Method and apparatus for the automatic setting of the optimum operating point of a d-c voltage source
First Claim
1. In a method for automatically setting the optimum operating point of a d-c voltage source having internal resistance, especially of a solar generator, comprising:
- (a) setting a reference value for an electrical state variable which determines the operating point of the d-c voltage source, by means of which the power consumption of a controllable energy converter connected to the d-c voltage source is controlled or regulated, the improvement comprising;
(b) temporarily impressing on the reference value, a supplemental reference value at given time intervals;
(c) determining the differential change of the power output of the d-c voltage source caused by this impression; and
(d) after the impression of the supplemental reference value has ended, changing the reference value, with the sign of the reference value change, for a determined positive differential change of the delivered power, equal to the sign of the supplemental reference value, and opposite to the sign of the supplemental reference value if the differential power is found to be negative.
1 Assignment
0 Petitions
Accused Products
Abstract
Solar generators, fuel cells and similar d-c voltage sources have a current-voltage characteristic, on which at one point ("maximum power point" MPP) the maximum power can be taken from the d-c voltage source. In an arrangement, in which a d-c voltage source feeds a consumer through a controllable power converter, the optimum operating point is automatically set by setting a reference value for the voltage or the current into the converter, and impressing a supplemental reference value temporarily thereon as a disturbance variable at certain time intervals. If due to the impression, the output power of the d-c voltage source increases, the reference value is adjusted in the direction of the supplemental reference value. If, on the other hand, the sign of the power change is negative, the reference value is changed opposite to the sign of the supplemental reference value. After a finite number of reference value changes, the instantaneous operating point is this brought to the optimum operating point. Since the sign of the power change is determined through evaluation of the derivative with respect to time of the actual power value, the amplitude of the disturbance variable can be chosen very small, so that the operation of the consumer is not impaired.
13 Citations
10 Claims
-
1. In a method for automatically setting the optimum operating point of a d-c voltage source having internal resistance, especially of a solar generator, comprising:
-
(a) setting a reference value for an electrical state variable which determines the operating point of the d-c voltage source, by means of which the power consumption of a controllable energy converter connected to the d-c voltage source is controlled or regulated, the improvement comprising; (b) temporarily impressing on the reference value, a supplemental reference value at given time intervals; (c) determining the differential change of the power output of the d-c voltage source caused by this impression; and (d) after the impression of the supplemental reference value has ended, changing the reference value, with the sign of the reference value change, for a determined positive differential change of the delivered power, equal to the sign of the supplemental reference value, and opposite to the sign of the supplemental reference value if the differential power is found to be negative. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. Apparatus for automatically setting the optimum operating point of a d-c voltage source having internal resistance, especially of a solar generator, comprising
(a) a controllable energy transmitter connected to the d-c voltage source; -
(b) a control device for the energy transmitter, having an input for accepting a command variable as a reference value for an electrical state variable of the d-c voltage source; (c) a reference value former for forming a reference value, having its output coupled to said command variable input; (d) a timing stage for generating a supplemental value output signal; (e) means to temporarily add said supplemental reference value to said reference value; (f) means for sensing the output power of said energy transmitter; (g) an evaluating circuit for determining the derivative with respect to time of the power output, having the output of said means for sensing as an input as it changes due to the addition of said supplemental reference value; and (h) means, providing an input to said reference value former, for readjusting the reference value furnished by said reference value former as a function of the sign of the differential power change determined by said evaluating circuit. - View Dependent Claims (8, 9, 10)
-
Specification