Test setup for Power meters

Some cases have been reported recently where the operation of static electricity meters for active energy has been influenced by various equipment generating disturbances in the frequency range of 2–150 kHz. This matter has been discussed at both WELMEC and CENELEC TC13 meetings since the end of 2010.

Causes of these disturbances include PLC-communications, electronics such as solar inverters, switching power supplies and inverters.

TÜV Rheinland in the Netherlands developed a test setup for immunity investigation of electromagnetic disturbances in the frequency range of 2–150 kHz and their effect on static electricity meters. Tests are performed based on the EMC standard IEC 61000-4-19:2014.

With a positive result manufacturers of kWh-meters can demonstrate to authorities and energy suppliers that their electricity meters (Wh/kWh) are immune to interference in the frequency range of 2 to 150 kHz.

With TÜV Rheinland Product Testing and Certification, you will:

• Ensure your compliance with the legal requirements of the EMC directive
• Compliance with the relevant standards as well as interoperability.
• Improve your market position with tested products
• Competitively position your products with our independent third party test certification
• Benefit from fast turnaround times and our long-standing experience
• Benefit from TÜV Rheinland’s exclusive, one-stop service Electromagnetic Compatibility (EMC), Safety and Telecom
• Obtaining specific certification marks from industry alliances such as ZigBee and Wi-Fi
• Compliance with local government and legal requirements

For measuring problems with interference on electric power the EMC standard IEC 61000-4-19-2014 is used. In the test a high frequent current is passed through the energy meter. We can also help you with EMC, safety and telecom tests.

Measurement setup other electrical equipment

In the IEC 61000-4-19: 2014 measurements are described for immunity measurements in the range from 2 kHz to 150 kHz to other electrical equipment. We also test other electrical equipment besides energy meters. It is expected that the IEC 61000-4-19 is incorporated into several product standards.

Electric energy meters, marked with CE and M and assessed according to the applicable harmonized standard, have under certain circumstances turned out not to be immune to specific types of electromagnetic disturbances. The disturbances are usually caused by common types of electronic equipment in households and light industries. The results of the disturbances are abnormal meter registering values.

As the meters are used for invoicing, it causes customers to be charged the wrong amounts by electricity companies.

The disturbances are a specific type of conducted high frequency current “wavelike phenomenon” in the frequency range 2–150 kHz. Although the disturbance is not constantly present in the power network it cannot be defined as transient. The bandwidth can vary from narrowband PLC-signals to larger bandwidths, such as switching frequencies from power supplies and broadband noise.

The disturbances, apart from intended signalling, can be described as injections of current into the distribution net by third party auxiliary equipment or electric devices close to the meter (“upstream or downstream” in relation to the meter). Examples of such equipment are PV inverters, frequency converters, heat pumps, domestic electronic equipment, automatic garage doors, refrigerators and dimmers.

It should be emphasised that in cases where meters have been influenced, these disturbances have caused abnormal meter register values during exposure, but the meters are not damaged permanently when exposed.

Some notified bodies demand that MID module B & D show conformity in the 2–150 kHz range otherwise no more meters are allowed to be in the market! Utilities state that they will not purchase meters that are not immune to this electromagnetic disturbance. We help you with testing the meters.

WELMEC 11 states that manufacturers have to declare and prove that their meters are immune to this electromagnetic disturbance in the frequency range of 2–150 kHz

To test according to the EMC standard IEC61000-4-19: 2014 TÜV Rheinland has developed a simulation test setup.

Backed with a positive test result of this simulation test, manufacturers can show Notified Bodies (NoBo), customers and utility companies that their Watt-hour meters or other electrical equipment are immune to this electromagnetic disturbance in the frequency range of 2–150 kHz..

For the NMI, Nederlands Meetinstituut, this test is compulsory.