Application of the Xinshida EP6 Inverter in Cell Manufacturing for Lithium Battery Equipment Industry
2025-06-04
Application of the Xinshida EP6 Inverter in Cell Manufacturing for Lithium Battery Equipment Industry
Project Background
With the rapid development of the global new energy industry, lithium-battery production capacity continues to expand, and environmental regulations in various countries are becoming increasingly stringent, placing higher demands on the environmental performance of equipment.
Roots pumps and screw pumps play a crucial role in key processes of lithium-battery production, including cell drying, electrolyte filling, vacuum maintenance, and degassing. The Xinshida EP6 frequency converter, serving as the core drive and control device, provides outstanding performance support for both Roots pumps and screw pumps.
Customer needs
Enable Roots pumps and screw pumps to have stronger startup adaptability, more stable operation, and a more energy-efficient operating mode.
Xinshida Solution
Scheme advantages
1. Smooth startup
The cell drying process places extremely high demands on the stability of the vacuum system, requiring rapid removal of moisture under high-vacuum conditions at a level of 10⁻² Pa. Before battery encapsulation, internal gases must be removed, necessitating long-term maintenance of stable vacuum and the ability to adapt to periodic load fluctuations.
Traditional Roots pumps, when started under high pressure differentials, are prone to causing a surge in current, overloading the motor, and even leading to motor burnout, making it difficult to meet this demand. The EP6 variable frequency drive from Xinsida, with its constant-current control during startup, can reduce the inrush current, ensure smooth starting, and minimize the impact on the power grid.
2. Startup waveform of the Roots pump driven by the EP6 inverter
The figure above shows the startup waveform of a Roots pump. As can be seen from the waveform, the current during startup changes smoothly, and the inrush current is higher than the current when the equipment is running steadily. This current characteristic ensures that the Roots pump achieves a smooth, shock-free startup. Meanwhile, under conditions with higher pressure, the larger inrush current also guarantees the Roots pump’s ability to start reliably.
3. With dynamic speed adjustment
During electrolyte filling, it is essential to maintain a vacuum environment to ensure thorough penetration of the electrolyte and prevent bubble formation. This places high demands on the response speed and pressure control accuracy of the vacuum system. The Xinshida EP6 frequency converter features a built-in PID function that allows the pressure sensor signal to be connected directly to the converter. Based on the required vacuum level, the converter automatically adjusts the pump speed, striking a balance between pumping rate and energy consumption.
4. Lower energy consumption
During load-matching operation, lithium-battery production experiences periodic fluctuations in load. The frequency converter can adjust the rotational speed of the screw pump or Roots pump according to actual demand, thereby avoiding energy waste caused by fixed rotational speeds.
5. Stable and durable
By using a frequency converter, the rotational speed can be smoothly adjusted, effectively reducing mechanical shocks and significantly lowering equipment operating noise while extending the service life of the equipment. In addition, the frequency converter is equipped with an overcurrent frequency reduction function: under special operating conditions—such as when a sudden pressure surge causes the current to rise to the current-limiting threshold—it can automatically reduce the frequency, thereby decreasing the equipment failure rate and ensuring stable operation.
6. Advanced control algorithms
The Xinshida EP6 inverter features a built-in GVC control mode. Upon startup, after injecting DC current, it switches to constant-current control. The magnitude of the constant-current can be set between 0% and 120% of the motor’s rated current. The switching point for constant-current operation can be configured according to the load conditions, enabling the inverter to deliver stronger starting performance and better adaptability to various processes.
7. Hardware-based voltage detection
The Xinshida EP6 frequency converter features built-in input voltage detection hardware. When multiple-stage pumps are operating simultaneously, the hardware-based voltage detection enables “fly-start” operation, which helps prevent overvoltage and overcurrent faults caused by process conditions and reduces the equipment failure rate.
Scheme Composition
18 units of the new Shida EP6 high-performance vector frequency converters
Associated products
ET6/EP6/EH6/ES6/EM6 Intelligent Flexible Variable Frequency Drive
Project Results
In the production process of a decompression additive for electrolyte used by a large lithium-ion battery manufacturer, an EP6 frequency converter is employed to drive a Roots screw pump unit for vacuum extraction. With the frequency converter working in conjunction with a pressure sensor, the vacuum level reaches 99.8 kPa, and the pressure control accuracy is 0.1 kPa, providing highly favorable conditions for electrolyte filling.
Reactor and Roots screw pump unit
EP6 Inverter Cabinet
