Photovoltaic inverter fault ride-through performance testing method and system

Abstract

The present invention provides a photovoltaic inverter fault ride-through performance test method and system, constructs a semi-physical photovoltaic inverter model; performs a fault ride-through test on the semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic; determines whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test; and the topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter. The semi-physical photovoltaic inverter model is determined by an actual photovoltaic inverter and the fault ride-through performance test of the semi-physical photovoltaic inverter model is implemented. When the active power response curve and the reactive power response curve of the virtual power circuit are inconsistent with the active power response curve and the reactive power response curve of the actual power circuit, the virtual power circuit needs to be adjusted to avoid using a large and costly actual power circuit, thereby greatly improving the accuracy and efficiency of the test, shortening the test time, and reducing the test cost.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and in particular to a method and system for testing fault ride-through performance of a photovoltaic inverter. Background Art

[0002] As the installed capacity of photovoltaic power stations continues to increase, their impact on the power grid is increasing. In order to ensure the safe operation of the power grid, the power grid company requires that the inverters used in photovoltaic power stations comply with the requirements of the national standard GB / T 19964-2012 "Technical Regulations for Photovoltaic Power Stations Connected to the Power System". At the same time, in order to ensure the safe and stable operation of the power grid and the consumption of clean energy, various regions have put forward some special requirements for the fault ride-through performance of photovoltaic power stations based on their own power grid characteristics and power supply structure.

[0003] Newly built photovoltaic power stations only need to use photovoltaic inverters that meet the requirements. Existing photovoltaic power stations need to transform the photovoltaic inverters, and after the transformation, their fault ride-through performance needs to be tested. The current photovoltaic inverter fault ride-through performance tests include semi-physical tests and physical tests. The semi-physical test generally adopts a combination of physical controllers and virtual power circuits, but the test accuracy is low. There are two types of physical tests: (1) On-site testing, a large fault ride-through detection device is transported to the power station site to simulate power grid faults and test the performance of the photovoltaic inverter. The test process affects the power generation of the photovoltaic power station; (2) Laboratory testing, the inverter is dismantled and sent to the laboratory, and the fault ride-through detection device is used in the laboratory to simulate power grid faults and test the performance of the photovoltaic inverter. Both of these physical testing methods have the disadvantages of low testing efficiency and high cost. Summary of the invention

[0004] In order to overcome the shortcomings of low test accuracy, low test efficiency and high cost in the above-mentioned prior art, the present invention provides a photovoltaic inverter fault ride-through performance test method, comprising:

[0005] Construct a semi-physical photovoltaic inverter model based on the RT-lab semi-physical simulation platform;

[0006] Conduct fault ride-through test on the semi-physical photovoltaic inverter model to obtain the fault ride-through response characteristics;

[0007] Based on the fault ride-through response characteristic, it is determined whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test.

[0008] The topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter.

[0009] A semi-physical photovoltaic inverter model is built based on the RT-lab semi-physical simulation platform, including:

[0010] Based on the topological structure of the actual power circuit in the actual photovoltaic inverter, a virtual power circuit consistent with the topological structure of the actual power circuit is built on the RT-lab semi-physical simulation platform;

[0011] Perform power performance test on the virtual power circuit to obtain a power response curve;

[0012] A consistency check is performed on the power response curve, and a semi-physical photovoltaic inverter model is determined based on the consistency check result.

[0013] Perform power performance test on the virtual power circuit to obtain the power response curve, including:

[0014] Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively;

[0015] Based on the preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to the preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively.

[0016] Performing a consistency check on the power response curve and determining a semi-physical photovoltaic inverter model based on the consistency check result, including:

[0017] The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency check; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error;

[0018] Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

[0019] The fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the fault ride-through response characteristics, including:

[0020] Based on the pre-built high voltage ride-through test model, a high voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the high voltage fault ride-through response characteristics;

[0021] Based on the pre-built low voltage ride-through test model, a low voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the low voltage fault ride-through response characteristics.

[0022] The low voltage ride through test model includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short circuit reactor X2;

[0023] After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

[0024] The high voltage ride through test model includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R;

[0025] After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the power grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

[0026] The determining whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test based on the fault ride-through response characteristic includes:

[0027] Determine whether the high voltage fault ride-through response characteristics and the low voltage fault ride-through response characteristics meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test.

[0028] On the other hand, the present invention also provides a photovoltaic inverter fault ride-through performance testing system, comprising:

[0029] Modeling module, used to build a semi-physical photovoltaic inverter model based on the RT-lab semi-physical simulation platform;

[0030] A test module is used to perform a fault ride-through test on a semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic;

[0031] A determination module, configured to determine whether a semi-physical photovoltaic inverter model passes a fault ride-through performance test based on the fault ride-through response characteristic;

[0032] The topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter.

[0033] The modeling modules include:

[0034] The first modeling unit is used to build a virtual power circuit on the RT-lab semi-physical simulation platform based on the topology of the actual power circuit in the actual photovoltaic inverter;

[0035] A first testing unit is used to perform a power performance test on the virtual power circuit to obtain a power response curve;

[0036] The testing unit is used to perform consistency testing on the power response curve and determine the semi-physical photovoltaic inverter model based on the consistency testing result.

[0037] The first testing unit is specifically used for:

[0038] Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively;

[0039] Based on the preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to the preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively.

[0040] The inspection unit is specifically used for:

[0041] The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency check; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error;

[0042] Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

[0043] The test module includes:

[0044] A modeling unit, used to construct a high voltage ride through test model and a low voltage ride through test model;

[0045] The second test unit is used to perform a high voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the high voltage ride-through test model to obtain a high voltage fault ride-through response characteristic;

[0046] The third test unit is used to perform a low voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the low voltage ride-through test model to obtain a low voltage fault ride-through response characteristic.

[0047] The low voltage ride through test model constructed by the modeling unit includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short circuit reactor X2;

[0048] After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

[0049] The high voltage ride through test model constructed by the modeling unit includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R;

[0050] After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the power grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

[0051] Determine the module specifically for:

[0052] Determine whether the high voltage fault ride-through response characteristics and the low voltage fault ride-through response characteristics meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test.

[0053] The technical solution provided by the present invention has the following beneficial effects:

[0054] In the photovoltaic inverter fault ride-through performance test method provided by the present invention, a semi-physical photovoltaic inverter model is constructed based on the RT-lab semi-physical simulation platform; a fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic; based on the fault ride-through response characteristic, it is determined whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test; the topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter, the semi-physical photovoltaic inverter model is determined through the actual photovoltaic inverter and the fault ride-through performance test of the semi-physical photovoltaic inverter model is implemented, the use of a physical power circuit is avoided, the accuracy and efficiency of the test are greatly improved, and the test cost is reduced;

[0055] The present invention requires adjusting the virtual power circuit when the active power response curve and reactive power response curve of the virtual power circuit are inconsistent with the active power response curve and reactive power response curve of the actual power circuit, thereby avoiding the use of a virtual power circuit that is inconsistent with the response characteristics of the actual power circuit, thereby greatly improving the test accuracy;

[0056] The present invention performs a fault ride-through performance test on a semi-physical photovoltaic inverter model composed of a virtual power circuit having the same response characteristics as an actual power circuit, thereby avoiding the use of a bulky and costly actual power circuit and shortening the test time. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a block diagram of a photovoltaic inverter fault ride-through performance testing method according to an embodiment of the present invention;

[0058] Figure 2 is a schematic diagram of a semi-physical photovoltaic inverter model in an embodiment of the present invention;

[0059] Figure 3 is a schematic diagram of an active power reduction curve of a photovoltaic inverter preset in an embodiment of the present invention;

[0060] Figure 4 is a schematic diagram of an active power rise curve of a photovoltaic inverter preset in an embodiment of the present invention;

[0061] Figure 5 is a structural diagram of a low voltage ride through test model in an embodiment of the present invention;

[0062] Figure 6 is a structural diagram of a high voltage ride through test model in an embodiment of the present invention;

[0063] Figure 7 It is a flow chart of a photovoltaic inverter fault ride-through performance testing method in an embodiment of the present invention. DETAILED DESCRIPTION

[0064] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0065] Example 1

[0066] Embodiment 1 of the present invention provides a method for testing the fault ride-through performance of a photovoltaic inverter. The specific flow chart is as follows: Figure 1 As shown, the specific process is as follows:

[0067] S101: Construct a semi-physical photovoltaic inverter model based on the RT-lab semi-physical simulation platform;

[0068] S102: performing a fault ride-through test on a semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic;

[0069] S103: determining whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test based on the fault ride-through response characteristics;

[0070] The topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter.

[0071] The actual photovoltaic inverter includes an actual controller and an actual power circuit;

[0072] The semi-physical photovoltaic inverter model includes the actual controller and the virtual power circuit, such as Figure 2 shown.

[0073] like Figure 7 As shown in the figure, a semi-physical photovoltaic inverter model is built based on the RT-lab semi-physical simulation platform, including:

[0074] Based on the topological structure of the actual power circuit in the actual photovoltaic inverter, a virtual power circuit consistent with the topological structure of the actual power circuit is built on the simulation platform; the simulation platform used in Embodiment 1 of the present invention is the RT-lab simulation platform, that is, the virtual power circuit is built on the RT-lab simulation platform;

[0075] Perform power performance test on the virtual power circuit to obtain a power response curve;

[0076] The power response curve is checked for consistency, and the semi-physical photovoltaic inverter model is determined based on the consistency check results.

[0077] Perform power performance test on the virtual power circuit to obtain the power response curve, including:

[0078] Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively;

[0079] Based on the preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to the preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively.

[0080] Perform consistency check on the power response curve and determine the semi-physical photovoltaic inverter model based on the consistency check result, including:

[0081] The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency test; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error;

[0082] Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

[0083] In Embodiment 1 of the present invention, the preset active power reference value is determined by the size of the load connected to the photovoltaic inverter, and the active power reference value can be specifically set to 20%, 40%, 60% and 80% of the total rated power of the photovoltaic inverter. The preset reactive power error and the preset active power error are both 1%, and the parameters of the virtual power circuit based on the parameters of the actual power circuit specifically adjust the filter capacitor, resistance value and inductance value of the virtual power circuit.

[0084] In Example 1 of the present invention, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively. Specifically, according to the preset active power curve of the photovoltaic inverter, the average active power of the actual power circuit and the virtual power circuit is calculated every 0.2 seconds, and all calculated active power averages are fitted to obtain active power response curves of the actual power circuit and the virtual power circuit respectively. Similarly, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively. Specifically, according to the preset reactive power curve of the photovoltaic inverter, the average reactive power of the actual power circuit and the virtual power circuit is calculated every 0.2 seconds, and all calculated active power averages are fitted to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively.

[0085] The above-mentioned preset photovoltaic inverter active power curve includes a preset photovoltaic inverter active power reduction curve (such as Figure 3 ) and the preset PV inverter active power rise curve (as shown in Figure 4 shown).

[0086] Perform fault ride-through test on the semi-physical photovoltaic inverter model to obtain the fault ride-through response characteristics, including:

[0087] Based on the pre-built high voltage ride-through test model, a high voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the high voltage fault ride-through response characteristics;

[0088] Based on the pre-built low voltage ride-through test model, a low voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the low voltage fault ride-through response characteristics.

[0089] like Figure 5 As shown, the low voltage ride-through test model includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short-circuit reactor X2;

[0090] After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

[0091] The low voltage ride-through test model of Embodiment 1 of the present invention satisfies:

[0092] a) Capable of simulating three-phase symmetrical voltage drop, phase-to-phase voltage drop and single-phase voltage drop;

[0093] b) Both the current limiting reactor X1 and the short-circuit reactor X2 should be adjustable and can produce a voltage drop of 0 to 90% at the voltage drop point A;

[0094] c) The ratio of the reactance value to the resistance value of the current limiting reactor X1 and the short-circuit reactor X2 is at least greater than 3;

[0095] d) The three-phase symmetrical short-circuit capacity at voltage drop point A is more than three times the total rated power of the photovoltaic inverter;

[0096] e) The voltage step time is less than 20ms, that is, the voltage drop time is less than 20ms.

[0097] like Figure 6 As shown, the high voltage ride through test model includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R;

[0098] After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

[0099] The high voltage ride through test model of Embodiment 1 of the present invention satisfies:

[0100] a) Can simulate three-phase symmetrical voltage rise;

[0101] b) At least one of the current limiting inductor L, the damping capacitor C and the damping resistor R should be adjustable to produce voltage increases of different amplitudes at the voltage increase point B;

[0102] c) The ratio of the inductance value to the resistance value in the current limiting inductor L is at least greater than 3;

[0103] d) The three-phase symmetrical short-circuit capacity at voltage rise point B should be more than three times the total rated power of the photovoltaic inverter;

[0104] e) The voltage step time should be less than 20ms, that is, the voltage rise time should be less than 20ms.

[0105] like Figure 7 As shown, whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test is determined based on the fault ride-through response characteristics, including:

[0106] It is determined whether the high voltage fault ride-through response characteristic and the low voltage fault ride-through response characteristic both meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test. In Embodiment 1 of the present invention, it is specifically determined whether the high voltage fault ride-through response characteristic and the low voltage fault ride-through response characteristic both meet the technical requirements of the photovoltaic power generation grid-connected inverter of GB / T 37408.

[0107] Example 2

[0108] Based on the same inventive concept, Embodiment 2 of the present invention further provides a photovoltaic inverter fault ride-through performance test system, and the functions of each component are described in detail below:

[0109] Modeling module, used to build a semi-physical photovoltaic inverter model based on the RT-lab semi-physical simulation platform;

[0110] A test module is used to perform a fault ride-through test on a semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic;

[0111] The determination module is used to determine whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test based on the fault ride-through response characteristics.

[0112] The actual photovoltaic inverter includes an actual controller and an actual power circuit;

[0113] The semi-physical photovoltaic inverter model includes the actual controller and the virtual power circuit;

[0114] The topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter.

[0115] The modeling modules include:

[0116] The first modeling unit is used to build a virtual power circuit on the RT-lab semi-physical simulation platform based on the topology of the actual power circuit in the actual photovoltaic inverter;

[0117] A first testing unit is used to perform a power performance test on the virtual power circuit to obtain a power response curve;

[0118] The inspection unit is used to perform consistency inspection on the power response curve and determine the semi-physical photovoltaic inverter model based on the consistency inspection result.

[0119] The first test unit is specifically used for:

[0120] Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively;

[0121] Based on the preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to the preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively.

[0122] The inspection unit is specifically used for:

[0123] The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency test; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error;

[0124] Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

[0125] The test modules include:

[0126] A modeling unit, used to construct a high voltage ride through test model and a low voltage ride through test model;

[0127] The second test unit is used to perform a high voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the high voltage ride-through test model to obtain a high voltage fault ride-through response characteristic;

[0128] The third test unit is used to perform a low voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the low voltage ride-through test model to obtain a low voltage fault ride-through response characteristic.

[0129] The low voltage ride-through test model built by the modeling unit includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short-circuit reactor X2;

[0130] After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

[0131] The high voltage ride-through test model built by the modeling unit includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R;

[0132] After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

[0133] Determine the module specifically for:

[0134] It is determined whether the high voltage fault ride-through response characteristic and the low voltage fault ride-through response characteristic both meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test. In Embodiment 2 of the present invention, it is specifically determined whether the high voltage fault ride-through response characteristic and the low voltage fault ride-through response characteristic both meet the technical requirements of the photovoltaic power generation grid-connected inverter of GB / T 37408.

[0135] For the convenience of description, the various parts of the above device are divided into various modules or units according to their functions and described separately. Of course, when implementing the present application, the functions of each module or unit can be implemented in the same or multiple software or hardware.

[0136] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0137] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0138] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0139] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Ordinary technicians in the relevant field can still modify or make equivalent substitutions to the specific implementation methods of the present invention with reference to the above embodiments. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention are within the protection scope of the present invention to be approved.

Claims

1. A photovoltaic inverter fault ride-through performance testing method, characterized in that: include: Construct a semi-physical photovoltaic inverter model based on the RT-lab semi-physical simulation platform; Conduct fault ride-through test on the semi-physical photovoltaic inverter model to obtain the fault ride-through response characteristics; determining whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test based on the fault ride-through response characteristic; Wherein, the topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter; The semi-physical photovoltaic inverter model is constructed based on the RT-lab semi-physical simulation platform, including: Based on the topology of the actual power circuit in the actual photovoltaic inverter, a virtual power circuit consistent with the topology of the actual power circuit is built on the RT-lab semi-physical simulation platform; Perform power performance test on the virtual power circuit to obtain a power response curve; Performing a consistency check on the power response curve, and determining a semi-physical photovoltaic inverter model based on the consistency check result; The power performance test of the virtual power circuit is performed to obtain a power response curve, including: Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively; Based on a preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively; The performing consistency check on the power response curve and determining a semi-physical photovoltaic inverter model based on the consistency check result includes: The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency check; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error; Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

2. The photovoltaic inverter fault ride-through performance testing method according to claim 1, characterized in that: The fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the fault ride-through response characteristics, including: Based on the pre-built high voltage ride-through test model, a high voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the high voltage fault ride-through response characteristics; Based on the pre-built low voltage ride-through test model, a low voltage fault ride-through test is performed on the semi-physical photovoltaic inverter model to obtain the low voltage fault ride-through response characteristics.

3. The photovoltaic inverter fault ride-through performance testing method according to claim 2, characterized in that: The low voltage ride through test model includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short circuit reactor X2; After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

4. The photovoltaic inverter fault ride-through performance testing method according to claim 2, characterized in that: The high voltage ride through test model includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R; After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the power grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

5. The photovoltaic inverter fault ride-through performance testing method according to claim 2, characterized in that: The determining whether the semi-physical photovoltaic inverter model passes the fault ride-through performance test based on the fault ride-through response characteristic includes: Determine whether the high voltage fault ride-through response characteristics and the low voltage fault ride-through response characteristics meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test.

6. A photovoltaic inverter fault ride-through performance test system, characterized in that: include: Modeling module, based on RT-lab semi-physical simulation platform to build and determine the semi-physical photovoltaic inverter model; A test module is used to perform a fault ride-through test on a semi-physical photovoltaic inverter model to obtain a fault ride-through response characteristic; A determination module, configured to determine whether a semi-physical photovoltaic inverter model passes a fault ride-through performance test based on the fault ride-through response characteristic; Wherein, the topological structure of the semi-physical photovoltaic inverter model is consistent with the topological structure of the physical photovoltaic inverter; The modeling module includes: The first modeling unit is used to build a virtual power circuit on the RT-lab semi-physical simulation platform based on the topology of the actual power circuit in the actual photovoltaic inverter; A first testing unit is used to perform a power performance test on the virtual power circuit to obtain a power response curve; A testing unit, configured to perform a consistency test on the power response curve and determine a semi-physical photovoltaic inverter model based on a consistency test result; The first testing unit is specifically used for: Based on a preset active power reference value, active power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset active power curve of the photovoltaic inverter to obtain active power response curves of the actual power circuit and the virtual power circuit respectively; Based on a preset reactive power reference value, reactive power performance tests are performed on the actual power circuit and the virtual power circuit respectively according to a preset reactive power curve of the photovoltaic inverter to obtain reactive power response curves of the actual power circuit and the virtual power circuit respectively; The inspection unit is specifically used for: The active power response curve and reactive power response curve of the virtual power circuit are compared with the active power response curve and reactive power response curve of the actual power circuit respectively: if the error between the active power response curve of the virtual power circuit and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve of the virtual power circuit and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error, it is determined that the power response curve passes the consistency check; otherwise, the parameters of the virtual power circuit are adjusted based on the parameters of the actual power circuit to obtain a virtual power circuit in which the error between the active power response curve and the active power response curve of the actual power circuit does not exceed the preset active power error, and the error between the reactive power response curve and the reactive power response curve of the actual power circuit does not exceed the preset reactive power error; Based on the virtual power circuit and the actual controller, a semi-physical photovoltaic inverter model is obtained.

7. The photovoltaic inverter fault ride-through performance test system according to claim 6, characterized in that: The test module includes: A second modeling unit, used for building a high voltage ride through test model and a low voltage ride through test model; The second test unit is used to perform a high voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the high voltage ride-through test model to obtain a high voltage fault ride-through response characteristic; The third test unit is used to perform a low voltage fault ride-through test on the semi-physical photovoltaic inverter model based on the low voltage ride-through test model to obtain a low voltage fault ride-through response characteristic.

8. The photovoltaic inverter fault ride-through performance test system according to claim 7, characterized in that: The low voltage ride through test model constructed by the modeling unit includes a parallel switch S1, a current limiting reactor X1, a series switch S2 and a short circuit reactor X2; After the parallel switch S1 is connected in parallel with the current limiting reactor X1, one end is connected to the photovoltaic inverter and the other end is connected to the grid. One end of the short-circuit reactor X2 is connected to the voltage drop point A between the photovoltaic inverter and the current limiting reactor X1 through the series switch S2, and the other end is grounded.

9. The photovoltaic inverter fault ride-through performance test system according to claim 7, characterized in that: The high voltage ride through test model constructed by the modeling unit includes a parallel switch S3, a current limiting inductor L, a series switch S4, a damping capacitor C and a damping resistor R; After the parallel switch S3 is connected in parallel with the current limiting inductor L, it is connected to the photovoltaic inverter, and the other end is connected to the power grid. After the damping capacitor C and the damping resistor R are connected in series, one end is connected to the voltage increase point B between the photovoltaic inverter and the current limiting inductor L through the series switch S4, and the other end is grounded.

10. The photovoltaic inverter fault ride-through performance test system according to claim 7, characterized in that: The determination module is specifically used for: Determine whether the high voltage fault ride-through response characteristics and the low voltage fault ride-through response characteristics meet the technical requirements of the photovoltaic inverter. If so, the semi-physical photovoltaic inverter model passes the fault ride-through test, otherwise the semi-physical photovoltaic inverter model fails the fault ride-through test.

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