Comparison of advantages and disadvantages of induction furnace series resonant power supply and parallel resonant power supply:
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project name |
Series induction furnace |
Parallel induction furnace |
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Power factor
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High power factor:. ≥0 95, because the series rectifier intermediate frequency furnace of all SCR are in the fully open state |
Low power factor:≤0 .92, because the rectifier and intermediate frequency furnace with all SCR are in a semi-open state (according to the national grid requirements need to add extra compensation)
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Output voltage waveform |
Rectangular wave
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Sine wave
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Output current waveform
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Sine wave |
Rectangular wave
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Induction coil fundamental voltage
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Q× inverter output voltage
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Inverter output voltage
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Induction coil fundamental current |
Inverter output current
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Q× inverter output current
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DC filter
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Large capacitance
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Large reactance
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harmonic |
Low harmonics, low pollution to the grid |
High harmonics, large pollution to the power grid |
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effectiveness |
High efficiency can be 10%-20% higher than parallel power supply |
Low efficiency because of low power factor and large harmonic pollution |
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start up
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Startup success rate is 100%
Because the series resonant power supply is frequency modulated, the power is adjusted by adjusting the frequency of the inverter, so the starting rate is high.
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Start success rate<100% It is difficult to start the device under heavy load conditions.
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use
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Easy to use Series resonant power supply can realize one-to-one, one-to-two, one-to-three, and other working modes
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Inconvenient to use The parallel resonant power supply can only achieve one-to-one operation mode.
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protection
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Complete protection Overcurrent protection, overvoltage protection, phase loss protection, high water temperature protection, low water temperature protection, high water pressure, low water pressure, etc.
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Complete protection Overcurrent protection, overvoltage protection, phase loss protection, high water temperature protection, low water temperature protection, high water pressure, low water pressure, etc.
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Reliability
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High reliability Proven reliability exceeds parallel resonant power supply in field use
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High reliability
The technology is more mature than the series resonant power supply. |
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Equipment cost
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High equipment cost Because the tank current passes through the thyristor filter, it uses capacitive filtering.
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Low equipment cost
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Energy saving
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10% to 20% energy saving compared to parallel power supply
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Relative series is not energy efficient.
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