Method for powering mining equipment
View Patent ↗Certain exemplary embodiments can include a static DC electric drive system for mining equipment. The drive system can include: an active front end adapted to receive an AC voltage and output a substantially constant DC voltage; and a DC chopper coupled to the active front end, the DC chopper adapted to receive the substantially constant DC voltage and output a variable DC voltage.
1. A method comprising:
to control a speed of a motor, via an electric drive system comprising a first direct current (DC) chopper and a second DC chopper, providing current to the motor, said second DC chopper in an anti-parallel arrangement with said first DC chopper, said first DC chopper adapted to provide current to said motor in a first current direction, said second DC chopper adapted to provide current to said motor in a second current direction, each of said first DC chopper and said second DC chopper adapted to act as DC voltage regulators.
2. The method of claim 1 , further comprising:
via said first DC chopper, generating a Pulse Wave Modulated DC voltage, said first DC chopper comprising:
a plurality of IGBT transistors;
firing circuit to fire the IGBT transistors; and
a digital control circuit.
3. The method of claim 1 , further comprising:
via said first DC chopper, generating a Pulse Wave Modulated DC voltage having a variable amplitude.
4. The method of claim 1 , further comprising:
via said first DC chopper, generating a continuously variable time-averaged voltage output.
5. The method of claim 1 , further comprising:
in association with a variable DC voltage, providing a total harmonic distortion.
6. The method of claim 1 , further comprising:
providing a variable power factor associated with a variable DC voltage.
7. The method of claim 1 , further comprising:
providing a variable DC voltage.
8. The method of claim 1 , further comprising:
Providing a variable DC voltage to said motor.
9. The method of claim 1 , wherein:
said motor is a DC propel motor.
10. The method of claim 1 , wherein:
said motor is a DC hoist motor.
11. The method of claim 1 , wherein:
said motor is a DC swing motor.
12. The method of claim 1 , wherein:
said motor is a DC crowd motor.
13. The method of claim 1 , wherein:
said motor is a DC drag motor.
14. The method of claim 1 , wherein:
said first DC chopper is coupled to an active front end.
15. The method of claim 1 , wherein:
Said first DC chopper is coupled to an active front end comprising:
an input reactor;
a plurality of IGBT transistors and anti parallel diodes in a bridge configuration;
a firing circuit to fire the IGBT transistors; and
a digital control circuit.
16. The method of claim 1 , wherein said electric drive system comprises:
no power factor compensation equipment.
17. The method of claim 1 , wherein said electric drive system comprises:
no harmonic filters.
18. The method of claim 1 , wherein:
said electric drive system is comprised by a mining excavator.
19. The method of claim 1 , wherein:
said electric drive system is comprised by a shovel.
20. The method of claim 1 , wherein:
the electric drive system is comprised by a drag line.