I. Project Background
With the rapid development of scientific research, import and export trade has also increased, and the throughput of bulk cargo has shown a significant growth trend. Intelligent loading and unloading technology is now widely used in bulk cargo terminals. However, due to the relatively late development of bulk cargo terminals in my country, they have traditionally relied on grab bucket operations, and their facilities, equipment, loading, unloading, storage, and transportation levels are relatively backward. This results in shortcomings such as high energy consumption, low efficiency, and poor environmental performance. Therefore, it is essential to adopt advanced intelligent loading and unloading technology for bulk cargo terminals.
II. Customer Needs
A company in Hangzhou is dedicated to researching the front-end technologies of dock loading and unloading equipment, and the screw unloader is one of them. In the early days, the coal mining machine used an AC asynchronous motor, and cooling was achieved by a tail cooling fan. However, compared with synchronous motors, asynchronous motors have external factors such as large size, low power density, poor heat dissipation environment, and poor protection. They also have high energy consumption, low operating efficiency, and generate a lot of dust during operation, which causes great pollution to the environment.
III. Invt Solution
According to the technical requirements of the screw unloader, in order to adapt to the load characteristics, the frequency converter needs to have the functional characteristics of an "excavator". That is, when the load is too large and exceeds the set limit value, the frequency converter limits the current and maintains the current state, while giving an overload warning, similar to the overload pressure relief state of an excavator; when the load drops to the allowable range, it returns to the working state before the current limiting and continues to operate.
To address this issue, INVT has launched the GD350-19 system solution, with the following features:
1. It has energy feedback capabilities, allowing excess energy from operation to be fed back to the power grid;
2. Equipped with a multi-pole synchronous motor and designed with a dedicated "excavator" function;
3. Supports closed-loop control using a resolver encoder;
This inverter solution is highly efficient in loading and unloading and environmentally friendly. Compared with traditional solutions, it reduces the number of resistors, braking units, etc.
Electrical main circuit block diagram
IV. Customer Value
●High efficiency: Designed with a dedicated "excavator" function to enhance unloading capacity.
●Energy saving: The system has an energy feedback function, which improves the energy utilization efficiency of the entire system;
●Environmentally friendly: Utilizing a resolver encoder to achieve closed-loop control reduces dust pollution and minimizes the spillage of dust and materials;
●Cost: Energy conservation and operational reliability reduce the long-term operating costs of the ship unloader, and labor costs can be saved by reducing the workforce.
●Noise: The equipment operates smoothly and reliably, and will not cause noise pollution to the surrounding environment;
●Function: Equipped with Profinet communication capabilities, various statuses are aggregated in real time to the DCS front end, facilitating data acquisition and control by the host computer;
Customer site application diagram
V. Summary of the Plan
Screw unloaders are a type of coal unloading machinery used in docks or thermal power plants. The INVT GD350-19, when applied to this equipment, offers advantages such as superior functionality and convenient maintenance and operation. In particular, its dedicated "excavator" function ensures efficient unloading and improves overall economic benefits.
After more than 20 years of development and accumulation, INVT has gained increasing recognition and favor from customers by relying on its accumulated technological advantages, high-quality and stable products, and comprehensive after-sales service.
