Mitsubishi FR - S500 Regarding power harmonics, Japanese power harmonic suppression guideline

1.5.9 Regarding power harmonics

The inverter may generate power harmonics from its converter circuit to affect the power generator, power capacitor etc. Power harmonics are different from noise and leakage currents in source, frequency band and transmission path. Take the following counter measure suppression techniques.

The following table indicates differences between harmonics and noise:

Item	Harmonics	Noise
Frequency	Normally 40th to 50th degrees or	High frequency (several 10kHz
	less (up to 3kHz or less)	to MHz order)
Environment	To-electric channel, power	To-space, distance, wiring path
	impedance
Quantitative	Theoretical calculation possible	Random occurrence, quantitative
understanding		grasping difficult
Generated amount	Nearly proportional to load	Change with current	variation
		ratio (larger as switching speed
	capacity
		increases)
Affected equipment	Specified in standard per	Different depending on	maker's
immunity	equipment	equipment specifications
Suppression example	Provide reactor.	Increase distance.

Suppression technique Harmonic currents produced on the power supply side by the inverter change with such conditions as whether there are wiring impedances and a power factor improving

NFB

Inverter

Power factor

improving DC reactor Motor

IM

reactor and the magnitudes of output frequency and output current on the load side.

Power factor	Do not provide power factor
improving AC reactor	improving capacitor.

For the output frequency and output current, we understand that they should be calculated in the conditions under the rated load at the maximum operating frequency.

CAUTION

The power factor improving capacitor and surge suppressor on the inverter output side may be overheated or damaged by the harmonic components of the inverter output. Also, since an excessive current flows in the inverter to activate overcurrent protection, do not provide a capacitor and surge suppressor on the inverter output side when the motor is driven by the inverter. To improve the power factor, insert a power factor improving reactor in the inverter's primary side or DC circuit. For full information, refer to page 18.

1.5.10 Japanese power harmonic suppression guideline

Harmonic currents flow from the inverter to a power receiving point via a power transformer. The harmonic suppression guideline was established to protect other consumers from these outgoing harmonics.

1)[Harmonic suppression guideline for household appliances and general-purpose products]

The "harmonic suppression guideline for household appliances and general-purpose products" issued by ex-Ministry of International Trade and Industry (present Ministry of Economy, Trade and Industry) in September, 1994 applies to the FR-S500 series other than the three-phase 400V class. By installing the FR-BEL or FR-BAL power factor improving reactor, this product complies with the "harmonic suppression techniques for transistorized inverters (input current 20A or less)" established by the Japan Electrical Manufacturers' Association.

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