Dual pinion drive system
View Patent ↗A system and method are disclosed for controlling electrical machines including a controller component which receives a first signal providing a measured parameter of the electrical machine and a second signal providing a reference parameter of the electrical machine, using the first and second signals being used to produce a first control signal. A first filter component receives the first signal from the electrical machine and uses the first signal to produce a second control signal. A second filter component receives a third signal which relates to a reference parameter of a second electrical machine and uses the third signal to produce a third control signal. The system and second control signals are used to produce a first output control signal for provision to the first electrical machine, and the first and third control signals are used produce a second output control signal for provision to the second electrical machine.
1. A control system for controlling a mechanical system having first and second electrical machines, the control system comprising:
a controller component, a first output component, a second output component, a first filter component, and a second filter component;
wherein the controller component is operable to receive a first signal which relates to a measured parameter of a first electrical machine and a second signal which relates to a reference parameter of the first electrical machine, the controller component being operable to use the first signal and the second signal to produce a first control signal;
the first filter component is operable to receive the first signal from the first electrical machine and to use the first signal to produce a second control signal;
the second filter component is operable to receive a third signal which relates to a measured parameter of a second electrical machine and to use the third signal to produce a third control signal;
the first output component is operable to receive the first control signal and the second control signal and to combine the first and second control signals to produce a first output control signal for provision to the first electrical machine; and
the second output component is operable to receive the first control signal and the third control signal and to combine the first and third control signals to produce a second output control signal for provision to the second electrical machine.
2. A control system as claimed in claim 1 , wherein the first signal comprises a measured rotational speed of the first electrical machine, the second electrical signal comprises a reference rotational speed of the first electrical machine, and the third signal comprises a measured rotational speed of the second electrical machine.
3. A control system as claimed in claim 1 , wherein the third signal comprises a reference rotational speed.
4. A control system as claimed in claim 1 , in combination with first and second electrical machines, each mechanically coupled to a load.
5. A control system as claimed in claim 4 , wherein each mechanical coupling is a flexible coupling.
6. A control system as claimed in claim 1 , in combination with first and the second electrical machines which each act upon a load, and wherein the first and the second electrical machines are mechanically coupled to one another via the load.
7. A control system as claimed in claim 6 , wherein each mechanical coupling is a flexible coupling.
8. A control system as claimed in claim 1 , wherein the third signal comprises a reference rotational speed.
9. A control system as claimed in claim 1 , wherein a combination of the first and second control signals in the first output component to produce a first output control signal comprises the subtraction of the second control signal from the first control signal.
10. A control system as claimed in claim 1 , wherein the first filter component and the second filter component each comprise a band pass filter.
11. A control system as claimed in claim 1 , wherein a filter functions of the first filter component and the second filter component comprise a natural frequency of the mechanical system.
12. A control system as claimed in claim 11 , wherein the filter functions of the first filter component and the second filter component comprise a first natural frequency of the mechanical system.
13. A control system as claimed in claim 11 , wherein the filter functions of the first filter component and the second filter component comprise
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14. A control system as claimed in claim 1 , wherein the mechanical system comprises a dual pinion drive system.
15. A control system as claimed in claim 1 , wherein the mechanical system comprises a dual pinion drive cement mill.
16. A control system as claimed in claim 1 , wherein the controller component comprises a PI controller.
17. A method for controlling a mechanical system having first and second electrical machines, the method comprising:
receiving a first signal relating to a measured rotational speed of the first electrical machine;
receiving a second signal relating to a first reference rotational speed of the first electrical machine;
receiving a third signal relating to a measured rotational speed of a second electrical machine;
producing a first control signal from the first and second signals using a controller component;
producing a second control signal from the first signal using a first filter component;
producing a third control signal from the third signal using a second filter component;
producing a first output control signal from the first and the second control signals using a first output component;
producing a second output control signal from the first and third control signals using a second output component;
supplying the first output control signal to the first electrical machine; and
supplying the second output control signal to the second electrical machine.
18. A method as claimed in claim 17 , comprising:
mechanically coupling each of the first and second electrical machines to a load.
19. A method as claimed in claim 17 , comprising:
mechanically coupling the first and second electrical machines to one another via a load, and wherein the first and the second electrical machines each act upon the load.