Power supply system and control method of a power supply system

Abstract

The application provides a power supply system and a control method of the power supply system. The power supply system comprises a direct-current voltage conversion device, an inverter and a diode. The direct-current voltage conversion device comprises a controller and a direct-current voltage conversion circuit. The controller is configured to control the direct-current voltage conversion circuit to receive power output by a power generation module, and output a voltage to the inverter through a direct-current bus after direct-current conversion. The diode is connected in series with the direct-current bus. The controller is configured to control the output voltage of the direct-current voltage conversion circuit, so that the diode is in a conduction state, detect a voltage on the direct-current bus, and determine whether high-voltage ride-through of the power supply system occurs according to the voltage on the direct-current bus. The power supply system and the control method of the power supply system provided by the application can realize fault isolation and rapid detection of high-voltage ride-through at the same time, and improve the efficiency of detecting high-voltage ride-through.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of circuit, more particularly, to a power supply system and a control method of the power supply system. BACKGROUND

[0002] High voltage ride-through (HVRT) refers to the ability to ensure continuous operation of a power station without disconnection from the grid within a certain voltage rise range and time interval when the voltage at the grid connection point of the photovoltaic power station rises due to power system accidents.

[0003] During high voltage ride-through, due to the rapid rise of the AC grid side voltage, the voltage on the DC bus will be raised synchronously due to the limitation of the control loop of the inverter circuit on the pulse width modulation (PWM) modulation ratio. At this time, in the early stage of the fault process, the voltage conversion circuit (for example, a boost circuit) has not received information of the grid side fault (for example, the voltage of the power signal between the AC grid and the inverter circuit), and the control of the power system is in the normal working state of maximum power point tracking (MPPT). Before the voltage conversion circuit receives the information of the grid side fault and completes the DC bus voltage control process according to the information of the grid side fault, the voltage of the voltage conversion circuit side DC bus cannot keep up with the rise of the voltage of the inverter circuit side DC bus, which often leads to the situation that the DC side power cannot be smoothly sent out and the power is uncontrollable.

[0004] A known technology is to connect a diode in series on the DC bus, which is turned on when the voltage conversion circuit outputs power and is turned off when the voltage conversion circuit receives power. When high voltage ride-through occurs, the diode can quickly reverse and be turned off to achieve the effect of fault isolation. However, after that, the voltage conversion circuit cannot accurately detect the inverter bus, so it cannot quickly determine that high voltage ride-through has occurred.

[0005] Therefore, there is an urgent need for a power supply system and a control method of the power supply system, which can quickly detect high voltage ride-through while achieving fault isolation, and improve the efficiency of detecting high voltage ride-through. SUMMARY

[0006] The present application provides a power supply system and a control method of the power supply system, which can quickly detect high voltage ride-through while achieving fault isolation, and improve the efficiency of detecting high voltage ride-through.

[0007] In a first aspect, a power supply system is provided. The system includes a DC voltage conversion device, including a controller and a DC voltage conversion circuit, the controller configured to control the DC voltage conversion circuit to receive power output by a power generation module and output a DC voltage to a DC bus after DC conversion; an inverter configured to receive the output DC voltage from the DC voltage conversion circuit through the DC bus and supply power to a power grid after AC conversion from the DC voltage; and a diode connected in series with the DC bus, the diode being turned on when the DC voltage conversion circuit outputs power and turned off when the DC voltage conversion circuit receives power. The controller is further configured to control the output DC voltage of the DC voltage conversion circuit to keep the diode turned on, and detect a voltage on the DC bus when the diode is turned on and determine whether the power supply system is in high voltage ride through according to the voltage on the DC bus.

[0008] According to the scheme of the present application, the DC voltage conversion device controls the output DC voltage of the DC voltage conversion circuit to keep the diode turned on, so that whether the power supply system is in high voltage ride through can be determined according to the voltage on the DC bus, and the detection of high voltage ride through can be quickly realized while fault isolation is achieved, thereby improving the efficiency of detecting high voltage ride through.

[0009] In combination with the first aspect, in some implementations of the first aspect, the controller is specifically configured to determine whether the diode is turned off by monitoring a current on the DC bus, and quickly control the output DC voltage of the DC voltage conversion circuit to make a voltage difference across the diode greater than a turn-on threshold of the diode when it is determined that the diode is turned off.

[0010] The controller is specifically configured to monitor a current voltage of the DC bus, and determine that the power supply system is in high voltage ride through when it is determined that the voltage of the DC bus is greater than or equal to a first DC bus voltage, where the first DC bus voltage is greater than a rated AC line voltage peak of the inverter.

[0011] In this way, when the diode is turned off, the DC voltage conversion device quickly restores the small current turn-on state of the diode, so that whether the power supply system is in high voltage ride through can be determined according to the voltage on the DC bus, and the detection of high voltage ride through can be quickly realized while fault isolation is achieved, thereby improving the efficiency of detecting high voltage ride through.

[0012] In combination with the first aspect, in some implementations of the first aspect, the controller is further configured to control an output power of the DC voltage conversion circuit to be a first power when it is determined that the power supply system is in high voltage ride through, where a deviation between the first power and an output power of the DC voltage conversion circuit before the power supply system is in high voltage ride through is less than a first power deviation threshold.

[0013] The controller is specifically configured to: in a case where it is determined that the power supply system is in high-voltage ride-through, control the output voltage and / or the output current of the direct-current voltage conversion circuit, so that the output power of the direct-current voltage conversion circuit is a first power.

[0014] According to the scheme of the present application, in a case where it is determined that the power supply system is in high-voltage ride-through, the direct-current voltage conversion device controls the output power of the direct-current voltage conversion circuit to deviate from the output power before the power supply system is in high-voltage ride-through by less than a first power deviation threshold, thereby avoiding the problem of active power imbalance that may exist in the alternating-current power grid during high-voltage ride-through, meeting the technical requirement that the output active power during grid failure is unchanged from the output active power before the failure, and improving the stability of the alternating-current power grid.

[0015] In a second aspect, a power supply system is provided, which includes: a direct-current voltage conversion device including a first controller and a direct-current voltage conversion circuit, the first controller being configured to control the direct-current voltage conversion circuit to receive electrical energy output by a power generation module and output a voltage through a direct-current bus to an inverter after direct-current conversion; the inverter including a second controller and an inverter circuit, the second controller being configured to control the inverter circuit to receive the output voltage of the direct-current voltage conversion circuit through the direct-current bus and supply power to a power grid after direct-current-to-alternating-current conversion; a diode connected in series with the direct-current bus, the diode being conductive in a case where the direct-current voltage conversion circuit outputs electrical energy and being non-conductive in a case where the direct-current voltage conversion circuit receives electrical energy; a first circuit connected in parallel with the diode, the first circuit having a current less than a preset first current value when conductive; the second controller being further configured to control the first circuit to be conductive in a case where it is determined that the power grid is in high-voltage failure and to be non-conductive in a case where it is determined that the power grid is not in high-voltage failure; and the first controller being further configured to detect the voltage on the direct-current bus and determine whether the power supply system is in high-voltage ride-through according to the voltage on the direct-current bus.

[0016] According to the scheme of the present application, the inverter controls the first circuit to be conductive in a case where the power grid is in high-voltage failure and to be non-conductive in a case where the power grid is not in high-voltage failure, so that the direct-current voltage conversion device can determine whether the power supply system is in high-voltage ride-through according to the voltage on the direct-current bus, thereby achieving fault isolation while quickly detecting high-voltage ride-through and improving the efficiency of detecting high-voltage ride-through.

[0017] In combination with the second aspect, in some implementations of the second aspect, the first controller is specifically configured to: monitor the current voltage of the direct-current bus; and in a case where it is determined that the voltage of the direct-current bus is greater than or equal to a first direct-current bus voltage, determine that the power supply system is in high-voltage ride-through, wherein the first direct-current bus voltage is greater than the peak value of the rated alternating-current line voltage of the inverter.

[0018] In this way, the direct-current voltage conversion device can determine whether the power supply system has high-voltage ride-through according to whether the voltage on the direct-current bus is greater than the preset first direct-current bus voltage, and can quickly realize detection of high-voltage ride-through and improve the efficiency of detecting high-voltage ride-through.

[0019] With reference to the second aspect, in some implementations of the second aspect, the first controller is further configured to: in a case where it is determined that the power supply system has high-voltage ride-through, control the output power of the direct-current voltage conversion circuit to be a first power, wherein the first power deviates from the output power of the direct-current voltage conversion circuit before the power supply system has high-voltage ride-through by less than a first power deviation threshold.

[0020] The first controller is specifically configured to: in a case where it is determined that the power supply system has high-voltage ride-through, control the output voltage and / or the output current of the direct-current voltage conversion circuit, so that the output power of the direct-current voltage conversion circuit is the first power.

[0021] According to the scheme of the present application, in a case where it is determined that the power supply system has high-voltage ride-through, the direct-current voltage conversion device controls the output power of the direct-current voltage conversion circuit to deviate from the output power before the power supply system has high-voltage ride-through by less than a first power deviation threshold, thereby avoiding the problem of active power imbalance that may exist in the alternating-current power grid during high-voltage ride-through, meeting the technical requirement that the output active power during grid failure is unchanged from the active power before failure, and improving the stability of the alternating-current power grid.

[0022] Optionally, the first circuit includes an anti-reverse insulate-gate bipolar transistor (IGBT).

[0023] In a third aspect, a control method of a power supply system is provided. The method is performed by the power supply system, and the power supply system includes: a direct-current voltage conversion device including a controller and a direct-current voltage conversion circuit, the controller being configured to control the direct-current voltage conversion circuit to receive electrical energy output by a power generation module and output a voltage through a direct-current bus after direct-current conversion; an inverter configured to receive the output voltage of the direct-current voltage conversion circuit through the direct-current bus and supply power to a power grid after direct-current-to-alternating-current conversion; and a diode connected in series with the direct-current bus, the diode being conductive when the direct-current voltage conversion circuit outputs electrical energy and being non-conductive when the direct-current voltage conversion circuit receives electrical energy.

[0024] The method includes: the controller controls the output voltage of the direct-current voltage conversion circuit, so that the diode is in a conductive state; and the controller detects a voltage on the direct-current bus in a case where the diode is in the conductive state, and determines whether the power supply system has high-voltage ride-through according to the voltage on the direct-current bus.

[0025] According to the scheme, the direct-current voltage conversion device controls the output voltage of the direct-current voltage conversion circuit so that the diode is in a conducting state, thereby determining whether high-voltage ride-through occurs according to the voltage on the direct-current bus, and quickly detecting high-voltage ride-through while achieving fault isolation, thereby improving the efficiency of detecting high-voltage ride-through.

[0026] In combination with the third aspect, in some implementations of the third aspect, the controller controls the output voltage of the direct-current voltage conversion circuit so that the diode is in a conducting state, including: the controller determines that the diode is cut off by monitoring the current on the direct-current bus; and in the case that the diode is cut off, the controller controls the output voltage of the direct-current voltage conversion circuit so that the voltage difference across the diode is greater than the conducting threshold value of the diode.

[0027] The controller detects the voltage on the direct-current bus and determines whether high-voltage ride-through occurs in the power supply system according to the voltage on the direct-current bus, including: the controller monitors the current voltage of the direct-current bus; and in the case that the voltage of the direct-current bus is greater than or equal to the first direct-current bus voltage, the controller determines that high-voltage ride-through occurs in the power supply system, wherein the first direct-current bus voltage is greater than the rated alternating current line voltage peak value of the inverter.

[0028] In this way, when the diode is cut off, the direct-current voltage conversion device quickly recovers the small current conducting state of the diode, thereby determining whether high-voltage ride-through occurs in the power supply system according to the voltage on the direct-current bus, and quickly detecting high-voltage ride-through while achieving fault isolation, thereby improving the efficiency of detecting high-voltage ride-through.

[0029] In combination with the third aspect, in some implementations of the third aspect, the method further includes: in the case that the controller determines that high-voltage ride-through occurs in the power supply system, the controller controls the output power of the direct-current voltage conversion circuit to be a first power, wherein the deviation of the first power from the output power of the direct-current voltage conversion circuit before high-voltage ride-through occurs in the power supply system is less than a first power deviation threshold.

[0030] In the case that the controller determines that high-voltage ride-through occurs in the power supply system, the controller controls the output power of the direct-current voltage conversion circuit to be a first power, including: the controller controls the output voltage and / or output current of the direct-current voltage conversion circuit to make the output power of the direct-current voltage conversion circuit be the first power in the case that the controller determines that high-voltage ride-through occurs in the power supply system.

[0031] According to the scheme, when it is determined that the power supply system is in high-voltage ride-through, the DC voltage conversion device controls the output power of the DC voltage conversion circuit to deviate from the output power before the high-voltage ride-through by less than a first power deviation threshold, thereby avoiding the problem of active power imbalance that may exist in the AC power grid during the high-voltage ride-through, meeting the technical requirement that the output active power during the grid fault is unchanged from the output active power before the fault, and improving the stability of the AC power grid.

[0032] In a fourth aspect, a control method of a power supply system is provided. The method is performed by the power supply system, and the power supply system includes: a DC voltage conversion device including a first controller and a DC voltage conversion circuit, the first controller being configured to control the DC voltage conversion circuit to receive electrical energy output by a power generation module and output a DC voltage to an inverter through a DC bus after DC conversion; the inverter including a second controller and an inverter circuit, the second controller being configured to control the inverter circuit to receive the output DC voltage of the DC voltage conversion circuit through the DC bus and supply power to a power grid after AC conversion from DC; a diode connected in series with the DC bus, the diode being conductive when the DC voltage conversion circuit outputs electrical energy and being non-conductive when the DC voltage conversion circuit receives electrical energy; and a first circuit connected in parallel with the diode, the first circuit having a current less than a preset first current value when the first circuit is conductive.

[0033] The method includes: the second controller controlling the first circuit to be conductive when it is determined that the power grid has a high-voltage fault, and controlling the first circuit to be non-conductive when it is determined that the power grid does not have a high-voltage fault; and the first controller detecting a voltage on the DC bus and determining whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus.

[0034] According to the scheme, the inverter controls the first circuit to be conductive when the power grid has a high-voltage fault and to be non-conductive when the power grid does not have a high-voltage fault, so that the DC voltage conversion device can determine whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus, the detection of the high-voltage ride-through can be quickly implemented while fault isolation is implemented, and the efficiency of detecting the high-voltage ride-through is improved.

[0035] In combination with the fourth aspect, in some implementations of the fourth aspect, the first controller detects the voltage on the DC bus and determines whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus, including: the first controller monitoring a current voltage of the DC bus; and determining that the power supply system has a high-voltage ride-through when it is determined that the voltage of the DC bus is greater than or equal to a first DC bus voltage, where the first DC bus voltage is greater than a rated AC line voltage peak value of the inverter.

[0036] In this way, the direct-current voltage conversion device can determine whether the power supply system has high-voltage ride-through according to whether the voltage on the direct-current bus is greater than or equal to the preset first direct-current bus voltage, and can quickly realize detection of high-voltage ride-through and improve the efficiency of detecting high-voltage ride-through.

[0037] With reference to the fourth aspect, in some implementations of the fourth aspect, the method further includes: in a case where the first controller determines that the power supply system has high-voltage ride-through, controlling, by the first controller, the output power of the direct-current voltage conversion circuit to be a first power, wherein a deviation between the first power and the output power of the direct-current voltage conversion circuit before the power supply system has high-voltage ride-through is less than a first power deviation threshold.

[0038] In a case where the first controller determines that the power supply system has high-voltage ride-through, controlling, by the first controller, the output power of the direct-current voltage conversion circuit to be a first power includes: in a case where the first controller determines that the power supply system has high-voltage ride-through, controlling, by the first controller, the output voltage and / or the output current of the direct-current voltage conversion circuit, so that the output power of the direct-current voltage conversion circuit is the first power.

[0039] According to the scheme of the present application, in a case where the direct-current voltage conversion device determines that the power supply system has high-voltage ride-through, the output power of the direct-current voltage conversion circuit is controlled to deviate from the output power before the power supply system has high-voltage ride-through by less than a first power deviation threshold, thereby avoiding the problem of active power imbalance that may exist in the alternating-current power grid during high-voltage ride-through, meeting the technical requirement that the output active power during power grid failure is unchanged from the output active power before failure, and improving the stability of the alternating-current power grid.

[0040] Optionally, the first circuit includes an anti-reverse insulated gate bipolar transistor (IGBT). BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is an example structure schematic diagram of a power supply system suitable for embodiments of the present application.

[0042] Figure 2 is an example structure schematic diagram of a power supply system suitable for existing power supply systems.

[0043] Figure 3 is an example structure schematic diagram of a power supply system of embodiments of the present application.

[0044] Figure 4 is another example structure schematic diagram of a power supply system of embodiments of the present application.

[0045] Figure 5 is still another example structure schematic diagram of a power supply system of embodiments of the present application.

[0046] Figure 6is an example schematic diagram of a control method of a power supply system according to an embodiment of the present application.

[0047] Figure 7 is another example schematic diagram of a control method of a power supply system according to an embodiment of the present application.

[0048] Figure 8 is a structural schematic diagram of a control device according to an embodiment of the present application. DETAILED DESCRIPTION

[0049] The technical solutions in the present application will be described below with reference to the accompanying drawings.

[0050] In order to facilitate the understanding of the embodiments of the present application, the application scenarios of the embodiments of the present application will be introduced below. Figure 1 and Figure 2 The application scenarios of the embodiments of the present application will be introduced below.

[0051] Figure 1 is an example structural schematic diagram of a power supply system according to an embodiment of the present application. As shown in Figure 1 , the power supply system 100 can generate alternating current and provide the generated alternating current to the power grid 160 for power supply. The power supply system 100 can include a power generation module 110 and a control system 101, and the control system 101 includes a direct current voltage conversion device 120, a diode 140, and an inverter 150. The power generation module 110 can output generated power to the direct current voltage conversion device 120. The direct current voltage conversion device 120 can receive the power output by the power generation module 110 and output the power to the inverter 150 through a direct current bus 130 after direct current conversion. The inverter 150 can accept the power of the direct current voltage conversion device 120 and supply power to the power grid after direct current-to-alternating current conversion. The power of the power generation module 110 is output to the direct current bus 130 after direct current voltage conversion by the direct current voltage conversion device 120. The direct current bus 130 connects the direct current voltage conversion device 120 and the inverter 150, and the power of the direct current voltage conversion device 120 and the inverter 150 is transmitted through the direct current bus 130. The inverter 150 can monitor the grid voltage, and when a high voltage fault occurs in the grid according to the grid voltage, the voltage of the direct current bus 130 is raised to a certain threshold value. The direct current voltage conversion device 120 detects the voltage of the direct current bus, and when a high voltage ride-through condition is determined according to the voltage of the bus, the voltage of the bus is controlled to a higher threshold value, thereby ensuring the realization of high voltage ride-through.

[0052] However, in actual application, in order to avoid fault diffusion caused by short circuit on the DC bus 130, a diode 140 is usually connected in series on the DC bus 130. The diode 140 is turned on when the DC voltage conversion device outputs electric energy, and is turned off when the DC voltage conversion circuit receives electric energy, thereby playing a role of fault isolation. When a high-voltage fault occurs in the power grid, after the DC bus 130 voltage on the inverter 150 side rises, the diode 140 is quickly reversed and turned off, which causes the DC voltage conversion device 120 to fail to accurately detect the inverter bus, so that it cannot quickly determine whether a high-voltage ride-through occurs, and cannot accurately control the output power.

[0053] It should be understood that the embodiments of the present application do not limit the connection relationship of the circuit, and in actual application, Figure 1 Each component in the above-mentioned power supply system 100 can be connected with other devices, for example, the output end of the inverter 150 can be directly connected to the power grid 160, or can be connected to the power grid 160 through a transformer. For another example, the power generation module 110 only has a photovoltaic (PV) array input, and can also have other energy sources, such as a battery.

[0054] It should also be understood that in the present application, the topology of the DC voltage conversion device 120 can be a Buck converter, a Boost converter, a Buck-Boost converter or a Boost-Buck converter, which can be isolated or non-isolated. The present application does not limit the topology of the DC voltage conversion device 120 or the inverter 150. For example, the DC voltage conversion device 120 can be referred to as a DC / DC converter. The inverter 150 can also be referred to as a power conversion system (PCS) or a DC / AC converter.

[0055] One of the existing high-voltage ride-through technologies suitable for power supply systems is to inform the DC voltage conversion device of the occurrence of high-voltage ride-through through a long-distance high-speed communication line, as shown in Figure 2 The power supply system 200 includes a power generation module 210 and a control system 201. In the control system 201, the inverter 250 is connected to the DC voltage conversion device 220 through a high-speed communication line 270, and the rest of the structure is the same as the power supply system 100 shown in Figure 1 The power supply system 100 shown in the above-mentioned embodiment.

[0056] Inverter 250 monitors the voltage of grid 260. When it is determined that a high voltage fault has occurred in grid 260 based on the grid voltage, it notifies DC voltage conversion device 220 of the high voltage fault through high-speed communication line 270. After learning of the high voltage fault, DC voltage conversion device 220 increases the voltage of DC bus 230 to ensure the smooth output of DC power, thereby achieving high voltage ride-through.

[0057] However, in practical applications, there is a significant delay in transmitting the detected AC grid voltage change to the voltage conversion circuit for control. For example, during the change in inverter 250 output power, the required bus voltage changes with the grid voltage and output power. At this time, the DC voltage converter 220 cannot adjust the DC bus 230 voltage in time, potentially causing large power fluctuations. Furthermore, when the output power increases, the system's output power response speed depends on the DC bus voltage loop control parameters of the DC voltage converter 220, affecting the power control response speed. In addition, this method requires the installation of a high-speed communication line, incurring additional design and maintenance costs, which is detrimental to large-scale application.

[0058] For the reasons mentioned above, this application provides a power supply system that does not rely on high-speed communication lines and can quickly detect high-voltage ride-through while achieving fault isolation, thereby improving the efficiency of high-voltage ride-through detection.

[0059] Figure 3 A schematic diagram of an example of a power supply system provided in an embodiment of this application is shown. For example... Figure 3 As shown, the power supply system 300 includes a power generation module 310 and a control system 301. In the control system 301, the DC-DC voltage conversion device 320 includes a controller 321 and a DC-DC voltage conversion circuit 322. The remaining structure is similar to... Figure 1 The power supply system 100 shown is the same, and will not be described again here.

[0060] In this embodiment, the controller 321 can control the DC-DC voltage conversion circuit 322 to receive the electrical energy output from the power generation module 310, and after DC-DC conversion, output voltage to the inverter 350 through the DC bus 330. Simultaneously, the controller 321 can also control the output voltage of the DC-DC voltage conversion circuit 322 to keep the diode 340 in a conducting state. With the diode 340 in a conducting state, the controller 321 can, with reference to existing technology, detect the voltage on the DC bus 330 and determine whether a high-voltage ride-through has occurred in the power supply system 300 based on the voltage on the DC bus 330.

[0061] Specifically, the controller 321 can monitor the current on the DC bus 330, and in the case that the current on the DC bus 330 is less than the conduction current of the diode 340, rapidly control the output voltage of the DC voltage conversion circuit 322 so that the voltage difference across the diode 340 is greater than the conduction threshold. For example, when the inverter 350 detects that the power grid 360 has a high voltage fault, the voltage of the DC bus 330 is raised to a first DC bus voltage, where the first DC bus voltage is greater than the rated AC line voltage peak of the inverter. When the DC bus voltage on the inverter 350 side is greater than the DC bus voltage on the DC voltage conversion device 320 side, the DC voltage conversion circuit 322 receives electrical energy, and the diode 340 in series on the DC bus 330 is rapidly turned off due to the voltage difference between the positive and negative electrodes being less than the threshold voltage, so that the current on the DC bus 330 is less than the conduction current of the diode 340. At this time, the controller 321 can rapidly control the output voltage of the DC voltage conversion circuit 322 so that the voltage difference across the diode 340 is greater than the conduction threshold. In this case, the controller 321 can monitor the current voltage of the DC bus 330, and in the case that the voltage of the DC bus 330 is greater than or equal to the first DC bus voltage, determine that the power supply system 300 has a high voltage ride-through. Where the first DC bus voltage is greater than the rated AC line voltage peak of the inverter.

[0062] In this way, when the diode is turned off, the DC voltage conversion device rapidly restores the diode small current conduction state, so that it can be determined whether the power supply system has a high voltage ride-through according to the voltage on the DC bus, and the detection of high voltage ride-through can be quickly realized while realizing fault isolation, thereby improving the efficiency of detecting high voltage ride-through.

[0063] It should be understood that how the inverter 350 specifically determines that the power grid 360 has a high voltage fault can be set according to actual conditions, or can refer to existing technologies, and the present application does not limit this. For example, if the grid voltage is greater than a predetermined voltage threshold and reaches a specified time (such as 2ms), it is determined that the power grid enters a high voltage fault.

[0064] As a possible implementation, the controller 321 can also control the output power of the DC voltage conversion circuit 322 when determining that the power supply system 300 is in high voltage ride through. For example, to improve the stability of the AC power grid, the output power of the DC voltage conversion circuit 322 can be controlled to be a first power, where the deviation of the first power from the output power of the DC voltage conversion circuit 322 before the high voltage ride through of the power supply system 300 is less than a first power deviation threshold. As an example but not limitation, the first power can be the output power of the DC voltage conversion circuit 322 40 ms before the controller 321 detects the high voltage ride through, and the first power deviation threshold can be a preset value, for example, 10% of the rated output power. That is, the controller 321 can adjust the output power of the DC voltage conversion circuit 322 to the output power 40 ms before the high voltage ride through is detected by controlling the output voltage and / or output current of the DC voltage conversion circuit 322, where the deviation value can be 10% of the output power.

[0065] In this way, the problem of active power imbalance that may exist in the AC power grid during high voltage ride through is avoided, the technical requirement that the active power output during grid failure is unchanged from the active power output before failure is met, and the stability of the AC power grid is improved.

[0066] According to the scheme of the present application, the DC voltage conversion device determines whether high voltage ride through occurs by controlling the output voltage of the DC voltage conversion circuit so that the diode is in a conducting state, so that high voltage ride through detection can be quickly realized while achieving fault isolation, and the efficiency of high voltage ride through detection is improved.

[0067] Figure 4 Another example structure of the power supply system provided by the embodiment of the present application is shown. As shown in Figure 4 The power supply system 400 includes a power generation module 410 and a control system 401. In the control system 401, the DC voltage conversion device 420 includes a first controller 421 and a DC voltage conversion circuit 422, the inverter 450 includes a second controller 451 and an inverter circuit 452, and the first circuit 470 is connected in parallel with the diode 440, and the current of the first circuit when conducting is less than a preset first current value. The remaining structure is the same as that of the power supply system 100 shown in Figure 1

[0068] ​In the embodiment of the present application, the first controller 421 can control the direct current voltage conversion circuit 422 to receive the electric energy output by the power generation module 410, and output the voltage to the inverter 450 through the direct current bus 430 after direct current conversion. The second controller 451 is configured to control the inverter circuit 452 to receive the output voltage of the direct current voltage conversion circuit 422 through the direct current bus 430, and supply power to the power grid 460 after direct current to alternating current conversion. The second controller 451 is further configured to control the first circuit 470 to be turned on when it is determined that the high voltage fault occurs in the power grid 460, and control the first circuit 470 to be turned off when it is determined that the high voltage fault does not occur in the power grid 460. The first controller 421 is further configured to detect the voltage on the direct current bus 430, and determine that the high voltage ride-through occurs in the power supply system 400 according to the voltage on the direct current bus 430.

[0069] For example, when the second controller 451 in the inverter 450 detects that the high voltage fault occurs in the power grid 460, the voltage of the direct current bus 430 is raised to a first direct current bus voltage, where the first direct current bus voltage is greater than the rated alternating current line voltage peak value of the inverter, for example, the first direct current bus voltage can be set to 1.1 times of the rated alternating current line voltage peak value of the inverter. When the direct current bus voltage on the inverter 450 side is greater than the direct current bus voltage on the direct current voltage conversion device 420 side, the direct current voltage conversion circuit 422 receives the electric energy, and the diode 440 connected in series on the direct current bus 430 is quickly cut off because the voltage difference between the anode and the cathode is less than the threshold voltage. At this time, the second controller 451 can quickly control the first circuit 470 to be turned on, and the current of the first circuit 470 when turned on is less than a preset first current value, so that the devices in the system will not be damaged due to excessive current when the first circuit 470 is turned on. The size of the first current value can be determined according to practice, for example, the first current value is less than the rated current value of the power supply system. In this case, the first controller 421 can monitor the current voltage of the direct current bus 430, and determine that the high voltage ride-through occurs in the power supply system 400 when it is determined that the voltage of the direct current bus 430 is greater than or equal to the first direct current bus voltage.

[0070] In this way, when the inverter detects that the high voltage fault occurs in the power grid and raises the bus voltage, the first circuit can be controlled to be turned on, so that the direct current voltage conversion device can determine whether the high voltage ride-through occurs in the power supply system according to the voltage on the direct current bus, and the detection of the high voltage ride-through can be quickly realized while the fault isolation is realized, and the efficiency of detecting the high voltage ride-through is improved.

[0071] It should be understood that how the inverter 450 specifically determines that the power grid 460 has a high voltage fault can be set according to actual conditions, or can refer to prior art, and the present application does not limit this. For example, if the power grid voltage is greater than a preset voltage threshold and reaches a specified time (such as 2ms), it is determined that the power grid has a high voltage fault.

[0072] As a possible implementation, the first controller 421 can also control the output power of the direct current voltage conversion circuit 422 in the case of determining that the power supply system 400 has a high voltage ride-through. For example, in order to improve the stability of the alternating current power grid, the output power of the direct current voltage conversion circuit 422 can be controlled to be a first power, wherein the deviation of the first power from the output power of the direct current voltage conversion circuit 422 before the power supply system 400 has a high voltage ride-through is less than a first power deviation threshold. As an example but not as a limitation, the first power can be the output power of the direct current voltage conversion circuit 422 at 40ms before the first controller 421 detects the high voltage ride-through, and the first power deviation threshold can be a preset value, for example, 10% of the rated output power. That is, the first controller 421 can adjust the output power of the direct current voltage conversion circuit 422 to the output power at 40ms before the high voltage ride-through is detected by controlling the output voltage and / or output current of the direct current voltage conversion circuit 422, wherein the deviation value can be 10% of the output power.

[0073] In this way, the problem of active power imbalance that may exist in the alternating current power grid during high voltage ride-through is avoided, the technical requirement that the active power output during the power grid fault is unchanged from the active power output before the fault is met, and the stability of the alternating current power grid is improved.

[0074] According to the scheme of the present application, the inverter controls the first circuit to be turned on in the case of a high voltage fault of the power grid and to be turned off in the case of no high voltage fault, so that the direct current voltage conversion device can determine whether the power supply system has a high voltage ride-through according to the voltage on the direct current bus. The detection of high voltage ride-through can be quickly realized while realizing fault isolation, and the efficiency of detecting high voltage ride-through is improved.

[0075] In the embodiments of the present application, the first circuit can have various structures. For example, Figure 5 A possible structure of the first circuit is shown, that is, the first circuit can be an anti-IGBT 570. As a preferred implementation, the anti-IGBT 570 can realize the above Figure 4All functions of the first circuit described herein. For example, when diode 540 is off, it is controlled to conduct by the second controller 551, and the current during conduction is less than a preset first current value, so that the devices in the system will not be damaged due to excessive current. This allows the DC-DC voltage conversion device to determine whether a high-voltage ride-through has occurred in the power supply system based on the voltage on the DC bus, enabling rapid high-voltage ride-through detection while achieving fault isolation, thus improving the efficiency of high-voltage ride-through detection. Of course, the first circuit can also be other circuits that can make the conduction current less than the aforementioned preset first current value; this application does not limit it.

[0076] Figure 6 A schematic diagram of an example control method for a power supply system provided in an embodiment of this application is shown. This control method can be... Figure 3 The controller 321 in the power supply system 300 shown is executed.

[0077] The S610 determines whether the diode is off by monitoring the current on the DC bus.

[0078] Specifically, the monitoring of the current on DC bus 330 can be performed by... Figure 3 The DC-DC voltage converter 320 shown includes a monitoring circuit, for example... Figure 3 The controller 321 located in the DC voltage conversion device 320 shown in the figure can have a communication interface with the DC bus 330 to monitor the current on the DC bus.

[0079] When the diode is detected to be off, step S620 can be executed to control the output voltage of the DC voltage conversion circuit so that the voltage difference across the diode is greater than the conduction threshold.

[0080] When diode 340 is in the conducting state, for example, if it is detected that diode 340 is not turned off or if step S620 is completed so that diode 340 is not turned off, step S630 can be executed to monitor the current voltage of DC bus 330.

[0081] It should be understood that the circuit or unit for monitoring the voltage on the DC bus 330 may be the same as or different from the circuit or unit for monitoring the current described above, and the embodiments of this application do not limit it.

[0082] This allows diode 340 to remain in the conducting state, thus enabling the determination of whether a high-voltage ride-through has occurred in the power supply system based on the voltage on the DC bus. This allows for rapid detection of high-voltage ride-through while achieving fault isolation, thereby improving the efficiency of high-voltage ride-through detection.

[0083] S640 determines whether a high-voltage ride-through has occurred based on the voltage on the DC bus.

[0084] Specifically, it can be determined whether the high voltage ride through occurs according to whether the voltage on the DC bus 330 is greater than or equal to a first DC bus voltage, where the first DC bus voltage is greater than the rated AC line voltage peak of the inverter, for example, the first DC bus voltage can be set to 1.1 times the rated AC line voltage peak of the inverter. When it is determined that the voltage on the DC bus 330 is less than the first DC bus voltage, it is determined that the high voltage ride through does not occur, and then the steps in S630 are repeatedly executed to monitor the current voltage on the DC bus 330. When it is determined that the voltage on the DC bus 330 is greater than or equal to the first DC bus voltage, it is determined that the high voltage ride through occurs, and then the steps in S650 are executed.

[0085] S650, controlling the output power of the DC voltage conversion circuit to be a first power.

[0086] Wherein the deviation of the first power from the output power of the DC voltage conversion circuit 322 before the high voltage ride through of the power supply system 300 is less than a first power deviation threshold. As an example but not limitation, the first power can be the output power of the DC voltage conversion circuit 322 when the controller 321 detects 40 ms before the high voltage ride through, and the first power deviation threshold can be a preset value, for example, 10% of the rated output power. That is, the controller 321 can adjust the output power of the DC voltage conversion circuit 322 to the output power when the high voltage ride through is detected 40 ms before by controlling the output voltage and / or output current of the DC voltage conversion circuit 322, where the deviation value can be 10% of the output power.

[0087] In this way, the problem of active power imbalance that may exist in the AC power grid during the high voltage ride through is avoided, the technical requirement that the active power output during the grid fault is unchanged from the active power output before the fault is met, and the stability of the AC power grid is improved.

[0088] According to the scheme of the present application, the DC voltage conversion device can determine whether the high voltage ride through occurs according to the voltage on the DC bus by controlling the output voltage of the DC voltage conversion circuit so that the diode is in the conducting state, which can quickly realize the detection of the high voltage ride through while realizing the fault isolation, and improve the efficiency of detecting the high voltage ride through.

[0089] Figure 7 Another example of the control method of the power supply system provided by the embodiment of the present application is shown. The control method can be executed by Figure 4The first controller 421 and the second controller 451 in the power supply system 400 shown in FIG. 4 cooperate to perform. Wherein steps S710, S720 and S730 are performed by the second controller 451 located in the inverter 450, and steps S740, S750 and S760 are performed by the first controller 421 located in the DC voltage conversion device 420.

[0090] S710, monitoring the grid voltage.

[0091] Specifically, the monitoring of the grid 460 voltage can be implemented by a circuit with a monitoring function in the inverter 450 shown in FIG. 4, for example, Figure 4 Figure 4 The second controller 451 in the inverter 450 shown in FIG. 4, the circuit or controller with a monitoring function can have a communication interface with the grid 460, thereby realizing the monitoring of the grid voltage.

[0092] S720, determining whether a high voltage fault occurs according to the grid voltage.

[0093] It should be understood that how the second controller 451 specifically determines that the grid 460 has a high voltage fault can be set according to actual conditions, and can also refer to existing technologies, and the present application does not limit this. For example, if the grid voltage is greater than a preset voltage threshold and reaches a specified time (such as 2ms), it is determined that the grid has a high voltage fault.

[0094] When it is determined that no high voltage fault occurs, the operation of step S710 is repeatedly performed to monitor the voltage of the grid 460. When it is determined that a high voltage fault occurs, step S730 is performed to control the first circuit to be turned on.

[0095] In the embodiments of the present application, the first circuit can be an anti-reverse insulated gate bipolar transistor (IGBT), or other circuits that can make the conduction current less than a preset first current value, which can make the devices in the system not be damaged due to excessive current when the first circuit 470 is turned on. The size of the first current value can be determined according to practice, and as an example, the first current value is less than the rated current value of the power supply system.

[0096] ​According to the prior art, when the second controller 451 in the inverter 450 detects a high voltage fault in the power grid 460, the voltage of the DC bus 430 is raised to a first DC bus voltage, where the first DC bus voltage is greater than the peak voltage of the power grid. When the DC bus voltage on the inverter 450 side is greater than the DC bus voltage on the DC voltage conversion device 420 side, the DC voltage conversion circuit 422 receives electric energy, and the diode 440 connected in series on the DC bus 430 is quickly cut off due to the voltage difference between the anode and the cathode being less than a threshold voltage, so that the current on the DC bus 430 is cut off. At this time, the second controller 451 can quickly control the first circuit 470 to be turned on, and the current of the first circuit 470 when turned on is less than the above-mentioned preset first current value.

[0097] In this case, the first controller 421 can perform step S740 of monitoring the current voltage of the DC bus.

[0098] Specifically, the monitoring of the voltage on the DC bus 430 can be implemented by a circuit with a monitoring function in the DC voltage conversion device 420 shown in FIG. 4, for example, the first controller 421 in the DC voltage conversion device 420 shown in FIG. 4. Figure 4 Figure 4 The circuit or controller with a monitoring function can have a communication interface with the DC bus 430, so as to realize the monitoring of the voltage of the DC bus.

[0099] S750, determining whether a high voltage ride-through occurs according to the voltage of the DC bus.

[0100] Specifically, it can be determined whether a high voltage ride-through occurs according to whether the voltage on the DC bus 430 is greater than or equal to a first DC bus voltage, where the first DC bus voltage is greater than the rated AC line voltage peak of the inverter. When it is determined that the voltage on the DC bus 430 is less than the first DC bus voltage, it is determined that no high voltage ride-through occurs, and then the step of monitoring the current voltage of the DC bus 430 in S730 is repeatedly performed. When it is determined that the voltage on the DC bus 430 is greater than or equal to the first DC bus voltage, it is determined that a high voltage ride-through occurs, and then the step in S760 is continued to be performed.

[0101] S760, controlling the output power of the DC voltage conversion circuit to be a first power.

[0102] ​The first power is the output power of the DC voltage conversion circuit 422 detected by the first controller 421 40 ms before the high voltage ride-through occurs in the power supply system 400, and the first power deviation threshold is a preset value, for example, 10% of the rated output power. That is, the first controller 421 can adjust the output power of the DC voltage conversion circuit 422 to the output power detected 40 ms before the high voltage ride-through occurs by controlling the output voltage and / or the output current of the DC voltage conversion circuit 422, and the deviation value can be 10% of the output power.

[0103] In this way, the problem of active power imbalance that may exist in the AC power grid during the high voltage ride-through is avoided, the technical requirement that the active power output during the power grid fault is unchanged from the active power output before the fault is met, and the stability of the AC power grid is improved.

[0104] According to the scheme of the present application, the inverter control first circuit is turned on in the case of high voltage fault of the power grid and is turned off in the case of no high voltage fault, so that the DC voltage conversion device can determine whether the high voltage ride-through occurs in the power supply system according to the voltage on the DC bus, the detection of the high voltage ride-through can be quickly realized while the fault isolation is realized, and the efficiency of detecting the high voltage ride-through is improved.

[0105] Figure 8 A structure schematic diagram of a control device provided by an embodiment of the present application is shown. The control device includes a processor 810, a communication interface 820. Optionally, the control device can further include a memory 830. Optionally, the memory 830 can be included in the processor 810. The processor 810, the communication interface 820 and the memory 830 communicate with each other through an internal connection path, the memory 830 is used to store instructions, and the processor 810 is used to execute the instructions stored in the memory 830 to implement the control method provided by the embodiment of the present application.

[0106] Optionally, the control device can be used to perform the functions of the controller 321 in Figure 3 or the first controller 421 and the second controller 451 in Figure 4 .

[0107] Optionally, the control device can be further used to perform the control method shown in Figure 6 or Figure 7 .

[0108] As used in this description, the terms "component," "module," "system", and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution and a component can be localized, partially localized, or distributed across two or more computers or other processing devices. Also, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and / or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems via the signal).

[0109] Those skilled in the art can clearly understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0110] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0111] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be realized by other ways. For example, the above-described device embodiments are only schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interface, device or unit, and can be electrical, mechanical or other forms.

[0112] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e. can be located in one place or can be distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0113] In addition, each function unit in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit.

[0114] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0115] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A power supply system characterized by comprising: The application relates to a direct-current voltage conversion device, an inverter and a control method thereof. The direct-current voltage conversion device comprises a controller and a direct-current voltage conversion circuit, the controller is used for controlling the direct-current voltage conversion circuit to receive electric energy output by a power generation module and output voltage to an inverter through a direct-current bus after direct-current conversion; The inverter is used for receiving the output voltage of the direct-current voltage conversion circuit through the direct-current bus and supplying power to a power grid after direct-current-to-alternating-current conversion; A diode is connected in series to the direct-current bus, the diode is turned on when the direct-current voltage conversion circuit outputs electric energy and is turned off when the direct-current voltage conversion circuit receives electric energy; The controller is further used for: determining whether the diode is turned off by monitoring the current on the direct-current bus; controlling the output voltage of the direct-current voltage conversion circuit so that the voltage difference between the two ends of the diode is greater than the turn-on threshold value of the diode to make the diode in the turned-on state when it is determined that the diode is turned off; detecting the voltage on the direct-current bus and determining whether high-voltage ride-through of the power supply system occurs according to the voltage on the direct-current bus when the diode is in the turned-on state.

2. The system of claim 1, wherein, The controller is specifically used for: monitoring the current voltage of the direct-current bus; determining that high-voltage ride-through of the power supply system occurs when it is determined that the voltage of the direct-current bus is greater than or equal to a first direct-current bus voltage, wherein the first direct-current bus voltage is greater than the rated alternating-current line voltage peak value of the inverter.

3. The system of claim 1 or 2, wherein, The controller is further used for: controlling the output power of the direct-current voltage conversion circuit to be a first power when it is determined that high-voltage ride-through of the power supply system occurs, wherein the deviation between the first power and the output power of the direct-current voltage conversion circuit before high-voltage ride-through of the power supply system occurs is less than a first power deviation threshold value.

4. The system of claim 3, wherein, The controller is specifically used for: controlling the output voltage and / or output current of the direct-current voltage conversion circuit to make the output power of the direct-current voltage conversion circuit be the first power when it is determined that high-voltage ride-through of the power supply system occurs.

5. A power supply system characterized by comprising: The application relates to a direct-current voltage conversion device, an inverter and a control method thereof. The direct-current voltage conversion device comprises a first controller and a direct-current voltage conversion circuit, the first controller is used for controlling the direct-current voltage conversion circuit to receive electric energy output by a power generation module and output voltage to an inverter through a direct-current bus after direct-current conversion; The inverter comprises a second controller and an inverter circuit, the second controller is used for controlling the inverter circuit to receive the output voltage of the direct-current voltage conversion circuit through the direct-current bus and supply power to a power grid after direct-current-to-alternating-current conversion; A diode is connected in series to the direct-current bus, the diode is turned on when the direct-current voltage conversion circuit outputs electric energy and is turned off when the direct-current voltage conversion circuit receives electric energy; A first circuit is connected in parallel to the diode, the current of the first circuit when turned on is less than a preset first current value; The second controller is further configured to control the first circuit to be turned on in a case where it is determined that the power grid has a high-voltage fault, and to be turned off in a case where it is determined that the power grid does not have a high-voltage fault. The first controller is further configured to detect a voltage on the DC bus, and determine whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus.

6. The system of claim 5, wherein, The first controller is specifically configured to: monitor a current voltage on the DC bus; determine that the power supply system has a high-voltage ride-through in a case where it is determined that the voltage on the DC bus is greater than or equal to a first DC bus voltage, wherein the first DC bus voltage is greater than a peak value of a rated AC line voltage of the inverter.

7. The system of claim 5 or 6, wherein, The first controller is further configured to: control an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system has a high-voltage ride-through, wherein a deviation of the first power from an output power of the DC voltage conversion circuit before the power supply system has a high-voltage ride-through is less than a first power deviation threshold.

8. The system of claim 7, wherein, The first controller is specifically configured to: control an output voltage and / or an output current of the DC voltage conversion circuit in a case where it is determined that the power supply system has a high-voltage ride-through, so that the output power of the DC voltage conversion circuit is the first power.

9. The system of claim 5 or 6, wherein, The first circuit includes an anti-reverse insulated gate bipolar transistor (IGBT).

10. A control method of a power supply system, characterized by, The power supply system includes: a DC voltage conversion device including a controller and a DC voltage conversion circuit, the controller being configured to control the DC voltage conversion circuit to receive electrical energy output by a power generation module, and output a voltage through a DC bus to an inverter after DC conversion; the inverter being configured to receive the output voltage of the DC voltage conversion circuit through the DC bus, and supply power to a power grid after DC-AC conversion; a diode connected in series with the DC bus, the diode being turned on in a case where the DC voltage conversion circuit outputs electrical energy, and being turned off in a case where the DC voltage conversion circuit receives electrical energy; The method includes: the controller determines whether the diode is turned off by monitoring a current on the DC bus; the controller controls an output voltage of the DC voltage conversion circuit in a case where it is determined that the diode is turned off, so that a voltage difference across the diode is greater than a turn-on threshold of the diode, so that the diode is in a turned-on state; the controller detects a voltage on the DC bus in a case where the diode is in the turned-on state, and determines whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus.

11. The method of claim 10, wherein, The controller detects a voltage on the DC bus, and determines whether the power supply system has a high-voltage ride-through according to the voltage on the DC bus, including: the controller monitors a current voltage on the DC bus; The controller determines that the power supply system has high voltage ride through in a case where it is determined that the voltage of the DC bus is greater than or equal to a first DC bus voltage, wherein the first DC bus voltage is greater than a rated AC line voltage peak value of the inverter.

12. The method according to claim 10 or 11, characterized in that, The method further comprises: The controller controls an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system has high voltage ride through, wherein a deviation of the first power from an output power of the DC voltage conversion circuit before the power supply system has high voltage ride through is less than a first power deviation threshold.

13. The method of claim 12, wherein, The controller controls an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system has high voltage ride through, comprising: The controller controls an output voltage and / or an output current of the DC voltage conversion circuit in a case where it is determined that the power supply system has high voltage ride through, so that the output power of the DC voltage conversion circuit is the first power.

14. A control method of a power supply system, characterized by, The power supply system comprises: The DC voltage conversion device comprises a first controller and a DC voltage conversion circuit, the first controller is configured to control the DC voltage conversion circuit to receive electric energy output by the power generation module, and output a voltage through a DC bus after DC conversion; The inverter comprises a second controller and an inversion circuit, the second controller is configured to control the inversion circuit to receive the output voltage of the DC voltage conversion circuit through the DC bus, and supply power to the power grid after DC-AC conversion; A diode is connected in series with the DC bus, the diode is turned on in a case where the DC voltage conversion circuit outputs electric energy, and is turned off in a case where the DC voltage conversion circuit receives electric energy; A first circuit is connected in parallel with the diode, a current of the first circuit when turned on is less than a preset first current value; The method comprises: The second controller controls the first circuit to be turned on in a case where it is determined that the power grid has high voltage fault, and controls the first circuit to be turned off in a case where it is determined that the power grid does not have high voltage fault; The first controller detects a voltage on the DC bus, and determines whether the power supply system has high voltage ride through according to the voltage of the DC bus.

15. The method of claim 14, wherein, The first controller detects a voltage on the DC bus, and determines whether the power supply system has high voltage ride through according to the voltage of the DC bus, comprising: The first controller monitors a current voltage of the DC bus; The controller determines that the power supply system has high voltage ride through in a case where it is determined that the voltage of the DC bus is greater than or equal to a first DC bus voltage, wherein the first DC bus voltage is greater than a rated AC line voltage peak value of the inverter.

16. The method according to claim 14 or 15, characterized in that The method further comprises: The first controller controls an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system is in high voltage ride through, and the deviation of the first power from an output power of the DC voltage conversion circuit before the power supply system is in high voltage ride through is less than a first power deviation threshold.

17. The method of claim 16, wherein, The first controller controls an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system is in high voltage ride through, and the first power includes: The first controller controls an output power of the DC voltage conversion circuit to be a first power in a case where it is determined that the power supply system is in high voltage ride through, and the first controller controls an output voltage and / or an output current of the DC voltage conversion circuit to make the output power of the DC voltage conversion circuit be the first power.

18. The method of claim 14 or 15, wherein, The first circuit includes an anti-reverse insulated gate bipolar transistor (IGBT).

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