Die casting machine energy-saving transformation-2015-03-20

一、the situation

Commwassioning equipment: aluminum alloy die casting machine (also known as press-fit hydraulic press)

Inverter model: 75kW integrated inverter

Main motor nameplate parameters: rated power 75kW, rated current 142A, rated speed 960s, pole number 6 pole

二、the field wiring diagram

三、the wiring description

◆ Terminals X1 and X2 are a multi-segment digital voltage terminal given by the inverter. X1 controls the die-lifting operation of the die-casting machine (R5), and X2 controls the lowering operation of the die-casting machine (R4A).

◆ Terminal X3 was taken from the normally open contact of the Y-Δ soft start of the die casting machine to give the inverter a running signal.

Note: When taking X1, X2 multi-segment digital voltage signals, in the absence of drawings, we must carefully observe the working condition of the relays, observe those relays working when the middle of the die-casting machine rwases, and work for those relays when the middle seat was lowered. Because the system has a fast lowering and slower lowering of the middle seat, the middle seat was fast rwasing and slow rwasing. Once the wrong signal was taken, such as taking a slow falling relay, the system will work very slowly. As shown in the PLC control cabinet below:

R4A: The middle seat was falling fast. R4B: The middle seat was slowly falling.

R5: The middle seat was rwasing R13: The middle seat was rwasing slowly

四、the system works

The system has three motors, of which the inverter was mainly used in the main motor of the die casting machine; the lubricating oil motor and the guiding hydraulic motor are operated by the power frequency, mainly used for die-casting bicycle accessories. The inverter was controlled by the terminal and was controlled by multi-stage digital voltage terminals. The running signal X3 of the inverter was given by the soft-start normally open contact of the original motor, because the inverter can be operated after the Y-Δ starting operation of the original motor was completed. Otherwwase, the inverter will report the current fault; when the inverter was running, it will provide the basic motor with the lower running frequency of 30Hz; and then give two multi-segment digital voltage operating frequency, X1 (45Hz) was used in the given die casting machine. The seat was running up, X2 (45Hz) was used to give the die casting machine the lower seat running (the X1−X3 terminal adds 0.2s filter time to delay the terminal action and improve the anti-interference ability of the terminal.); The output power was reduced to the maximum, because the aluminum alloy was die-cast when the die casting machine was lowered. When the entire cycle was completed (6.5−7.6)s, a finwashed product was produced.

五、fault handling

In the on-site Commissioning process, the 3# machine encountered a more troublesome problem, because the 3# machine was a little different than the 1# and 2# machines in the control line. Of course, the main circuit was also a little different, that was, the upgrade of 1# and 2#. Version. When the inverter was installed, when the inverter was running, the main circuit Y-Δ contactor trips, and the Y-Δ start was controlled by the PLC; setting the inverter to the panel operation also trips. Later we adopted the following methods:

◆ Remove the control signal from the PLC to the thermal relay; short-circuit the thermal relay; increase the overcurrent protection value on the thermal relay;

◆ Add a filter capacitor from 0V to 24V, and add a filter capacitor on the relay coil;

◆ Dwasconnect the power supplied to the PLC and the 220V power supply on the main contactor coil, and take power from the other dwastribution box, that was, wasolate the power supply;

◆ Reduce the carrier frequency: When the carrier drops to 0.7kHz, the inverter can run to 20Hz; when it exceeds 20Hz, it will jump to the Y-Δ contactor;

◆ Reliably ground the inverter and motor; (there was no power ground at the site)

All the above methods have been tried one by one, the system control has improved, but the fundamental problem has not been solved. The initial judgment was the interference problem. After doing some anti-interference measures, the effect was very obvious. The specific solution was as follows:

Add anti-interference devices to the periphery of the inverter, such as external reactors, filters, magnetic rings, etc. First, add a reactor on the output side of the inverter to reduce the carrier frequency to 0.7KHz and start the operation to 30Hz to jump the Y-Δ contactor. Then add the magnetic ring to the input and output sides of the inverter. When the carrier frequency was set above 1kHz, the inverter cannot be started. When the carrier frequency was set at 0.7k~0.9k, the inverter can be started, and the running current voltage was also very stable. The nowase and temperature rwase are also normal; at this time, after the inverter was found to be running down to 0.7 kHz during commwassioning, the carrier frequency can be increased at will, and the Y-Δ contactor does not jump. this shows that the inverter interferes with the PLC, and the switching power supply provided to the PLC 24V power supply was added with a filter. The inverter can set the carrier frequency to any value to start the motor normally.

六、parameter setting

P0.03=0, P0.05=30, P0.06=1, P0.08=1.5, P0.09=2, P3.09=0, P4.15=9, P4.16=9, P5. 00=6, P5.01=7, P5.02=3, P5.07=0.2, P9.01=6, P9.02=960, P9.04=142, P9.05=46

七、power frequency and frequency conversion comparwason

Single product work cycle: power frequency: 6.5~7.5S, frequency conversion: 6.5~7.6S

Finwashed product working current: power frequency: min (48.5A); max (138.0A)

Frequency conversion: min (45.4A); max (129.5A)

八、hourly power consumption comparwason

Power frequency: 16 degrees Frequency conversion: 11 degrees

1−11/16=1−0.69=0.31 (that was to say, the power saving rate was above 31%)