Measuring device for volt-ampere characteristic curve of high-voltage photovoltaic module

Abstract

The invention belongs to the technical field of photovoltaic module measurement, and particularly relates to a volt-ampere characteristic curve measuring device for a high-voltage photovoltaic module, and the device comprises a switch control circuit which comprises an insulated gate transistor Q2 and an insulated gate transistor Q3 which are connected in series, and the collector electrode of the insulated gate transistor Q2 is connected with the DC input end of the photovoltaic module in series; the voltage-sharing circuit is connected in parallel with the switch control circuit; the driving circuit is used for outputting a driving signal to the insulated gate transistor Q3; according to the device, the voltage-sharing circuit is adopted to realize the synchronous driving of the linear region of the series IGBTs, so that the problem that a traditional circuit based on a pulse transformer or bootstrap boost can only adapt to the switching working region of the IGBTs and cannot meet the accurate regulation and control requirements on the linear working state of the IGBTs in the volt-ampere characteristic measurement of the solar photovoltaic module is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic module volt-ampere characteristic measurement, and particularly relates to a high-voltage photovoltaic module volt-ampere characteristic curve measurement device. BACKGROUND

[0002] In the fault diagnosis process of a photovoltaic cell panel, in order to accurately detect the performance parameters of the cell panel to locate the fault, related equipment generally relies on a high-power electronic load method to realize simulation and measurement of the output characteristics of the photovoltaic cell panel. However, the existing photovoltaic cell panel fault diagnosis equipment has obvious deficiencies in actual application.

[0003] To realize the function of a high-power electronic load, a conventional high-power electronic load usually adopts a design in which an IGBT tube works in a switching zone. This design puts forward higher requirements for the high-speed response capability and control precision of a hardware circuit, and therefore a high-speed drive chip must be matched to ensure stable operation of the circuit. However, the high-speed drive chip not only greatly increases the hardware cost, but also has higher technical difficulty in the corresponding software development process, resulting in high overall cost and long development cycle of the scheme, which cannot adapt to the mass production and low-cost demand of handheld diagnosis equipment.

[0004] In addition, to adapt to the portability and low-cost demand of handheld equipment, the current conventional handheld scheme generally selects to make the IGBT tube work in a linear zone to simplify the drive design and reduce the cost. However, this scheme is limited by the power tolerance limit of a single IGBT, and the output power is difficult to improve, which cannot meet the measurement demand of increasingly popular higher-power photovoltaic arrays, and limits the application range of handheld diagnosis equipment.

[0005] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can include information that does not constitute prior art known by those skilled in the art. SUMMARY

[0006] In view of at least one of the above technical problems, the present application provides a high-voltage photovoltaic module volt-ampere characteristic curve measurement device.

[0007] The present application provides a high-voltage photovoltaic module volt-ampere characteristic curve measurement device, which comprises: a switch control circuit, the switch control circuit comprising an insulated gate transistor Q2 and an insulated gate transistor Q3 connected in series, the collector of the insulated gate transistor Q2 being connected in series with a direct current input end of the photovoltaic module; a voltage equalization circuit, the voltage equalization circuit being connected in parallel with the switch control circuit; a drive circuit, the drive circuit being configured to output a drive signal to the insulated gate transistor Q3; When the drive circuit changes the drive signal output to the insulated gate transistor Q3, the potential of the gate of the insulated gate transistor Q2 changes, the synchronous drive of the insulated gate transistor Q2 and the insulated gate transistor Q3 is realized, and the dynamic voltage equalization of the insulated gate transistor Q2 and the insulated gate transistor Q3 in the on state is realized through the internal voltage feedback under the joint action of the switch control circuit and the voltage equalization circuit.

[0008] The device realizes the linear region synchronous drive of the series IGBT by using the voltage equalization circuit, solves the problem that the traditional circuit based on the pulse transformer or the bootstrap voltage boosting can only adapt to the switching working region of the IGBT and cannot meet the precise regulation and control demand of the linear working state of the IGBT in the measurement of the volt-ampere characteristic of the solar photovoltaic module.

[0009] In some possible implementations, the drive circuit is configured to output a voltage pulse with different amplitudes to the insulated gate transistor Q3, and the voltage pulse is the drive signal.

[0010] In some possible implementations, the device further includes a master control circuit and a synchronous sampling circuit, the master control circuit is configured to control the drive unit to output the voltage pulse with different amplitudes, and the master control circuit is further configured to control the synchronous sampling circuit to collect the voltage of the direct current input end and the current flowing through the switch control circuit during the duration of the pulse, so as to obtain the data points on the volt-ampere 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, a first end of the first voltage equalization unit is connected with the collector of the insulated gate transistor Q2, a first end of the second voltage equalization unit is connected with a second end of the first voltage equalization unit and the gate of the insulated gate transistor Q2, a second end of the second voltage equalization unit is connected with a first end of the third voltage equalization unit and the gate of the insulated gate transistor Q3, and a second end 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 smaller than the total resistance of the first voltage equalization unit.

[0013] In some possible implementations, the device includes a fault circuit breaker in series with the insulated gate transistor Q2, and the fault circuit breaker is configured to realize the safe shutdown of the circuit.

[0014] In some possible implementation manners, the fault breaking circuit comprises a low-voltage driving amplification circuit, an isolation control circuit, and a on-off circuit. The low-voltage driving amplification circuit is configured to output a control signal. The isolation control circuit is configured to be turned on or turned off according to the control signal. When the isolation control circuit is turned on, the on-off circuit is turned on, and the insulated gate transistor Q2 is connected in series with the direct-current input end of the photovoltaic module. When the isolation control circuit is turned off, the on-off circuit is turned off, and the insulated gate transistor Q2 is disconnected from the direct-current input end of the photovoltaic module.

[0015] In some possible implementation manners, the low-voltage driving amplification circuit comprises three transistors Q33, Q34, and Q35. The base of the transistor Q35 is connected with an initial signal control end. The emitter of the transistor Q35 is grounded. The base of the transistor Q34 is connected with the collector of the transistor Q35. The emitter of the transistor Q34 is grounded. The base of the transistor Q33 is connected with the collector of the transistor Q34. The collector and the emitter of the transistor Q33 are connected with the isolation control circuit respectively.

[0016] In some possible implementation manners, the isolation control circuit comprises an optical coupler U16. One end of the optical coupler U16 is connected with the low-voltage driving amplification circuit. The other end of the optical coupler U16 is connected with the on-off circuit.

[0017] In some possible implementation manners, the on-off circuit comprises a transistor Q8 and an insulated gate transistor Q6. The emitter of the transistor Q8 is connected with the isolation control circuit and the gate of the insulated gate transistor Q6 respectively. The collector of the transistor Q8 is connected with the emitter of the insulated gate transistor Q6 and the isolation control circuit respectively. The insulated gate transistor Q6 is connected in series with the insulated gate transistor Q2.

[0018] The application will be further described below in conjunction with the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0020] Figure 1 FIG. 1 is a structural schematic diagram of a high-voltage photovoltaic module voltage-current characteristic curve measuring device provided by an embodiment of the present application; Figure 2 FIG. 2 is a circuit diagram of a switch control circuit in the embodiment; Figure 1 Figure 3 FIG. 3 is a circuit diagram of an isolation control circuit and an on-off circuit in the embodiment; Figure 1 FIG. 3 is a circuit diagram of an isolation control circuit and an on-off circuit in the embodiment;​Figure 4 is Figure 1 a circuit diagram of a low-voltage drive amplification circuit; Figure 5 is Figure 1 a circuit diagram of a low-voltage drive amplification circuit; DETAILED DESCRIPTION

[0021] In order to make the above objectives, features and advantages of the present application more apparent, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a number of ways other than those described herein without departing from the spirit of the present application. It is therefore intended that the present application not be limited to the embodiments disclosed herein for purposes of craftsmanship.

[0022] Before introducing the high-voltage photovoltaic module volt-ampere characteristic curve measuring device, the background art will be introduced first.

[0023] The existing high-precision high-power test equipment is bulky and costly, and is not suitable for outdoor portable operation. The power tolerance of conventional handheld equipment is limited, and cannot meet the measurement requirements of 1500V level high-voltage photovoltaic array.

[0024] In order to improve the power upper limit within limited volume and cost, the most direct method is to connect multiple IGBTs in series to share high voltage. In the IGBT series structure, the emitter potential of the high-side IGBT is floating, and the conventional drive circuit with ground reference cannot effectively control it. The existing high-side drive scheme, such as bootstrap boost and pulse transformer, is only suitable for the switching state of IGBT, i.e. fully on or fully off, In order to simplify the circuit and reduce the cost, the IGBT needs to work in the linear region, which can be understood as a variable resistor. The traditional scheme cannot realize the linear regulation of the high-side IGBT. When the IGBT works in the linear region, a small difference in drive voltage will cause a huge change in the voltage drop across it, making it impossible for the series-connected IGBTs to share the total voltage equally. This will cause one of the IGBTs to withstand a voltage far exceeding its rated value and be damaged.

[0025] Based on the above background, a high-voltage photovoltaic module volt-ampere characteristic curve measuring device is provided, as shown in Figures 1 to 5 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 circuit breaker 600.

[0026] The switch control circuit 100 comprises the series-connected insulated gate transistor Q2 and insulated gate transistor Q3, the collector of the insulated gate transistor Q2 is connected in series with the direct current input end of the photovoltaic module; the voltage equalization circuit 200 is connected in parallel with the switch control circuit 100; the driving circuit 300 is used for outputting a driving signal to the insulated gate transistor Q3; the main control circuit 400 is used for controlling the driving unit to output voltage pulses with different amplitudes, and the main control circuit 400 is also used for controlling the synchronous sampling circuit 500 to collect the voltage of the direct current input end and the current flowing through the switch control circuit 100 during the duration of the pulse, so as to obtain the data points on the volt-ampere characteristic curve of the high-voltage photovoltaic module.

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

[0028] The voltage equalization circuit 200 is connected in parallel with the switch control circuit 100, and it can be understood that the voltage equalization circuit 200 divides the high voltage of the direct current input end of the photovoltaic module, thereby naturally lifting the gate control point potential of the high-side IGBT to the vicinity of the floating emitter potential, solving the reference point problem of the high-side drive. When the driving circuit 300 changes the gate voltage of the low-side IGBT, through the coupling of the voltage equalization circuit 200, the gate voltage of the high-side IGBT also changes, realizing synchronous driving. In addition, the two IGBTs of the high-side and the low-side have negative feedback self-stability. When the voltage borne by the high-side IGBT is too high, the emitter potential will decrease, which will in turn increase the driving voltage between the gate and the emitter of the high-side IGBT, prompting it to be further turned on, thereby reducing its own voltage drop, and finally making the two IGBTs automatically tend to be in a voltage equalization state.

[0029] That is, 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, the insulated gate transistor Q2 and the insulated gate transistor Q3 are synchronously driven, and through the joint action of the switch control circuit 100 and the voltage equalization circuit 200, the dynamic voltage equalization of the insulated gate transistor Q2 and the insulated gate transistor Q3 in the on state is realized through internal voltage feedback.

[0030] The device adopts the voltage equalization circuit 200 to realize the linear region synchronous driving of the series-connected IGBT, solving the problem that the traditional circuit based on the pulse transformer or self-boosting can only adapt to the switching working region of the IGBT, and cannot meet the precise regulation and control demand of the linear working state of the IGBT in the volt-ampere characteristic measurement of the solar photovoltaic module.

[0031] To thoroughly avoid the stability risk of closed-loop control, the application adopts open-loop driving combined with software scanning mode for measurement. It can be understood that the main control circuit 400 does not attempt to accurately control a constant current, but outputs a series of driving voltages of different amplitudes to the gate of the low-side IGBT in the form of very short pulses. During each pulse, the voltage and current values of the high-speed synchronous sampling circuit are collected. By quickly scanning in the effective driving voltage interval, a series of voltage and current data points can be obtained, and a complete volt-ampere characteristic curve can be drawn.

[0032] Specifically, according to the IGBT output characteristic, when the collector-emitter voltage is constant or changes little, changing the control level can change the corresponding output current. In addition, the photovoltaic source is different from the ideal voltage source, and there is an upper limit of the maximum short-circuit current, so the control voltage Vgemax corresponding to the maximum DC input end of the photovoltaic module Imax and the control voltage Vgemin corresponding to the minimum value Imin can be actually tested by setting the gate voltage value from high to low (for example: from 15V to 8V in 40 segments). Scanning, the two voltages are the upper and lower limits of the effective control voltage scanning interval, and the interval is segmented in the program and output in the form of pulse scanning, which can realize the current scanning of the equivalent closed-loop scheme. That is, the driving circuit 300 outputs voltage pulses of different amplitudes to the insulated gate transistor Q3, and the voltage pulse is a driving signal.

[0033] When measuring, the main control circuit 400 outputs a voltage pulse of a specific amplitude to the low-side IGBT through the DAC. Through the voltage equalization circuit 200, the high-side IGBT is synchronously driven, and under the action of negative feedback, the two IGBTs reach dynamic voltage equalization. At this time, the two IGBTs in series act as an equivalent load, and the photovoltaic module works stably. In the stable period of the pulse, the synchronous sampling circuit 500 collects the voltage and current in the loop and outputs it to the main control circuit 400 for saving. The main control circuit 400 starts to output the next pulse of different amplitude, and repeats the above steps until all segmented points are output in the form of pulse. The main control circuit 400 draws the volt-ampere characteristic curve by collecting all the collected data.

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

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

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

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

[0038] When the high voltage of the photovoltaic module flows into the ground through the switch control circuit 100 and the voltage equalization circuit 200, the voltage of the node D can be regarded as V+ / 2, where V+ is the high voltage of the photovoltaic module, because the two insulated gate transistors are in the off state and the equivalent internal resistance in the voltage equalization state is almost consistent. In addition, the voltage of the node B can be regarded as V+ / 2 because the resistances of the first voltage equalization unit 210 and the second voltage equalization unit 220 are the same. Thus, when the resistance value satisfies R9 BDThe voltage of node C is close to 0. On this basis, if the voltage of node C is changed by the driving circuit 300, i.e. the gate voltage of the insulated gate transistor Q3, the voltage of node B will also be raised, thereby realizing the synchronous driving of the double tubes.

[0039] However, when the voltage of node C changes, due to the high voltage of the photovoltaic module being unchanged, the voltage difference V AC between node A and node C decreases, and the voltage of node B after being divided by the voltage equalization circuit 200 will be raised by a smaller amplitude ΔVB than ΔVC, causing the conduction degree of the insulated gate transistor Q2 to be lower than that of the insulated gate transistor Q3, and the insulated gate transistor Q2 will bear a greater voltage drop. However, since the series IGBT series voltage division ratio is negatively correlated with the conduction degree, the increase in the voltage drop of the insulated gate transistor Q2 means that the voltage of its emitter, i.e. the voltage of node D, decreases, and its actual driving voltage V BD instead increases, thereby promoting the conduction of the insulated gate transistor Q2. Due to the existence of this internal feedback, the IGBT series loop will eventually stabilize in an approximately voltage-equalized state.

[0040] It can be understood that when the driving circuit 300 outputs voltage pulses of different amplitudes to the insulated gate transistor Q3, although the voltage of node C changes, the series loop of the insulated gate transistors Q2 and Q3 is always stabilized in a voltage-equalized state.

[0041] As shown in FIG. 6, in some embodiments, the device includes a fault circuit breaking circuit 600, which is connected in series with the insulated gate transistor Q2, and is used to realize circuit safety shutdown. Figures 1 to 4 The fault circuit breaking circuit 600 includes a low-voltage driving amplification circuit, an isolation control circuit, and a on-off circuit. The low-voltage driving amplification circuit is used to output a control signal. The isolation control circuit is used to turn on or turn off according to the control signal. When the isolation control circuit is turned on, the on-off circuit is turned on, and the insulated gate transistor Q2 is connected in series with the direct current input end of the photovoltaic module. When the isolation control circuit is turned off, the on-off circuit is turned off, and the insulated gate transistor Q2 is disconnected from the direct current input end of the photovoltaic module.

[0042] The low-voltage driving amplification circuit includes transistors Q33, Q34, and Q35. The base of the transistor Q35 is connected with an initial signal control end. The emitter of the transistor Q35 is grounded. The base of the transistor Q34 is connected with the collector of the transistor Q35. The emitter of the transistor Q34 is grounded. The base of the transistor Q33 is connected with the collector of the transistor Q34. The collector and the emitter of the transistor Q33 are respectively connected with the isolation control circuit.

[0043]

[0044] ​The low-voltage driving amplification circuit further comprises resistors R225, R226, R227, R229, R231, R232, R234, R230 and a transistor Q32, wherein the resistors R225, R226 and R227 are connected in sequence, the resistor R225 is connected in parallel with the transistor Q33, the resistor R230 is connected with the base and the emitter of the transistor Q33 respectively, the resistor R229 is connected with the collector and the base of the transistor Q33 respectively, the resistor R231 is connected with the base of the transistor Q33 and the collector of the transistor Q34 respectively, the resistor R232 is connected to the collector of the transistor Q35, and the resistor R234 is connected between the transistor Q35 and the main control circuit 400.

[0045] The isolation control circuit comprises an optical coupler U16, one end of the optical coupler U16 is connected with the low-voltage driving amplification circuit, and the other end of the optical coupler U16 is connected with the on-off circuit.

[0046] The on-off circuit comprises a transistor Q8 and an insulated gate transistor Q6, the emitter of the transistor Q8 is connected with the isolation control circuit and the gate of the insulated gate transistor Q6 respectively, the collector of the transistor Q8 is connected with the emitter of the insulated gate transistor Q6 respectively, and the insulated gate transistor Q6 is connected in series with the insulated gate transistor Q2.

[0047] When working normally, the main control circuit 400 outputs a high level, the transistor Q35 is turned on, the collector potential of the transistor Q35 is lowered, the base potential of the transistor Q34 is lowered, the transistor Q34 is turned off, and the collector of the transistor Q34 is pulled up to a high level. The high level of the collector of the transistor Q34 is supplied to the base of the transistor Q33 through the resistor R231, so that the transistor Q33 is turned on, and the transistor Q33 outputs an effective signal to the isolation control circuit. After receiving the signal of the transistor Q33, the isolation control circuit is turned on, and then the insulated gate transistor Q6 is turned on.

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

[0049] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the description of the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0050] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise specifically limited.

[0051] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments, without departing from the scope of the technical solutions of the present application, using the methods and technical contents disclosed above. Therefore, any equivalent changes made in accordance with the shape, structure and principle of the present application, without departing from the technical solutions of the present application, should be covered by the protection scope of the present 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 synchronous driving of the insulated gate transistors Q2 and Q3, together with the switching control circuit and the voltage equalization circuit, achieves dynamic voltage equalization of the insulated gate transistors Q2 and Q3 in the on state through internal voltage feedback.

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 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.

5. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 4, 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.

6. 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.

7. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 6, 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.

8. The high-voltage photovoltaic module current-voltage characteristic curve measuring device according to claim 7, 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.

9. The high-voltage photovoltaic module volt-ampere characteristic curve measuring device according to claim 7, 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.

10. The high-voltage photovoltaic module current-voltage characteristic curve measuring device according to claim 7, 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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