High voltage photovoltaic module volt-ampere characteristic curve measuring device

Abstract

This application belongs to the field of photovoltaic module measurement technology, and particularly relates to a device for measuring the current-voltage characteristic curve of a high-voltage photovoltaic module. The device includes: a switch control circuit including an insulated-gate transistor Q2 and an insulated-gate transistor Q3 connected in series, with the collector of the insulated-gate transistor Q2 connected in series with the DC input terminal of the photovoltaic module; a voltage equalization circuit connected in parallel with the switch control circuit; and a drive circuit for outputting a drive signal to the insulated-gate transistor Q3. This device uses a voltage equalization circuit to achieve synchronous drive of the linear region of the series IGBT, which solves the problem that traditional circuits based on pulse transformers or bootstrap voltage boosting can only adapt to the switching operating region of the IGBT transistor and cannot meet the precise control requirements of the linear operating state of the IGBT in the measurement of the current-voltage characteristic of solar photovoltaic modules.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module current-voltage characteristic measurement technology, and in particular to a device for measuring the current-voltage characteristic curve of a high-voltage photovoltaic module. Background Technology

[0002] In the fault diagnosis of photovoltaic (PV) panels, to accurately detect panel performance parameters and locate faults, related equipment generally relies on high-power electronic load methods to simulate and measure the output characteristics of PV panels. However, existing PV panel fault diagnosis equipment has significant shortcomings in practical applications.

[0003] To achieve high-power electronic load functionality, conventional high-power electronic loads often employ IGBT transistors operating in the switching region. This design places high demands on the high-speed response capability and control precision of the hardware circuitry, thus requiring a high-speed driver chip to ensure stable circuit operation. However, high-speed driver chips not only significantly increase hardware costs, but their corresponding software development process also presents significant technical challenges. This results in an overall high cost and long development cycle for this solution, making it unsuitable for the mass production and low-cost requirements of handheld diagnostic devices.

[0004] Furthermore, to meet the portability and low-cost requirements of handheld devices, current conventional handheld solutions generally choose to operate the IGBT in the linear region to simplify drive design and reduce costs. However, this solution is limited by the power tolerance limit of a single IGBT, making it difficult to increase its output power and meet the measurement needs of the increasingly popular higher-power photovoltaic arrays, thus limiting the applicability of handheld diagnostic devices.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] In view of at least one of the above technical problems, this application provides a device for measuring the current-voltage characteristic curve of a high-voltage photovoltaic module.

[0007] This application provides a device for measuring the voltage-current characteristic curve of a high-voltage photovoltaic module, the device comprising: The switching control circuit includes an insulated-gate transistor Q2 and an insulated-gate transistor Q3 connected in series. The collector of the insulated-gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. The voltage equalization circuit is connected in parallel with the switch control circuit. The driving circuit is used to output a driving signal to the insulated gate transistor Q3. When the driving circuit changes the driving signal output to the insulated gate transistor Q3, the potential of the gate of the insulated gate transistor Q2 changes. The insulated gate transistors Q2 and Q3 are driven synchronously, and with the combined action of the switching control circuit and the voltage equalization circuit, dynamic voltage equalization of the insulated gate transistors Q2 and Q3 in the on state is achieved through internal voltage feedback.

[0008] This device uses a voltage equalization circuit to achieve synchronous driving of the linear region of series IGBTs, which solves the problem that traditional circuits based on pulse transformers or bootstrap voltage boosting can only be adapted to the switching operating region of IGBT tubes and cannot meet the precise control requirements of IGBT linear operating state in the measurement of the current-voltage characteristics of solar photovoltaic modules.

[0009] In some possible implementations, the driving circuit is used to output voltage pulses of different amplitudes to the insulated gate transistor Q3, which are driving signals.

[0010] In some possible implementations, a main control circuit and a synchronous sampling circuit are also included. The main control circuit is used to control the drive unit to output voltage pulses of different amplitudes. The main control circuit is also used to control the synchronous sampling circuit to collect the voltage at the DC input terminal and the current flowing through the switch control circuit during the pulse duration, so as to obtain data points on the voltage-current characteristic curve of the high-voltage photovoltaic module.

[0011] In some possible implementations, the voltage equalization circuit includes a first voltage equalization unit, a second voltage equalization unit, and a third voltage equalization unit. The first terminal of the first voltage equalization unit is connected to the collector of the insulated gate transistor Q2. The first terminal of the second voltage equalization unit is connected to the second terminal of the first voltage equalization unit and the gate of the insulated gate transistor Q2. The second terminal of the second voltage equalization unit is connected to the first terminal of the third voltage equalization unit and the gate of the insulated gate transistor Q3. The second terminal of the third voltage equalization unit is grounded.

[0012] In some possible implementations, the total resistance of the first voltage equalization unit is equal to the total resistance of the second voltage equalization unit, and the total resistance of the third voltage equalization unit is less than the total resistance of the first voltage equalization unit.

[0013] In some possible implementations, the device includes a fault-breaking circuit connected in series with the insulated-gate transistor Q2, which is used to achieve safe circuit disconnection.

[0014] In some possible implementations, the fault-breaking circuit includes a low-voltage drive amplifier circuit, an isolation control circuit, and a switching circuit. The low-voltage drive amplifier circuit is used to output a control signal, and the isolation control circuit is used to turn on or off according to the control signal. When the isolation control circuit is on, the switching circuit is on, and the insulated gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. When the isolation control circuit is off, the switching circuit is off, and the insulated gate transistor Q2 is disconnected from the DC input terminal of the photovoltaic module.

[0015] In some possible implementations, the low-voltage drive amplifier circuit includes transistors Q33, Q34, and Q35. The base of transistor Q35 is connected to the initial signal control terminal, and the emitter of transistor Q35 is grounded. The base of transistor Q34 is connected to the collector of transistor Q35, and the emitter of transistor Q34 is grounded. The base of transistor Q33 is connected to the collector of transistor Q34, and the collector and emitter of transistor Q33 are respectively connected to the isolation control circuit.

[0016] In some possible implementations, the isolation control circuit includes an optocoupler U16, one end of which is connected to a low-voltage drive amplifier circuit, and the other end of which is connected to an on / off circuit.

[0017] In some possible implementations, the switching circuit includes a transistor Q8 and an insulated-gate transistor Q6. The emitter of transistor Q8 is connected to the isolation control circuit and the gate of insulated-gate transistor Q6, respectively. The collector of transistor Q8 is connected to the isolation control circuit and the emitter of insulated-gate transistor Q6, respectively. Insulated-gate transistor Q6 is connected in series with insulated-gate transistor Q2.

[0018] The present application will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the high-voltage photovoltaic module current-voltage characteristic curve measuring device provided in the embodiments of this application; Figure 2 yes Figure 1 Circuit diagram of the switch control circuit; Figure 3 yes Figure 1 Circuit diagram of the medium isolation control circuit and the on / off circuit; Figure 4 yes Figure 1 Circuit diagram of medium and low voltage drive amplifier circuit; Figure 5 yes Figure 1 Circuit diagram of the driving circuit; Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] Before introducing the measuring device for the voltage-current characteristic curve of high-voltage photovoltaic modules, let's first introduce the background technology.

[0023] Existing high-precision, high-power testing equipment is bulky and expensive, making it unsuitable for portable outdoor operations. Conventional handheld devices have limited power tolerance and cannot meet the measurement requirements of 1500V-level high-voltage photovoltaic arrays.

[0024] To increase the power limit within a limited size and cost, the most direct method is to connect multiple IGBTs in series to share the high voltage. In an IGBT series structure, the emitter potential of the high-side IGBT is floating, and conventional ground-referenced drive circuits cannot effectively control it. Existing high-side drive solutions, such as bootstrap and pulse transformers, are only applicable to the switching state of the IGBT, i.e., fully on or fully off. To simplify the circuit and reduce costs, this application requires the IGBT to operate in the linear region, which can be understood as acting as a variable resistor. Traditional solutions cannot achieve linear adjustment of the high-side IGBT. When the IGBT operates in the linear region, even a tiny difference in the drive voltage will cause a huge change in the voltage drop across its terminals, making it impossible for the series-connected IGBTs to share the total voltage evenly. This can cause one of the IGBTs to withstand a voltage far exceeding its rated value and be damaged.

[0025] Based on the above background, a device for measuring the volt-ampere characteristic curve of a high-voltage photovoltaic module is provided, such as... Figures 1 to 5 As shown, the device includes: a switch control circuit 100, a voltage equalization circuit 200, a drive circuit 300, a main control circuit 400, a synchronous sampling circuit 500, and a fault disconnect circuit 600.

[0026] The switching control circuit 100 includes an insulated-gate transistor Q2 and an insulated-gate transistor Q3 connected in series. The collector of the insulated-gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. The voltage equalization circuit 200 is connected in parallel with the switching control circuit 100. The driving circuit 300 is used to output a driving signal to the insulated-gate transistor Q3. The main control circuit 400 is used to control the driving unit to output voltage pulses of different amplitudes. The main control circuit 400 is also used to control the synchronous sampling circuit 500 to collect the voltage of the DC input terminal and the current flowing through the switching control circuit 100 during the pulse duration to obtain data points on the voltage-current characteristic curve of the high-voltage photovoltaic module.

[0027] It is worth noting that insulated gate transistor Q2 is a high-side IGBT, and insulated gate transistor Q3 is a low-side IGBT.

[0028] The voltage equalization circuit 200 is connected in parallel with the switching control circuit 100. It can be understood that the voltage equalization circuit 200 divides the high voltage at the DC input terminal of the photovoltaic module, thereby naturally raising the gate control point potential of the high-side IGBT to near its floating emitter potential, solving the reference point problem for high-side drive. When the drive circuit 300 changes the gate voltage of the low-side IGBT, the gate voltage of the high-side IGBT also changes through the coupling of the voltage equalization circuit 200, achieving synchronous drive. Furthermore, the two IGBTs on the high and low sides possess negative feedback self-stability. When the voltage across the high-side IGBT is too high, its emitter potential decreases, which in turn increases the drive voltage between the gate and emitter of the high-side IGBT, prompting it to conduct further, thereby reducing its own voltage drop, and ultimately causing the two IGBTs to automatically tend towards a voltage equalization state.

[0029] In other words, when the driving circuit 300 changes the driving signal output to the insulated gate transistor Q3, the potential of the gate of the insulated gate transistor Q2 changes, and the insulated gate transistors Q2 and Q3 are driven synchronously. With the combined action of the switch control circuit 100 and the voltage equalization circuit 200, dynamic voltage equalization of the insulated gate transistors Q2 and Q3 in the on state is achieved through internal voltage feedback.

[0030] This device uses a voltage equalization circuit 200 to achieve synchronous driving of the linear region of series IGBTs. This solves the problem that traditional circuits based on pulse transformers or bootstrap voltage boosting can only be adapted to the switching operating region of IGBTs and cannot meet the precise control requirements of IGBT linear operating state in the measurement of the current-voltage characteristics of solar photovoltaic modules.

[0031] To completely avoid the stability risks of closed-loop control, this application employs an open-loop drive combined with software scanning for measurement. Understandably, the main control circuit 400 does not attempt to precisely control a constant current, but rather outputs a series of drive voltages of varying amplitudes to the gate of the low-side IGBT in the form of extremely short pulses. During each pulse, the voltage and current values ​​of the acquisition circuit are rapidly collected. By performing a rapid scan within the effective drive voltage range, a series of voltage and current data points can be obtained, thereby plotting a complete volt-ampere characteristic curve.

[0032] Specifically, based on the IGBT output characteristics, when the collector-emitter voltage remains constant or changes only slightly, changing the control level can alter the corresponding output current. Furthermore, unlike an ideal voltage source, a photovoltaic source has a maximum short-circuit current limit. Therefore, by setting the gate level value from high to low (e.g., scanning downwards in 40 segments from 15V to 8V), the control voltage Vgemax corresponding to the maximum value Imax and the control voltage Vgemin corresponding to the minimum value Imin at the DC input terminal of the photovoltaic module can be actually tested. These two voltages are the upper and lower limits of the effective control voltage scanning range. By segmenting points within this range in the program and scanning the output in pulse form, the equivalent closed-loop current scanning scheme can be achieved. In other words, the drive circuit 300 outputs voltage pulses of different amplitudes to the insulated-gate transistor Q3; these voltage pulses serve as the drive signal.

[0033] During measurement, the main control circuit 400 outputs a voltage pulse of a specific amplitude to the low-side IGBT via a DAC. Through the voltage equalization circuit 200, the high-side IGBT is synchronously driven, and under negative feedback, the two IGBTs achieve dynamic voltage equalization. At this time, the two IGBTs connected in series act as an equivalent load, stabilizing the photovoltaic module's operation. During the pulse's stabilization period, the synchronous sampling circuit 500 collects the voltage and current in the loop and outputs them to the main control circuit 400 for storage. The main control circuit 400 then starts outputting the next pulse of a different amplitude and repeats the above steps until all segmented sampling points are output in pulse form. The main control circuit 400 plots all collected data into an volt-ampere characteristic curve.

[0034] like Figures 1 to 4As shown, in some embodiments, the voltage equalizing circuit 200 includes a first voltage equalizing unit 210, a second voltage equalizing unit 220 and a third voltage equalizing unit 230. A first end of the first voltage equalizing unit 210 is connected to the collector of the insulated gate transistor Q2, a first end of the second voltage equalizing unit 220 is connected to a second end of the first voltage equalizing unit 210 and the gate of the insulated gate transistor Q2, a second end of the second voltage equalizing unit 220 is connected to a first end of the third voltage equalizing unit 230 and the gate of the insulated gate transistor Q3, and a second end of the third voltage equalizing unit 230 is grounded. The total resistance of the first voltage equalizing unit 210 is equal to the total resistance of the second voltage equalizing unit 220, and the total resistance of the third voltage equalizing unit 230 is smaller than the total resistance of the first voltage equalizing unit 210.

[0035] The first voltage equalizing unit 210 may include resistors R2, R3, R4, R5, and the resistors R2, R3, R4, R5 are connected in series. The second voltage equalizing unit 220 may include resistors R6, R7, R8, R9, and the resistors R6, R7, R8, R9 are connected in series. The third voltage equalizing unit 230 may include a resistor R11, and the resistor R11 is connected to the resistor R9.

[0036] The total resistance of the first voltage equalizing unit 210 is equal to the total resistance of the second voltage equalizing unit 220, and the total resistance of the third voltage equalizing unit 230 is smaller than the total resistance of the first voltage equalizing unit 210. That is, the sum of the resistances of resistors R2, R3, R4, and R5 is equal to the sum of the resistances of resistors R6, R7, R8, and R9, and both the sum of the resistances of resistors R2, R3, R4, and R5 and the sum of the resistances of resistors R6, R7, R8, and R9 are greater than the resistance of resistor R9.

[0037] Please refer to Figure 2 , assuming that the connection point between the collector of the insulated gate transistor Q2 and the first voltage equalizing unit is node A. Assuming that the connection point among the gate of the insulated gate transistor Q2, the first voltage equalizing unit and the second voltage equalizing unit is node B. Assuming that the connection point between the gate of the insulated gate transistor Q3 and the second voltage equalizing unit is node C. Assuming that the connection point between the emitter of the insulated gate transistor Q2 and the collector of the insulated gate transistor Q3 is node D.

[0038] When the high voltage of the photovoltaic module flows into the ground through the switch control circuit 100 and the voltage equalizing circuit 200, since the equivalent internal resistances of the two insulated gate transistors in the off state and the voltage equalizing state are almost the same, the voltage of node D can be regarded as V+ / 2, where V+ is the high voltage of the photovoltaic module. In addition, since the resistances of the first voltage equalizing unit 210 and the second voltage equalizing unit 220 are the same, the voltage of node B can be regarded as V+ / 2. Thus, when the resistance values satisfy R9 < R1+R2+R3+R4 = R5+R6+R7+R8, V BDIt is close to 0. Based on this, if the voltage of node C, that is, the gate voltage of the insulated gate transistor Q3, is changed by the driving circuit 300, the voltage of node B will also be raised, thereby realizing the synchronous driving of the two transistors.

[0039] However, when the voltage at node C changes, the voltage difference V between node A and node C remains constant because the high voltage of the photovoltaic module remains constant. AC As the voltage drops, the voltage rise ΔVB at node B after the 200V voltage divider in the voltage equalization circuit will be less than ΔVC. This causes the conduction level of insulated-gate transistor Q2 to be lower than that of insulated-gate transistor Q3, resulting in a larger voltage drop for Q2. However, since the series voltage division ratio of series IGBTs is negatively correlated with the conduction level, the increased voltage drop of insulated-gate transistor Q2 means a decrease in its emitter voltage, i.e., the voltage at node D, and its actual drive voltage V. BD Instead, it increases, which in turn promotes the conduction of the insulated-gate transistor Q2. Due to this internal feedback, the IGBT series circuit will eventually stabilize in an approximately equal voltage state.

[0040] It is understandable that when the driving circuit 300 outputs voltage pulses of different amplitudes to the insulated gate transistor Q3, although the voltage at node C changes, the series circuit of insulated gate transistors Q2 and Q3 remains stable in a voltage equalization state.

[0041] like Figures 1 to 4 As shown, in some embodiments, the device includes a fault-breaking circuit 600 connected in series with an insulated gate transistor Q2, and the fault-breaking circuit 600 is used to achieve safe circuit disconnection.

[0042] The fault circuit interrupter 600 includes a low-voltage drive amplifier circuit, an isolation control circuit, and a switching circuit. The low-voltage drive amplifier circuit is used to output a control signal, and the isolation control circuit is used to turn on or off according to the control signal. When the isolation control circuit is on, the switching circuit is on, and the insulated gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. When the isolation control circuit is off, the switching circuit is off, and the insulated gate transistor Q2 is disconnected from the DC input terminal of the photovoltaic module.

[0043] The low-voltage drive amplifier circuit includes transistors Q33, Q34, and Q35. The base of transistor Q35 is connected to the initial signal control terminal, and the emitter of transistor Q35 is grounded. The base of transistor Q34 is connected to the collector of transistor Q35, and the emitter of transistor Q34 is grounded. The base of transistor Q33 is connected to the collector of transistor Q34, and the collector and emitter of transistor Q33 are connected to the isolation control circuit.

[0044] The low-voltage drive amplifier circuit also includes resistors R225, R226, R227, R229, R231, R232, R234, R230 and transistor Q32. Among them, resistors R225, R226, R227 and transistor Q32 are connected in sequence. Resistor R225 is connected in parallel with transistor Q33. Resistor R230 is connected to the base and emitter of transistor Q33 respectively. Resistor R229 is connected to the collector and base of transistor Q33 respectively. Resistor R231 is connected to the base of transistor Q33 and the collector of transistor Q34 respectively. Resistor R232 is connected to the collector of transistor Q35. Resistor R234 is connected between transistor Q35 and the main control circuit 400.

[0045] The isolation control circuit includes an optocoupler U16, one end of which is connected to a low-voltage drive amplifier circuit, and the other end of which is connected to an on / off circuit.

[0046] The switching circuit includes transistor Q8 and insulated-gate transistor Q6. The emitter of transistor Q8 is connected to the isolation control circuit and the gate of insulated-gate transistor Q6, respectively. The collector of transistor Q8 is connected to the isolation control circuit and the emitter of insulated-gate transistor Q6, respectively. Insulated-gate transistor Q6 is connected in series with insulated-gate transistor Q2.

[0047] When operating normally, the main control circuit 400 outputs a high level, turning on transistor Q35. The collector potential of transistor Q35 decreases, causing the base potential of transistor Q34 to decrease, turning off transistor Q34 and pulling its collector high. The high level from the collector of transistor Q34 is then supplied to the base of transistor Q33 through resistor R231, turning on transistor Q33. Transistor Q33 outputs a valid signal to the isolation control circuit. Upon receiving the signal from transistor Q33, the isolation control circuit turns on optocoupler U16, which in turn turns on the insulated-gate transistor Q6.

[0048] When a fault occurs, the main control circuit 400 outputs a low level, transistor Q33 is cut off, optocoupler U16 is not turned on, and insulated gate transistor Q6 is cut off.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0051] The above are merely preferred embodiments of this application and do not constitute any limitation on this application. Any person skilled in the art can make many possible variations and modifications to the technical solution of this application, or modify it into equivalent embodiments, without departing from the scope of the technical solution of this application. Therefore, all equivalent changes made based on the shape, structure, and principle of this application without departing from the content of the technical solution of this application should be covered within the protection scope of this application.

Claims

1. A device for measuring the volt-ampere characteristic curve of a high-voltage photovoltaic module, characterized in that, The device includes: A switching control circuit, comprising an insulated-gate transistor Q2 and an insulated-gate transistor Q3 connected in series, wherein the collector of the insulated-gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. A voltage equalization circuit, wherein the voltage equalization circuit is connected in parallel with the switch control circuit; The driving circuit is used to output a driving signal to the insulated gate transistor Q3; When the driving circuit changes the driving signal output to the insulated gate transistor Q3, the potential of the gate of the insulated gate transistor Q2 changes. The insulated gate transistors Q2 and Q3 are driven synchronously, and with the combined action of the switch control circuit and the voltage equalization circuit, the dynamic voltage equalization of the insulated gate transistors Q2 and Q3 in the on state is achieved through internal voltage feedback. The voltage equalization circuit includes a first voltage equalization unit, a second voltage equalization unit, and a third voltage equalization unit. The first terminal of the first voltage equalization unit is connected to the collector of the insulated gate transistor Q2. The first terminal of the second voltage equalization unit is connected to the second terminal of the first voltage equalization unit and the gate of the insulated gate transistor Q2. The second terminal of the second voltage equalization unit is connected to the first terminal of the third voltage equalization unit and the gate of the insulated gate transistor Q3. The second terminal of the third voltage equalization unit is grounded.

2. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 1, characterized in that, The driving circuit is used to output voltage pulses of different amplitudes to the insulated gate transistor Q3, and the voltage pulses are the driving signals.

3. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 2, characterized in that, It also includes a main control circuit and a synchronous sampling circuit. The main control circuit is used to control the drive unit to output voltage pulses of different amplitudes. The main control circuit is also used to control the synchronous sampling circuit to collect the voltage of the DC input terminal and the current flowing through the switch control circuit during the pulse duration, so as to obtain data points on the voltage-current characteristic curve of the high-voltage photovoltaic module.

4. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 1, characterized in that, The total resistance of the first voltage equalization unit is equal to the total resistance of the second voltage equalization unit, and the total resistance of the third voltage equalization unit is less than the total resistance of the first voltage equalization unit.

5. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 1, characterized in that, The device includes a fault-breaking circuit connected in series with the insulated gate transistor Q2, and the fault-breaking circuit is used to achieve safe circuit disconnection.

6. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 5, characterized in that, The fault circuit interrupter includes a low-voltage drive amplifier circuit, an isolation control circuit, and a switching circuit. The low-voltage drive amplifier circuit is used to output a control signal. The isolation control circuit is used to turn on or off according to the control signal. When the isolation control circuit is on, the switching circuit is on, and the insulated gate transistor Q2 is connected in series with the DC input terminal of the photovoltaic module. When the isolation control circuit is off, the switching circuit is off, and the insulated gate transistor Q2 is disconnected from the DC input terminal of the photovoltaic module.

7. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 6, characterized in that, The low-voltage drive amplifier circuit includes transistors Q33, Q34, and Q35. The base of transistor Q35 is connected to the initial signal control terminal, and the emitter of transistor Q35 is grounded. The base of transistor Q34 is connected to the collector of transistor Q35, and the emitter of transistor Q34 is grounded. The base of transistor Q33 is connected to the collector of transistor Q34, and the collector and emitter of transistor Q33 are respectively connected to the isolation control circuit.

8. The high-voltage photovoltaic module current-voltage characteristic curve measuring device according to claim 6, characterized in that, The isolation control circuit includes an optocoupler U16, one end of which is connected to the low-voltage drive amplifier circuit, and the other end of which is connected to the on / off circuit.

9. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 6, characterized in that, The switching circuit includes a transistor Q8 and an insulated-gate transistor Q6. The emitter of the transistor Q8 is connected to the isolation control circuit and the gate of the insulated-gate transistor Q6, respectively. The collector of the transistor Q8 is connected to the isolation control circuit and the emitter of the insulated-gate transistor Q6, respectively. The insulated-gate transistor Q6 is connected in series with the insulated-gate transistor Q2.

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