuracy.
- Isoband V (up to 8 MHz): This sensor offers a unique combination of high-isolation, high voltage measurement and high-bandwidth, making it a perfect choice for measuring fast transients, PWM switching and high-frequency signals with 0.2% accuracy.
Your application requires more than 8MHz bandwidth? Try our high-bandwidth, non isolated sensors:
- Entube DE-HB (up to 20 MHz): A high bandwidth differential voltage sensor
- Entube Z (up to 50 MHz): A compact, single ended voltage sensor with the highest bandwidth
Current Measurement
- IsoBlock I-ZF: An isolated, contactless current sensor that uses a zero-flux technique for measurements with up to 0.01% accuracy. Ideal for monitoring both input and output currents and identifying overcurrent or load imbalance. Available from 50A to 2000A ranges.
- IsoBlock I-ST: Isolated shunt-based current sensor designed for low to mid range input. Enables simultaneous and isolated monitoring of all three motor phases to detect unbalances. Input ranges available from 100mA to 100A.
Conclusion
Verivolt delivers precision voltage and current sensing solutions tailored for the dynamic requirements of VFD systems. Our sensors provide the performance, accuracy, and isolation needed to ensure optimal motor monitoring. Visit our website to explore products designed to meet the evolving challenges of this industry.
Accurate Current and Voltage Sensing
EV Charging companies are being challenged to overcome barriers of existing technologies with the goal of shortening charging times and increasing product safety. One of the critical aspects of this race is accurate current and voltage sensing as it is applied more often than ever on several architectures of EV Chargers.
Key Considerations
Accurate and fast voltage and current sensing will allow designers to guarantee proper thermal management and effective implementation of their control strategies, impacting in safety. Key aspects to consider when selecting your sensors are:
- Measurement range
- Isolation
- Bandwidth
Off-the-shelf
custom sensors
Verivolt designs and manufactures off-the-shelf and custom sensors that are currently used by EV charger companies in product design, implementation, validation, and test. We partner with designers, engineers and scientists understanding their needs and applying our transducer and precision measurement expertise to their design goals.
If you need to perform accurate measurements for voltage and current signals, visit our product selection pages at Voltage Sensors and Current Sensors or contact our specialists at sales@verivolt.com.