TWI740490B - Solar power generation system and test method - Google Patents

Abstract

The present disclosure relates to a test method for testing a solar power generation system. The solar power generation system includes a solar panel and a DC-AC converter. When the DC-AC converter is in a power generation mode, an electrical energy generated by the solar panel is transmitted to an external power grid through the DC-AC converter. When the DC-AC converter is in a test mode different from the power generation mode, controlling the DC-AC converter to draw electrical energy from the external power grid to generate a testing electrical energy and transmit it to the solar panel, so that when the testing electrical energy passes through the solar panel, a test device obtains a test result of the solar panel.

Description

Solar power generation system and detection method

The present disclosure relates to a solar power generation system and a detection method, especially a technology for detecting whether the solar panel is abnormal.

The principle of solar power generation is to use solar panels made of photoelectric semiconductors to absorb sunlight and convert light energy into electrical energy to output voltage or current. However, after a long-term operation of the solar power system, the solar panel will suffer from performance degradation due to various factors, such as being hit by an external object or damage to internal components. Therefore, regular inspections are required to ensure the normal operation of the solar power generation system.

An implementation aspect of this case is a detection method for detecting the solar power generation system. The solar power generation system includes a solar panel and a DC-AC converter. When the DC-AC converter is in power generation mode, the photovoltaic power generated by the solar panel is transmitted to the external power grid through the DC-AC converter. The detection method includes: when the direct-to-ac converter enters the detection that is different from the power generation mode In the mode, the DC-AC converter is controlled to draw power from the external power grid, generate detection power and transmit it to the solar panel, so that the detection instrument obtains the detection result of the solar panel when the detection power passes through the solar panel.

Another implementation aspect of this case is a solar power generation system including a DC-AC converter and a control unit. The DC-AC converter is coupled between the external power grid and the solar panel. The control unit is coupled to the DC-AC converter, and the control unit is used for controlling the DC-AC converter to switch between the power generation mode and the detection mode. When the DC-AC converter is in the power generation mode, the photovoltaic energy generated by the solar panel is converted and transmitted to the external power grid by the DC-AC converter. When the DC-AC converter is in the detection mode, the control unit controls the DC-AC converter to draw power from the external power grid and generate detection power to be sent to the solar panel, so that the solar panel can be detected by the detection instrument when the detection power passes. result.

In the case that the solar power generation system provides detection power to the solar panel, the detection instrument will be able to easily and effectively detect whether the solar panel is normal or damaged.

100: Solar power system

110,110A-110E: Direct AC converter

120: control unit

121: current sensor

130, 130A, 130B: DC converter

131, 131A, 131B: Diode

132: Inductance

140, 740: Bypass switch circuit

141,641,741,742: Bypass switching element

142: One-way components

521a-521d: current sensor

541: Insulated gate bipolar transistor switch

542: Relay

621a-621d: current sensor

821a, 821b: current sensor

840: Bypass switch circuit

Vs: Connect node

Vc: bus voltage

C: Energy storage capacitor

D: Testing equipment

E: External grid

SP, SP1-SP4: solar panels

T1, T2: Transistor switch

Ta, Ta: Toggle switch

W51-W55, WA1-WA5, WB1-WB5: switching element

S401-S408: steps

Figure 1 is a schematic diagram of a solar power generation system according to some embodiments.

Figure 2A is a schematic diagram of a solar power generation system according to some embodiments.

Figure 2B is a schematic diagram of a solar power generation system according to some embodiments.

Figures 3A to 3E are schematic diagrams of DC-AC converters according to some embodiments.

Figure 4 is a flow chart of the detection method according to some embodiments.

FIG. 5A is a schematic diagram of a solar power generation system according to some embodiments.

FIG. 5B is a schematic diagram of a solar power generation system according to some embodiments.

Figure 6A is a schematic diagram of a solar power generation system according to some embodiments.

Figure 6B is a schematic diagram of a solar power generation system according to some embodiments.

FIG. 7A is a schematic diagram of a solar power generation system according to some embodiments.

FIG. 7B is a schematic diagram of a solar power generation system according to some embodiments.

Figure 8 is a schematic diagram of a solar power generation system according to some embodiments.

Hereinafter, a plurality of embodiments of the present invention will be disclosed in drawings. Many practical details will be described in the following description, but these practical details should not be used to limit the present invention. In some implementations, these practical details are unnecessary. To simplify the drawings, some conventionally used structures and elements are shown in the drawings in a simple and schematic manner. In this text, when a component is referred to as "connected" or "coupled", it can refer to "electrical connection" or "electrical coupling", and can also be used to mean that two or more components cooperate or interact with each other. . Although terms such as “first”, “second”, etc. are used herein to describe different elements, the terms are only used to distinguish elements or operations described in the same technical terms. Unless the context clearly indicates, the terms do not specifically refer to or imply order or sequence, nor are they used to limit the present invention.

As shown in FIG. 1, in one embodiment, the solar power generation system 100 includes at least a solar panel SP, a DC-AC converter 110 and a control unit 120. The direct-to-ac converter 110 is coupled to the external power grid E and solar energy Between the boards SP, the control unit 120 is coupled to the DC-AC converter 110. When the solar panel SP is irradiated by sunlight, voltage or current will be generated due to the photoelectric effect. To facilitate the description of the present disclosure, the aforementioned state of power generation is referred to herein as the “power generation mode” of the solar power generation system 100 or the DC-AC converter 110. In addition, since those skilled in the art can understand the structure and principle of the solar panel SP, it will not be repeated here. In addition to the aforementioned "power generation mode", when the solar panel SP is not exposed to sunlight, the solar power system 100 can receive the electric energy from the external power grid E through the direct-to-ac converter 110, so that the direct-to-ac Power is supplied, thereby detecting the state of the solar panel SP. Here, the aforementioned detection process is referred to as the “detection mode” of the solar power generation system 100 or the DC-AC converter 110.

In one embodiment, the control unit 120 is used to control the DC/AC converter 110 to switch between the power generation mode and the detection mode. In other words, when the DC-AC converter 110 is in the “power generation mode”, the photovoltaic power generated by the solar panel SP according to the light will pass through the DC-AC converter 110 and be transmitted to the external power grid E. Conversely, when the DC-AC converter 110 is in the “detection mode”, the control unit 120 will control the DC-AC converter 110 to draw power from the external power grid E to generate detection power, and transmit the detection power to the solar panel SP. Accordingly, when receiving and detecting electric energy, the electrical characteristics (such as voltage, current, impedance) or physical state (temperature) of the solar panel SP can be detected by the detection instrument D, and then whether there is an abnormality in each part of the solar panel SP. In one embodiment, the control unit 120 is used to perform various calculations or judgments, and can be implemented by a microcontroller, a microprocessor, or a digital signal processor. processor), application specific integrated circuit (ASIC) or logic circuit.

In some embodiments, the detection instrument D can be used to detect and determine the magnitude of the detected electrical energy flowing into the solar panel SP, for example, to detect whether the current or voltage is abnormal. The detection instrument D may also include a thermal imager or a spectrum analyzer. In the detection mode, a thermal imager or a spectrum analyzer is used to shoot the detection image of the solar panel SP with the detection current flowing in. Then, the detection image is analyzed by the detection instrument D or other analysis instruments (for example, the temperature is determined by the color of the image) to determine whether the solar panel is normal or damaged. The solar power generation system 100 of the present disclosure changes the electrical characteristics or physical state of the solar panel SP through reverse power supply (that is, the electrical energy of the external power grid E is captured by the DC-AC converter 110 and supplied to the solar panel SP). . Inspectors will be able to inspect multiple solar panels SP simply and quickly through the inspection instrument D, greatly improving the inspection efficiency.

As shown in FIG. 1, in some embodiments, the solar power generation system 100 further includes a DC converter 130. The DC converter 130 is coupled between the solar panel SP and the DC-AC converter 110 (eg, connected to the bus bar Vc and the connection node Vs of the solar panel SP, respectively), and is used to convert the electric energy generated by the solar panel SP. In operation, when the power generation mode is operating, the first DC voltage generated by the solar panel SP is first converted into the second DC voltage by the DC converter 130. Then, the second DC voltage is converted into an output AC voltage by the DC-AC converter 110, and the DC-AC converter 110 transmits the output AC voltage to the external power grid E. However, this disclosure does not Not limited to this, in other embodiments, the DC-to-AC converter 110 can also be directly coupled to the solar panel SP without passing through the DC converter 130.

In other embodiments, the solar power generation system 100 further includes an energy storage capacitor C, which is coupled between the solar panel SP and the DC-AC converter 110 (in different embodiments, the energy storage capacitor C can also be coupled in parallel to DC to AC converter 110 and DC converter 130). When the detection mode is in operation, the energy storage capacitor C and the DC-AC converter 110 cooperate to provide detection power to be transmitted to the solar panel SP. For example, after the DC-to-AC converter 110 extracts electric energy from the external power grid E and converts it into a DC voltage, the electric energy corresponding to the DC voltage can be stored in the energy storage capacitor C, and the electric energy required for the detection operation is transferred through the discharge To solar panel SP.

In FIGS. 2A and 2B, similar elements and principles related to the embodiment in FIG. 1 have been described previously, and will not be repeated. As shown in FIG. 2A, in some embodiments, the solar power generation system 100 further includes a bypass switch circuit 140. The bypass switch circuit 140 is connected in parallel with the DC converter 130 and is coupled between the solar panel SP and the DC AC converter 110. The control unit 120 is coupled to the bypass switch circuit 140. In operation, when the detection mode is operating, the control unit 120 is used to control the bypass switch circuit 140 to turn on, so that the detection power is transmitted from the DC-to-AC converter 110 to the solar panel SP via the bypass switch circuit 140. As shown in FIG. 2B, in some embodiments, the bypass switch circuit 140 includes a bypass switch element 141 and a unidirectional conducting element 142 (such as a diode). The bypass switch element 141 is coupled to the control unit 120 and is controlled by the control unit 120 to be turned on or off, thereby controlling the on or off of the entire bypass switch circuit 140. The unidirectional conduction element 142 is used to prevent Only when the DC-AC converter 110 is in the power generation mode, the bypass switch circuit 140 is turned on by mistake.

In some embodiments, the DC converter 130 is a unidirectional DC converter for receiving the first DC voltage generated by the solar panel SP to generate a second DC voltage, and outputting the second DC voltage to the DC/AC converter 110 . As shown in FIG. 2A, in some embodiments, the DC converter 130 includes a diode 131 and an inductor 132, and the bypass switch circuit 140 is connected in parallel with the diode 131 and the inductor 132 of the DC converter 130. The direction of the current passing through the diode 131 is from the solar panel SP to the DC-AC converter 110. Although the circuit structure of the DC converter 130 in the embodiment shown in FIG. 2B is different from that shown in FIG. 2A, those skilled in the art can understand the operation of the DC converter 130, and will not be repeated here.

Figures 3A to 3E are schematic diagrams of the DC-AC converters 110A-110E according to some embodiments of the present disclosure. The DC-AC converter 110 may also be a bidirectional DC-AC converter. In Figure 3A, the DC-to-AC converter 110A includes at least two transistor switches T1 and T2. The aforementioned control unit 120 can respectively control the on and off of the transistor switches T1 and T2 to switch the input and output directions of the DC-AC converter 110. Although the circuit structure of the DC-AC converters 110B to 110E in the embodiment shown in Figs. 3B to 3E is different from that shown in Fig. 3A, anyone in the art can understand the circuit structure and operation of Figs. 3A to 3E. I will not repeat them here.

Hereinafter, FIG. 4 is used in conjunction with the solar power generation system 100 shown in FIGS. 2A and 2B to illustrate the steps of the solar power generation system 100 in different operation modes. As shown in Figure 4, in step S401, The control unit 120 determines that the DC-AC converter 110 is to be selectively controlled in the "generation mode" or the "detection mode". If the control unit 120 wants to control the DC/AC converter 110 in the "generation mode", step S402 is performed. In step S402, the control unit 120 turns off the bypass switch circuit 140. Next, in step S403, the DC converter 130 converts the first DC voltage generated by the solar panel SP into a second DC voltage. In step S404, the DC-AC converter 110 receives the second DC voltage, converts the second DC voltage into an AC voltage, and outputs it to the external power grid E.

If the control unit 120 wants to control the DC/AC converter 110 in the "detection mode", step S405 is performed. In step S405, the control unit 120 turns on the bypass switch circuit 140. Next, in step S406, the control unit 120 controls the DC-to-AC converter 110 to draw power from the external power grid E to generate detected power. Then, in step S407, the DC-to-AC converter 110 transmits the detected electric energy to the solar panel SP through the bypass switch circuit 140. In step S408, the detection instrument D detects the electrical characteristics or physical state of the solar panel SP to obtain a detection result (such as a detection image), and analyzes whether the solar panel SP is normal or damaged.

On the other hand, in some embodiments, as shown in Figures 2A and 2B, the control unit 120 detects the voltage difference between the DC-AC converter 110 and the solar panel SP, and then controls the bypass switch according to the detection result. The on or off state of the circuit 140. In one embodiment, the control unit 120 is used to detect whether the bus voltage Vc between the DC-AC converter 110 and the DC converter 130 has returned to zero (that is, whether the cross-voltage of the energy storage capacitor C has returned to zero), so as to prevent The residual voltage causes the internal circuit of the solar power generation system 100 damage. In another embodiment, the control unit 120 detects whether the busbar voltage Vc and the voltage of the connection node Vs of the solar panel SP are equipotential to confirm whether there is a residual voltage in the solar power generation system 100.

For example, in operation, if the power generation mode is to be re-entered after the detection is completed, the control unit 120 will control the DC-to-AC converter 110 to stop generating the detected power. Next, the control unit 120 detects whether the bus voltage Vc between the DC-AC converter 110 and the DC converter 130 has returned to zero, or detects whether the bus voltage Vc and the voltage of the connection node Vs of the solar panel SP are equipotential. If the bus voltage Vc is zero, or the bus voltage Vc and the voltage of the connection node Vs are at the same potential, the control unit 120 controls the bypass switch circuit 140 to switch from the on state to the off state. Similarly, if it enters the detection mode after being in the power generation mode for a period of time, the control unit 120 controls the bypass switch circuit 140 to switch from the off state to the on state. Then, the control unit 120 controls the DC-AC converter 110 to draw power from the external power grid E to generate detected power.

In the detection mode, the control unit 120 can adjust the voltage level or current level of the detected electric energy. Please refer to FIG. 2A. In some embodiments, the solar power generation system 100 further includes a current sensor 121. The current sensor 121 is coupled to the control unit 120 to detect the current flowing into the solar panel SP, and return it to the control unit 120, so that the control unit 120 can adjust the current flowing into the solar panel SP according to the detected current. Current.

In some embodiments, the solar power generation system 100 includes a set current value. By setting the set current value, the current flowing into the solar panel SP will not be too high and cause damage to the solar panel SP. The set current value can be It is preset, and can also be input by the user or adjusted at any time. After the control unit 120 receives the detected current value returned by the current sensor 121, the control unit 120 compares the detected current value with the set current value, and controls the DC-AC converter 110 according to the comparison result, so that the DC-AC conversion The device 110 changes the magnitude of the detected power output. For example, when the detected current value is greater than the set current value, the voltage level or current level of the detected electrical energy is reduced; when the detected current value is less than the set current value, the voltage level or current level of the detected electrical energy is increased. In some embodiments, the set current value is an ideal current range when the DC-AC converter 110 is in the "detection mode". The value or range of the set current value can be set by the user.

The detection method can also be applied to simultaneously detect multiple sets of solar panels. In FIGS. 5A and 5B, similar elements and principles related to the embodiment in FIG. 1 have been described previously, and will not be repeated. As shown in FIG. 5A, the solar power generation system 500 includes a plurality of switching elements W51 to W55. The bypass switch circuit 140 is coupled to the solar panel SP1 through the switching elements W51, W52, W53, and is coupled to the other solar panel SP2 through the switching elements W51, W54, W55. The two solar panels SP1 and SP2 are coupled in parallel with each other. In the detection mode, if the switching elements W51 to W55 are all turned on, the solar power generation system 500 will be able to provide detection power to the solar panels SP1 and SP2 at the same time. Detection instrument D (such as: thermal imager or spectrum analyzer) can simultaneously detect the electrical characteristics or physical state of the solar panels SP1 and SP2.

In summary, if the switching elements W51, W52, and W53 are turned on, and the switching elements W54, W55 are turned off, the solar power generation system 500 will only provide detection power to the solar panel SP1. Similarly, if the switching element W51, When W54 and W55 are turned on, and the switching elements W52 and W53 are turned off, the solar power generation system 500 will only provide detection power to the solar panel SP2. The control unit 120 may control the bypass switch circuit 140 to switch the mode when the voltage difference between the DC-AC converter 110 and the solar panel SP is zero. In other embodiments, as shown in FIG. 5B, the solar power generation system 500 can be coupled to the solar panels SP1, SP2 through the switching elements W51, W52, W54 (ie, no switching elements W53, W55 are required), or alternatively Ground detection of different solar panels SP1 and SP2. The operation of the switching elements W51, W52, and W54 is similar to the above. In some embodiments, the bypass switch circuit 140 shown in FIGS. 5A and 5B may include a bidirectional switch element, for example, an insulated gate bipolar transistor switch 541 (IGBT) or a relay 542, but It is not limited to the above.

In one embodiment, as shown in Figure 5A, the solar power generation system 500 detects the current flowing through the switching elements W52 and W54 through the current sensors 521a and 521b, and can calculate the current flowing through the switching element W51. size. The operation of the current sensors 521a and 521b is the same as that of the embodiment described in FIG. 2A, and is electrically connected to the control unit 120 so as to return the detected data to the control unit 120. In one embodiment, as shown in Figure 5B, the solar power generation system 500 detects the magnitude of the current flowing through the switching elements W51 and W54 through the current sensors 521c and 521d, and then calculates the amount of current flowing through the switching element W52. The magnitude of the current.

In some embodiments, the control unit 120 can also receive the detected current values returned by all the current sensors 521a and 521b. Control unit 120 All the detected current values are compared with the set current values, and the DC-AC converter 110 is controlled according to the comparison result, so that the DC-AC converter 110 changes the voltage level or the current magnitude of the detected electric energy output. In some embodiments, as long as one of the detected current values is greater than the set current value (or the control unit 120 compares the maximum detected current value with the set current value), the control unit 120 will control the DC-AC converter 110 to decrease Detect electrical energy.

When detecting a large number of solar panels, the DC/AC converter of the solar power generation system can be connected in parallel with multiple sets of DC converters, and then through multiple sets of DC converters in parallel with multiple sets of solar panels to improve the DC/AC converter in power generation mode s efficiency. In FIGS. 6A and 6B, similar elements and principles related to the embodiment in FIG. 1 have been described previously, and will not be repeated.

As shown in FIG. 6A, the DC to AC converter 110 is coupled to two sets of DC converters 130A and 130B. The bypass switch circuit 140 is connected to the switching elements WA1 and WB1 through two paths, respectively. The switching element WA1 is connected to the solar panels SP1 and SP2 through the switching elements WA2 and WA4, respectively, and connected to the switching elements WA3 and WA5. The switching element WB1 is connected to the solar panels SP3 and SP4 through the switching elements WB2 and WA4, respectively, and connected to the switching elements WB3 and WB5. The bypass switch circuit 140 includes a bypass switch element 641 (such as an insulated gate bipolar transistor switch) and two unidirectional conduction elements 142. When the bypass switch element 641 is controlled and turned on by the control unit 120, the solar panels SP1 to SP4 can be detected similarly to the foregoing. Similarly, the bypass switch circuit 140 in FIG. 6B includes two bypass switch elements 641 and 642 (such as IGBT) and a unidirectional conduction element 142 coupled to each other. When bypassing the switching element 641 and the corresponding switching element When WA1~WA5 are turned on, the solar power generation system 600 detects the solar panels SP1~SP2. Conversely, when the bypass switching element 642 and the corresponding switching elements WB1 to WB5 are turned on, the solar power generation system 600 detects the solar panels SP3 to SP4. In other embodiments, the solar power generation system 600 may be provided with an independent set of bypass switch elements 641 and 642 for each solar panel SP1 and SP2 to switch between the detection mode and the power generation mode.

In one embodiment, as shown in FIGS. 6A and 6B, the solar power generation system 100 detects the currents flowing through the switching elements WA2 and WA4 connected to the solar panel SP2 through the current sensors 621a and 621b, and accordingly The magnitude of the current flowing through the switching element WA1 can be calculated. Similarly, the solar power generation system 100 detects the currents flowing through the switching elements WB2 and WB4 connected to the solar panel SP4 through the current sensors 621c and 621d, respectively, and can calculate the currents flowing through the switching element WB1 accordingly. In addition, a current sensor can also be installed between the switching elements WA1 and WA4 to calculate the current flowing through the switching element WA2.

The "bypass switch circuit" and its "bypass switch element" in this disclosure are not limited to those shown in Figures 1 to 6B, and can form a transmission between the DC-AC converter and the solar panel in the detection mode. The circuit that detects the electrical energy path can be used as a "bypass switch circuit" and its "bypass switch element". In FIG. 7A, the similar elements and principles related to the embodiment in FIG. 5A have been described previously, and will not be repeated. As shown in the figure, in some embodiments, the bypass switch circuit 740 may include an insulated gate bipolar transistor switch, or an insulated gate bipolar transistor switch. In the detection mode, the control unit 120 controls the isolation gate bipolar transistor switch to turn on, so that the detected electrical energy is transmitted to the solar panel SP1 or SP2 through the bypass switch circuit 740. In some embodiments, the DC converter 130 in the solar power generation system 700 includes a diode 131. In this case, the parasitic diode in the insulated gate bipolar transistor switch can be used as a diode. For example, the DC converter 130 includes a diode 131, and the diode 131 can be realized by a parasitic diode of an insulated gate bipolar transistor switch in the bypass switch circuit 740. The diode 131 and the insulated gate bipolar transistor switch are also coupled in parallel (similar to the circuit in Figure 5A). FIG. 7B is a schematic diagram of a solar power generation system 700 according to different embodiments of the present disclosure. Similar components and principles related to the embodiment in FIG. 6B have been described previously, and will not be repeated. The bypass switch circuit in the figure includes bypass switch elements 741 and 742, and the parasitic diodes in the elements can be used as the diodes 131A and 131B in the DC converters 130A and 130B, respectively.

As shown in FIG. 8, in this embodiment, the bypass switch circuit 840 and the DC converter 130 of the solar power generation system 800 are coupled to the controlled switch 850 and the switching elements WA, WB, and WC. In addition, the DC converter 130 also includes two switching switches Ta and Tb. The control terminals of the switches Ta and Tb are coupled to the control unit 120 and can be controlled by the control unit 120 to be turned on or off. In the power generation mode, the switching elements WA~WC and the transfer switches Ta~Tb are controlled to be turned on, and the bypass switch circuit 840 and the controlled switch 850 are turned off. At this time, the parasitic diode in the bypass switch circuit 840 will serve as the diode 131 in the DC converter 130. The photovoltaic energy generated by the solar panels SP1 and SP2 will pass through the parasitic diodes of the controlled switch 850, It is processed by the DC converter 130 and the DC AC converter 110 and output to the external power grid E. On the other hand, in the detection mode, the bypass switch circuit 840, the controlled switch 850, the switching elements WA, WB, and WC are turned on, and the changeover switches Ta, Tb are turned off, so that the DC converter 130 is turned off. At this time, the DC-AC converter 110 can draw power from the external power grid E to transmit the detected power to the solar panels SP1 and SP2 through the bypass switch circuit 840 and the controlled switch 850 that is turned on.

Similar to the previous embodiment, in one embodiment, as shown in Fig. 8, the solar power generation system 100 detects the magnitude of the current flowing through the switching elements WA, WB connected to the solar panel SP2 through the current sensors 821a, 821b, respectively , And can calculate the size of the current flowing through the switching element WC.

100: Solar power system

110: Direct AC converter

120: control unit

121: current sensor

130: DC converter

131: Diode

132: Inductance

140: Bypass switch circuit

Vc: bus voltage

Vs: Connect node

C: Energy storage capacitor

E: External grid

SP: Solar Panel

Claims (20)

A detection method is used to detect a solar power generation system. The solar power generation system includes a solar panel and a DC AC converter. When the DC AC converter is in a power generation mode, a photovoltaic power generated by the solar panel passes through the solar panel. The DC-AC converter is transmitted to an external power grid, and the detection method includes: when the DC-AC converter enters a detection mode different from the power generation mode, controlling the DC-AC converter to draw power from the external power grid to generate a detection The electric energy is transmitted to the solar panel, so that the solar panel obtains the detection result of the solar panel by a detection instrument when the detected electric power passes. The detection method according to claim 1, wherein the solar power generation system further includes a DC converter and a bypass switch circuit, the DC converter is coupled between the solar panel and the DC AC converter, and is in the power generation mode The solar panel generates a first DC voltage, the first DC voltage is converted into a second DC voltage by the DC converter, and the second DC voltage is converted into an output AC voltage by the DC converter and transmitted to the External power grid, the bypass switch circuit is connected in parallel with the DC converter and is coupled between the solar panel and the DC AC converter, and the detection method includes: in the detection mode, controlling the bypass switch circuit to be turned on to make The detected electric energy is transmitted to the solar panel by the DC-AC converter through the bypass switch circuit. The detection method according to claim 2, wherein when the solar power generation system enters the detection mode from the power generation mode, the detection method includes: controlling the bypass switch circuit to switch from an off state to an on state; and controlling the direct AC The converter draws electric energy from the external grid to generate the detected electric energy. The detection method according to claim 2, wherein when the solar power generation system ends the detection mode and returns to the power generation mode, the detection method includes: controlling the DC-AC converter to stop generating the detection power; and detecting the DC-AC converter And the voltage difference between the solar panel and the solar panel; and controlling the bypass switch circuit to switch from the on state to the off state. The detection method according to claim 1, wherein the solar power generation system further includes an energy storage capacitor coupled between the solar panel and the DC-AC converter, and in the detection mode, the energy storage capacitor The capacitor cooperates with the direct-to-ac converter to provide the detected electrical energy to be transmitted to the solar panel. The detection method according to claim 1, wherein the detection method further comprises: in the detection mode, detecting the magnitude of the detection electric energy flowing into the solar panel. The detection method according to claim 1, wherein the detection method further comprises: in the detection mode, using a thermal imager or a spectrum analyzer to take a detection image of one of the solar panels with the detection electric energy flowing in; and The detection image is analyzed to determine whether the solar panel is normal or damaged. The detection method according to claim 1, wherein the detection method further comprises: receiving a detection current value returned by a current sensor; comparing the detection current value with a set current value; and controlling the direct current value according to the comparison result AC converter to adjust the voltage level or current magnitude of the detected electrical energy. A solar power generation system includes: a DC converter, coupled between an external power grid and a solar panel; and a control unit, coupled to the DC converter, the control unit is used to control the DC converter in Switch between a power generation mode and a detection mode; wherein, when the direct-to-ac When the converter is in the detection mode, the control unit controls The direct-to-ac converter draws electric energy from the external power grid and generates a detected electric energy to be transmitted to the solar panel, so that the solar panel obtains the detection result of the solar panel by a detecting instrument when the detected electric energy passes. The solar power generation system according to claim 9, wherein the solar power generation system further comprises: a DC converter, coupled between the solar panel and the DC converter, and in the power generation mode, the solar panel generates a first A DC voltage, the first DC voltage is converted into a second DC voltage by the DC converter, and the second DC voltage is converted into an output AC voltage by the DC converter and transmitted to the external power grid. The solar power generation system of claim 10, wherein the solar power generation system further comprises: a bypass switch circuit connected in parallel with the DC converter and coupled between the solar panel and the DC AC converter, and the control unit is coupled The bypass switch circuit is connected, wherein, in the detection mode, the control unit controls the bypass switch circuit to conduct, so that the detected electric energy is transmitted to the solar panel from the DC-AC converter through the bypass switch circuit. The solar power generation system according to claim 11, wherein the DC converter includes a diode, the diode is connected in parallel with the bypass switch circuit, and a direction of current passing through the diode is from the solar panel Past The direct-to-ac converter. The solar power generation system according to claim 12, wherein the DC converter further includes an inductor, and the bypass switch circuit is connected in parallel with the diode and the inductor of the DC converter. The solar power generation system according to claim 11, wherein when the solar power generation system enters the detection mode from the power generation mode, the control unit controls the bypass switch circuit to switch from the off state to the on state; and the control unit controls the The DC-AC converter draws electric energy from the external power grid to generate the detected electric energy. The solar power generation system according to claim 11, wherein when the solar power generation system ends the detection mode and returns to the power generation mode, the control unit controls the direct-to-ac converter to stop generating the detection power; the control unit detects the direct current The voltage difference between the AC converter and the solar panel; and the control unit controls the bypass switch circuit to switch from the on state to the off state. The solar power generation system according to claim 9, wherein the solar power generation system further comprises an energy storage capacitor, the energy storage capacitor is coupled between the solar panel and the DC-AC converter, and in the detection mode, the The energy storage capacitor cooperates with the direct-to-ac converter to provide the detected electric energy to be transmitted to the solar panel. The solar power generation system according to claim 10, wherein the DC converter is a unidirectional DC converter, and the unidirectional DC converter is used for generating the second DC voltage according to the first DC voltage of the solar panel as an input As output to the DC-AC converter. The solar power system according to claim 9, wherein the solar power system further comprises: a current sensor, and in the detection mode, the current sensor is used to detect the magnitude of the detected electrical energy flowing into the solar panel. The solar power generation system according to claim 9, wherein the DC-AC converter is a two-way DC-AC converter. The solar power generation system according to claim 9, wherein the control unit is further used for receiving a detection current value returned by a current sensor, and comparing the detection current value with a set current value; the control unit is used for The DC-AC converter is controlled according to the comparison result to adjust the voltage level or current of the detected electric energy.

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