In recent years, with the development of inverter technology, its reliability has been greatly improved, production costs have been reduced, and superior braking control characteristics have been widely used in various industries. The following describes the use of Hailipu inverter in a crane factory in Zhejiang. Use in cranes.
First, the system configuration
According to the characteristics and technical requirements of the crane motor drive, HOLIP-A series inverters are selected as the motor drive for the large and small travel agencies. There are front and rear trolleys running direction, trolley running direction is about. According to the operating speed requirements are divided into 1 - 4 files. Acceleration and deceleration time is 3 - 6s. Usually, the trolley travel mechanism uses a motor, while the trolley travel mechanism uses 2 to 4 motors. The inertia of large and small cars is also large. In order to prevent the motor from being reversed and the load is reversed, the motor is in a state of power generation and overvoltage is generated. Therefore, the large and small car inverters are equipped with a braking unit and braking resistor to release energy. Considering the vibration of the machine and the reaction torque when the moving path twists, it is necessary to pay full attention to the structure of the machine, and the braking resistor value should be selected according to the working conditions that absorb the maximum regenerative electric energy. The entire electrical system of the crane is controlled by the PLC. The inverter receives the PLC control signal through the digital terminal. Small cranes can also use inverter built-in PLC control, the circuit is simple and easy to use.
Inverter capacity decision:
1. Capacity P at constant load movement
P=(W×u×V)/6120×η(KW)
Where: W—Rated weight (kg)
U—movement resistance
V—Rated Speed ​​η—Mechanical Efficiency In the case of outdoor, the moving resistance must also include wind resistance and increased resistance due to the inclination of the moving path (level).
2. Inverter Capacity Inverter Rated Current > Motor Rated Current ×(k1×k3)/k2
Where: k1 - the required maximum torque ÷ motor rated torque
K2 - 1.5 (overload capability of the inverter)
K3 - 1.1 (margin)
Second, the main parameters of the inverter settings
When the cart has several motors, it should run at a linear frequency/voltage characteristic. 1-4 speed change with fixed frequency setting 1st gear = 5HZ, 2nd gear = 10HZ, 3rd gear = 25HZ, 4th gear = 50HZ, at the same time, using the brake's brake on and off functions to control the machine by the output relay contacts The brakes prevent the walking mechanism from moving freely due to external forces when the motor stops. Pay attention to the adjustment of the intermediate voltage and torque compensation. Acceleration/deceleration time is appropriate due to the size of the tonnage of the crane.
CD012=6, CD013=6, CD033=1, CD058=02, CD059=04, CD076=2, CD000=5, CD080=10, CD081=25, CD082=50
Third, the conclusion
After the crane is driven by the inverter, the performance of the whole machine is greatly improved, such as high efficiency, good power factor, significant energy saving effect, simple external wiring, reduced wiring cost, stepless speed regulation, smooth and stable walking, and simple motor construction. High reliability, can be used in harsh environments, greatly reducing the maintenance workload and wearing parts, greatly improving the maintenance performance; the inverter has complete protection functions, such as overcurrent, overload, overvoltage, etc. And stop, reducing crane failures and improving safety performance. At the same time, the frequency converter has a current limiting function. The soft start can reduce the impact on the power grid during start-up and is conducive to the normal operation of other equipment in the workshop.
First, the system configuration
According to the characteristics and technical requirements of the crane motor drive, HOLIP-A series inverters are selected as the motor drive for the large and small travel agencies. There are front and rear trolleys running direction, trolley running direction is about. According to the operating speed requirements are divided into 1 - 4 files. Acceleration and deceleration time is 3 - 6s. Usually, the trolley travel mechanism uses a motor, while the trolley travel mechanism uses 2 to 4 motors. The inertia of large and small cars is also large. In order to prevent the motor from being reversed and the load is reversed, the motor is in a state of power generation and overvoltage is generated. Therefore, the large and small car inverters are equipped with a braking unit and braking resistor to release energy. Considering the vibration of the machine and the reaction torque when the moving path twists, it is necessary to pay full attention to the structure of the machine, and the braking resistor value should be selected according to the working conditions that absorb the maximum regenerative electric energy. The entire electrical system of the crane is controlled by the PLC. The inverter receives the PLC control signal through the digital terminal. Small cranes can also use inverter built-in PLC control, the circuit is simple and easy to use.
Inverter capacity decision:
1. Capacity P at constant load movement
P=(W×u×V)/6120×η(KW)
Where: W—Rated weight (kg)
U—movement resistance
V—Rated Speed ​​η—Mechanical Efficiency In the case of outdoor, the moving resistance must also include wind resistance and increased resistance due to the inclination of the moving path (level).
2. Inverter Capacity Inverter Rated Current > Motor Rated Current ×(k1×k3)/k2
Where: k1 - the required maximum torque ÷ motor rated torque
K2 - 1.5 (overload capability of the inverter)
K3 - 1.1 (margin)
Second, the main parameters of the inverter settings
When the cart has several motors, it should run at a linear frequency/voltage characteristic. 1-4 speed change with fixed frequency setting 1st gear = 5HZ, 2nd gear = 10HZ, 3rd gear = 25HZ, 4th gear = 50HZ, at the same time, using the brake's brake on and off functions to control the machine by the output relay contacts The brakes prevent the walking mechanism from moving freely due to external forces when the motor stops. Pay attention to the adjustment of the intermediate voltage and torque compensation. Acceleration/deceleration time is appropriate due to the size of the tonnage of the crane.
CD012=6, CD013=6, CD033=1, CD058=02, CD059=04, CD076=2, CD000=5, CD080=10, CD081=25, CD082=50
Third, the conclusion
After the crane is driven by the inverter, the performance of the whole machine is greatly improved, such as high efficiency, good power factor, significant energy saving effect, simple external wiring, reduced wiring cost, stepless speed regulation, smooth and stable walking, and simple motor construction. High reliability, can be used in harsh environments, greatly reducing the maintenance workload and wearing parts, greatly improving the maintenance performance; the inverter has complete protection functions, such as overcurrent, overload, overvoltage, etc. And stop, reducing crane failures and improving safety performance. At the same time, the frequency converter has a current limiting function. The soft start can reduce the impact on the power grid during start-up and is conducive to the normal operation of other equipment in the workshop.