CN108181967B - Short-circuit current maximum power point tracking circuit for thermoelectric generator and control method thereof - Google Patents
Short-circuit current maximum power point tracking circuit for thermoelectric generator and control method thereof Download PDFInfo
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Abstract
The invention discloses a short-circuit current maximum power point tracking circuit for a thermoelectric generator and a control method thereof, wherein the short-circuit current maximum power point tracking circuit comprises a main circuit without an input capacitor, and the main circuit without the input capacitor comprises the thermoelectric generator and a Boost circuit; the output end of the equivalent circuit of the thermoelectric generator is connected with the input end of the Boost circuit; boost circuit includes inductance L 1 The method comprises the steps of carrying out a first treatment on the surface of the Inductance L 1 And a switch tube S 1 And a switch tube S 2 Connecting; switch tube S 2 And output filter capacitor C 1 And a load R L The input capacitor C is connected with the Boost input end of the main circuit without input capacitor 2 The serial branch is connected with the switching tube and controls the input capacitor C through the digital control chip 2 Whether to access the circuit. The invention collects the inductance L by analyzing the equivalent model of the temperature difference piece and the working mode of the Boost main circuit 1 Current, according to inductance L 1 The current value and the slope of the current rising section calculate the short-circuit current of the temperature difference sheet, and the maximum power point condition i of MPPT of the temperature difference power generation short-circuit current method is realized through an incremental PI controller TEG ＝I SC No difference tracking of/2.
Description
Technical Field
The invention belongs to the technical field of thermoelectric generation, and particularly relates to a short-circuit current maximum power point tracking circuit for a thermoelectric generator and a control method thereof.
Background
Thermoelectric generation is a technology for directly converting heat energy into electric energy by using thermoelectric materials, and has the advantages of no noise, no vibration, no emission of harmful substances, high reliability, no abrasion, convenient movement, long service life and the like. The method is mainly applied to the fields of aerospace and military in early stage, and is gradually applied to the fields of traffic, industrial waste heat and waste heat recovery, power generation and the like along with technical progress. Although the thermoelectric generation sheet has been developed to a great extent, the efficiency is still lower at present, so in order to fully utilize energy sources, a maximum power point tracking technology (MPPT: maximum power point tracking) is introduced to realize the maximum power transmission output by the thermoelectric generation sheet.
The main principle of semiconductor thermoelectric generation is Seebeck effect, which is accompanied by Peltier effect, thomson effect, joule effect, fourier effect, etc. The seebeck effect is also known as the first thermoelectric effect: a thermoelectric phenomenon that causes a voltage difference between two substances due to a temperature difference of two different electrical conductors or semiconductors, this voltage is called seebeck voltage, as follows:
ΔU＝α(T h -T o )
wherein: alpha is the seebeck coefficient of the material; t (T) h Is the temperature of the hot end of a conductor or a semiconductor; t (T) c Is the cold end temperature of a conductor or a semiconductor.
The existing thermoelectric generation MPPT method has the following defects:
1. the disturbance observation method needs to collect two amounts of voltage and current, and can still oscillate continuously even if the maximum power point is tracked;
2. the implementation of the conductivity increment method also needs to measure two quantities of voltage and current, and the method can continuously oscillate when working at a steady state, and often has static difference;
3. the open circuit voltage method is a method commonly used in various documents at present, and depends on the inherent characteristics of a thermoelectric generation sheet, but a plurality of switching tubes and capacitors are often needed for acquiring open circuit voltage and average voltage, the structure is complex, and in the time period of sampling the open circuit voltage each time, the TEG needs to be disconnected from a main circuit, so that the electric energy generated by the TEG is wasted in the time period;
4. the traditional short-circuit current method is only remained in the theoretical stage, and hardly adopted in practice, so that a short-circuit power supply brings a plurality of unstable factors, and the connection between the TEG and a main circuit is also required to be disconnected.
Disclosure of Invention
The invention aims to overcome the defects of the prior art, and provides a circuit for tracking the maximum power point of short-circuit current of a thermoelectric generator and a control method thereof, so as to solve the problem of low maximum power transmission efficiency of the conventional thermoelectric generation sheet.
In order to achieve the above purpose, the invention adopts the following technical scheme:
the circuit structure of the short-circuit current MPPT for thermoelectric generation comprises a main circuit without an input capacitor; the main circuit without the input capacitor comprises a thermoelectric generator and a Boost circuit; the equivalent circuit of the thermoelectric generator is a constant voltage source V oc And internal resistance R in Is a series of (1); the output end of the equivalent circuit of the thermoelectric generator is connected with the input end of the Boost circuit; boost circuit includes inductance L 1 The method comprises the steps of carrying out a first treatment on the surface of the Inductance L 1 And a switch tube S 1 And a switch tube S 2 Connected in parallel; switch tube S 2 And output filter capacitor C 1 And a load R L Connecting; filter capacitor C 1 And a load R L Connected in parallel.
Preferably, the inductance L 1 One side is provided with a digital control chip for collecting inductance current.
Preferably, the digital control chip model is STM32F407VET6.
Preferably, the circuit further comprises an input capacitor main circuit; the main circuit with input capacitor comprises a main circuit without input capacitor and an input capacitor C connected with the input end of the Boost circuit of the main circuit without input capacitor 2 And a switch tube S 3 Is a series branch of (c).
A control method for a short-circuit current maximum power point tracking circuit of a thermoelectric generator, comprising:
collecting inductance L in a plurality of continuous periods 1 Is set according to the current value of (1);
closing switch tubeS 1 The thermoelectric generator is an inductance L 1 Charging, inductance L 1 Current rise, inductance L is calculated 1 Rate of change of current rise phase;
inductance L 1 The circuit structure during charging is subjected to Norton equivalent transformation according to the inductance L 1 Current value at current rising stage, rate of change of current, main switching tube S 1 The KCL equation of the conduction mode equivalent circuit is calculated to obtain the expression of the short-circuit current,
wherein I is SC Is the short-circuit current of the thermoelectric generator, L 1 Inductance of the main inductor of the converter, R in Is equivalent internal resistance of thermoelectric generator, i L Is the inductance L 1 Current, i' L Is the inductance L 1 The first derivative of the current, in a discrete system, when the sampling period is small, can be approximated by a first order difference quotient instead of the first derivative of its continuous function;
obtaining inductance L 1 The inductance current values at any two moments (point a and point b) are calculated, the first-order center difference quotient of the two inductance current values is carried into the expression of the short-circuit current, the short-circuit current value is calculated,
wherein i is L(a) For the current value of point a, i L(b) For the b point current value, i' L(a) Is a point difference quotient, i' L(b) Is the point b difference quotient;
calculating inductance L 1 The root mean square value of the current in a plurality of periods to obtain the output current of the thermoelectric generator
i TEG And adjusts the switch tube S according to the incremental PI control 1 Up to the output current i of the thermoelectric generator TEG Equal to short-circuit current I SC Half of (i.e. real)And outputting the maximum power of the thermoelectric generation sheet.
Preferably, the inductance L 1 The calculation formula of the change rate in the current rising stage is as follows:
wherein,,is the inductance L 1 Derivative of current, V TEG Is the output voltage of the thermoelectric generator.
Preferably, the inductance L 1 The calculation formula of the change rate in the current falling stage is as follows:
where Vo is the voltage across the load.
Preferably, the collected inductor current is filtered firstly, and the method comprises the following steps:
removing burrs and peak values in the current data, and supplementing the removed parts by using a linear interpolation method;
selecting an FIR low-pass filter with a Hamming window to filter high-frequency noise in the current data;
and performing median average filtering on the obtained multiple groups of short-circuit current values.
Preferably, the method further comprises:
during the current sampling period, the topology with the input capacitor turns off the input capacitor branch series switching tube S in advance 3 Switch tube S 1 On time S 2 Turn-off, the thermoelectric generator is the main inductance L 1 Charging, load R L From output filter capacitor C 1 Supplying power; switch tube S 1 S at turn-off 2 Conduction, thermoelectric generator and main inductance L 1 Series connection is output filter capacitor C 1 Load R L Power supply, all inductances L according to several successive cycles 1 Calculating the mean square of the current value of (2)Root, obtain the effective value i of the output current of the temperature difference piece TEG The method comprises the steps of carrying out a first treatment on the surface of the The effective value i TEG And I SC The difference/2 is used as the error amount for the incremental PI control.
The tracking circuit for the maximum power point of the short-circuit current of the thermoelectric generator and the control method thereof have the following beneficial effects:
the invention collects the inductance L by analyzing the equivalent model of the temperature difference piece and the working mode of the Boost main circuit 1 Current, according to inductance L 1 The current value and the slope of the current rising section calculate the short-circuit current of the temperature difference sheet, and the maximum power point condition i of MPPT of the temperature difference power generation short-circuit current method is realized through an incremental PI controller TEG ＝I SC No difference tracking of/2.
Drawings
Fig. 1 is a system block diagram of a circuit structure of a short-circuit current MPPT for thermoelectric generation without an input capacitor.
Fig. 2 is a circuit configuration diagram of a main circuit without input capacitor for short-circuit current MPPT of thermoelectric generation.
Fig. 3 is a circuit configuration diagram of a main circuit with input capacitor for short-circuit current MPPT of thermoelectric generation
Fig. 4 is a waveform diagram of the main circuit parameters of the input-free capacitor of the short-circuit current MPPT for thermoelectric generation.
Fig. 5 is a waveform diagram of the main circuit parameters with input capacitance for the short-circuit current MPPT of thermoelectric generation
Fig. 6 is a circuit diagram of a norton equivalent transformation circuit of TEG and an inductor L1 when a switching tube S1 of a circuit structure of a short-circuit current MPPT for thermoelectric generation is closed.
Fig. 7 is a flowchart of calculating and filtering short-circuit current and TEG output current in a maximum power point tracking circuit of short-circuit current and a control method thereof for a thermoelectric generator.
Fig. 8 is a software control flow chart of a main circuit without input capacitance for a maximum short-circuit current power point tracking circuit of a thermoelectric generator.
Fig. 9 is a TEG equivalent circuit diagram.
FIG. 10 is a graph of TEG V-I versus P-I.
Fig. 11 is a waveform diagram of the effective values of no input capacitance, short circuit current and TEG output current.
FIG. 12 shows the inductance L of an equivalent TEG without input capacitance under different open circuit voltage conditions 1 Simulation result waveform diagrams of current, TEG output power and load power.
FIG. 13 shows the inductance L of an equivalent TEG at an open circuit voltage of 20V without input capacitance 1 Simulation result detail waveform diagrams of current, TEG output power and load power.
Fig. 14 is a circuit configuration and control block diagram with input capacitance.
Fig. 15 is a flowchart for realizing MPPT with a short-circuit current of an input capacitor.
Fig. 16 is a waveform diagram of simulation results with effective values of input capacitance, short-circuit current and TEG output current.
FIG. 17 shows inductance L of an equivalent TEG with input capacitance under different open circuit voltage conditions 1 Simulation result waveform diagrams of current, TEG output power and load power.
FIG. 18 shows the inductance L of an equivalent TEG at an open circuit voltage of 20V without input capacitance 1 Simulation result detail waveform diagrams of current, TEG output power and load power.
Detailed Description
The following description of the embodiments of the present invention is provided to facilitate understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and all the inventions which make use of the inventive concept are protected by the spirit and scope of the present invention as defined and defined in the appended claims to those skilled in the art.
According to one embodiment of the application, the temperature difference generator comprises a temperature difference generator and a Boost circuit, and the temperature difference generator is divided into two cases of an input capacitor and a no-input capacitor according to whether the input capacitor exists or not.
The no input capacitance is as follows:
referring to fig. 1 and 2, the circuit structure: the equivalent circuit of the thermoelectric generator is a constant voltage source V oc And internal resistance R in The output end of the equivalent circuit of the thermoelectric generator is connected with the input end of the Boost circuit, and the Boost circuit comprises a sequential inductance L 1 Inductance L 1 And a switch tube S 1 And a switch tube S 2 Connected, switch tube S 1 And a switch tube S 2 Are all connected with a load; the load comprises a capacitor C arranged in parallel 1 And a load R L 。
According to one embodiment of the present application, referring to fig. 7, the thermoelectric generator model is equivalent to a constant voltage source Voc in series with an equivalent resistance Rin. Referring to fig. 10, in combination with the V-I and P-I graphs of the TEG and the maximum power transfer theorem, the load can obtain maximum power when the load impedance value is equal to the internal resistance of the TEG array.
The temperature difference generating device is applied to the temperature difference generating device, and the output current I of the temperature difference generator is equal to I by adjusting the switching duty ratio of the switching tube of the DC/DC converter SC /2。
Current collection, referring to fig. 1, in inductor L 1 A digital control chip is arranged on the output side of the capacitor, and the model of the digital control chip is STM32F407VET6 for collecting inductance L in continuous period 1 Is set in the above-described range). The temperature difference generator (hereinafter referred to as TEG) is TEG1-199-1.4-0.5, and has internal resistance R at 150 DEG C in The resistance of (2) was 3.07. OMEGA.
Referring to fig. 4, inductance L 1 The current rise phase corresponds to the 0-DT phase of FIG. 4:
switch tube S 1 Closed conduction, the thermoelectric generator is an inductance L 1 Charging, inductance L 1 The current gradually rises and the internal resistance R of the TEG in Voltage drop increases, output voltage V TEG The short-circuit current of the thermoelectric generator is reduced,
wherein I is SC Is the short-circuit current of the thermoelectric generator, L 1 Inductance of the main inductor of the converter, R in Is equivalent internal resistance of thermoelectric generator, i L Is the inductance L1 current，i’ L Is the first derivative of the inductor L1 current.
Inductance L 1 The current drop phase corresponds to the DT-T phase in fig. 4:
switch tube S 1 Disconnection, inductance L 1 Is connected with the load and is a capacitor C 1 And a load R L Power supply, inductance L 1 Current drop, TEG internal resistance R in Voltage drop is reduced, TEG output voltage rises, inductance L 1 The rate of change in the current drop phase is,
where Vo is the voltage across the load.
Referring to fig. 4 and 6, when the inductor L1 current is in the 0-DT phase, the circuit is subjected to the norton equivalent transformation, and the KCL equation is written for the column of fig. 6:
according to inductance L 1 Rate of change in current rise phase, inductance L 1 The change rate of the current falling stage and the KCL equation of the equivalent circuit after transformation are calculated to obtain the expression of the short-circuit current,
as can be seen from the calculation of the short-circuit current, at least two independent groups of i are required for the specific value of the short-circuit current L And i' L The short-circuit current I can be calculated SC 。
Calculating a short circuit current value:
inductance L acquired by digital control chip 1 The current value is a discrete point set, at a higher levelAt the sampling frequency of (2), there may be a first order center difference quotient to approximately replace inductance L 1 A current value.
At several collected inductances L 1 In the current data, the inductance L is selected 1 Any two points (which can be called as a point and b point) of the current rising stage calculate the first-order center difference quotient value i 'respectively' L (a)，i′ L (b) Inductance L combining point a and point b 1 Current value i L (a)，i L (b) The specific value of the short-circuit current is calculated and obtained in the expression of the short-circuit current:
to sum up, to achieve a short-circuit current solution, at least one complete period of inductance L needs to be acquired 1 A current value.
Referring to fig. 8, filtering of short-circuit current:
the invention is based on Boost converter as main circuit topology, along with main switch tube S 1 And S is 2 The voltage and the current pulsate along with the on and off of the switch tube, and the sharp pulse generated at the moment of the on and off of the switch tube is transmitted along the main circuit and is superposed on the current waveform to form noise, and the noise with the same or odd times of the operating frequency of the switch tube appears in the circuit. On the one hand, the electromagnetic wave is transmitted to the sampling circuit through the main circuit line, and on the other hand, the main circuit of the converter radiates a large amount of electromagnetic wave to the surrounding space, and the nearby signal amplifying circuit is interfered by the electromagnetic field. Additional noise, including input-related noise and quantization noise, is often introduced during the ADC conversion process of the digital control chip, and this noise can only be filtered out by the digital control chip invoking the software filter.
When the short-circuit current is calculated, the topology without the input capacitor is directly collected, the topology with the input capacitor can firstly disconnect the input capacitor, the current waveform at the moment is similar to a triangular wave, the triangular wave consists of a fundamental wave and odd harmonics according to Fourier series analysis of periodic triangular waves, if only 7 harmonics and less components of the triangular wave are considered for a converter with the switching frequency of 20KHz, the cut-off frequency of a filter is required to be larger than 140KHz, and too low cut-off frequency of the filter can filter out too much effective components, and a large amount of noise signals can be remained when too high.
The current peak at the moment of switching on and switching off of the switching tube is often larger, and the first-order low-pass filter cannot effectively filter such peak signals, so that burrs and peak values are removed from collected data, and the point is complemented by a linear interpolation method; the high frequency noise is then filtered out by a hamming windowed FIR low pass filter. According to the foregoing, the corresponding short-circuit current is calculated by taking a plurality of groups of values at the current rising stage, and in view of the fact that the low-pass filter filters out the effective components of part of the current waveform, the triangular wave becomes smooth at the turning points of the wave crest and the wave trough, if the data point of the short-circuit current calculation is close to the wave trough, the calculated short-circuit current is higher, otherwise, the data point is close to the wave crest, the calculated short-circuit current value is lower. And therefore, the median value and the average value are adopted for filtering the multiple groups of short-circuit currents.
Referring to fig. 1, the implementation of maximum power output of the thermoelectric generation chip:
switch on the switching tube S 1 Inductance L 1 Is a capacitor C 1 And a load R L Power supply, all inductances L according to several successive cycles 1 The root mean square of the current value of the temperature difference piece is calculated to obtain the effective value i of the output current of the temperature difference piece TEG . Record the effective value i TEG As a feedback value, I SC And/2 is a desired value, and the difference between the feedback value and the desired value is used as the error amount of the incremental PI control.
Record I SC The expected value of/2 is taken as a control target, and the inductance L is calculated 1 The root mean square value of the current in a plurality of periods is used for obtaining the output current I of the thermoelectric generator, and the duty ratio of the switching tube S1 is regulated according to the incremental PI control until the output current I of the thermoelectric generator is equal to I SC And 2, outputting the maximum power of the thermoelectric generation sheet.
Simulation verification:
referring to fig. 2, simulation is performed under MATLAB simulink, a constant value resistor equivalent TEG array is connected in series through a voltage source, the initial value of the voltage source is 10V, the voltage source rises to 20V after 0.3s, the voltage source falls to 15V after 0.6s, and the constant value resistor is 5Ω. The synchronous Boost converter is adopted, the inductance is 500 mu H, the MOSFET on-resistance is 8mΩ, the output filter capacitance is 220 mu f, the load is 50 Ω fixed value resistance, and the switching frequency is 20KHz. The theoretical parameter values of each stage are calculated according to the electric parameters and are shown in the following table.
Referring to fig. 11-13, the electrical parameters obtained from the simulation results are shown in the following table,
according to the data in the table, the short-circuit current estimation accuracy reaches 99.84%, and the PI controller can track the maximum power point. Because the fluctuation of the TEG output voltage and current is large, the actual working point fluctuates near the maximum power point.
According to the invention, the output end of the thermoelectric generator (TEG) and the Boost circuit are used, only one current sensor (digital control chip) is needed to collect real-time data of the current of the inductor L1, so that the short-circuit current is calculated, and the output current of the TEG is regulated through the short-circuit current, so that the output of the maximum power of the thermoelectric generation sheet is realized.
According to one embodiment of the present application, a main circuit with an input capacitor is as follows:
the circuit structure is shown in fig. 3, and the flow is shown in fig. 15. And simulated under MATLAB simulink. And the voltage source is connected with the fixed value resistor equivalent TEG array in series, the initial value of the voltage source is 10V, the rising time is 20V after 0.3s, the rising time is 15V after 0.6s, and the fixed value resistor is 5 omega. The synchronous Boost converter is adopted, the input capacitance is 100 mu f, the inductance is 500 mu H, the MOSFET on-resistance is 8mΩ, the output filter capacitance is 220 mu f, the load is 50 Ω fixed value resistance, and the switching frequency is 20KHz.
Simulation of various parametric waveforms referring to fig. 15-18, and from which input capacitance simulation result parameters are derived, see the following table:
according to the data in the table, the estimation accuracy of the short-circuit current tends to 100%, the PI controller can accurately track the maximum power point, and compared with a scheme without an input capacitor, the scheme can effectively reduce the output voltage and current ripple of the TEG and improve the overall efficiency.
Although specific embodiments of the invention have been described in detail with reference to the accompanying drawings, it should not be construed as limiting the scope of protection of the present patent. Various modifications and variations which may be made by those skilled in the art without the creative effort are within the scope of the patent described in the claims.
Claims (5)
1. A control method for a short-circuit current maximum power point tracking circuit of a thermoelectric generator is characterized in that the short-circuit current maximum power point tracking circuit comprises a main circuit without an input capacitor; the main circuit without the input capacitor comprises a thermoelectric generator and a Boost circuit; the equivalent circuit of the thermoelectric generator is a constant voltage source V oc And internal resistance R in Is a series of (1); the output end of the equivalent circuit of the thermoelectric generator is connected with the input end of the Boost circuit; the Boost circuit comprises an inductor L 1 The method comprises the steps of carrying out a first treatment on the surface of the The inductance L 1 One end of (2) and internal resistance R in Is connected with the other end of the switch tube S 1 And a switch tube S 2 Is connected with one end of the connecting rod; the switch tube S 2 Respectively with the other end of the output filter capacitor C 1 And a load R L Is connected with one end of the connecting rod; the output filter capacitor C 1 And a load R L Connected in parallel and load R L And the other end of the switch tube S 1 The other end and constant voltage source V oc One end is connected;
the inductance L 1 One side is provided with a digital control chip for collecting inductance current;
the model of the digital control chip is STM32F407VET6;
returning bagIncludes an input capacitor main circuit; the main circuit with the input capacitor comprises a main circuit without the input capacitor and an input capacitor C connected with the input end of a Boost circuit of the main circuit without the input capacitor 2 And a switch tube S 3 The output end of the serial branch is respectively connected with the output end of the Boost circuit and the constant voltage source V oc One end is connected;
the control method comprises the following steps:
collecting inductance L in a plurality of continuous periods 1 Is set according to the current value of (1);
closing the switching tube S 1 The thermoelectric generator is an inductance L 1 Charging, inductance L 1 Current rise, inductance L is calculated 1 Rate of change of current rise phase;
inductance L 1 The circuit structure during charging is subjected to Norton equivalent transformation according to the inductance L 1 Current value at current rising stage, rate of change of current, main switching tube S 1 The KCL equation of the conduction mode equivalent circuit is calculated to obtain the expression of the short-circuit current,
wherein I is SC Is the short-circuit current of the thermoelectric generator, L 1 Inductance of the main inductor of the converter, R in Is equivalent internal resistance of thermoelectric generator, i L Is the inductance L 1 Current, i' L Is the inductance L 1 The first derivative of the current, in a discrete system, when the sampling period is small, can be approximated by a first order difference quotient instead of the first derivative of its continuous function;
obtaining inductance L 1 Inductance current values at any two moments (point a and point b), calculating first-order center difference quotient values of the two inductance current values, bringing the two first-order center difference quotient values into an expression of short-circuit current, calculating to obtain the short-circuit current value,
wherein i is L(a) For the current value of point a, i L(b) For the b point current value, i' L(a) Is a point difference quotient, i' L(b) Is the point b difference quotient;
calculating inductance L 1 The root mean square value of the current in a plurality of periods to obtain the output current of the thermoelectric generator
i TEG And adjusts the switch tube S according to the incremental PI control 1 Up to the output current i of the thermoelectric generator TEG Equal to short-circuit current I SC Half of the maximum power of the thermoelectric generator is output.
2. The control method for a short-circuit current maximum power point tracking circuit of a thermoelectric generator according to claim 1, wherein the inductance L 1 The calculation formula of the change rate in the current rising stage is as follows:
wherein,,is the inductance L 1 Derivative of current, V TEG Is the output voltage of the thermoelectric generator.
3. The control method of the maximum short-circuit current power point tracking circuit for a thermoelectric generator according to claim 2, wherein the inductance L 1 The calculation formula of the change rate in the current falling stage is as follows:
where Vo is the voltage across the load.
4. The control method for a short-circuit current maximum power point tracking circuit of a thermoelectric generator according to claim 1, wherein the collected inductor current is filtered first, and the method comprises the steps of:
removing burrs and peak values in the current data, and supplementing the removed parts by using a linear interpolation method;
selecting an FIR low-pass filter with a Hamming window to filter high-frequency noise in the current data;
and performing median average filtering on the obtained multiple groups of short-circuit current values.
5. The control method for a short-circuit current maximum power point tracking circuit of a thermoelectric generator according to claim 1, further comprising:
during the current sampling period, the topology with the input capacitor turns off the input capacitor branch series switching tube S in advance 3 Switch tube S 1 On time S 2 Turn-off, the thermoelectric generator is the main inductance L 1 Charging, load R L From output filter capacitor C 1 Supplying power; switch tube S 1 S at turn-off 2 Conduction, thermoelectric generator and main inductance L 1 Series connection is output filter capacitor C 1 Load R L Power supply, all inductances L according to several successive cycles 1 The root mean square of the current value of the temperature difference piece is calculated to obtain the effective value i of the output current of the temperature difference piece TEG The method comprises the steps of carrying out a first treatment on the surface of the The effective value i TEG And I SC The difference/2 is used as the error amount for the incremental PI control.
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| CN109521349B (en) * | 2018-11-19 | 2020-11-24 | 河北科技大学 | Method and system for measuring maximum output power of semiconductor power generation module |
| CN112615548A (en) * | 2020-12-21 | 2021-04-06 | 四川升华电源科技有限公司 | DCM frequency conversion control method based on flyback DC-DC converter |
| CN113110689B (en) * | 2021-04-25 | 2022-07-22 | 江苏大学 | Maximum power point tracking controller considering reverse temperature difference and control method |
| CN115826669B (en) * | 2022-11-26 | 2024-04-12 | 天津大学 | Combined maximum power point tracking control method of photovoltaic power generation system |
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