Why Servo Press Save Energy

The energy consumption of servo presses has always been a concern for everyone. I will explain it from the following aspects.

1. Specific energy-saving calculation principle

2. Working principle of our servo system energy recovery unit

Specific energy-saving calculation principle

1. Taking the double-point 400ton press as an example, the three-phase asynchronous motor is 45KW. As long as the press is turned on, whether it is stamping or not, the motor is running and consuming power, especially when stamping, it is running at 45KW.

1. When uses servo motor, although the servo motor is 254KW, there is no power consumption as long as the press is not running (motor on but no stroke running). When running in stretching mode, it is basically 150~180 degrees (crankshaft angle, 1/12 of the entire crankshaft), and other angles are basically no-load operation (basically 8KW). According to the above calculation: 254*1/12+8*11/12=29.17KW, in summary, in the case of continuous operation, it is basically 29.17/45=0.65, which can save 35% of energy. If the customer uses a single stamping, the energy saving is more obvious (the slider stops at the top dead center, and the servo press does not consume energy.

In addition, there is a misunderstanding that the rated power of the servo motor is very large, and the factory power grid requires a lot. In fact, the rated power of the servo motor only means that the servo motor has this torque (energy). The servo motor is directly driven by our servo drive and is not directly connected to the factory power grid. The specific current is completed by the built-in inverter of the servo drive and has no direct connection with the factory power grid input line. According to the actual experience of our current customers, the factory power consumption is saved, and the input line only needs to be 10~20% thicker than the current ordinary press wire diameter.

Working principle of our servo system energy recovery unit

The drive control integrated machine is equipped with an energy feedback unit as standard.

The capacitor module is used for charging and discharging, which can achieve energy saving and environmental protection, and the capacitor is monitored from many aspects during operation, and the system will be safer and more reliable. At the same time, the capacitor module has a smaller installation area.

The working logic of the servo drive capacitor energy storage is a power storage technology that improves the performance and efficiency of the servo drive by storing electrical energy in capacitors so that energy can be released when needed. Specifically, when the drive requires a lot of power, the capacitor releases the stored energy to meet the needs of the drive. When the drive requires less power, the capacitor will recharge so that it can release energy again when it is needed next time. This capacitor energy storage technology can improve the response speed and accuracy of the servo drive, while also reducing energy consumption and grid load.

Description of the working state of the energy storage capacitor:

1. Start-up acceleration stage: At this time, the capacitor is in the discharge process, the capacitor charge is reduced, and the bus voltage is reduced

2. Deceleration stage before contacting the mold: At this time, it is the braking stage, the capacitor is in the charging process, the capacitor charge increases, and the bus voltage increases.

3. Pressing the mold down stage: At this time, the capacitor is in the discharge process, and the bus voltage decreases

4. Return stage: When the contact mold has not been separated, this is the braking stage, the capacitor is in the charging process, and the bus voltage increases. If the voltage exceeds the brake unit start voltage, the brake is turned on. If the braking power is less than the brake unit power at this time, the capacitor is in the discharge process, and the bus voltage decreases; if the braking power is greater than the brake unit power at this time, the capacitor is still in the charging process, and the bus voltage increases further.

5. After leaving the mold: At this time, it is in the return acceleration stage, the capacitor is in the discharge process, the capacitor charge decreases, and the bus voltage decreases.

6. When approaching the top dead center, it is in the return deceleration stage, the capacitor is in the charging process, the bus voltage increases, and after exceeding the brake unit start voltage, the brake works. If the braking power is less than the braking unit power, the capacitor is in the discharging process and the bus voltage decreases; if the braking power is greater than the braking unit power, the capacitor is charged and the bus voltage increases.