Dynamic performance test method for energy dissipation branch in energy self-balancing flexible direct-current valve, and related apparatus

Abstract

A dynamic performance test method for an energy dissipation branch in an energy self-balancing flexible direct-current valve, and a related apparatus. The method comprises: after a test valve is connected to a test system, presetting test parameters of the test valve, and adjusting operating parameters to make the test valve operate under a maximum continuous current operating condition; next, starting a dynamic characteristic test for an energy dissipation branch, and adjusting the modulation wave amplitude of a bridge arm where an auxiliary test valve is located, so as to boost the voltages of sub-modules of the test valve; on the basis of the average voltage of the sub-modules of the test valve, turning the energy dissipation branch on or off, and also adjusting the phase angle and the modulation wave amplitude of the bridge arm where the auxiliary test valve is located; on the basis of the magnitudes of the average absorbed energy and the maximum absorbed energy of energy dissipation resistors in the sub-modules, repeating the preceding two steps; and finally, on the basis of the voltage unbalance degree of the sub-modules and the absorbed energy unbalance degree of the resistors, evaluating a test result. Therefore, the problem of the existing operation test systems being prone to oscillation during the overall operation of an energy dissipation branch, which further triggers system protection tripping and eventually leads to test failure, is solved.

Description

Test method and related equipment for dynamic performance of energy self-balancing flexible straight valve energy discharge branch

[0001] This application claims priority to Chinese Patent Application No. 202411512971.4, filed on October 28, 2024, entitled “Dynamic Performance Test Method and Related Device for Energy Self-Balancing Flexible Straight Valve Energy Discharge Branch”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of flexible DC transmission technology in power systems, and in particular to a dynamic performance test method and related apparatus for a self-balancing flexible DC valve energy discharge branch. Background Technology

[0003] Flexible DC transmission converter valves, with their flexibility, controllability, and high efficiency, have broad application prospects in DC transmission and renewable energy power generation and grid connection. For islanded transmission applications such as offshore wind power flexible DC transmission, to limit overvoltage caused by surplus power during receiving-end faults, flexible DC systems based on conventional MMC topologies require the addition of AC or DC energy dissipation devices, increasing construction costs. Currently, energy self-balancing flexible DC valves, with submodules possessing active energy discharge branches, can eliminate the need for energy dissipation devices and reduce submodule capacitance, representing a new technology for solving the surplus power problem during AC faults at the receiving end of offshore wind power flexible DC systems.

[0004] The energy self-balancing flexible direct valve topology is shown in Figure 2. The sub-modules in the bridge arm can adopt a hybrid cascade structure of full and half bridges. Unlike conventional MMC sub-modules, each sub-module capacitor has a discharge branch composed of a fully controlled power electronic switch and a resistor connected in parallel across its terminals.

[0005] The energy-balancing flexible DC valve bridge arm submodule's energy-draining branch adopts a valve-controlled unified triggering strategy. When the entire bridge arm experiences overvoltage, the energy-draining resistor in the submodule's energy-draining branch is activated under unified control to reduce the capacitor voltage and ensure the submodule's safety. The balancing effect of the submodule voltage and the energy absorbed by the energy-draining resistor during the energy-draining branch's operation is a key design consideration for the energy-balancing flexible DC valve's energy-draining branch. If the submodule voltage and the energy absorbed by the energy-draining resistor within the bridge arm cannot be balanced, uneven voltage distribution between submodules and excessive energy absorption will occur, causing the submodule's energy-draining branch to prematurely disconnect. Ultimately, this may lead to system fault ride-through failure and system lockout tripping.

[0006] Currently, existing technologies do not conduct research on the dynamic performance testing of the energy self-balancing flexible DC valve's energy discharge branch during operation, nor are there specific testing methods for the dynamic performance of the energy self-balancing flexible DC valve's energy discharge branch. Existing flexible DC valve testing systems also lack the function of overall bridge arm voltage boosting, and have poor dynamic control stability, making them prone to oscillations during the overall operation of the energy discharge branch, leading to system protection tripping and ultimately test failure. Summary of the Invention

[0007] This application provides a dynamic performance test method and related device for the energy self-balancing flexible DC valve energy discharge branch, which solves the problem that the existing operation test system cannot raise the voltage of the energy self-balancing flexible DC valve sub-module as a whole, and the energy discharge branch is triggered uniformly, which easily causes oscillation during the overall operation of the energy discharge branch, resulting in system protection tripping and ultimately test failure.

[0008] In view of this, the first aspect of this application provides a dynamic performance test method for the energy discharge branch of an energy self-balancing flexible direct current valve. The energy discharge branch is composed of a fully controllable power electronic switch and an energy discharge resistor. The energy self-balancing flexible direct current valve to be tested is connected to the test system as a test valve. The sub-module of the energy self-balancing flexible direct current valve has a built-in control device with a function to detect operating parameters and a valve control with calculation and control functions. The test system includes: a DC voltage source, a bridge arm 1 composed of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor.

[0009] The method includes:

[0010] S1. After the test valve is connected to the test system, the test parameters of the test valve are preset, including: the input voltage U of the energy dissipation branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu ;

[0011] S2. By setting the operating parameters of the bridge arm 1 and the bridge arm 2, the bridge arm 2 is made to operate under the condition of continuous maximum current.

[0012] S3. By adjusting the modulation amplitude value of the bridge arm 1, the voltage of the submodule where the test valve is located is increased;

[0013] S4. Based on the average voltage of the submodule where the test sample valve is located, the energy discharge branch is switched on or off. At the same time, the modulation wave phase angle and the modulation wave amplitude of the bridge arm 1 are adjusted, and then step S5 is executed.

[0014] S5. Calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E... smu Return to step S3 until the average absorbed energy is not less than the maximum absorbed energy E. smu And calculate the voltage imbalance of the submodule where the test sample valve is located and the energy absorption imbalance of the leakage resistor;

[0015] S6. Analyze the dynamic performance of the energy discharge branch in the energy self-balancing flexible valve based on the voltage imbalance and the absorbed energy imbalance.

[0016] Optionally, step S2 includes:

[0017] By setting the modulation amplitude values ​​of both bridge arm 1 and bridge arm 2 to n1, the voltage of the submodule containing the test valve is not lower than the rated operating voltage U. sm1 And let the phase angle of the modulation wave of the bridge arm 2 be θ = θ1, so that the current of the bridge arm 2 is not lower than the maximum continuous operating current.

[0018] Optionally, step S3 includes:

[0019] Within one power frequency cycle, the modulation amplitude of the bridge arm 1 is adjusted to n2, thereby increasing the voltage of the submodule where the test valve is located.

[0020] in, The condition (n+1) ≥ n2 > n1 is satisfied.

[0021] In the formula, n1 and n2 are both modulation wave amplitude values ​​of the bridge arm, U u U is the input voltage. sm1 The rated operating voltage is [value].

[0022] Optionally, step S4 includes:

[0023] The average voltage U of the submodule containing the test sample valve is obtained through the valve control calculation. avg；

[0024] When the average voltage U avg >The input voltage U u At that time, the valve control uniformly triggers the energy discharge branch of the test sample valve, and sets the modulation wave phase angle difference θ = 0 of bridge arm 2, and reduces the modulation wave amplitude of bridge arm 1 from n2 to n1;

[0025] When the average voltage U avg <The input voltage U u At that time, the valve control system will lock the energy discharge branch of the test valve and set the phase angle difference θ = θ1 of the bridge arm 2, so that the submodule where the test valve is located will resume operation under the condition of continuous maximum current.

[0026] Optionally, calculating the average absorbed energy of the leakage resistor includes:

[0027] The average absorbed energy of the leakage resistor is calculated based on the average absorbed energy calculation formula.

[0028] The formula for calculating the average absorbed energy is as follows:

[0029] In the formula, E avgE represents the average energy absorbed by the leakage resistor. N The value of energy absorbed by the corresponding numbered submodule is given, where n is the number of sample valve submodules.

[0030] Optionally, the calculation of the voltage imbalance of the submodule where the test valve is located and the energy absorption imbalance of the leakage resistor includes:

[0031] The voltage imbalance of the test sample valve in the sub-module is calculated based on the voltage imbalance calculation formula, and the energy absorption imbalance of the leakage resistor is calculated based on the energy absorption imbalance calculation formula.

[0032] The formula for calculating the voltage imbalance is as follows:

[0033] In the formula, δ U U represents the voltage imbalance of the submodule containing the test valve. max U is the highest voltage of the test valve submodule. min U is the lowest voltage of the test valve submodule. avg The average voltage;

[0034] The formula for calculating the energy imbalance of the energy leakage resistor is as follows:

[0035] In the formula, δ E E represents the energy absorption imbalance of the leakage resistor. max E represents the maximum energy absorbed by the test valve submodule. min E represents the minimum energy absorbed by the test valve submodule. avg The average energy absorbed by the leakage resistor.

[0036] Optionally, step S6 includes:

[0037] When the voltage imbalance is less than a preset percentage and the energy absorption imbalance is less than a preset percentage, the dynamic performance of the energy release branch in the test valve is deemed qualified.

[0038] The second aspect of this application provides a dynamic performance test device for the energy discharge branch of an energy self-balancing flexible direct current valve. The energy discharge branch consists of a fully controllable power electronic switch and an energy discharge resistor. The energy self-balancing flexible direct current valve to be tested is connected to the test system as a test valve. The sub-module of the energy self-balancing flexible direct current valve has a built-in control device with a function to detect operating parameters and a valve control with calculation and control functions. The test system includes: a DC voltage source, a bridge arm 1 consisting of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor.

[0039] The device includes:

[0040] The first setting unit is used to preset the test parameters of the test valve after the test valve is connected to the test system. The test parameters include the input voltage U of the energy dissipation branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu ;

[0041] The second setting unit is used to set the operating parameters of the bridge arm 1 and the bridge arm 2 so that the bridge arm 2 operates under the condition of continuous maximum current.

[0042] The first test unit is used to increase the voltage of the submodule where the test valve is located by adjusting the modulation amplitude value of the bridge arm 1.

[0043] The second test unit is used to switch the energy discharge branch on or off according to the average voltage of the submodule where the test sample valve is located, and after adjusting the modulation wave phase angle and the modulation wave amplitude of the bridge arm 1, it executes step S5.

[0044] The third test unit is used to calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E, the test is conducted. smu The first test unit is triggered until the average absorbed energy is not less than the maximum absorbed energy E. smu And calculate the voltage imbalance of the submodule where the test sample valve is located and the energy absorption imbalance of the leakage resistor;

[0045] The fourth test unit is used to analyze the dynamic performance of the energy discharge branch in the energy self-balancing flexible valve based on the voltage imbalance and the absorbed energy imbalance.

[0046] A third aspect of this application provides a dynamic performance testing device for an energy self-balancing flexible direct valve energy discharge branch, the device comprising a processor and a memory:

[0047] The memory is used to store program code and transmit the program code to the processor;

[0048] The processor is configured to execute the steps of the dynamic performance test method for the energy self-balancing flexible direct valve energy discharge branch as described in the first aspect above, according to the instructions in the program code.

[0049] The fourth aspect of this application provides a computer-readable storage medium for storing program code for executing the dynamic performance test method for the energy self-balancing flexible direct valve energy discharge branch described in the first aspect above.

[0050] As can be seen from the above technical solutions, this application has the following advantages:

[0051] This application provides a dynamic performance test method for the energy discharge branch of an energy self-balancing flexible DC valve. Based on an existing flexible DC converter valve operation test system, it simulates a system fault during normal operation of the energy self-balancing flexible DC valve, leading to overall overpressure of the bridge arm. The method uniformly triggers the energy discharge branch of each sub-module in the energy self-balancing flexible DC valve, verifying the voltage equalization, resistance energy balance, and energy tolerance among the sub-modules. This overcomes the lack of effective testing methods during the operation of the energy discharge branch of the energy self-balancing flexible DC valve and solves the problem that existing operation test systems cannot raise the voltage of the sub-modules of the energy self-balancing flexible DC valve as a whole, and the uniform triggering of the energy discharge branch easily leads to oscillations during the overall operation of the energy discharge branch, resulting in system protection tripping and ultimately test failure. This application can be carried out using an existing mature flexible DC converter valve operation test system, eliminating the need for a new test system, and has the advantages of low investment and simple testing method. Attached Figure Description

[0052] Figure 1 is a flowchart illustrating a dynamic performance test method for an energy self-balancing flexible direct valve energy discharge branch provided in an embodiment of this application;

[0053] Figure 2 is a topology diagram of the energy self-balancing flexible straight valve provided in the embodiment of this application;

[0054] Figure 3 shows the topology of the dynamic performance test system for the energy self-balancing flexible straight valve energy discharge branch provided in the embodiment of this application;

[0055] Figure 4 is a diagram showing the effect of the test method provided in the embodiment of this application;

[0056] Figure 5 is a diagram showing the effect of uneven energy absorption by the voltage and resistance of the submodule provided in the embodiment of this application.

[0057] Figure 6 is a schematic diagram of the structure of a dynamic performance test device for an energy self-balancing flexible straight valve energy discharge branch provided in an embodiment of this application. Detailed Implementation

[0058] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0059] Please refer to Figure 1. This application provides a dynamic performance test method for the energy discharge branch of an energy self-balancing flexible DC valve. The energy discharge branch consists of a fully controllable power electronic switch and an energy discharge resistor. The energy self-balancing flexible DC valve under test is connected to the test system as a test valve. The sub-module of the energy self-balancing flexible DC valve has a built-in control device with the function of detecting operating parameters and a valve control with calculation and control functions. The test system includes a DC voltage source, a test valve, and a source module. When the overall system is over-voltaged, the energy discharge branch of the bridge arm sub-module is actively activated to discharge energy, reduce capacitor voltage, and ensure the safety of the converter valve equipment.

[0060] It should be noted that, in one embodiment, the dynamic performance test system of the energy self-balancing flexible DC valve energy discharge branch of this application is shown in Figure 3; the test system mainly includes: a DC voltage source, a bridge arm 1 composed of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor.

[0061] The methods include:

[0062] Step 101: After the test valve is connected to the test system, preset the test parameters for the test valve. The test parameters include: the input voltage U of the energy dissipation branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu .

[0063] It should be noted that before starting the dynamic performance test of the energy self-balancing flexible direct current valve's energy discharge branch, that is, before the energy self-balancing flexible direct current valve assembly is connected to the test system as the test valve, the test parameters of the test valve need to be preset. The test parameters include: the input voltage U of the energy discharge branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu Among them, the input voltage U of the energy dissipation branch u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu The set value is determined based on the design parameters of the flexible straight-line engineering to which the test valve belongs.

[0064] Step 102: By setting the operating parameters of bridge arm 1 and bridge arm 2, bridge arm 2 is made to operate under the condition of continuous maximum current.

[0065] In one embodiment, step 102 includes:

[0066] By setting the modulation amplitude values ​​of both bridge arm 1 and bridge arm 2 to n1, the voltage of the submodule containing the test valve is not lower than the rated operating voltage U. sm1 And let the phase angle of the modulation wave of bridge arm 2 be θ = θ1, so that the current of bridge arm 2 is not lower than the maximum continuous operating current.

[0067] It should be noted that, in order to ensure that the submodule containing the test valve operates under the maximum current continuous operation condition, specifically, the modulation amplitude values ​​of the bridge arms containing both the test valve and the test valve (i.e., bridge arm 1 and bridge arm 2) are both given as n1 (n1 is a positive integer), and the voltage of the submodule containing the test valve is not lower than the rated operating voltage U. sm1 Let the phase angle of the modulation wave of the bridge arm where the test valve is located be θ = θ1, so that the current of the bridge arm 2 where the test valve is located is not lower than the maximum continuous operating current.

[0068] Step 103: By adjusting the modulation amplitude value of bridge arm 1, the voltage of the submodule where the test valve is located is increased.

[0069] In one embodiment, step 103 includes:

[0070] Within one power frequency cycle, adjust the modulation amplitude of bridge arm 1 to n2 to raise the voltage of the submodule where the test valve is located;

[0071] in, The condition (n+1) ≥ n2 > n1 is satisfied.

[0072] In the formula, n1 and n2 are both modulation wave amplitude values ​​of the bridge arm, U u For the applied voltage, U sm1 This is the rated operating voltage.

[0073] Understandably, step 103 initiates the dynamic performance test of the energy leakage branch. First, step 103 adjusts the modulation amplitude value of the bridge arm 1 where the test valve is located, thereby increasing the voltage of the submodule of the test valve.

[0074] Step 104: Based on the average voltage of the submodule where the test sample valve is located, switch the energy discharge branch on or off. At the same time, adjust the modulation wave phase angle and the modulation wave amplitude of bridge arm 1, and then proceed to step 105.

[0075] In one embodiment, step 104 includes:

[0076] The average voltage U of the submodule containing the test sample valve is obtained through valve control calculation. avg；

[0077] When the average voltage U avg > Input voltage U u At that time, the valve control uniformly triggers the energy discharge branch of the test sample valve, and sets the phase angle difference of the modulation wave of bridge arm 2 to θ = 0, and reduces the modulation wave amplitude of bridge arm 1 from n2 to n1.

[0078] When the average voltage U avg < Input voltage U u At that time, the valve control system will lock the energy discharge branch of the test valve and set the phase angle difference θ = θ1 of bridge arm 2 so that the submodule where the test valve is located will resume operation under the condition of continuous maximum current.

[0079] It should be noted that the energy self-balancing flexible direct current valve submodule has a built-in control device that monitors the submodule's working status in real time. The capacitor voltage and the energy-absorbing resistor absorb energy and upload it to the valve control. The submodule and energy-absorbing resistor are switched on and off according to the valve control's instructions.

[0080] Step 105: Calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E... smu Return to step 103 until the average absorbed energy is not less than the maximum absorbed energy E. smu The voltage imbalance and energy absorption imbalance of the leakage resistor in the submodule where the test sample valve is located are calculated.

[0081] In one embodiment, calculating the average absorbed energy of the leakage resistor in step 105 includes:

[0082] The average absorbed energy of the leakage resistor is calculated based on the formula for calculating the average absorbed energy.

[0083] The formula for calculating the average absorbed energy is as follows:

[0084] In the formula, E avg E represents the average energy absorbed by the energy-discharging resistor. N The value of energy absorbed by the corresponding numbered submodule is given, where n is the number of sample valve submodules.

[0085] It should be noted that all calculations in this application are performed through valve control.

[0086] In one embodiment, step 105, calculating the voltage imbalance and energy absorption imbalance of the leakage resistor in the submodule containing the test valve, includes:

[0087] The voltage imbalance of the sample valve in the submodule is calculated based on the voltage imbalance calculation formula, and the energy absorption imbalance of the leakage resistor is calculated based on the leakage resistor calculation formula.

[0088] The formula for calculating voltage imbalance is as follows:

[0089] In the formula, δ U U represents the voltage imbalance of the submodule containing the test valve. max U is the highest voltage of the test valve module. min U is the lowest voltage of the test valve submodule. avg Average voltage;

[0090] The formula for calculating the leakage resistance is:

[0091] In the formula, δ EE represents the unevenness of energy absorption by the energy-discharging resistor. max E represents the maximum energy absorbed by the test valve submodule. min E represents the minimum energy absorbed by the test valve submodule. avg This represents the average energy absorbed by the leakage resistor.

[0092] Step 106: Analyze the dynamic performance of the energy discharge branch in the self-balancing flexible valve based on the voltage imbalance and the energy absorption imbalance.

[0093] In one embodiment, step 106 includes:

[0094] When the voltage imbalance is less than a preset percentage and the energy absorption imbalance is less than a preset percentage, the dynamic performance of the energy release branch in the test valve is deemed qualified.

[0095] It should be noted that, specifically, for example, if the voltage imbalance of the test valve submodule is detected to be <10% during the operation of the energy discharge branch, and the energy absorption imbalance of the energy discharge resistor of the test valve submodule is detected to be <10% after the test, then the dynamic performance of the test valve energy discharge branch is deemed qualified; otherwise, it is deemed unqualified.

[0096] The following is a description of the test results obtained according to the test method of this application:

[0097] As shown in Figure 4, the first window at the top displays the voltage of the test valve bridge arm (red) and the voltage of the auxiliary test valve bridge arm (black). The dynamic performance test of the energy dissipation branch starts at 3 seconds. Before 3 seconds, both bridge arms output a level of 4 (modulation amplitude of 4). After the dynamic performance test of the energy dissipation branch starts at 3 seconds, within 20ms, the modulation amplitude of the auxiliary test valve bridge arm is adjusted to 6, and the bridge arm outputs a maximum level of 6, charging the test valve submodule. The upper right corner of the first window shows the magnified waveform at 3 seconds, demonstrating the change in the level. The second window displays the bridge arm current. Before 3 seconds and after 3.6 seconds, it operates under the maximum current continuous operation condition. Between 3 seconds and 3.6 seconds, due to the operation of the energy dissipation branch, the phase angle is adjusted, and the bridge arm current decreases. The third window displays the capacitor voltage of the test valve submodule. It can be seen that it starts to rise at 3 seconds, reaching a maximum of 3050V when the energy dissipation branch is activated. The fourth window displays the energy dissipation branch conduction command. The system remained running during the test. This diagram only shows the electrical quantity changes during one energy discharge branch operation. Based on the relationship between the average energy absorbed and the maximum energy absorbed by the energy discharge resistor of the submodule, multiple tests can be conducted.

[0098] As shown in Figure 5, the effect diagram of the submodule voltage and energy absorption imbalance of the energy leakage resistor obtained according to the test method provided in this application shows that the submodule voltage imbalance during the operation of the energy leakage branch is <3.5%, and the energy absorption imbalance of the energy leakage resistor of the test valve submodule after the test is <7.0%, thus determining that the dynamic performance of the energy leakage branch of the test valve is qualified. According to the test method provided in this invention, the entire test process verifies the dynamic performance of the energy leakage branch of the energy self-balancing flexible valve.

[0099] In summary, this application proposes a dynamic performance test method for the energy-self-balancing flexible DC valve's energy-discharge branch. Based on an existing flexible DC converter valve operation test system, it simulates a system fault during normal operation of the energy-self-balancing flexible DC valve, leading to overall overpressure of the bridge arm. This method uniformly triggers the energy-discharge branch of each sub-module within the energy-self-balancing flexible DC valve, verifying the voltage equalization, resistance energy balance, and energy tolerance among the sub-modules. This overcomes the lack of effective testing methods during the operation of the energy-discharge branch of the energy-self-balancing flexible DC valve and solves the problem that existing operation test systems cannot raise the voltage of all sub-modules of the energy-self-balancing flexible DC valve as a whole, and the uniform triggering of the energy-discharge branch easily leads to oscillations during the overall operation of the energy-discharge branch, resulting in system protection tripping and ultimately test failure. This application can utilize an existing mature flexible DC converter valve operation test system, eliminating the need for a new test system and offering advantages such as low investment and simple testing methods.

[0100] The above is a dynamic performance test method for the energy self-balancing flexible straight valve energy discharge branch provided in the embodiments of this application. The following is a dynamic performance test device for the energy self-balancing flexible straight valve energy discharge branch provided in the embodiments of this application.

[0101] Please refer to Figure 2. This application provides a dynamic performance test device for the energy self-balancing flexible direct current valve energy discharge branch. The energy discharge branch consists of a fully controllable power electronic switch and an energy discharge resistor. The energy self-balancing flexible direct current valve to be tested is connected to the test system as a test valve. The sub-module of the energy self-balancing flexible direct current valve has a built-in control device with the function of detecting operating parameters and a valve control with the function of calculation and control. The test system includes: a DC voltage source, a bridge arm 1 consisting of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor.

[0102] The device includes:

[0103] The first setting unit 201 is used to preset the test parameters of the test valve after the test valve is connected to the test system. The test parameters include: the input voltage U of the energy leakage branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu .

[0104] The second setting unit 202 is used to set the operating parameters of bridge arm 1 and bridge arm 2 so that bridge arm 2 operates under the condition of continuous maximum current.

[0105] The first test unit 203 is used to raise the voltage of the submodule where the test valve is located by adjusting the modulation amplitude value of the bridge arm 1.

[0106] The second test unit 204 is used to switch the energy discharge branch on or off according to the average voltage of the submodule where the test valve is located, and then execute step S5 after adjusting the modulation wave phase angle and the modulation wave amplitude of bridge arm 1.

[0107] The third test unit 205 is used to calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E... smu The first test unit 203 is triggered until the average absorbed energy is not less than the maximum absorbed energy E. smu The voltage imbalance and energy absorption imbalance of the leakage resistor in the submodule where the test sample valve is located are calculated.

[0108] The fourth test unit 206 is used to analyze the dynamic performance of the energy discharge branch in the energy self-balancing flexible direct current valve based on voltage imbalance and absorbed energy imbalance.

[0109] Furthermore, this application embodiment also provides a dynamic performance testing device for the energy self-balancing flexible direct valve energy discharge branch, the device including a processor and a memory:

[0110] The memory is used to store program code and transmit the program code to the processor;

[0111] The processor is used to execute the steps of the dynamic performance test method for the energy self-balancing flexible direct valve energy discharge branch as described in the above method embodiments, according to the instructions in the program code.

[0112] Furthermore, this application embodiment also provides a computer-readable storage medium for storing program code for executing the methods described in the above method embodiments.

[0113] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the system and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0114] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0115] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0116] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0117] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0118] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0119] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0120] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A test method for the dynamic performance of an energy self-balancing flexible direct valve energy discharge branch, characterized in that, The energy leakage branch consists of a fully controlled power electronic switch and an energy leakage resistor. The energy self-balancing flexible direct current valve to be tested is connected to the test system as the test valve. The sub-module of the energy self-balancing flexible direct current valve has a built-in control device with the function of detecting operating parameters and a valve control with the function of calculation and control. The test system includes: a DC voltage source, a bridge arm 1 consisting of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor. The methods include: S1. After the test valve is connected to the test system, the test parameters of the test valve are preset, including: the input voltage U of the energy dissipation branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu ; S2. By setting the operating parameters of the bridge arm 1 and the bridge arm 2, the bridge arm 2 is made to operate under the condition of continuous maximum current. S3. By adjusting the modulation amplitude value of the bridge arm 1, the voltage of the submodule where the test valve is located is increased; S4. Based on the average voltage of the submodule where the test sample valve is located, the energy discharge branch is switched on or off. At the same time, the modulation wave phase angle and the modulation wave amplitude of the bridge arm 1 are adjusted, and then step S5 is executed. S5. Calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E... smu Return to step S3 until the average absorbed energy is not less than the maximum absorbed energy E. smu And calculate the voltage imbalance of the submodule where the test sample valve is located and the energy absorption imbalance of the leakage resistor; S6. Analyze the dynamic performance of the energy discharge branch in the energy self-balancing flexible valve based on the voltage imbalance and the absorbed energy imbalance.

2. The test method for dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 1, characterized in that, Step S2 includes: By setting the modulation amplitude values ​​of both bridge arm 1 and bridge arm 2 to n1, the voltage of the submodule containing the test valve is not lower than the rated operating voltage U. sm1 And let the phase angle of the modulation wave of the bridge arm 2 be θ = θ1, so that the current of the bridge arm 2 is not lower than the maximum continuous operating current.

3. The test method for dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 2, characterized in that, Step S3 includes: Within one power frequency cycle, the modulation amplitude of the bridge arm 1 is adjusted to n2, thereby increasing the voltage of the submodule where the test valve is located. in, The condition (n+1) ≥ n2 > n1 is satisfied. In the formula, n1 and n2 are both modulation wave amplitude values ​​of the bridge arm, U u U is the input voltage. sm1 The rated operating voltage is [value].

4. The test method for the dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 2, characterized in that, Step S4 includes: The average voltage U of the submodule containing the test sample valve is obtained through the valve control calculation. avg； When the average voltage U avg >The input voltage U u At that time, the valve control uniformly triggers the energy discharge branch of the test sample valve, and sets the modulation wave phase angle difference θ = 0 of bridge arm 2, and reduces the modulation wave amplitude of bridge arm 1 from n2 to n1; When the average voltage U avg <The input voltage U u At that time, the valve control system will lock the energy discharge branch of the test valve and set the phase angle difference θ = θ1 of the bridge arm 2, so that the submodule where the test valve is located will resume operation under the condition of continuous maximum current.

5. The test method for dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 2, characterized in that, The calculation of the average absorbed energy of the leakage resistor includes: The average absorbed energy of the leakage resistor is calculated based on the average absorbed energy calculation formula. The formula for calculating the average absorbed energy is as follows: In the formula, E avg E represents the average energy absorbed by the leakage resistor. N The value of energy absorbed by the corresponding numbered submodule is given, where n is the number of sample valve submodules.

6. The test method for dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 2, characterized in that, The calculation of the voltage imbalance of the submodule where the test sample valve is located and the energy absorption imbalance of the leakage resistor includes: The voltage imbalance of the test sample valve in the sub-module is calculated based on the voltage imbalance calculation formula, and the energy absorption imbalance of the leakage resistor is calculated based on the energy absorption imbalance calculation formula. The formula for calculating the voltage imbalance is as follows: In the formula, δ U U represents the voltage imbalance of the submodule containing the test valve. max U is the highest voltage of the test valve module. min U is the lowest voltage of the test valve submodule. avg The average voltage; The formula for calculating the energy imbalance of the energy leakage resistor is as follows: In the formula, δ E E represents the energy absorption imbalance of the leakage resistor. max E represents the maximum energy absorbed by the test valve submodule. min E represents the minimum energy absorbed by the test valve submodule. avg The average energy absorbed by the leakage resistor.

7. The test method for dynamic performance of the energy self-balancing flexible direct valve energy discharge branch according to claim 1, characterized in that, Step S6 includes: When the voltage imbalance is less than a preset percentage and the energy absorption imbalance is less than a preset percentage, the dynamic performance of the energy release branch in the test valve is deemed qualified.

8. A dynamic performance test device for the energy self-balancing flexible direct valve energy discharge branch, characterized in that, The energy leakage branch consists of a fully controlled power electronic switch and an energy leakage resistor. The energy self-balancing flexible direct current valve to be tested is connected to the test system as the test valve. The sub-module of the energy self-balancing flexible direct current valve has a built-in control device with the function of detecting operating parameters and a valve control with the function of calculation and control. The test system includes: a DC voltage source, a bridge arm 1 consisting of a test valve and a source module, a bridge arm 2 where the test valve is located, and a connecting reactor. The device includes: The first setting unit is used to preset the test parameters of the test valve after the test valve is connected to the test system. The test parameters include the input voltage U of the energy dissipation branch. u Cut-off voltage U d The maximum energy absorbed by the leakage resistor E smu ; The second setting unit is used to set the operating parameters of the bridge arm 1 and the bridge arm 2 so that the bridge arm 2 operates under the condition of continuous maximum current. The first test unit is used to increase the voltage of the submodule where the test valve is located by adjusting the modulation amplitude value of the bridge arm 1. The second test unit is used to switch the energy discharge branch on or off according to the average voltage of the submodule where the test sample valve is located, and after adjusting the modulation wave phase angle and the modulation wave amplitude of the bridge arm 1, it executes step S5. The third test unit is used to calculate the average absorbed energy of the leakage resistor. When the average absorbed energy is less than the maximum absorbed energy E, the test is conducted. smu The first test unit is triggered until the average absorbed energy is not less than the maximum absorbed energy E. smu And calculate the voltage imbalance of the submodule where the test sample valve is located and the energy absorption imbalance of the leakage resistor; The fourth test unit is used to analyze the dynamic performance of the energy discharge branch in the energy self-balancing flexible valve based on the voltage imbalance and the absorbed energy imbalance.

9. A dynamic performance testing device for the energy self-balancing flexible direct valve energy discharge branch, characterized in that, The device includes a processor and a memory: The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the dynamic performance test method for the energy self-balancing flexible straight valve energy discharge branch according to the instructions in the program code as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the dynamic performance test method for the energy self-balancing flexible direct valve energy discharge branch according to any one of claims 1-7.

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