The components of the parallel intermediate frequency furnace :
Parallel intermediate frequency furnace mainly includes intermediate frequency power supply, parallel inverter, aluminum shell furnace body or steel shell furnace body (the furnace body can be matched with selection)
The reason for choosing a parallel intermediate frequency furnace :
In the design of the parallel intermediate frequency furnace, the control circuit requires only two transformers and one control circuit board in addition to the conventional main circuit. The contactor, intermediate relay, and other auxiliary circuits are completely removed, so that the whole set of equipment is rarely connected. Moreover, since the three-phase AC input does not have to distinguish the phase sequence, the intermediate frequency output line does not have to distinguish the phase, which makes the user's on-site debugging more convenient. .
1, constant power control system digital (highly integrated control circuit),
2, constant power thyristor frequency power supply system is the company developed the intelligent controller. Mainly composed of regulator, phase shift controller, protection circuit, start-up calculation circuit, frequency tracking, inverter pulse formation, pulse amplification and power drive. After being digitized, it becomes a special chip, which is specially applied to the control of thyristor parallel inverter intermediate frequency power supply.
3 , Inverter control reference to the United States ABB , Ajax , Japan Fuji Electric and other foreign advanced control technology, self-developed inverter control technology, has a strong anti-interference ability.
4, the control panel for the digital integration panel board, digital trigger, high reliability, high precision, easy to debug without relay element, etc., no long-term temperature drift, the operating point stabilization.
5 , with perfect multi-level protection (water pressure, phase loss, under voltage, over current, over voltage, off time, straight through, operation interlock, etc.)
The startup mode is advanced sweep type, which stimulates the zero-voltage start, enabling the operator to achieve 100% successful start without selecting the start voltage and start frequency .
6. It can adjust the matching according to the change of load, and improve the melting and heating speed to save energy ( 10% ).
7. It has the following instrument indications: output voltage meter, output power meter, working frequency meter, medium frequency current meter, power factor meter, input voltage meter, earth leakage meter and fault warning indication. ( Electrical meter is installed between transformer and intermediate frequency power cabinet
8 , power start performance: reliability start-up (whether empty, full load). The power supply adopts a zero-voltage automatic sweeping start mode and has a frequent start function. The startup success rate is guaranteed to be 100% both under heavy load and no load .
9, when the heavy load is reduced commutation angle relative increase in voltage, reducing the current, power supply close to optimum (nominal) light load, increasing the commutation angle relative reduction ,, voltage, increasing the current, the power supply Working close to the best value (rated value)
10 , using parallel compensation circuit to reduce the loss of the transmission line In order to reduce the loss on the intermediate frequency transmission line, the compensation capacitor of the inverter is connected in series double voltage form. This connection allows the voltage on the electric furnace to be doubled compared to the inverter output voltage. In this way, the output current becomes 50 % of the original at the same output power , so that the loss on the intermediate frequency transmission line is reduced by 1/4 .
The advantages of parallel intermediate frequency furnace:
1. Due to the characteristics of the parallel resonant circuit, the variable frequency power supply with parallel resonance has good protection when the circuit is short-circuited. Because the reactor device with buffer function installed in the intermediate circuit can effectively suppress the rapid rise of current, it can be reliably turned off when the circuit fails.
2 , parallel resonant frequency conversion environmental source also has very low loss on the inverter side (because the large current only works in the resonant circuit) and precise coil voltage control (to make full use of the highest power of the capacitor group)
3 , the technology is mature, the performance of the whole machine is stable and reliable, and has a competitive advantage.
4, the operation is simple, easy to use
5 , the maintenance speed is fast, the maintenance difficulty and maintenance costs are low!
6 , the price is relatively cheap.
