Introduction：
Vertical lathes are large mechanical equipment used to process large and heavy workpieces with large radial dimensions and relatively small axial dimensions and complex shapes. Such as the cylindrical surface, end surface, conical surface, cylindrical hole, conical hole, etc. of various discs, wheels and sleeves. Threading, spherical turning, profiling, milling and grinding are also possible with the aid of additional devices. The spindle of large machine tools is controlled by D32 inverter to achieve stable speed control, with good low-frequency torque characteristics and fast response speed. Fast braking and stopping are realized by braking unit and braking resistor.
Features：
D32 is a wall-mounted inverter, the power range is 0.75KW-500KW, the voltage level of the incoming line voltage is 380V-480V, and the control method is vector control without speed sensor. D32 has a wealth of control devices, including 8 digital inputs (LI1-LI8), 2 analog inputs (AI), 2 relay outputs (TA), 2 analog outputs (AO), 5V auxiliary power supply for analog power supply Fixed input, 24V auxiliary power supply is used for digital input, all LI/TA, AI/AO can be freely programmed to define functions.
MODBUS interface is standard configuration of D32 without option. The D32 can be connected to higher-level automation systems via MODBUS.
Advantage：
Provide 0.5Hz 150% rated torque, easy to start the spindle motor;
With excellent speed control accuracy, the control accuracy is 0.2%, and accurate speed control is achieved;
With good field weakening control, it can achieve precise control even when running at high frequency;
It has the advantage of fast torque response, and when the load fluctuates, the current fluctuation is small;
It has good overload capacity and environmental adaptability, and has high operational reliability;
Superior AVR function, super grid adaptability, guarantee output voltage, current and speed stability;
Excellent current limiting characteristics, strong overload capacity, can effectively reduce frequency conversion overload, over-current protection, maximum limit to ensure production continuity;
It has strong environmental adaptability, and the completely independent air duct design can greatly improve the resistance to harsh environments such as oil pollution, dust and damp heat.
System Introduction：
In this system, the spindle of a 55KW vertical lathe is driven by a D32 75KW frequency converter, and a fast braking stop is realized through an external braking unit and braking resistor. Constant-speed cutting is achieved through open-loop vector control, and the speed variation caused by load changes is very small. The inverter is started through the control terminal, and the speed given is controlled by the 0-10V analog voltage signal of the control system. When the motor runs at 70Hz, the speed fluctuation is less than 1 rpm, and the current fluctuation is less than 1A, realizing precise speed control.
Technical Parameter：
| Inverter technical parameters | Device configuration | |
 Model: D32-X | Output current: 150A | One D32 inverter |
| Input voltage: 3-phase, 380-480V | Frequency range: 0-400Hz | 55kW Spindle motor and lathe load |
| Input frequency: 50/60Hz ±5% | Overload capacity: 150%, 60 seconds | Brake unit |
| Output power: 75KW | Ambient temperature: -10-40°C | Braking resistor |
| Output voltage: 0-480V (the maximum value is determined by the input voltage) | Protection level: IP20 | |
On Site Usage：
According to the on-site space situation, a D32 series inverter is installed in the control cabinet, and the inverter installation and on-site motor are as shown in the figure
Running Result：
The vertical lathe control system using D32 inverter has been put into operation for more than three years, and has achieved good economic and social benefits:
The control device operates reliably, has good environmental adaptability, can resist harsh environments such as oil pollution, dust and damp heat, and has a low failure rate;
Excellent current limiting characteristics, strong overload capacity, can effectively reduce frequency conversion overload, overcurrent protection, and maximize production continuity;
The speed control precision is high, and the production products are more in line with the requirements; the vertical lathe control system using the QD6000 inverter has been put into operation for more than three years, and has achieved good economic benefits and results.
Customer Benefits：
The inverter and spindle motor run stably, reducing maintenance costs;
The comprehensive protection function of the inverter ensures maximum production continuity;
The production of products is more in line with the requirements, and the defect rate is greatly reduced.