INVT VFD Solutions for Coal Mining Applications

1. Industry Background and Challenges

The mining industry operates under extremely demanding conditions, including heavy loads, frequent start-stop cycles, high dust and humidity, and complex electrical environments.

Traditional motor control solutions usually exist the problems of low efficiency, high maintenance costs, and limited adaptability to complex working conditions.

With the increasing requirement on energy saving, safety, and intelligence, mining enterprises are seeking reliable variable frequency drive (VFD) solutions that can ensure stable operation, reduce energy consumption, and improve overall system reliability.

Figure 1 Situation of Mining Industry

2. INVT VFD Solution Overview for Mining Industry

INVT provides a comprehensive VFD solution portfolio specifically designed for mining applications. The solutions are characterized by high torque output, strong overload capability, excellent environmental adaptability, and advanced protection functions.

Our mining VFD solutions cover a wide range of applications, including conveyors, hoists, pumps, fans, crushers, and auxiliary systems, ensuring safe, stable, and efficient operation under harsh conditions.

Figure 2 VFD solution portfolio of INVT

3. Typical Application Cases

3.1 Belt conveyor system

In a project at a mine in Yongcheng, Henan, INVT adopted GD3000-01-500G-12, a mid-voltage VFD to build the belt conveyor system.

Figure 3 The belt conveyor

In this application, GD3000 enables Wide input voltage design of 1140 V ±15% to fully adapt the harsh and unstable power grid conditions in mining applications. By adopting advanced open-loop vector control technology to control the Low-speed permanent magnet synchronous motor, the system achieve 200% high-torque heavy-load start at 1 Hz, ensuring reliable low-speed startup. In the meantime, flexible belt coupling, with CAN master–slave communication extends the lifespan and communication efficiency.

Figure 4 The control mode

3.2 Mine hoist system

For mine hoist systems, safety and reliability are critical.

Figure 5 The hoist system

The GD3000-11-400G-12 was used in the hoisting of a mine hoist in Liupanshui, Guizhou, to provide precise speed control, fast dynamic response, and multiple safety protection mechanisms, ensuring smooth acceleration, deceleration, and accurate positioning.

The main features of the system we build are bellowing:

• Permanent Magnet Synchronous Direct Drive, eliminating complex gearbox and reduction mechanisms, significantly reducing maintenance time and costs.

• 200% starting torque, enabling low-speed, high-torque heavy-load starting.

• Four-quadrant operation, eliminating braking units to achieve energy saving and emission reduction.

• Integrated fault black box function, providing real-time monitoring and recording of product operating status.

Figure 6 The mine hoist system

The solution effectively enhances operational safety, transport efficiency and reduces energy consumption.

3.3 Scraper conveyor system

The application of GD3000 series VFDs on a coal face scraper conveyor can achieve high-power control and effective thermal management.

3.3.1 Yangmei Group Coal Face Scraper Conveyor

The Solution of GD3000 at Yangmei Group Coal Face Scraper Conveyor is bellowing:

Figure 7 Structure of the scraper conveyor

• Product: GD3000-01-3*1250G-33

• Cable Length: 3500 m

• Power Balancing: Achieved power balancing through CAN base on master–slave communication

• Cooling Design: Triple water-cooled design effectively solves high-power thermal dissipation problems

3.3.2 Shandong Coal Face Scraper Conveyor

Then the solution of GD3000 at Shandong Coal Face Scraper Conveyor is bellowing:

Figure 8 Part of the scraper conveyor

• Product: GD3000-01A-1250G-33

• Motor Type: Permanent magnet synchronous motor with integrated VFD

• Master–Slave Layout: Master and slave units installed at head and tail of conveyor, achieving power balancing through CAN fiber

• Control Mode: Closed-loop vector control, 0 Hz & 200% heavy-load start

Figure 9 Solution of the scraper machine

These solutions offer high reliability through master-slave CAN communication, ensuring balanced power distribution and reducing load fluctuations across the equipment. Its superior cooling capability is achieved with a triple water-cooling design, enabling continuous high-power operation without overheating. Precise control is provided by the integration of closed-loop vector control with permanent magnet synchronous motors, allowing low-frequency, high-torque starts with excellent stability. In addition, the system is highly expendable, making it suitable for long conveyor distances and complex operating conditions.

3.4 Emulsion pump system

In a mine project at Yulin, Shaanxi, INVT used the GD3000-01-315G-12 to build the emulsion pump system.

Figure 10 The emulsion pump system

In this application, we adopted the PID to achieve constant pressure automatic control, ensuring high efficiency and energy savings. Aiming for minimizing mechanical wear and prolongs equipment life, we reduced the using of relief valve. Seamless frequency conversion switching enables disturbance-free operation during manual or automatic mode transitions. And three-level topology reduces reactor requirements, lowering overall system cost and dimension.

Figure 11 The emulsion pump system

3.5 Rope-less hoist system

Here is one application of GD2000 on a rope-less hoist at a mine bureau in Hunan.

Figure 12 The rope-less hoist

The GD2000-31-110G-06 VFD played a key role in this application. the motor is an asynchronous motor and controlled by open-loop vector control The VFD’s 660V ±15% Wide Voltage Input ensures stable and reliable operation of the system. Also, the four-quadrant operation of the VFD regenerates energy back to the grid, enabling effective energy-saving. And the High Starting Torque provides superior overload capability for demanding operational conditions.

Figure 13 The rope-less hoist system

3.6 Ventilation fan system

In the application of INVT VFDs in mine ventilation fans, we used GD3000-01-200G-12 / GD2000-01-110G-06 to establish the system. And the highlight features are as following:

• Wide Power Grid Tolerance: ±15% wide-voltage design ensures stable and reliable operation under harsh grid conditions

• Motor Type: Induction motor with VF control

• Startup Mode: VFD soft start supported, and one-duty-one-standby configuration available

• Protection Functions: Comprehensive protections including short-circuit, overload, overvoltage, undervoltage, phase loss, etc.

Figure 14 The ventilation fan system

3.7 Energy storage emergency ventilation fan

Regarding to customer’s need at a mine in Hebei, INVT applied GD3000-01-110G-12 (HDC) as a solution towards the energy storage emergency ventilation fan.

Figure 15 The energy storage emergency ventilation fan

The Power Supply of the system is the energy storage battery supply, 320 VDC. And the system is dedicated for mine emergency ventilation, fast switchover to ensure underground safety. No complex filtering transformer or boost solution was required, making the system architecture simple with high efficiency and reliability. Certainly, it equipped with multiple protections including short-circuit, overload, overvoltage, undervoltage, and phase loss protection.

Figure 16 The system circuit

3.8 Coal mine system

INVT adopted GD1000-31A-110G-12 to build the coal mine longwall face system. And the features of the system are bellowing:

• Applied to shearer travel and shuttle car travel

• Supports continuous four-quadrant operation

• 8G vibration resistance, high reliability, maintenance-free design

• ±20% ultra-wide input voltage range, resistant to power frequency equipment start/stop impact

Figure 17 The coal mine system

3.9 Motor testing platform

Apart from the coal mining industry, INVT's mid-voltage VFDs can also be used in laboratories. Here is an example of application of GD3000-00-400G-12 in motor testing platform.

Figure 18 The motor testing platform

Here gives the information of one motor test platform:

• Application Scenarios: CRRC traction motors, wind power generators

• Test Objects: Permanent magnet synchronous motors (PMSM), induction motors

• System Solution: Output sine wave filter

• Control Modes: Open-loop vector control, closed-loop vector control

Figure 19 Some testing result of the platform

4. Extended Applications of Mid-Voltage Products

INVT mid-voltage VFDs offer many expandable application scenarios. Below are some representative examples:

Figure 20 Extended applications of mid-voltage products

5. Product Advantages and Features Highlights

The core advantages of INVT mining VFD solutions include:

• Strong overload capability suitable for heavy-duty applications

• Excellent adaptability to harsh environments including dust, humidity, vibration etc.

• Comprehensive protection functions for motors and systems

• Energy-saving operation with reduced operating costs

These features make INVT a trusted solution provider for mining enterprises all over the world.

6. Conclusion and Global Value

Through extensive practical applications in the mining industry, INVT VFD solutions have demonstrated excellent reliability, performance, and economic benefits.

Our solutions help customers achieve safer manufacture, lower energy consumption, and higher operational efficiency.

For the future, INVT continuously provide trusted industry automation solutions and supporting the sustainable industry development.