summary
Since computer loads and single-phase nonlinear loads like electronic fluorescent light were spread,
zero-sequence harmonic current of neutral wires has caused severe errors of electric equipment,
such as distribution line overheating and malfunction of circuit breakers and relays.
The Zero Sequence Harmonic Filter (ZSF) is a semi-permanent filter designed and manufactured to minimize zero-sequence impedance. Therefore, it can keep performance in any positions from the secondary terminal of transformer to the panel board at the end of load, and has an easy-to-install structure.
The filter is capable of removing over 90% zero-sequence harmonic current depending on an installation position in order to stabilize the power quality of systems. It is widely applied to three-phase four-wire distribution systems.
The Zero Sequence Harmonic Filter (ZSF) is a semi-permanent filter designed and manufactured to minimize zero-sequence impedance. Therefore, it can keep performance in any positions from the secondary terminal of transformer to the panel board at the end of load, and has an easy-to-install structure.
The filter is capable of removing over 90% zero-sequence harmonic current depending on an installation position in order to stabilize the power quality of systems. It is widely applied to three-phase four-wire distribution systems.
- Problems of zero-sequence harmonic
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- Circuit breaker trip by overcurrent
- Temperature rise and thermal degradation of transformer
- Malfunction of protective equipment
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- Neutral conductor overheating and fire occurrence
- Communication problem
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- Application
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고조파 적용 Application loads Computer, OA device, electronic stabilizer, medical device, broadcasting system, single-phase SCR heater, single-phase UPS Application systems Three-phase four-wire distribution system Application places Information processing center, factory, hospital, building, office, oficetel, school, apartment, computer academy
- Problems of zero-sequence harmonic
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- Step1. Find an appropriate place for installation
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- Find a good place to install ZSF.
- The closer the ZSF is to a load, the more the reduction rate can be generated.
- Step2. Measure the maximum current of neutral
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- To select a ZSF rate, it is very important to measure the maximum current.
- If a product is selected with no measurement of current, it is necessary to set the maximum current of neutral to a value three times higher than single-phase current.
- Step3. Select in the table of standard rating
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- Based on the maximum current value of neutral, select a ZSF in the stable of standard rating.
