Nowadays, power electronic devices play a significant role in industries and there are more demands each year according to the economic growth. Current examples of power electronic devices include UPS (uninterruptible power supply), switching for power supply, inverter and electric car system. These devices need to be designed properly to prevent noise inside the electrical system after the electronic device is connected to the electricity. Therefore, the measurement of electrical quality is the priority in the evaluation of the quality of the electrical system at a particular place.
To design and produce these power electronic devices, there must be industrial standards such as IEC 6100-3-2 Class A to D to monitor and control the noise caused by harmonic frequencies. This is aimed to prevent problems inside the electrical system. Therefore, the production of these devices before entering the market needs to meet the standards in order to reduce the harmonics. However, this procedure requires a high cost and as such the ability to detect the sources as well as to resolve the problems beforehand can save a lot of cost.
As mentioned, the factor which helps the design and the verification of the quality of the power electronic devices is a measuring device called Power Analyzer. In general, Power Analyzer display the output in terms of number, voltage, current, workload, power factor suitable for permanent installation. It monitors the changes in the number in order to get the whole picture of the electrical system. Another important device, Oscilloscope is a measuring device which displays the output in terms of electrical waves suitable for an in-depth analysis of electrical equipment. However, it is not suitable for the direct measurement of electrical power because it cannot accept high input. Nowadays, there is a new device which combines these two devices and this new equipment is called Integrated Power Analyzer which can analyze numbers and electrical waves as well as give more details. It can also be used to analyze electrical appliances from 1 to 3 phases.
An example of measuring the electrical parameter by using Integrated Power Analyzer shows that the voltage, the current and the power as well as the phase angle and power factor in the numerical format. At the same time, the machine displays the electrical waves so that we can analyze the behavior of the current flow inside the electrical appliance. We can see the period in which the current flows and the period with the highest power amount.
An example of measuring efficiency of the electrical appliance such as invert or power supply which requires the conversion of electricity such as from direct current to alternating current by measuring the power flowing in and the power flowing out of the electrical appliance.
The calculation can be done in terms of percentage as follows:
No electrical appliance can achieve 100% efficiency because under the electrical process, the device will usually lose its power due to various factors such as heat.
Harmonics in the electrical system will cause damage such as the overheat in the lead cable and the transformer, resulting in the electrical flow in Neutral Line and the circuit breaker trip. Moreover, there are other frequencies to distort other system and these reduce the lifetime of the motor and the transformer. Power Analyzer can measure electrical harmonics in the format of bar chart so that we can see the voltage of harmonic frequencies and the values in comparison to the IEC 61000-3-2 standards.
References: IRC Technologies Inc.