Method and energy harvesting system for extracting maximum power from input source
Provided are a method and energy harvesting system for extracting maximum power from an input source. When the energy harvesting system includes a converter, a sensing part, an artificial intelligence (AI) calculator, and a resistor part, the method includes: sensing an input voltage and an input current from the input source using the sensing part, converting the input voltage and the input current corresponding to analog values into digital values through an analog-to-digital converter (ADC) block, and transmitting the digital values to the AI calculator; calculating input power on the basis of the digital values using the AI calculator and acquiring an optimal sampling ratio for extracting maximum power on the basis of the input power; controlling a resistor divider ratio on the basis of the optimal sampling ratio to equalize a sampling ratio to the optimal sampling ratio; and performing a regulation operation through the converter.
1 . A method for extracting maximum power from an input source when an energy harvesting system for extracting the maximum power includes a converter, a sensing part, an artificial intelligence (AI) calculator, and a resistor part, the method comprising:
(a) sensing, by the energy harvesting system, an input voltage and an input current from the input source using the sensing part, converting the input voltage and the input current which correspond to analog values into digital values through an analog-to-digital converter (ADC) block, and transmitting the digital values to the AI calculator;
(b) calculating, by the energy harvesting system, input power on the basis of the digital values using the AI calculator and acquiring a first sampling ratio for extracting maximum power on the basis of the input power;
(c) controlling, by the energy harvesting system, a resistor divider ratio on the basis of the first sampling ratio to equalize a sampling ratio to the first sampling ratio; and
(d) after a sampling operation based on the first sampling ratio is completed, performing, by the energy harvesting system, a regulation operation through the converter,
wherein, when there is a data table in which an input voltage for a table and an output voltage for a table and efficiency in accordance with an input current for a table are recorded for each of a plurality of sampling ratios, the energy harvesting system acquires, using the AI calculator, the first sampling ratio among the plurality of sampling ratios included in the data table on the basis of i) the calculated input power and ii) an output voltage determined through an output voltage monitoring circuit, and
wherein the energy harvesting system acquires the output voltage corresponding to an analog value every certain cycle using the output voltage monitoring circuit included in the converter, converts the output voltage into a digital value through the ADC block, and transfers the digital value to the AI calculator.
2 . The method of claim 1 , wherein the energy harvesting system acquires the input voltage and the input current corresponding to the analog values every certain cycle using the sensing part, converts the input voltage and the input current into the digital values through the ADC block, and transfers the digital values to the AI calculator.
3 . The method of claim 1 , wherein the energy harvesting system repeatedly performs the sampling operation of acquiring the first sampling ratio on the basis of the output voltage and the regulation operation based on a sampled voltage.
4 . The method of claim 1 , wherein the plurality of sampling ratios include 50%, 60%, 70%, 80%, and 90%.
5 . The method of claim 1 , wherein, when (i−1) a process until a maximum power point (MPP) voltage corresponding to an output voltage for extracting the maximum power is acquired and a sampling operation for the MPP voltage is performed is a first process and (i−2) a process until the input power is acquired on the basis of the input voltage and the input current sensed by the sensing part is a second process, while the first process and the second process are repeatedly performed, the energy harvesting system compares power corresponding to a specific MPP voltage with a specific input voltage and skips the first process at a certain time point in accordance with a comparison result to increase efficiency.
6 . The method of claim 5 , wherein, when the AI calculator is trained to estimate next power on the basis of the second process which is repeatedly performed, the first process is performed at time points t and t+1 in accordance with first cycles and the second process is performed in accordance with second cycles which are shorter than the first cycles,
the energy harvesting system sets a specific MPP voltage corresponding to a comparison reference to an MPP voltage acquired as a result of performing the first process at the time point t, acquires the specific input power estimated at the time point t+1 through the AI calculator, and compares power corresponding to the specific MPP voltage with the specific input power, and
the energy harvesting system 10 skips the first process at the time point t+1 (ii−1) when a difference value which is a comparison result is within a preset range, and replaces an MPP voltage acquired as a result of performing the first process at the time point t+1 with the specific MPP voltage (ii−2) when the difference value which is the comparison result deviates from the preset range.
7 . The method of claim 6 , wherein the preset range is within 10% of the power corresponding to the specific MPP voltage.
8 . An energy harvesting system that is a system for extracting maximum power from an input source, the system comprising:
a sensing part configured to sense an input voltage and an input current from the input source, convert the input voltage and the input current which correspond to analog values into digital values through an analog-to-digital (ADC) block, and transmit the digital values to an artificial intelligence (AI) calculator;
the AI calculator configured to calculate input power on the basis of the digital values and acquire a first sampling ratio for extracting maximum power on the basis of the input power;
a converter configured to perform a regulation operation after a sampling operation based on the first sampling ratio is completed, and
a resistor,
wherein a resistor divider ratio is controlled on the basis of the first sampling ratio to equalize a sampling ratio to the first sampling ratio,
wherein, when there is a data table in which an input voltage for a table and an output voltage for a table and efficiency in accordance with an input current for a table are recorded for each of a plurality of sampling ratios, the energy harvesting system acquires, using the AI calculator, the first sampling ratio among the plurality of sampling ratios included in the data table on the basis of i) the calculated input power and ii) an output voltage determined through an output voltage monitoring circuit, and
wherein the energy harvesting system acquires the output voltage corresponding to an analog value every certain cycle using the output voltage monitoring circuit included in the converter, converts the output voltage into a digital value through the ADC block, and transfers the digital value to the AI calculator.