A Flexible DC Control Strategy Testing System and Method

Abstract

The present invention discloses a flexible DC control strategy testing system and method. The testing system includes a testing subsystem and a real-time simulation subsystem that exchange data through optical fibers. The real-time simulation subsystem includes primary equipment and valve control equipment of the flexible DC system, which acquire three-phase voltage values, three-phase current values, and DC voltage values and send them to the testing subsystem. The testing subsystem includes several control strategy modules. The testing subsystem receives and sequentially performs control strategy tests on the three-phase voltage values, three-phase current values, and DC voltage values through several sub-modules, and sends the test results to the real-time simulation subsystem. By dividing the control strategy into different control strategy modules and sequentially testing and debugging the control strategy modules, the difficulty of testing is reduced, and the testing and debugging efficiency of the control strategy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of DC power transmission testing, and particularly relates to a flexible DC control strategy testing system and method. Background Art

[0002] The development of power transmission technology has experienced an evolution from DC to AC and then to the coexistence of AC and DC. With the progress of power electronics technology, flexible DC, as a new generation of DC power transmission technology, can solve many problems faced by current AC and DC power transmission technologies and is the main way to build a DC grid to absorb new energy power generation in the future. However, with the in-depth engineering application, the problem of system oscillation caused by the interaction between the flexible DC system and the AC system has become increasingly prominent, and the best solution to this problem is to shorten the control link delay, and thus it is necessary to reduce the control strategy execution period.

[0003] At present, in order to achieve a smaller link delay, the fastest execution period of the flexible DC power transmission control strategy has reached 20 us, but the flexible DC control strategy is very complex, and it is difficult to directly debug as a whole, resulting in problems such as a long debugging period and low debugging efficiency. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a flexible DC control strategy testing system and method, which divides the control strategy into different control strategy modules and tests and debugs the control strategy modules in sequence, reducing the testing difficulty and improving the testing and debugging efficiency of the control strategy.

[0005] To solve the above technical problems, a first aspect of the embodiments of the present invention provides a flexible DC control strategy testing system, including: a test subsystem and a real-time simulation subsystem that perform data exchange through optical fiber connection;

[0006] The real-time simulation subsystem includes: primary equipment and valve control equipment of the flexible DC system, which acquire three-phase voltage values, three-phase current values, and DC voltage values and send them to the test subsystem;

[0007] The test subsystem includes several control strategy modules. The test subsystem receives and performs control strategy tests on the three-phase voltage values, the three-phase current values, and the DC voltage values through several sub-modules in sequence, and sends the test results to the real-time simulation subsystem.

[0008] Further, the test subsystem includes: a first control strategy module, a second control strategy module, a third control strategy module, a fourth control strategy module, and a fifth control strategy module;

[0009] The first control strategy module includes: a phase-locked loop unit, a DQ inverse transformation unit, a bridge arm reference voltage calculation unit, and a DQ transformation function unit;

[0010] The second control strategy module includes: a positive-sequence inner-loop current D-axis control unit and a positive-sequence inner-loop current Q-axis control unit;

[0011] The third control strategy module includes: a DC voltage unit and an active power control unit;

[0012] The fourth control strategy module includes: a reactive power unit and an AC voltage control unit;

[0013] The fifth control strategy module includes: a negative-sequence inner-loop current D-axis control unit and a negative-sequence inner-loop current Q-axis control unit.

[0014] Furthermore, the real-time simulation subsystem and the test subsystem exchange data through optical fibers.

[0015] Correspondingly, a second aspect of the embodiments of the present invention provides a flexible DC control strategy testing method, which is tested through any of the above flexible DC control strategy testing systems, and includes the following steps:

[0016] Set the input voltage value of the first control strategy module to a first preset value;

[0017] Receive the control strategy input signal output by the real-time simulation subsystem, and test the first control strategy module, where the control strategy input signal includes: grid-side voltage, grid-side current, valve-side voltage, valve-side current, and DC voltage;

[0018] Judge whether the phase-locked function and the bridge arm reference voltage calculation function are normal;

[0019] If it is normal, it is determined that the control strategy of the first control strategy module meets the requirements;

[0020] If it is not normal, adjust the logic and / or timing of the first control strategy module, and test again.

[0021] Furthermore, after determining that the control strategy of the first control strategy module meets the requirements, it further includes:

[0022] Set the q-channel input current value and the d-channel input current value of the second control strategy module to a second preset value and a third preset value respectively;

[0023] Receive the control strategy input signal, and test the first control strategy module and the second control strategy module;

[0024] Judge whether the measured value of the active current is a fourth preset value and / or judge whether the measured value of the reactive current is a fifth preset value;

[0025] If so, it is determined that the control strategies of the first control strategy module and the second control strategy module meet the requirements;

[0026] If not, adjust the logic, parameters, and / or timing of the second control strategy module and test again.

[0027] Further, after determining that the control strategies of the first control strategy module and the second control strategy module meet the requirements, it further includes:

[0028] Set the q - path input current value of the second control strategy module to the second preset value;

[0029] Receive the control strategy input signal and test the first control strategy module, the second control strategy module, and the third control strategy module;

[0030] Judge whether the measured active power value is the sixth preset value and / or judge whether the measured DC voltage value is the seventh preset value;

[0031] If so, it is determined that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements;

[0032] If not, adjust the logic, parameters, and / or timing of the third control strategy module and test again.

[0033] Further, after determining that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements, it further includes:

[0034] Set the d - path input current value of the second control strategy module to the third preset value;

[0035] Receive the control strategy input signal and test the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module;

[0036] Judge whether the measured reactive power value is the eighth preset value and / or judge whether the measured AC voltage value is the ninth preset value;

[0037] If so, it is determined that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements;

[0038] If not, adjust the logic, parameters, and / or timing of the fourth control strategy module and test again.

[0039] Further, after determining that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements, the following steps are also included:

[0040] Receive the control strategy input signal, and test the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module;

[0041] Judge whether the active power measurement value is a sixth preset value, whether the DC voltage measurement value is a seventh preset value, whether the reactive power measurement value is an eighth preset value, and / or whether the AC voltage measurement value is a ninth preset value;

[0042] If so, determine that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module meet the requirements;

[0043] If not, adjust the logic, parameters, and / or timing of the fifth control strategy module, and perform the test again.

[0044] Further, the first preset value, the second preset value, the third preset value, the fourth preset value, the fifth preset value, the sixth preset value, the seventh preset value, the eighth preset value, and / or the ninth preset value take values in the range of 0 to 1.

[0045] The above technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0046] By dividing the control strategy into different control strategy modules and testing and debugging the control strategy modules in sequence, the difficulty of testing is reduced, and the testing and debugging efficiency of the control strategy is improved. Description of the Drawings

[0047] Figure 1 It is a schematic diagram of the soft straight feedforward decoupling control strategy in the prior art;

[0048] Figure 2 It is a schematic diagram of the control module of the soft straight feedforward decoupling control strategy provided by the embodiment of the present invention;

[0049] Figure 3 It is a test logic diagram of the flexible DC control strategy provided by the embodiment of the present invention. Detailed Embodiment

[0050] To make the objectives, technical solutions, and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following descriptions, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0051] Figure 1 is a schematic diagram of the soft straight-ahead feedforward decoupling control strategy in the prior art.

[0052] Please refer to Figure 1 , the soft straight-ahead feedforward decoupling control strategy is complex. When directly debugging seven PI controllers (two for the outer loop, two for the positive-sequence current inner loop, two for the negative-sequence current inner loop, and one for the phase-locked loop), there are disadvantages such as difficulty in adjusting the PI parameters. At the same time, there are disadvantages such as long debugging time and difficulty in problem location and verification in source code-level debugging.

[0053] Figure 2 is a schematic diagram of the control module of the soft straight-ahead feedforward decoupling control strategy provided by an embodiment of the present invention.

[0054] Please refer to Figure 2 , a first aspect of the embodiment of the present invention provides a flexible DC control strategy test system, including: a test subsystem and a real-time simulation subsystem that exchange data through optical fiber connections; the real-time simulation subsystem includes: primary equipment and valve control equipment of the flexible DC system, which acquire three-phase voltage values, three-phase current values, and DC voltage values and send them to the test subsystem; the test subsystem includes several control strategy modules. The test subsystem receives and sequentially performs control strategy tests on the three-phase voltage values, three-phase current values, and DC voltage values through several sub-modules, and sends the test results to the real-time simulation subsystem.

[0055] Through the above flexible DC control strategy test system, step-by-step testing and debugging of the control strategy can be realized. The testing of a single control strategy module is relatively simple, reducing the development difficulty for testers and providing judgment on whether the characteristic quantities of each module are normal, effectively improving the test efficiency.

[0056] In a specific implementation manner of this embodiment, the test subsystem includes: a first control strategy module, a second control strategy module, a third control strategy module, a fourth control strategy module, and a fifth control strategy module. The first control strategy module includes: a phase-locked loop unit, a DQ inverse transformation unit, a leg reference voltage calculation unit, and a DQ transformation function unit; the second control strategy module includes: a positive-sequence inner-loop current D-axis control unit and a positive-sequence inner-loop current Q-axis control unit; the third control strategy module includes: a DC voltage unit and an active power control unit; the fourth control strategy module includes: a reactive power unit and an AC voltage control unit; the fifth control strategy module includes: a negative-sequence inner-loop current D-axis control unit and a negative-sequence inner-loop current Q-axis control unit.

[0057] Specifically, the real-time simulation subsystem and the test subsystem exchange data through optical fibers. The entire test system can achieve functional testing through a fully digital optical fiber test system, with a simple implementation method and convenient analysis.

[0058] Figure 3 It is the test logic diagram of the flexible DC control strategy provided by the embodiment of the present invention.

[0059] Correspondingly, please refer to Figure 3 In the second aspect of the embodiment of the present invention, a flexible DC control strategy test method is provided. The test is performed through any of the above flexible DC control strategy test systems, and the method includes the following steps:

[0060] S110, set the input voltage value of the first control strategy module to a first preset value.

[0061] S120, receive the control strategy input signal output by the real-time simulation subsystem, and test the first control strategy module. Among them, the control strategy input signal includes: grid-side voltage, grid-side current, valve-side voltage, valve-side current, and DC voltage.

[0062] S130, determine whether the phase-locking function and the leg reference voltage calculation function are normal.

[0063] S140, if it is normal, determine that the control strategy of the first control strategy module meets the requirements.

[0064] S150, if it is not normal, adjust the logic and / or timing of the first control strategy module, and perform the test again.

[0065] Further, after step S140 determines that the control strategy of the first control strategy module meets the requirements, it further includes:

[0066] S210, set the q-channel input current value and the d-channel input current value of the second control strategy module to a second preset value and a third preset value respectively.

[0067] S220, receive the control strategy input signal and test the first control strategy module and the second control strategy module.

[0068] S230, determine whether the measured active current value is the fourth preset value and / or determine whether the measured reactive current value is the fifth preset value.

[0069] S240, if so, determine that the control strategies of the first control strategy module and the second control strategy module meet the requirements.

[0070] S250, if not, adjust the logic, parameters, and / or timing of the second control strategy module and test again.

[0071] Further, after step S240 determines that the control strategies of the first control strategy module and the second control strategy module meet the requirements, it further includes:

[0072] S310, set the q-path input current value of the second control strategy module to the second preset value.

[0073] S320, receive the control strategy input signal and test the first control strategy module, the second control strategy module, and the third control strategy module.

[0074] S330, determine whether the measured active power value is the sixth preset value and / or determine whether the measured DC voltage value is the seventh preset value.

[0075] S340, if so, determine that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements.

[0076] S350, if not, adjust the logic, parameters, and / or timing of the third control strategy module and test again.

[0077] Further, after step S340 determines that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements, it further includes:

[0078] S410, set the d-path input current value of the second control strategy module to the third preset value.

[0079] S420, receive the control strategy input signal and test the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module.

[0080] S430, determine whether the measured reactive power value is the eighth preset value and / or determine whether the measured AC voltage value is the ninth preset value.

[0081] S440, if so, it is determined that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements.

[0082] S450, if not, adjust the logic, parameters, and / or timing of the fourth control strategy module, and conduct the test again.

[0083] Further, after step S440 determines that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements, it further includes:

[0084] S510, receive the control strategy input signal, and conduct tests on the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module.

[0085] S520, determine whether the measured active power value is the sixth preset value, determine whether the measured DC voltage value is the seventh preset value, determine whether the measured reactive power value is the eighth preset value, and / or determine whether the measured AC voltage value is the ninth preset value.

[0086] S530, if so, it is determined that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module meet the requirements.

[0087] S540, if not, adjust the logic, parameters, and / or timing of the fifth control strategy module, and conduct the test again.

[0088] In the steps of the above test method, the first preset value, the second preset value, the third preset value, the fourth preset value, the fifth preset value, the sixth preset value, the seventh preset value, the eighth preset value, and / or the ninth preset value take values in the range of 0 to 1.

[0089] The embodiment of the present invention aims to protect a flexible DC control strategy test system and method, including: a test subsystem and a real-time simulation subsystem that exchange data through optical fiber connection; the real-time simulation subsystem includes: primary equipment and valve control equipment of the flexible DC system, which acquire three-phase voltage values, three-phase current values, and DC voltage values and send them to the test subsystem; the test subsystem includes several control strategy modules, and the test subsystem receives and conducts control strategy tests on the three-phase voltage values, three-phase current values, and DC voltage values through several sub-modules in sequence, and sends the test results to the real-time simulation subsystem. The above technical solution has the following effects:

[0090] By dividing the control strategy into different control strategy modules and conducting test debugging on the control strategy modules in sequence, the test difficulty is reduced, and the test and debugging efficiency of the control strategy is improved.

[0091] It should be understood that the above specific embodiments of the present invention are only used for illustrative explanation or interpretation of the principles of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A flexible DC control strategy test system, characterized in that, Including: A test subsystem and a real-time simulation subsystem for data exchange through optical fiber connection; The real-time simulation subsystem includes: primary equipment and valve control equipment of a flexible DC system, which acquire three-phase voltage values, three-phase current values, and DC voltage values and send them to the test subsystem; The test subsystem includes several control strategy modules. The test subsystem receives and sequentially performs control strategy tests on the three-phase voltage values, the three-phase current values, and the DC voltage values through several sub-modules, and sends the test results to the real-time simulation subsystem; The test subsystem includes: a first control strategy module, a second control strategy module, a third control strategy module, a fourth control strategy module, and a fifth control strategy module; The first control strategy module includes: a phase-locked loop unit, a DQ inverse transformation unit, a bridge arm reference voltage calculation unit, and a DQ transformation function unit; The second control strategy module includes: a positive sequence inner loop current D-axis control unit and a positive sequence inner loop current Q-axis control unit; The third control strategy module includes: a DC voltage unit and an active power control unit; The fourth control strategy module includes: a reactive power unit and an AC voltage control unit; The fifth control strategy module includes: a negative sequence inner loop current D-axis control unit and a negative sequence inner loop current Q-axis control unit.

2. The flexible DC control strategy test system according to claim 1, wherein The real-time simulation subsystem and the test subsystem perform data exchange through optical fiber.

3. A flexible DC control strategy testing method, characterized in that, Testing through the flexible DC control strategy test system according to claim 1 or 2 includes the following steps: Set the input voltage value of the first control strategy module to a first preset value; Receive the control strategy input signal output by the real-time simulation subsystem and test the first control strategy module, wherein the control strategy input signal includes: grid-side voltage, grid-side current, valve-side voltage, valve-side current, and DC voltage; Judge whether the phase-locking function and the bridge arm reference voltage calculation function are normal; If normal, it is determined that the control strategy of the first control strategy module meets the requirements; If not normal, adjust the logic and / or timing of the first control strategy module and test again.

4. The flexible DC control strategy testing method according to claim 3, characterized in that After determining that the control strategy of the first control strategy module meets the requirements, it further includes: Set the q-path input current value and the d-path input current value of the second control strategy module to a second preset value and a third preset value respectively; Receive the control strategy input signal and test the first control strategy module and the second control strategy module; Judge whether the active current measurement value is a fourth preset value and / or judge whether the reactive current measurement value is a fifth preset value; If so, it is determined that the control strategies of the first control strategy module and the second control strategy module meet the requirements; If not, adjust the logic, parameters, and / or timing of the second control strategy module and test again.

5. The flexible DC control strategy testing method according to claim 4, wherein After determining that the control strategies of the first control strategy module and the second control strategy module meet the requirements, it further includes: Set the q - path input current value of the second control strategy module to the second preset value; Receive the control strategy input signal and test the first control strategy module, the second control strategy module, and the third control strategy module; Judge whether the active power measurement value is the sixth preset value and / or judge whether the DC voltage measurement value is the seventh preset value; If so, determine that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements; If not, adjust the logic, parameters, and / or timing of the third control strategy module and test again.

6. The flexible DC control strategy testing method according to claim 5, characterized in that After determining that the control strategies of the first control strategy module, the second control strategy module, and the third control strategy module meet the requirements, it further includes: Set the d - path input current value of the second control strategy module to the third preset value; Receive the control strategy input signal and test the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module; Judge whether the reactive power measurement value is the eighth preset value and / or judge whether the AC voltage measurement value is the ninth preset value; If so, determine that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements; If not, adjust the logic, parameters, and / or timing of the fourth control strategy module and test again.

7. The flexible DC control strategy testing method according to claim 6, wherein After determining that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, and the fourth control strategy module meet the requirements, it further includes: Receive the control strategy input signal and test the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module; Judge whether the active power measurement value is the sixth preset value, judge whether the DC voltage measurement value is the seventh preset value, judge whether the reactive power measurement value is the eighth preset value, and / or judge whether the AC voltage measurement value is the ninth preset value; If so, determine that the control strategies of the first control strategy module, the second control strategy module, the third control strategy module, the fourth control strategy module, and the fifth control strategy module meet the requirements; If not, adjust the logic, parameters, and / or timing of the fifth control strategy module and test again.

8. The flexible DC control strategy testing method according to claim 7, wherein The first preset value, the second preset value, the third preset value, the fourth preset value, the fifth preset value, the sixth preset value, the seventh preset value, the eighth preset value, and / or the ninth preset value take values in the range of 0 to 1.

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