Sharing| Electromagnetic compatibility testing of power line communication (PLC) equipment

1.    Testing Scope

EN 50561-1 specifies the limits and measurement methods for radio interference characteristics of household communication equipment using low-voltage power devices as transmission media, applicable to PLC equipment communicating on media in the frequency range of 1.6065MHz to 30MHz.

2.    Test Project

The electromagnetic compatibility testing of PLC equipment includes conventional radiation, conduction testing, and four exclusive testing items. The functional status and note requirements of all tested equipment are shown in the following table:

3.    Test Requirements

Conventional radiation and conduction testing is a common testing item in the industry. The following text will focus on the installation methods, testing conditions, and limit value requirements for specific testing of PLC equipment in items 4-7 of the table.

1)  Conducted unsymmetrical disturbances for PLC ports

This test is conducted in accordance with the requirements of section 9.1 of EN 50561-1.

a. Setup :

NOTE 1:  Distance from AE to the reference ground plane (vertical or horizontal) is not critical.

NOTE 2:  Cable length between EUT and CS is 0,8 m (± 0,05 m).

b. EUT requires measurement under the following two conditions:

·The PLC function of EUT is in operation. That is to say, the testing that requires the PLC modem function to be effective should be conducted under the condition that the PLC utilization rate exceeds 10% and the transmission signal is set at its maximum level of at least 250 ms.

·Terminate user data exchange for EUT execution (without running 10% streams). The interference level in the frequency range of 150 kHz to 30 MHz should be measured without user data transmission.

·The tested PLC and the surrounding PLC are powered by two LISNs respectively, and the communication function between the two is achieved through a coupling unit. The receiver receives the test conducted interference signal through the power supply LISN of the tested PLC.

c. Limit:

2)  Dynamic power control for PLC ports

This test is conducted in accordance with the requirements of section 9.2 of EN 50561-1

a. Setup :

b. Test conditions

PLC wireless module function activated, PLC usage rate exceeds 10%, transmission signal set to maximum level and maintained for at least 250 milliseconds; Adjust the symmetric mode insertion loss (10dB, 20dB, 40dB,>40dB) in the coupled network to complete the full operating condition test.

c. Limit:

Dynamic power control PLC signal transmission level limits within the frequency range of 1606.5 MHz to 30 MHz

3)     Cognitive (dynamic) frequency exclusion

This test is conducted in accordance with the requirements of section 9.3 of EN 50561-1.

a. Setup :

b. Test condition

PLC wireless module function activated, PLC usage rate exceeds 10%, transmission signal set to maximum level and maintained for at least 250 milliseconds; Simulate broadcast signal injection interference to verify equipment frequency avoidance capability.

·Within 15 seconds of the interference signal being emitted, the equipment must completely avoid the interference frequency;

·Maintain avoidance mode and restore communication within 3 minutes after stopping interference.

c. Limit:

The establishment of the limit value for this test is as follows: when the bandwidth is ≥ 10kHz, the lowest level is 56dB (μ V) (using an average detector with a detection bandwidth of 9kHz)

4)     Conducted asymmetric disturbances for PLC ports

This test is conducted in accordance with the requirements of section 9.4 of EN 50561-1.

a. Setup :

b. Test condition

· Ensure the inherent symmetry of PLC ports, operate under all operating conditions, and use the methods and procedures provided in Section 9.4.

·The tested PLC and the surrounding PLC are powered by two LISNs respectively, and the communication function between the two is achieved through a coupling unit. The receiver adds an ISN between the tested PLC and the power supply LISN to receive the test conducted interference signal.

c. Limit:

BTL has many years of experience in electromagnetic compatibility testing and has established a professional technical service team with full project electromagnetic compatibility testing capabilities for PLC power line communication equipment. It can strictly complete testing in accordance with EN 50561-1 standards and issue CNAS and A2LA dual qualification testing reports, providing authoritative and professional technical support and solutions for PLC equipment research and development, compliance certification, and market access.

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