The specialist manufacturer of power quality analysers – Outram Research – has announced that the PM7000 has an improved “Interharmonics” option making it the first power quality analyser to record simultaneously all harmonics up to the 100th, on all three phases and the neutral, on either current or voltage. This new functionality makes it possible for engineers to now analyse quickly and then eliminate power quality problems found due to high-frequency harmonics generated by uninterruptable power supplies (UPSs), drives or inverters.
By simultaneously recording all current or voltage harmonics to the 100th and many other electrical parameters, the PM7000I looks to significantly reduce testing time, pinpointing potentially problematic higher-order harmonics and removing the need for a trial and error approach. For a 3-phase 4 wire wye configuration, the General Parameters function records over 70 power quality parameters in addition to the 400 streams of harmonic data. Because this is automatic, users find they have all the information they need without having to configure individual recording channels. Users can also choose one of thirteen different averaging intervals, from one second to two hours.
In addition to the General Parameter data, every PM7000 offers 32 detailed recording channels using Outram’s Single Cycle Adaptive Store that intelligently records power quality parameters such as voltage, current (including inrush current), harmonics, flicker, unbalance and power factor down to a single cycle without the need to set triggers or levels. In the PM7000I these channels can also be used to extend harmonic recordings up to the 127th order.
“Because legislation focuses on lower frequencies, manufacturers often concentrate on reducing the presence of the first 50 harmonics,” said John Outram, Managing Director of Outram Research. “However, users of drives, UPSs or inverters, such as data centres, power critical manufacturing facilities and solar power plants, may be affected by higher-order harmonics generated by these machines. These harmonics therefore need to be monitored and controlled to avoid problems such as overheating machinery or premature equipment replacement.”
Another concern is that higher-order harmonics, created by renewable generation connected at the transmission level, may be emerging on the HV networks. These can then percolate right down to the end user so need to be managed.”
The PM7000I Power Quality Analyser is available today from Outram Research and their distributors.