Method, apparatus and article for load stabilization
A system, method, and article for protecting a power source for a machine from sudden changes in load. In one embodiment, energy is wasted in a winding of a motor in response to a decrease in a load presented to the power source.
1. A control system for a machine, comprising:
a first bi-directional limiter comprising:
a first input to receive a signal corresponding to a desired energy-wasting component of a flux current;
a second input to receive a signal corresponding to a lower limit on the energy-wasting component of the flux current;
a third input to receive a signal corresponding to an upper limit on the energy-wasting component of the flux current; and
a first output; and
a proportional and integral regulator comprising:
a fourth input electrically coupled to the first output;
a fifth input to receive a signal for controlling a proportional gain of the proportional and integral regulator;
a sixth input to receive a signal for controlling an integral gain of the proportional and integral regulator; and
a second output.
2. The control system of claim 1 wherein the proportional and integral regulator further comprises a seventh input to receive a signal for limiting the output of the proportional and integral controller.
3. The control system of claim 2 , further comprising:
a first signal combiner comprising:
an eighth input to receive a signal corresponding to a maximum flux current;
a ninth input to receive a signal corresponding to a mode of operation of the machine; and
a third output electrically coupled to the seventh input.
4. The control system of claim 1 , further comprising:
a second bi-directional limiter comprising:
a seventh input electrically coupled to the second output;
a third output;
an eighth input to receive a signal for controlling a minimum value of the third output; and
a ninth input to receive a signal for controlling a maximum value of the third output.
5. The control system of claim 4 , further comprising:
a first signal combiner comprising:
a tenth input to receive a signal corresponding to a maximum flux current;
an eleventh input to receive a signal corresponding to a mode of operation of the machine; and
a fourth output electrically coupled to the ninth input.
6. The control system of claim 1 , further comprising:
a first signal combiner comprising:
a seventh input to receive a signal corresponding to a speed of a rotor of the machine;
an eighth input to receive a signal corresponding to an estimated torque of the rotor; and
a third output;
a first low-pass filter comprising:
a ninth input electrically coupled to the third output;
a tenth input to receive a signal corresponding to a first time constant; and
a fourth output; and
an adder comprising:
an eleventh input electrically coupled to the fourth output;
a twelfth input to receive a signal corresponding to a commanded level of energy wasting;
a thirteenth input to receive a signal corresponding to a loss of the machine; and
a fifth output electrically coupled to the first input.
7. The control system of claim 1 , further comprising:
a first low-pass filter comprising:
a seventh input electrically coupled to the first input;
an eighth input to receive a first time constant; and
a third output.
8. The control system of claim 7 , further comprising:
a comparator comprising:
a ninth input electrically coupled to the third output;
a tenth input to receive a threshold value; and
a fourth output.
9. The control system of claim 8 , further comprising:
a logical gate comprising:
an eleventh input electrically coupled to the fourth output;
a twelfth input to receive a signal corresponding to an operational mode of the machine; and
a fifth output.
10. The control system of claim 9 wherein the logical gate comprises an OR gate.
11. The control system of claim 9 wherein the logical gate comprises a NAND gate.
12. A control system for a machine, comprising:
a first signal combiner comprising:
a first input to receive a signal corresponding to a speed of the machine;
a second input to receive a signal corresponding to an estimated torque of the machine; and
a first output;
a first low-pass filter comprising:
a third input electrically coupled to the first output;
a fourth input to receive a signal corresponding to a first time constant; and
a second output;
an adder comprising:
a fifth input electrically coupled to the second output;
a sixth input to receive a signal corresponding to a loss of the machine;
a seventh input to receive a signal corresponding to a commanded energy-wasting flux current; and
a third output;
a first bi-directional limiter comprising:
an eighth input electrically coupled to the third output;
a fourth output;
a ninth input to receive a signal corresponding to an upper limit on the fourth output; and
a tenth input to receive a signal corresponding to a lower limit on the fourth output;
a proportional and integral regulator comprising:
an eleventh input electrically coupled to the fourth output;
a fifth output;
a twelfth input to receive a signal for controlling a proportional gain of the proportional and integral regulator; and
a thirteenth input to receive a signal for controlling an integral gain of the proportional and integral regulator; and
a second bi-directional limiter comprising:
a fourteenth input electrically coupled to the fifth output;
a sixth output;
a fifteenth input to receive a signal corresponding to a lower limit on the sixth output; and
a sixteenth input corresponding to an upper limit on the sixth output.