INVT GD5000 Series MVD Applied to Blower Fan in Andhra Pradesh

Summary：In this case, through introducing INVT GD5000 medium voltage VFD (variable frequency drive) applied to blower fan in Furnace dept. in the Shrikalahasti pipes pvt ltd to illustrate economy and characteristics of variable frequency drive, especially significant energy saving.

Keyword：GD5000medium voltage drive, Blower fan, energy saving.

1. Project introduction and analysis
Shrikalahasti pipes pvt Ltd is one steel manufacturer plant in Andra Pradesh .This plant belongs to Shrikalahasti group. This company is having the great competition with Jindal steel which is one of the repudiated steel companies in INDIA.
There are one main fans used baffle to control air speed and air flow. This is the old technology speed control method, through this way has below disadvantages:
1)    Narrow adjusted speed range.
Due to DOL control method can’t be elaboration and sensitive, so the system can’t adjust speed range.
2)    High power loss.
Because of old DOL method, motor runs always full speed, there is much power consumption during speed adjust period.

Figure 1.Shrikalahasti pipes Ltd

2. System Configuration
2.1 Motor introduction.
Detailed motor parameters are list as follow：

Table 1.Main fan motor Parameters

Figure 2.Themain fan motor nameplate

2.2 System solution.
Based on INVT experience on steel industry VFD renovation project, INVT can supply whole solution for the customer.
According to customer demand, the MVD consists of transformer cabinet, power cell cabinet and control cabinet & bypass cabinet. The GD5000 MVD has function of local/remote button and emergency stop button on control cabinet.
The suggested MVD model no.:

Table 2.VFDs for main fan

Main system diagram:

Figure 3.The system diagram

Figure 4: Main motor

Figure 5: GD5000-A3550-11-D with bypass cabinet

Figure 6.The Motor rotor

3.Application and Advantage

After using VFD, there are some major advantages as follow:
1.    Wide range speed adjusted.
Because VFD is a step-less speed regulation, the main fans can be run smoothly with wide speed range. It means that the speed adjusted can be elaboration and sensitive.
2.    Increase grid line power factor.
The grid line power factor is over 0.97. It can increase efficiency of the grid power.
3.    Energy saving.
The main fan and it system is running at optimal situation and can save energy. From the site real running situation, the energy saving ratio is about 30% by roughly calculate.

4.    Perfect output waveform.
Output waveform is perfect, less than 2% of distortion.
5.    Prolong motor working life time.
VFD can keep motor running at optimal situation.

4. Conclusion
Compared with old technology, the MVD driven method has many advantages. Especially significant energy saving. The energy saving ratio can reach 30%. The transformational VFD system works very well, customers are satisfied with INVT solution and INVT MVD met with customer’s requirements.
References
[1] GD5000 Series Medium-voltage Variable Frequency Speed Control System Manual.Shenzhen INVT Electric CO., LTD.