/1 Testing Harmonics and Flicker

/1 Harmonics & Flicker Two different test standards: EN & EN EN controls the level of distortion of the current drawn by all equipment rated up to 16 amps. 2.EN controls the level of voltages changes that equipment rated up to 16 amps will impose on the ac supply. Both standards have evolved over time –Harmonic standard. originally called IEC 555 Part –Flicker standard. originally called IEC 555 Part –Now referred to as EN & EN Standards –EN is short for Euro Norm; the version enforceable in law in European countries. The EN is usually identical to the IEC version.

/1 Current Harmonic Distortion Most modern power supplies draw current that is non- sinusoidal.

/1 Current Harmonic Distortion The distorted current causes problems for electricity suppliers, consumers and product manufacturers. The extra distorted current drawn does no useful work. The power factor is W This means more electricity must be generated, distributed and paid for than is consumed as useful energy. The current distortion leads to to the phenomenon of triplen harmonic currents flowing in the neutral of three-phase systems – a fire risk in large office installations. and to voltage distortion that can cause overheating in motors.

/1 Current Harmonic Distortion Fourier analysis is used to describe any repetitive waveform in terms of sine- waves that are at multiples of the fundamental frequency. EN controls current distortion by setting limits for the amplitude of the 1 st 40 current harmonics. 50HZ 100HZ 150HZ

/1 Requirements of EN How to measure to the harmonics is defined by EN It is a not a simple requirement. The following measurements must be made: Power, Power Factor, Voltage Harmonics, Fundamental Current, POHC (Partial Odd Harmonic Current) as well as Current Harmonics. And in a very specific way: NEW REQUIREMENTS Measurements are made every 200mS, continuously without gaps. (10 50Hz, 12 60Hz). Inter-harmonics must also be measured for current harmonics

/1 Requirements of EN Harmonic measurements every 200mS measurements! Continuous no-gap analysis All measurements filtered by 1.5s time-constant filter

/1 Inter-harmonic groups

/1 Example Inter-harmonic group 6 th harmonic 50Hz) 1/2

/1 Applying Limits to Harmonics - EN The limits for pass and fail are set by product groups called Classes: The limits are different for each harmonic and each of the 4 classes, A, B, C &D Class Determination is :- If device power is W and a PC, Monitor or TV then Class D If handheld portable tool, then Class B If Luminaries then Class C If not Class B,C, or D, or 3 phase then class A.

/1 Applying Limits to Harmonics - EN Example Class C limits - calculated from AH01 and PF Information from the PC Software ‘Help’ system

/1 Applying Limits to Harmonics - EN Limit 2 Limit 1

/1 Applying Limits to Harmonics - EN Maximum reading Vs Limit 2 Average reading Vs Limit 1 Limits are set for the average of each harmonic during the test (L1) AND the maximum of each harmonic (L2).

/1 Flicker - Causes The AC supply cabling to a building will have a source impedance Any variation of loads will cause a voltage change at the distribution point This fluctuation of voltage will then make the lamps “Flicker”

/1 Flicker –The Pst = 1 Curve The Human tolerance to light flicker is mapped on the Pst = 1curve. Any point on the curve has the same perceived level of annoyance Pst = Perceptibility short term

/1 EN – The Flickermeter For real-life random voltage changes, a flickermeter is used is used to duplicate the human perception of flicker. A flickermeter measures rms voltage changes every half-cycle (10ms) and filters the measurements just like the lamp-eye-brain chain. The filtered changes are classified to generate a table of the probability that a ‘class’ of voltage change will occur.

/1 Flicker Pst test results from Voltech software

/1 Measurement Equipment The Harmonics and Flicker standards require fast and accurate analysis of electrical power quantities: Continuous harmonics: 400+ measurements every 200ms. Discrete Fourier Transform for a reference instrument. Continuous voltage changes: every 10ms (1/2 Hz), real-time flickermeter processing. Limit checking and reports Calculation of harmonic limits from averaged and maximum readings Comparison to different class limits Recording and presentation of results

/1 The PM6000  Up to 6 wattmeter channels  Accuracy: 0.02% of reading, 0.05% of range  Bandwidth: 10MHz  Sampling rate: 40 MSPS  Display: Bright color VGA  Connectivity: RS232, IEEE488, Printer, Ethernet  Connectivity (Future Release): PCMCIA for analog I/O including torque and speed, USB

/1 PM6000 Measurement Channel DSP 200MHz PCI Bus Continuous 5 MSPS data from every channel. No analysis gaps, no missing data Pulse Transformers Data and control. Provide superior CMRR than opto- isolators A- D Convertor 14-bit 40MSPS Max 5MSPS Min Isolation 4kVpk CMRR: 60Hz 1MHz i v ±5V ±12V Built on 15+ years of Voltech analog know-how Unrivalled accuracy and bandwidth combination Layout and timing minimise phase delay for best Watts accuracy

/1 Why the Voltech PM6000? Processing power to perform discrete Fourier transform (DFT) analysis, harmonics and inter-harmonics every 200mS  Simultaneous voltage, current, power (W) and PF measurements as required  EN calls for synchronization accuracy of +/- 0.03%.  0.02% EN calls for crest factor of up to 4.  20 EN calls for nominal current input overload times 10 for 1 second.  250A Accuracy of voltage and current measurements 10 to 100 times better than standard requires.  Powerful PC software with comprehensive ‘help’ system  Full compliance tests with an AC source, or accurate pre-compliance from the ac line  20 years of digital power analyzer know-how. 

/1 References Harmonic Limits IEC Consol.Ed.2.1 (2001) All electrical and electronic equipment up to 16A. 220 to 240V 50 or 60Hz. IEC All electrical and electronic equipment rated 16A to 75A. 230/400V 50 or 60Hz. Harmonic Measuring Equipment IEC (2002)- 200ms window and Interharmonics requirement mandatory end 2007 Flicker Limits IEC Consol.Ed.1.1 (2001) All electrical and electronic equipment up to 16A. 220 to 250V line to neutral at 50Hz. IEC Ed.1 (2000) All electrical and electronic equipment 16A to 75A. 220 to 250V 50Hz. Flickermeters IEC Ed.1.1.(2003) Help information Voltech IEC61000 software for the PM6000. Standards from: Software from: (free download).

/1 End of Presentation Thanks for listening!