Solar cell simulator circuit based on diode array

Abstract

The utility model belongs to the technical field of power supplies, and particularly relates to a solar cell simulator circuit based on a diode array, which comprises a power supply, a solar cell load, a first proportion circuit, a first reference voltage, the diode array, a second proportion circuit, a second reference voltage and a sampling resistor, the first proportion circuit collects output voltage of a power supply, the collected output voltage and first reference voltage are added to serve as input of the diode array, the output end of the diode array is connected with one end of the sampling resistor, and the other end of the sampling resistor is connected with the power ground. The second proportional circuit collects the voltage at the two ends of the sampling resistor, and the voltage of the second reference resistor subtracts the voltage collected by the second proportional resistor to serve as the input of the power supply. According to the invention, the solar cell simulation function is realized based on the I-V of the diode array, a traditional realization mode is used, the cost is lower, the period is shorter, and the method has a better application prospect in the field of satellite solar cell simulators.

Description

Technical Field

[0001] The invention belongs to the technical field of power supply, and in particular relates to a solar cell simulator circuit based on a diode array. Background Art

[0002] Solar cells are an important part of solar power generation, and solar cell simulators are an important part of studying solar cell characteristics and evaluating the functions and performance of MPPT controllers.

[0003] In the prior art, the mainstream implementation method is a digital control solution based on DSP, single-chip microcomputer or dedicated control chip. The voltage of the power supply is collected and the current of the power supply is controlled by calculation or table lookup according to the preset value. The digital method has a long R&D cycle and high R&D cost, which leads to higher product prices. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention proposes a solar cell simulator circuit based on a diode array, comprising a power supply, a solar cell load, a first proportional circuit, a first reference voltage, a diode array, a second proportional circuit, a second reference voltage and a sampling resistor, wherein: the output of the power supply is connected to the solar cell load, the first proportional circuit collects the output voltage of the power supply, the first reference voltage is added to the voltage collected by the first proportional circuit through an adding circuit, the output of the adding circuit is used as the input of the diode array, the output end of the diode array is connected to one end of the sampling resistor, and the other end of the sampling resistor is connected to a power ground; the second proportional circuit collects the voltage across the sampling resistor, the voltage collected by the second proportional circuit is subtracted from the second reference voltage through a subtraction circuit, and the output of the subtraction circuit is used as the input of the power supply.

[0005] Further, the first reference voltage is used to increase the bias of the diode array starting voltage.

[0006] Preferably, the voltage value of the first reference voltage is a diode array starting voltage.

[0007] Further, the first proportional circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a second operational amplifier, an eighth resistor, a tenth resistor and a third operational amplifier, wherein:

[0008] One end of the third resistor is connected to the signal input end of the solar cell load, and the other end is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to one end of the sixth resistor and the non-inverting input end of the second operational amplifier;

[0009] The other end of the sixth resistor and one end of the fourth resistor are connected to the signal ground, and the other end of the fourth resistor is connected to the output end of the solar cell load;

[0010] The inverting input terminal of the second operational amplifier is connected to its output terminal and one end of the eighth resistor, the other end of the eighth resistor is connected to the non-inverting input terminal of the third operational amplifier, one end of the tenth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the output of the third operational amplifier and serves as the output of the first proportional circuit.

[0011] Furthermore, the voltage value sampled by the first proportional circuit is controlled by the resistance values ​​of the fifth resistor and the sixth resistor, and the sampling ratio k1 is expressed as R5 represents the resistance value of the fifth resistor, and R6 represents the resistance value of the sixth resistor.

[0012] Preferably, the sampling ratio of the first proportional circuit is set to the ratio of the forward conduction voltage range of the diode array to the no-load voltage of the solar cell.

[0013] Furthermore, the value of the second reference voltage is the value of the forward conduction current corresponding to the diode array endpoint voltage.

[0014] Further, the second proportional circuit includes a twelfth resistor, a thirteenth resistor, and a fourteenth resistor, wherein:

[0015] One end of the twelfth resistor is connected to the output end of the diode array, and the other end of the twelfth resistor is connected to the non-inverting input end of the fifth operational amplifier;

[0016] One end of the fourteenth resistor is connected to the power ground, and the other end is connected to one end of the thirteenth resistor and the inverting input end of the fifth operational amplifier;

[0017] The other end of the thirteenth resistor is connected to the output end of the fifth operational amplifier as the output of the second proportional circuit.

[0018] Further, the subtraction circuit includes a fourth operational amplifier, a seventh resistor, a ninth resistor and an eleventh resistor, wherein:

[0019] One end of the seventh resistor is connected to the output of the fourth operational amplifier, and the other end is connected to the inverting input terminal of the fourth operational amplifier and the output of the second proportional circuit and serves as the output of the subtraction circuit;

[0020] The second reference voltage is connected to one end of the ninth and eleventh resistors, the other end of the ninth resistor is connected to the functional ground, and the other end of the eleventh resistor is connected to the non-inverting input end of the fourth operational amplifier.

[0021] Further, the power supply includes a first operational amplifier, a capacitor, an N-type transistor, a first resistor, and a second resistor, wherein:

[0022] The voltage of the second reference resistor minus the voltage collected by the second proportional resistor is used as the non-inverting input terminal of the first operational amplifier;

[0023] The inverting input terminal of the first operational amplifier is connected to one end of the capacitor and one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor and the emitter of the N-type transistor; the other end of the second resistor is connected to the power ground;

[0024] The other end of the capacitor is connected to the output end of the first operational amplifier and the base of the N-type transistor. The collector of the N-type transistor is connected to the output end of the solar cell load as the output end of the power supply.

[0025] The present invention realizes the solar cell simulation function based on the IV of the diode array, uses the traditional implementation method, has lower cost and shorter cycle, and has good application prospects in the field of satellite solar cell simulators. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a circuit principle block diagram of a solar cell simulator based on a diode array of the present invention;

[0027] Figure 2 It is a typical circuit principle diagram of a solar cell simulator circuit based on a diode array of the present invention;

[0028] Figure 3 This is a power supply IV curve diagram of a solar cell simulator circuit based on a diode array of the present invention.

[0029] Figure 4 It is a power PV curve diagram in a solar cell simulator circuit based on a diode array of the present invention;

[0030] Among them, V in , the input voltage of the power supply; V out , the output voltage of the power supply; R1, the first resistor; R2, the second resistor; R3, the third resistor; R4, the fourth resistor; R5, the fifth resistor; R6, the sixth resistor; R7, the seventh resistor; R8, the eighth resistor; R9, the ninth resistor; R10, the tenth resistor; R11, the eleventh resistor; R12, the twelfth resistor; R13, the thirteenth resistor; R14, the fourteenth resistor; U1, the first operational amplifier; U2, the second operational amplifier; U3, the third operational amplifier; U4, the fourth operational amplifier; U5, the fifth operational amplifier; P1, the first transformer; P2, the second transformer; D1, the diode array; R sample , sampling resistor; C1, capacitor; S1, N-type transistor; V ref1 , the first reference voltage; V ref2 , a second reference voltage; I in , the input current of the power supply; V F , the input voltage of the diode array. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention proposes a solar cell simulator circuit based on a diode array. The present invention realizes the solar cell simulation function by analog control based on the IV characteristics of the diode array. The circuit includes a power supply, a solar cell load, a first proportional circuit, a first reference voltage V ref1 , diode array, second proportional circuit, second reference voltage V ref2 And a sampling resistor, wherein: the output of the power supply is connected to the solar cell load, the first proportional circuit collects the output voltage of the power supply, and the collected output voltage is added to the first reference voltage as the input of the diode array, and the output end of the diode array (the input voltage of this end is V F ) is connected to one end of the sampling resistor, and the other end of the sampling resistor is connected to the power ground; the second proportional circuit collects the voltage across the sampling resistor, and the voltage of the second reference resistor minus the voltage collected by the second proportional resistor is used as the input of the power supply to provide the input current I for the power supply in .

[0033] This embodiment proposes a solar cell simulator circuit based on a diode array, such as Figure 1 The circuit includes a power supply, a solar cell load, a proportional circuit 1, a reference voltage 1, an addition circuit, a diode array, a proportional circuit 2, a reference voltage 2, a subtraction circuit, and a sampling resistor R sample The output of the power supply is connected to the solar cell load, the proportional circuit 1 collects the output voltage of the power supply, the proportional circuit 1 and the reference voltage 1 are added through the adding circuit and then connected to the diode array, and the lower end of the diode array is connected to the sampling resistor R sample Connected, proportional circuit 2 collects the sampling resistor R sample The voltages at both ends, the reference voltage 2 and the proportional circuit 2 are subtracted by subtraction and then connected to the power supply.

[0034] As an optional implementation, the power supply is typically a linear power supply. As a preferred implementation, the power supply can be a DC / DC power supply.

[0035] As an optional implementation, the reference voltage 1 is an isolated power supply DC / DC power supply. As a preferred implementation, the reference voltage 1 is a linear power supply.

[0036] In this embodiment, the operational amplifier is LM358 or other similar devices.

[0037] As an optional implementation, the function of the proportional circuit 1 is to sample the output voltage of the power supply and apply the voltage to the diode array at a certain ratio. Generally, the ratio should be the forward conduction voltage range ΔV of the diode array. F Divide by the solar cell no-load voltage V oc ,Right now The ratio is configured by the resistance values ​​of R5 and R6, and the relationship is: For example, the starting voltage of the diode array is 0.5V (forward current I F =0.0001mA), the end voltage is 1.5V (forward conduction current I F =1A), the open circuit voltage of the solar cell array is 100V, then

[0038] In this embodiment, the function of the diode array is to provide a VI curve relationship and provide a reference for the power supply. Generally, the diode array can use the diode unit or array of an actual solar cell, or the unit or array of a general-purpose diode. Usually, the diode array does not need to have the ability to output power, and a low-power mW-level diode can be used to achieve it.

[0039] Proportional circuit 2 and R sample The function is to sample the forward conduction current I of the diode array. F In general, the output voltage of the proportional circuit 2 should be configured to be proportional to the forward conduction current I F The numerical ratio is 1. For example, the forward conduction current I F is 500mA, the sampling resistor R sample is 500mΩ, then the sampling resistor R sample The voltage across the two ends is 0.25V. At this time, the amplification ratio of proportional circuit 2 should be configured to 2 times to achieve an output of 500mV, and the ratio of R14 / R13 is 1.

[0040] The function of reference voltage 2 is to provide a bias voltage, which represents the current of the diode array. In general, the bias voltage should be the forward conduction current I corresponding to the end voltage of the diode array. F For example, the forward current I corresponding to the end voltage of the diode array is 1.5V. F If the current is 1A, the reference voltage 2 should be adjusted to 1V.

[0041] According to the working principle of the circuit, a 1N4148 diode and a BAT18 diode are connected in parallel as a diode array device. The IV curve and PV curve of the power supply are shown in the figure, which can fit the curve well.

[0042] Generally, the input voltage Vin can be configured as the no-load voltage Voc of the solar cell, and the short-circuit current Isc of the solar cell can be adjusted by adjusting R2. Appropriate diodes can be selected to configure different IV curves, and appropriate peripheral configurations must be configured for matching.

[0043] In this embodiment, a specific implementation of the first proportional circuit is proposed, such as Figure 2 , the first proportional circuit includes a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a second operational amplifier U2, an eighth resistor R8, a tenth resistor R10 and a third operational amplifier U3, wherein:

[0044] One end of the third resistor is connected to the signal input end of the solar cell load, and the other end is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to one end of the sixth resistor and the non-inverting input end of the second operational amplifier;

[0045] The other end of the sixth resistor and one end of the fourth resistor are connected to the signal ground, and the other end of the fourth resistor is connected to the output end of the solar cell load;

[0046] The inverting input terminal of the second operational amplifier is connected to its output terminal and one end of the eighth resistor, the other end of the eighth resistor is connected to the non-inverting input terminal of the third operational amplifier, one end of the tenth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the output of the third operational amplifier and serves as the output of the first proportional circuit.

[0047] As an optional implementation, in this embodiment, the adding circuit is implemented by a transformer, such as Figure 2 , isolated through the first transformer P1, and then added through the second transformer P2.

[0048] This embodiment proposes a specific implementation of the second proportional circuit, such as Figure 2 The second proportional circuit includes a fifth operational amplifier, a twelfth resistor R12, a thirteenth resistor R13, and a fourteenth resistor R14, wherein:

[0049] One end of the twelfth resistor is connected to the output end of the diode array, and the other end of the twelfth resistor is connected to the non-inverting input end of the fifth operational amplifier;

[0050] One end of the fourteenth resistor is connected to the power ground, and the other end is connected to one end of the thirteenth resistor and the inverting input end of the fifth operational amplifier;

[0051] The other end of the thirteenth resistor is connected to the output end of the fifth operational amplifier as the output of the second proportional circuit.

[0052] As an optional implementation, this embodiment implements the subtraction circuit through an operational amplifier, such as Figure 2 , the subtraction circuit includes a fourth operational amplifier U4, a seventh resistor R7, a ninth resistor R9 and an eleventh resistor R11, wherein:

[0053] One end of the seventh resistor is connected to the output of the fourth operational amplifier, and the other end is connected to the inverting input terminal of the fourth operational amplifier and the output of the second proportional circuit and serves as the output of the subtraction circuit;

[0054] The second reference voltage is connected to one end of the ninth and eleventh resistors, the other end of the ninth resistor is connected to the functional ground, and the other end of the eleventh resistor is connected to the non-inverting input end of the fourth operational amplifier.

[0055] This embodiment provides a specific implementation of the power supply circuit, such as Figure 2 , the power supply includes a first operational amplifier U1, a capacitor C1, an N-type transistor S1, a first resistor R1, and a second resistor R2, wherein:

[0056] The voltage of the second reference resistor minus the voltage collected by the second proportional resistor is used as the non-inverting input terminal of the first operational amplifier;

[0057] The inverting input terminal of the first operational amplifier is connected to one end of the capacitor and one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor and the emitter of the N-type transistor; the other end of the second resistor is connected to the power ground;

[0058] The other end of the capacitor is connected to the output end of the first operational amplifier and the base of the N-type transistor, and the collector of the N-type transistor is connected to the output end of the solar cell load as the output end of the power supply.

[0059] In this embodiment, the power ground is the common reference ground line with zero potential of the load circuit or the power driving circuit, and the signal ground is the zero potential of sensors and signal sources of various physical quantities and the common reference line (relative zero potential) in the circuit. In this field, the power ground and the signal ground are both zero potential lines. In general, the power ground mainly focuses on the stability and efficiency of large current circuits, while the signal ground pays more attention to reducing signal interference and ensuring the accuracy and stability of the signal.

[0060] The above embodiments further illustrate the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above embodiments are only preferred implementation modes of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made to the present invention within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A solar cell simulator circuit based on a diode array, characterized in that: The invention comprises a power supply, a solar cell load, a first proportional circuit, a first reference voltage, a diode array, a second proportional circuit, a second reference voltage and a sampling resistor, wherein: the output of the power supply is connected to the solar cell load, the first proportional circuit collects the output voltage of the power supply, the first reference voltage is added to the voltage collected by the first proportional circuit through an adding circuit, the output of the adding circuit is used as the input of the diode array, the output end of the diode array is connected to one end of the sampling resistor, and the other end of the sampling resistor is connected to the power ground; the second proportional circuit collects the voltage across the sampling resistor, the voltage collected by the second proportional circuit is subtracted from the second reference voltage through a subtraction circuit, and the output of the subtraction circuit is used as the input of the power supply.

2. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The first reference voltage is used to increase the bias of the diode array starting voltage.

3. A solar cell simulator circuit based on a diode array according to claim 1 or 2, characterized in that: The voltage value of the first reference voltage is the diode array starting voltage.

4. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The first proportional circuit includes a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a second operational amplifier, an eighth resistor, a tenth resistor and a third operational amplifier, wherein: One end of the third resistor is connected to the signal input end of the solar cell load, and the other end is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to one end of the sixth resistor and the non-inverting input end of the second operational amplifier (U2); The other end of the sixth resistor and one end of the fourth resistor are connected to the signal ground, and the other end of the fourth resistor is connected to the output end of the solar cell load; The inverting input terminal of the second operational amplifier is connected to its output terminal and one end of the eighth resistor, the other end of the eighth resistor is connected to the non-inverting input terminal of the third operational amplifier, one end of the tenth resistor is connected to the inverting input terminal of the third operational amplifier, and the other end is connected to the output of the third operational amplifier and serves as the output of the first proportional circuit.

5. A solar cell simulator circuit based on a diode array according to claim 4, characterized in that: The voltage value sampled by the first proportional circuit is controlled by the resistance values ​​of the fifth resistor and the sixth resistor. The sampling ratio k1 is expressed as R5 represents the resistance value of the fifth resistor, and R6 represents the resistance value of the sixth resistor.

6. A solar cell simulator circuit based on a diode array according to claim 4 or 5, characterized in that: The sampling ratio of the first proportional circuit is set to the ratio of the forward conduction voltage range of the diode array to the no-load voltage of the solar cell.

7. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The value of the second reference voltage is the value of the forward conduction current corresponding to the diode array endpoint voltage.

8. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The second proportional circuit includes a fifth operational amplifier, a twelfth resistor, a thirteenth resistor, and a fourteenth resistor, wherein: One end of the twelfth resistor is connected to the output end of the diode array, and the other end of the twelfth resistor is connected to the non-inverting input end of the fifth operational amplifier; One end of the fourteenth resistor is connected to the power ground, and the other end is connected to one end of the thirteenth resistor and the inverting input end of the fifth operational amplifier; The other end of the thirteenth resistor is connected to the output end of the fifth operational amplifier as the output of the second proportional circuit.

9. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The subtraction circuit includes a fourth operational amplifier, a seventh resistor, a ninth resistor and an eleventh resistor, wherein: One end of the seventh resistor is connected to the output of the fourth operational amplifier, and the other end is connected to the inverting input terminal of the fourth operational amplifier and the output of the second proportional circuit and serves as the output of the subtraction circuit; The second reference voltage is connected to one end of the ninth and eleventh resistors, the other end of the ninth resistor is connected to the functional ground, and the other end of the eleventh resistor is connected to the non-inverting input end of the fourth operational amplifier.

10. A solar cell simulator circuit based on a diode array according to claim 1, characterized in that: The power supply includes a first operational amplifier, a capacitor, an N-type transistor, a first resistor, and a second resistor, wherein: The voltage of the second reference resistor minus the voltage collected by the second proportional resistor is used as the non-inverting input terminal of the first operational amplifier; The inverting input terminal of the first operational amplifier is connected to one end of the capacitor and one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor and the emitter of the N-type transistor; the other end of the second resistor is connected to the power ground; The other end of the capacitor is connected to the output end of the first operational amplifier and the base of the N-type transistor. The collector of the N-type transistor is connected to the output end of the solar cell load as the output end of the power supply.

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