Application of INVT GD5000 Series VFD for Belt Conveyor

Abstract: 06 version of GD5000 all-in-one machine, fine base permanent magnet synchronous motor, master and slave control (one master and one slave).

Keywords: GD5000, synchronous motor, Medium-voltage Variable-frequency Drive, belt conveyor, open pit coal mine (Tian Chi), Xinjiang, China.

Introduction: The empty of belt occasionally starts abnormally.

1. The starting current of two frequency converters is very large, and the belt holder shakes greatly.

2.  The startup occasionally inverted phenomenon.)

Project overview: At the moment of startup of permanent magnet synchronous motor, there is a process of magnetic pole identification, which reflects the sound of "da da da" on the motor, and the motor may reverse 1°-5°, and then it will run in positive rotation, which is normal. The 06 version of GD5000 standard DSP 2.06 program is not ideal for the control effect of low-power, multi-pole permanent magnet synchronous motor. Especially in the field of magnetic pole identification is not good.

INVT Solution:

1 Brush the latest DSP ARM touch screen program, power on to check the program version number, and check whether the 29 groups of parameters are appropriate. The function code Settings are as follows:
1) P28.17 Reserved (number of enable ability of identification process unit) 0
2) P28.18 Retain (flux observer Kp) 4000
3) P28.19 Retention (PLL input frequency) 6000

2. Set motor parameters, VF mode, run to the rated frequency, by changing P13.15-16 parameters, adjust the oscillation factor, to ensure smooth operation in VF mode. Then do rotation self-learning for 2-3 times and record whether the motor parameters learned for many times are balanced. If they are, take the self-learning parameters of the last time. (If only input motor P2.10-15, self-learning fails, then ask the permanent magnet synchronous motor manufacturer for 2.16-2.20 parameters, manual input, and then self-learning in VF or vector 1 mode.)

3.   Set P00.00 as no PG vector 1. Start two permanent magnet synchronous motors separately and observe the current size and fluctuation in each frequency segment. Take the rated 10kv, 400kw, 42Hz, 84rpm, 26A motor as an example:0-10Hz, the current is about 5.2A; 10-41Hz, the current is about 2.6A; 41 Hz -42Hz, the current is less than 1A. The function code Settings are as follows:

1) P14.15D shaft pulling current 1 20%
2) P14.16 D shaft pulling current 2 10%
3) P14.17 Pull in current switching frequency point 10.
4.  Set the primary and secondary parameters, start the host on the spot, and check whether the primary and secondary hosts are synchronized. When the motor is empty, the running frequency of the slave machine may be a little smaller than that of the main machine, which is normal.

5. In debugging mode, test whether the master and slave machines fail respectively and whether the other machine stops.

6. Set other function codes to meet the control requirements on site. It is recommended that the hardware overcurrent point P13.12 should be less than 2 times of the rated current of the motor, not 1.9 times of the frequency converter.

7. After the motor coupling is connected, connect to the computer and monitor the waveforms of the two machines with workshop. Start locally or remotely and observe the waveform. Start and stop the system several times and check whether the system can start normally each time.

8. Observe the waveform again after loading. After stopping, restart the machine with heavy load several times and observe whether it can start normally. The following parameters affect the heavy load starting machine, different work conditions need to be tested.

Project Load Photo:

The project adopts GD5000 series MVD independently developed and produced by Shenzhen INVT Electric Co., Ltd., The MVD is a medium voltage variable frequency speed regulating device of vector control H bridge series multi-level technology. The original old system can still be used at present, so it will not be dismantled temporarily, and will be reserved as the backup system.

VFD principle

1) INVT GD5000 series VFD is a high-tech energy-saving product, which adopts advanced IGBT power unit multi-level technology, digital control technology and SPWM pulse width modulation technology. It has the advantages of high-power factor, high efficiency, energy saving, high stability, etc., and has the rated power energy feedback ability.

2) Each phase of the VFD is composed of six power units in series, and the three-phase Y is connected to the output. The output adopts the SPWM wave superimposed by 9 power units in 10 kV of each phase to form high-quality output waveform, which is supplied to the motor.

3) Optical fiber communication is adopted between control cabinet, power unit cabinet, transformer cabinet and bypass cabinet to prevent electromagnetic interference. Achieve complete isolation of high and low voltage, improve safety.

4) The input side of the power unit is composed of fuse, rectifier and filter parts, and the rectifier part is composed of six IGBT. The inverter consists of four IGBT H bridge inverter outputs, and the motor is driven by the unit series.

Application Advantages

1)  High reliability: The GD5000 series inverters of INVT have perfect protection functions, such as overcurrent, overvoltage, overload, stall and other protection functions.

2)  Small start-up current: The impact current in the process of starting and accelerating is small, and the maximum starting current in the process of accelerating does not exceed 1.9 times of the rated current.

3)  Wide range of speed regulation: VFD system belongs to the stepless of speed regulation, the motor control in the process of acceleration and deceleration is stable, the speed regulation is soft.

4) Production efficiency is high: The stability of the INVT GD5000 series VFD is high, and the speed does not change with the change of the load. The VFD can control the motor to run stably at a given speed.

5) Conclusion:  The practice has proved that the in-belt conveyor runs well after the technical transformation of VFD, the energy consumption of belt conveyor is reduced and the power factor of the power grid is also improved. Facts have proved that the Medium Voltage VFD has superior product performance, in the coal mining industry in the energy saving transformation application can create huge economic benefits, in the energy saving and environmental protection has played an important role. It can completely replace the traditional control mode and has very high promotion value.