Effect of standby mode operation of some household appliances on disturbance voltage and current in frequency range of 9–150 kHz produced by other equipment in low voltage network
Most household appliances commercially available today on the market are equipped with the inverter technology favoring to its smaller size, advanced performance, and energy efficient. Notwithstanding its benefits, unfortunately, this technology may introduce current disturbance according to its relevant frequency switching and eventually degrades power quality. The switching frequency of inverter for household appliances is generally in the range of 9-150 kHz causing the disturbance and may influence the working performance of other appliances. The voltage and current disturbances in the frequency range of 9-150 kHz are not completely covered and currently subject to standardization work. Some household appliances can be operated in standby mode in order to display the time and setting information or to allow them to operate quickly even though it also gives a drawback regarding to its energy consumed. This study investigates the characteristics of standby mode operation of some appliances and its effect to the voltage and current disturbance in the frequency range of 9-150 kHz. The result shows that the standby mode operation of particular household appliances can filter and significantly reduce the voltage and current disturbance in the low voltage (LV) installation network for specific frequency in the range of 9-150 kHz.
The properties and behavior of disturbances in the frequency range 9 kHz to 150 kHz produced by household appliances in a residential network environment
Many household appliances are equipped with inverter technology which may generate disturbances in the frequency range 9 kHz to 150 kHz. Since the standards managing the disturbance in this frequency range are not covering all household appliances, the effort to limit the disturbance produced by some appliances become less. The disturbance produced by the appliance may influence the operation performance of neighbor appliances which are connected to the same network. In the other hand, the neighbor appliances due to their internal properties may also influence the disturbance produced by the appliance. Some phenomena regarding the interaction of disturbance characteristics between appliances have been recognized and reported by some researchers, but no further analysis can be done due to the limited knowledge about this disturbance characteristics. 
The study focuses on observing the properties and behavior of disturbances in the frequency range 9 kHz to 150 kHz produced by some household appliances in a residential network environment. The disturbance properties and behavior are important to predict and investigate the disturbance occurred in the network. The effect of some parameters of residential network environment to the disturbances are observed including the variation of mains voltage level, the presence of neighbor appliances and the variation of mains network impedance. There are four main works conducted in this study, the first is identifying the internal impedance properties of appliances, the second is defining the disturbance properties and behavior for individual and simultaneous operation of appliances, the third is simulating the disturbance for simultaneous operation of appliances in residential network environment, and the last is reviewing the existing standards of disturbance in the frequency range 9 kHz to 150 kHz corresponding to the real residential network situations. The equipment under test used in this study are induction cooker, inverter microwave, conventional microwave, mixer, hand blender, water cooker, personal computer, notebook, television LED, hair dryer, electric massage, iron, compact fluorescent lamp and LED lamp. 
The disturbance emitted by each household appliance in the frequency range 9 kHz to 150 kHz has unique properties and behavior. The disturbance is affected by the presence of neighbor appliance in the network. The neighbor appliances, depending on their power consumption and internal impedance properties, may increase or decrease the disturbance occurred in the network. Besides, the mains voltage level and the mains network impedance variation are also influencing the disturbance. Some conditions in the real residential network environment may lead to the difference of disturbance obtained in the standard emission test and the real network environment. The user should be aware that there are situations in which the emission occurred in the field could be different.
MEASUREMENT AND ANALYSIS OF HIGH-FREQUENCY CONDUCTED DISTURBANCES
The frequency range above the “traditional” harmonic range up to about 2 to 3 kHz has been under investigation for a while but less attention has been paid to the frequency range slightly above. This paper presents measurements both in laboratory environment and in the field on different types of equipment and general long- term measurement on site in the low voltage network. The general aim of this paper is to increase the knowledge about voltage and current distortion in the frequency range above 2 kHz.