In modern electrical systems, from EV charging stations and industrial automation to power distribution systems, current sensors have become indispensable components. However, many engineers often overlook an important factor in selecting current sensors:

Possibility of noise reduction

In fact, in the European market, more and more engineers are looking for the following:

Current sensors with high noise immunity.

“Accuracy of current sensors in high-noise environments”

How to reduce electrical noise when measuring current

So the question is:
Why is noise reduction so important for modern sensors?

1.What is meant by “noise” in a current sensor?

In electrical systems, “noise” is not sound, but rather:

• Electromagnetic interference (EMI)
• High-frequency switching noise (from inverters, IGBTs, PWM)
• ground loop interference
• power pulse

The noise is especially intense in the following situations:

• Charging system for electric vehicles
• High-frequency switched-mode power supply
• DC leakage current superimposed on an AC signal
•  Industrial automation
• Variable frequency drive (VFD)
• PLC system failures
• Photovoltaic systems/energy storage systems
• Noise when turning on the inverter.
• These interferences can directly affect the accuracy of measurements and even lead to system failures.

Why is noise reduction so important?

1.Avoid accidental activation

The most serious problem with leakage current detection systems is the following:

Incorrect diagnosis of leakage current → System power supply failure

For example, when charging electric vehicles:

In fact, there is no danger at all.

However, this noise was mistakenly diagnosed as “residual current”.

Leads directly to:

• Load interruption
• User complaints
• Unstable system

 

2.Ensure accurate measurements

Noise can cause the following consequences:

• Fluctuation of the measured current value
• Accuracy has been reduced.
• Unstable data
• This is especially true for “low current detection (in the milliampere range)”, where the effect is even stronger.

In your product:

DC detection range up to 3-7 mA

Without quality noise reduction:

It’s virtually impossible to achieve that level of precision.

 

3.In compliance with European safety standards (important)

European market:

IEC 62955 (standard for charging electric vehicles)

Demand:

• Precise measurement of AC and DC residual current.
• Avoid accidental triggers.
• The system must be stable and reliable.

And also their products:

Supports alternating current (AC) and direct current (DC) testing
Compliant with IEC 62955 standard

This depends primarily on high noise reduction capabilities.

 

4.Improve system stability (system reliability)

A system that lacks good noise immunity results in the following:

• Random alarm signal
• signal fluctuations
• control system failure
• Their products include several important features designed specifically to solve noise problems 

How can highly effective noise reduction be achieved? (Based on the advantages of your product)

1.Limit value and hysteresis (anti-swing design)

Your product contains the following components:

Development of the activation threshold + recovery threshold (hysteresis)

Influence:

Avoid sudden signal changes at critical points.

To avoid malfunctions due to noise.

This is one of the most important projects for protection against industrial interference.

2.PWM status output signal (stable communication)

According to the data table (page 3):

• Under normal conditions, it emits a PWM signal with a frequency of 1 kHz.
• Advantages:
• Compared to analog signals, it is less susceptible to interference.
• Best suited for reading data from PLCs/microcontrollers.
• Capable of detecting changes in the system’s state.

3.Self-calibration and self-test function

Your product has the following characteristics:

• Automatic zero-point drift calibration
• Short-circuit current test simulation
• Notes on the technical documentation:
• Internally, the device generates an analog direct current of approximately 6.53 mA for detection.

Meaning:

• Eliminate errors caused by ambient noise.
• Ensuring long-term stability

4.Requirements for power supply stability (reduction of interference sources)

Product requirements:

Supply voltage ripple ≤150 mV

This indicates that the following factors were taken into consideration in the development of the system:

power supply noise suppression

To ensure measurement stability.

1.What happens if there is no noise reduction?

The most common practical problems faced by engineers are:

Unexpected power outage
Data loss
Certification test failure
Electric vehicle charging failure
Customer complaints

 

Main reason:

The problem is not that the sensor is inaccurate, but rather that its ability to withstand interference is insufficient.

1.What should engineers pay attention to when selecting products?

If you are an engineer from Europe, you should pay special attention to the following:

•  Resistance to interference
•  Deferred design (seismic resistance)
•  AC/DC detection capability
•  Self-diagnosis and calibration
•  Output signal type (PWM/digital)

1.Conclusion: Noise reduction = Safety + Precision + Compliance

In modern electrical systems:

Reducing noise levels is not just about “performance optimization”
It is also “of paramount importance for safety and compliance with regulatory standards”.

Especially in:

• Charging electric vehicles
• Industrial automation
• power supply system

A high-quality current sensor should possess the following properties:

• High noise immunity
  High detection accuracy
  Stable output power

 

CTA (Conversion Guide)

If you are looking for:

The current sensor complies with the IEC 62955 standard.

Includes AC/DC leakage current detection function.

High immunity to noise and low false alarm rate

For complete technical information or to request samples for testing, please contact us:

HYCA Series Residual Current Monitoring Module
Designed specifically for electric vehicle charging and safety systems

Compay：HEYI Electrical Co., Ltd.
Brand: HEYI/ASCT
Contact: Bethy
E-mail: heyi@heyiele.com             
Tel: 86-13968747975

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