Doubly-fed motor test system

Abstract

The utility model provides a doubly-fed motor test system, which comprises a rectifier transformer, a rectification AFE unit and a direct current bus which are sequentially connected with a main power grid, and further comprises an inversion unit connected with the direct current bus, and the inversion unit is connected with a doubly-fed joint debugging unit. The test system has complete functions, and one set of system can complete the whole set of type test item points of the doubly-fed wind power motor and considers part of wind power motor joint debugging tests. And double-feed type and joint debugging tests of different voltage levels such as low voltage and high voltage can be carried out. And moreover, stator side power supplies with different frequencies of 30-70Hz can be provided, and the requirements of different frequency systems at home and abroad are met.

Description

Technical Field

[0001] The utility model relates to the technical field of doubly-fed motor test equipment, in particular to a doubly-fed motor test system. Background Art

[0002] With the increase in the capacity of wind power units and the increasing cost pressure of wind power, various main engine manufacturers have taken the technical route of increasing the voltage level to reduce the cost of the unit. The voltage level has generally increased from 690V to 1140V (1380V). In order to reduce costs, some main engine manufacturers have increased the stator voltage of the double-fed motor to 10.5KV and directly connected to the grid to save the cost of transformers and inverters. Driven by cost pressure, higher voltage level motors are becoming more and more popular in the market. The double-fed test system solution of the double-fed motor test equipment in the existing technology has a single test function. The mainstream can only perform a single test point, and the load test and single-unit test cannot be performed on the same test bench. And only double-fed type or joint adjustment tests with a voltage level of 690V or 1140V can be performed.

[0003] Through searching, technical documents related to the doubly-fed motor test system have been disclosed in the prior art. For example, the invention patent publication document with the publication number "CN106199428A" and the name "High-voltage and high-power doubly-fed wind turbine test system and its measurement and control system" is disclosed. A high-voltage and high-power variable-speed constant-frequency doubly-fed asynchronous wind turbine test system is disclosed, in which an external auxiliary power supply is connected to the rotor converter transformer set, the stator end of the doubly-fed wind turbine generator and the high-voltage end of the phase-shifting transformer. The high-voltage end of the phase-shifting transformer has adjustable 6kV and 10kV taps, and multiple sets of phase-shifting and step-down secondary windings at its low-voltage end are connected to the input end of the frequency converter; and the output end of the frequency converter is connected to the traction motor to provide variable-frequency power for the traction motor. The doubly-fed wind turbine test system involved in the comparative document cannot provide stator-side power supplies of different frequencies, and cannot be used for doubly-fed motor type tests and joint adjustment tests of different frequencies.

[0004] For example, the invention patent publication document with the publication number "CN102288913A" and the name "A doubly-fed motor test system and its test method" is disclosed. A doubly-fed motor test system and its test method are disclosed, the system includes a generator unit, a motor unit and a system start-up unit, the generator unit includes a motor A and a doubly-fed inverter A, the motor unit includes a motor B and a doubly-fed inverter B, and the system start-up unit includes a stator short-circuit contactor A and a stator short-circuit contactor B; the motor A and the motor B are both doubly-fed motors of the same specifications and models, rigidly connected by a coupling. The method includes a stator short-circuit rotor variable frequency operation mode and a doubly-fed operation mode. This comparative document is similar to the above-mentioned comparative document, and it also cannot provide stator-side power supplies of different frequencies, and cannot be applied to doubly-fed motor type tests and joint adjustment tests of different frequencies.

[0005] Therefore, it is of great significance to propose a test equipment in this field that can have multi-functional joint adjustment and can adapt to doubly-fed motors of different frequencies. Utility Model Content

[0006] In view of the deficiencies in the prior art, the utility model provides a doubly-fed motor test system, comprising a rectifier transformer, a rectifier AFE unit and a DC bus connected to a main power grid in sequence, and also comprising an inverter unit connected to the DC bus, wherein the inverter unit is connected to a doubly-fed joint modulation unit.

[0007] Furthermore, the double-fed joint modulation unit includes a low-voltage double-fed joint modulation unit and a high-voltage double-fed joint modulation unit, the inverter unit is connected to a joint modulation transformer, and the joint modulation transformer is respectively connected to the low-voltage double-fed joint modulation unit and the high-voltage double-fed joint modulation unit.

[0008] Furthermore, there are two joint-modulation transformers, the low-voltage sides of the two joint-modulation transformers are both connected to the low-voltage double-fed joint-modulation unit, and the high-voltage sides are both connected to the high-voltage double-fed joint-modulation unit.

[0009] Alternatively, the primary side and the low-voltage secondary side of the coordinated transformer are short-circuited by a control switch.

[0010] Furthermore, the low-voltage double-fed joint regulation unit is connected to the stator measurement device in the low-voltage station and the external low-voltage joint regulation device through the low-voltage joint regulation switching switch 1, and the low-voltage side of the joint regulation transformer is connected to the frequency converter 1 through the low-voltage joint regulation switching switch 2. The frequency converter 1 is connected to the rotor joint regulation switching switch and then connected to the rotor measurement device in the station.

[0011] Furthermore, the high-voltage double-fed joint regulation unit is connected to the stator measurement device in the high-voltage station and the external high-voltage joint regulation device through the high-voltage joint regulation switching switch 1 respectively, the high-voltage side of the high-voltage joint regulation transformer is connected to the high-voltage joint regulation switching switch 2 through the high-voltage joint regulation transformer, and the high-voltage joint regulation switching switch 2 is connected to the rotor measurement device in the station after being connected to the rotor joint regulation switching switch through the frequency converter 1.

[0012] Furthermore, the low-voltage sides of the two coordinated transformers are connected to the low-voltage motor under test via a broadband measuring device.

[0013] Furthermore, the inverter unit is connected to the low-voltage test motor via a broadband measuring device.

[0014] Furthermore, the inverter unit is connected to the drag transformer, connected to the high-voltage power frequency measuring device, and then connected to the high-voltage test motor.

[0015] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0016] 1. The test system is fully functional. One set of system can complete the whole set of type test items of doubly-fed wind turbine motors and take into account some wind turbine motor joint adjustment tests.

[0017] 2. The test system can carry out double-fed type and joint adjustment tests at different voltage levels such as low voltage and high voltage.

[0018] 3. The test system can provide stator side power supply with different frequencies of 30-70Hz to meet the needs of different frequency standards at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 : Schematic diagram of the principle of the doubly-fed machine test system. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] like Figure 1 As shown, 1. A doubly-fed motor test system comprises a rectifier transformer 1, a rectifier AFE unit 2 and a DC bus 3 which are sequentially connected to a main power grid, and also comprises an inverter unit connected to the DC bus 3, wherein the inverter unit is connected to a doubly-fed joint modulation unit.

[0022] In this embodiment, the main grid is a 10KV incoming line, which is converted into DC through a rectifier transformer 1 and a rectifier AFE unit 2 and enters a DC bus 3. The DC bus 3 provides a DC power supply for a high-voltage test branch, a low-voltage test branch, a low-voltage permanent magnet / asynchronous branch, a high-voltage double-fed / asynchronous branch, a low-voltage double-fed branch, and a high / low-voltage double-fed joint adjustment branch. Since the low-voltage double-fed branch and the high / low-voltage double-fed joint adjustment branch of the double-fed joint adjustment unit are not directly connected to the grid, but are connected to the DC bus 3 through an inverter unit, the power input of the double-fed joint adjustment unit can be applied to different frequencies of 30-70Hz, which expands the scope of application of the test system.

[0023] In a more preferred embodiment, the double-fed joint modulation unit includes a low-voltage double-fed joint modulation unit and a high-voltage double-fed joint modulation unit, and the inverter unit is connected to the joint modulation transformer 4, and the joint modulation transformer 4 is respectively connected to the low-voltage double-fed joint modulation unit and the high-voltage double-fed joint modulation unit. In this embodiment, the inverter unit deploys a four-quadrant inverter unit in this embodiment, and the joint modulation transformer 4 adopts a three-winding transformer, whose primary side is connected to the inverter unit, the high-voltage side of the secondary side is connected to the high-voltage double-fed joint modulation unit, and the low-voltage side is connected to the low-voltage double-fed joint modulation unit.

[0024] In a more preferred embodiment, there are two coupling transformers 4, and the low-voltage sides of the two coupling transformers 4 are connected to the low-voltage double-fed coupling unit, and the high-voltage sides are connected to the high-voltage double-fed coupling unit. The two coupling transformers 4 expand the voltage applicable level of the double-fed coupling unit, so that it can perform double-fed types and coupling tests of different voltage levels such as low voltage and high voltage.

[0025] In a more preferred embodiment, the primary side and the low-voltage secondary side of the joint-adjusting transformer 4 are short-circuited by a control switch (not shown in the figure). In this embodiment, the primary side and the low-voltage secondary side are controlled to be short-circuited, and the inverter unit and the low-voltage double-fed joint-adjusting unit can be directly connected without passing through the transformer, further expanding the voltage applicable level of the double-fed joint-adjusting unit.

[0026] In a more preferred embodiment, the low-voltage double-fed joint adjustment unit is connected to the stator measurement device in the low-voltage station and the external low-voltage joint adjustment device through the low-voltage joint adjustment switching switch 15, and the low-voltage side of the joint adjustment transformer 4 is connected to the frequency converter 10 through the low-voltage joint adjustment switching switch 26, and the frequency converter 10 is connected to the rotor joint adjustment switching switch 9 and then connected to the rotor measurement device in the station. In this embodiment, the logic control of the low-voltage joint adjustment switching switch 15 and the low-voltage joint adjustment switching switch 26 can provide low-voltage double-fed joint adjustment tests under different working conditions. When the low-voltage joint adjustment switching switch 15 is switched to the station, the low-voltage secondary side of the joint adjustment transformer 4 is connected to the grid-connected device and the stator measurement device to provide power for the stator measurement. If the low-voltage joint adjustment switching switch 15 is switched to the external state, the low-voltage secondary side of the joint adjustment transformer 4 can be connected to the external frequency converter to provide joint adjustment power to the outside. Similarly, when the low-voltage joint adjustment switching switch 26 is switched to the station, power can be provided for the rotor broadband measurement device to perform the rotor broadband measurement test. When the low voltage joint adjustment switch 2 6 is switched to external connection, the external frequency converter can provide joint adjustment power to the outside. The combined joint adjustment of the above working conditions can be realized through the logic control of the low voltage joint adjustment switch 1 5 and the low voltage joint adjustment switch 2 6.

[0027] In a more preferred embodiment, the high-voltage double-fed joint adjustment unit is connected to the stator measurement device in the high-voltage station and the external high-voltage joint adjustment device through the high-voltage joint adjustment switching switch 17, and the high-voltage side of the high-voltage joint adjustment transformer 4 is connected to the high-voltage joint adjustment switching switch 28 through the high-voltage joint adjustment transformer 11, and the high-voltage joint adjustment switching switch 28 is connected to the rotor joint adjustment switching switch 9 through the frequency converter 10 and then connected to the rotor measurement device in the station. The combined joint adjustment working condition of the high-voltage double-fed joint adjustment unit is similar to the above-mentioned low-voltage double-fed joint adjustment unit. That is, when the high-voltage joint adjustment switching switch 17 is switched to the station, the high-voltage secondary side of the joint adjustment transformer 4 is connected to the grid-connected device and the stator measurement device to provide power for the stator measurement. If the high-voltage joint adjustment switching switch 17 is switched to external, the joint adjustment power supply can be provided to the outside through the external frequency converter after passing through the high-voltage joint adjustment transformer 11. Similarly, when the high-voltage joint adjustment switching switch 28 is switched to the station, power can be provided to the rotor broadband measurement device to perform the rotor broadband measurement test. When the high-voltage joint adjustment switch 28 is switched to external, an external inverter can be connected to provide joint adjustment power to the outside.

[0028] The above-mentioned in-station test and out-station joint adjustment can also cooperate with the rotor joint adjustment switch 9 to further realize the rotor wide-band measurement or external joint adjustment working condition. That is, when the low-voltage joint adjustment switch 26 and / or the high-voltage joint adjustment switch 28 are switched to the in-station, the rotor joint adjustment switch 9 is also switched to the in-station. At this time, the power output by the joint adjustment transformer 4 is provided for the rotor wide-band measurement through the frequency converter 10. If the low-voltage joint adjustment switch 26 and / or the high-voltage joint adjustment switch 28 are switched to external, the rotor joint adjustment switch 9 is also switched to external. At this time, the joint adjustment power supply can be provided to the outside through the external frequency converter.

[0029] In a more preferred embodiment, the low voltage sides of the two coordinated transformers 4 are connected to the low voltage motor under test through a broadband measurement device. The low voltage side output of the coordinated transformer 4 can directly provide power for the low voltage permanent magnet / synchronous test branch to drive the motor under test.

[0030] In a more preferred embodiment, the inverter unit is connected to the low-voltage test motor via a broadband measuring device.

[0031] In a more preferred embodiment, the inverter unit is connected to the drive transformer 12 and then to the high-voltage power frequency measuring device, and then to the high-voltage test motor. In this embodiment, the inverter unit provides power for the high-voltage test side and the low-voltage test side drive branch, so that the entire system can simultaneously drive the test motor and the tested motor for type testing.

[0032] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0033] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A doubly-fed generator test system, comprising a rectifier transformer (1), a rectifier AFE unit (2) and a DC bus (3) connected to a main power grid in sequence, characterized in that: It also includes an inverter unit connected to the DC bus (3), wherein the inverter unit is connected to the double-fed joint modulation unit.

2. The doubly-fed machine test system according to claim 1, characterized in that: The double-fed joint modulation unit comprises a low-voltage double-fed joint modulation unit and a high-voltage double-fed joint modulation unit, the inverter unit is connected to a joint modulation transformer (4), and the joint modulation transformer (4) is respectively connected to the low-voltage double-fed joint modulation unit and the high-voltage double-fed joint modulation unit.

3. The doubly-fed machine test system according to claim 2, characterized in that: There are two joint-modulation transformers (4), the low-voltage sides of the two joint-modulation transformers (4) are both connected to the low-voltage double-fed joint-modulation unit, and the high-voltage sides are both connected to the high-voltage double-fed joint-modulation unit.

4. The doubly-fed machine test system according to claim 2, characterized in that: The primary side and the low-voltage secondary side of the coordinated transformer (4) are short-circuited via a control switch.

5. The doubly-fed machine test system according to claim 3, characterized in that: The low-voltage double-fed joint regulation unit is connected to the stator measurement device in the low-voltage station and the external low-voltage joint regulation device respectively through the low-voltage joint regulation switching switch 1 (5); the low-voltage side of the joint regulation transformer (4) is connected to the frequency converter 1 (10) through the low-voltage joint regulation switching switch 2 (6); the frequency converter 1 (10) is connected to the rotor joint regulation switching switch (9) and then connected to the rotor measurement device in the station.

6. The doubly-fed machine test system according to claim 5, characterized in that: The high-voltage double-fed joint adjustment unit is connected to a stator measuring device in a high-voltage station and an external high-voltage joint adjustment device respectively through a high-voltage joint adjustment switching switch 1 (7); the high-voltage side of the high-voltage joint adjustment transformer (4) is connected to a high-voltage joint adjustment switching switch 2 (8) through a high-voltage joint adjustment transformer (11); the high-voltage joint adjustment switching switch 2 (8) is connected to a rotor joint adjustment switching switch (9) through a frequency converter 1 (10) and then connected to the rotor measuring device in the station.

7. The doubly-fed machine test system according to claim 6, characterized in that: The low-voltage sides of the two coordinated transformers (4) are connected to the low-voltage motor under test via a broadband measuring device.

8. The doubly-fed machine test system according to claim 7, characterized in that: The inverter unit is connected to the low-voltage test motor via a broadband measuring device.

9. The doubly-fed machine test system according to claim 8, characterized in that: The inverter unit is connected to a drag transformer (12), connected to a high-voltage power frequency measuring device, and then connected to a high-voltage test motor.

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