Valve assembly equivalent test circuit and valve assembly all-condition equivalent test method

Abstract

The invention provides a valve assembly equivalent test circuit and a valve assembly full-condition equivalent test method, and the circuit comprises a DC power supply unit, a first phase unit, a second phase unit and a common bridge arm which are connected in parallel. Each of the first phase unit and the second phase unit comprises two bridge arms which are connected in series; a common bridge arm is electrically connected between a connection point of the two serially connected bridge arms in the first phase unit and a connection point of the two serially connected bridge arms in the second phase unit; the common bridge arm is connected in series with the modular multi-level valve assembly to be tested; the direct-current power supply unit is used for charging the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm respectively; the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm are all used for generating test current used for testing the modularized multi-level valve assembly. As the bridge arms in the first phase unit and the second phase unit and the common bridge arm are independently adjusted, the test requirements of the direct-current transformer under all working conditions are met.

Description

Technical Field

[0001] The invention belongs to the technical field of direct current power transmission and direct current power grid, and in particular relates to a valve assembly equivalent test circuit and a valve assembly full-operating condition equivalent test method. Background Art

[0002] With the acceleration of energy transformation, achieving green and low-carbon development has become a global consensus. Flexible DC transmission technology has become a key means to achieve large-scale stable delivery of clean energy, and has gradually developed into multi-terminal and DC grid forms. As a key equipment in the DC grid, the DC transformer has the functions of realizing DC voltage conversion, system flow control and fault current limiting.

[0003] Although academia and industry have proposed a variety of high-voltage DC transformer topologies, in practical applications, DC transformers are mostly used in low-voltage and low-power applications, while the corresponding research on high-voltage and high-power DC transformers is not mature enough and remains in the theoretical research stage. Among the DC transformer topologies currently proposed, the T-type DC transformer adopts modular multi-level technology, which has the advantages of strong scalability, mature technology, and good economy. It is a topology with high engineering feasibility. Its topology is as follows Figure 1 shown.

[0004] In order to improve the reliability of the flexible DC transmission system, similar to the flexible DC converter valve, strict type tests need to be carried out on the DC transformer, mainly including insulation tests, operation tests and other test items. Among them, the operation test is mainly used to verify the function and performance of the equipment under actual engineering stress. Due to the characteristics of high voltage and high current of high-voltage and high-power DC transformers, it is impossible to use direct test methods to build a circuit that is completely consistent with the actual operating conditions. Only one or more valve components can be subjected to equivalent tests. At present, the most commonly used equivalent operation test circuit includes a test valve assembly, an auxiliary valve assembly and a set of energy supplement power supplies. There is a bridge arm reactance indirect to the valve assembly. The current stress that needs to be simulated is generated in the circuit through the AC and DC power exchange between the two bridge arms.

[0005] The power module types and electrical stresses used in T-type DC transformers and flexible DC converters are different. Unlike flexible DC converters, the ratio of AC and DC components in the bridge arm current in T-type DC transformers varies more widely. In actual applications, under certain operating conditions, the proportion of DC components in the bridge arm current of the DC transformer may even exceed 95%. At present, the traditional equivalent test circuit requires AC and DC energy exchange between the bridge arms to achieve energy balance. The adjustment range of the AC and DC component ratio in the bridge arm current is relatively narrow, which cannot meet the test requirements of the DC transformer under all operating conditions. Summary of the invention

[0006] In order to overcome the above-mentioned deficiencies of the prior art, in a first aspect, the present invention application proposes a valve assembly equivalent test circuit, comprising: a DC power supply unit, a first phase unit, a second phase unit and a common bridge arm respectively connected in parallel;

[0007] The first phase unit and the second phase unit each include two bridge arms connected in series;

[0008] The common bridge arm is electrically connected between the connection point of the two bridge arms connected in series in the first phase unit and the connection point of the two bridge arms connected in series in the second phase unit; the common bridge arm is connected in series with the modular multi-level valve assembly to be tested;

[0009] The DC power supply unit is used to charge the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm respectively;

[0010] After charging is completed, the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm are all used to generate a test current for testing the modular multi-level valve assembly.

[0011] Preferably, the DC power supply unit comprises a DC power supply and a smoothing reactor connected in series;

[0012] Each bridge arm in the first phase unit and the second phase unit comprises a first auxiliary valve assembly and a first bridge arm reactor connected in series, and the first auxiliary valve assembly comprises a plurality of first submodules connected in series;

[0013] The common bridge arm comprises a plurality of second auxiliary valve assemblies connected in series and a second bridge arm reactor; a plurality of the second auxiliary valve assemblies are connected in series with at least one of the modular multi-level valve assemblies to be tested; the second auxiliary valve assembly comprises a plurality of second sub-modules connected in series;

[0014] The modular multi-level valve assembly to be tested has a third submodule;

[0015] The first submodule is a half-bridge submodule or a full-bridge submodule, the second submodule is a half-bridge submodule or a full-bridge submodule, and the third submodule is a half-bridge submodule or a full-bridge submodule;

[0016] The first submodule, the second submodule and the third submodule contain capacitors for charging or discharging.

[0017] Preferably, the circuit further comprises:

[0018] A filter circuit is connected in parallel with the DC power supply unit, wherein the filter circuit comprises a resistor, a capacitor and a reactor connected in series.

[0019] Preferably, the circuit further includes: a transient electrical stress test circuit connected in parallel with the common bridge arm, the transient electrical stress test circuit including: switch S1, inductor L1, thyristor V1, diode D2, capacitor C1, capacitor C2, thyristor V3, inductor L2, switch S2, diode D1 and thyristor V2; the switch S1, the inductor L1, the thyristor V1, the diode D2, the capacitor C1, the capacitor C2, the thyristor V3, the inductor L2 and the switch S2 are connected in series in sequence, the thyristor V3 is connected in parallel with the thyristor V2, the diode D2 and the capacitor C1 are connected in parallel with the diode D1, and the two ends of the common bridge arm are respectively connected to the connection point between the switch S1 and the switch S2 and the connection point between the capacitor C1 and the capacitor C2.

[0020] In a second aspect, the present invention also proposes a full-condition equivalent test method for a valve assembly, comprising:

[0021] The DC power supply unit in the control valve assembly equivalent test circuit respectively charges the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm in the valve assembly equivalent test circuit;

[0022] After charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, and the test current is used to test the modular multi-level valve assembly connected in series with the common bridge arm.

[0023] Preferably, after the charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, including:

[0024] Control the first phase unit, the first auxiliary valve assembly in the second phase unit and the second auxiliary valve assembly in the common bridge arm to generate a voltage for testing the modular multi-level valve assembly according to the test current; control the modular multi-level valve assembly to be tested to generate the test voltage.

[0025] The waveform and phase of the voltage generated by the first auxiliary valve assembly in the first phase unit and the second phase unit are adjusted so that the current flowing through the modular multi-level valve assembly to be tested in the valve assembly equivalent test circuit reaches the test current, while keeping the voltage of the capacitor of the first submodule, the second submodule, and the third submodule in the modular multi-level valve assembly to be tested stable.

[0026] Preferably, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, including:

[0027] The bridge arm in the first phase unit, the second phase unit or the common bridge arm is adjusted so that the DC component of the test current reaches the target DC component, and the AC component of the test current reaches the target AC component; the target DC component and the target AC component are used to simulate the current stress to which the modular multi-level valve assembly is subjected in actual operation.

[0028] Preferably, after the charging is completed, after the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, the method further includes:

[0029] After charging is completed, the waveforms of the voltages generated by the first auxiliary valve assembly in the first phase unit and the second phase unit and the second auxiliary valve assembly in the common bridge arm are gradually adjusted until the current in the valve assembly equivalent test circuit is 0; the bridge arms and the common bridge arms in the first phase unit and the second phase unit are locked, and the DC power supply unit is disconnected to discharge the capacitors in the first submodule and the second submodule.

[0030] Preferably, the step of adjusting the bridge arm in the first phase unit, the second phase unit or the common bridge arm so that the DC component of the test current reaches a target DC component and the AC component of the test current reaches a target AC component includes:

[0031] Adjusting the voltage waveform amplitudes generated by the first auxiliary valve assemblies in the first phase unit and the second phase unit, adjusting the phase angle difference between the voltage waveforms generated by the two bridge arms of the first phase unit, and adjusting the phase angle difference between the voltage waveforms generated by the two bridge arms of the second phase unit, so that the DC component of the test current reaches the target DC component;

[0032] Adjust the voltage waveform amplitude generated by multiple first auxiliary valve components in the first phase unit and the second phase unit, adjust the phase angle difference between the voltage waveforms generated by the first phase unit and the second phase unit, and adjust the voltage waveform generated by the second auxiliary valve component in the common bridge arm, so that the AC component of the test current reaches the target AC component.

[0033] Preferably, the method further comprises:

[0034] Close the switch S1, and the DC power supply unit in the equivalent test circuit of the control valve assembly charges the capacitor C1 and the capacitor C2 respectively;

[0035] After the capacitors C1 and C2 are completely charged, the transient electrical stress test circuit is controlled to perform an overcurrent shutdown test and a short-circuit current test on the modular multi-level valve assembly.

[0036] The current shutoff test includes: locking the first auxiliary valve assembly and the second auxiliary valve assembly, closing the switch knife S1 and the switch knife S2, triggering the thyristor V1, and the modular multi-level valve assembly discharges through the inductor L1 and the diode D1 to generate an overcurrent. After detecting that the current reaches a preset current threshold, the modular multi-level valve assembly automatically locks to complete the overcurrent shutoff test;

[0037] The short-circuit current test includes triggering thyristors V2 and V3, and discharging capacitors C1 and C2 to the modular multi-level valve assembly through inductors L1 and L2 respectively, so that the modular multi-level valve assembly is subjected to the stress of the discharged current, thereby realizing the short-circuit current test.

[0038] In a third aspect, the present invention application further proposes an electronic device, comprising: at least one processor and a memory; the memory and the processor are connected via a bus;

[0039] The memory is used to store one or more programs;

[0040] When the one or more programs are executed by the at least one processor, the full-operating-condition equivalent test method for a valve assembly is implemented.

[0041] In a fourth aspect, the present invention application further proposes a readable storage medium having an execution program stored thereon, and when the execution program is executed, the full-operating-condition equivalent test method of a valve assembly is implemented.

[0042] Compared with the closest prior art, the present invention has the following beneficial effects:

[0043] A valve assembly equivalent test circuit of the present invention comprises: a DC power supply unit, a first phase unit, a second phase unit and a common bridge arm respectively connected in parallel; the first phase unit and the second phase unit each comprise two bridge arms connected in series; the common bridge arm is electrically connected between the connection point of the two bridge arms connected in series in the first phase unit and the connection point of the two bridge arms connected in series in the second phase unit; the common bridge arm is connected in series with a modular multi-level valve assembly to be tested; the DC power supply unit is used to charge the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm respectively; after charging is completed, the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm are all used to generate a test current for testing the modular multi-level valve assembly. When performing a steady-state stress equivalent test of the valve assembly, since the bridge arms in the first phase unit and the second phase unit and the common bridge arm can be adjusted separately, all working conditions of the DC transformer can be simulated, and the test requirements of the DC transformer under all working conditions can be met. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A topological diagram with high engineering feasibility in the prior art;

[0045] Figure 2 A structural diagram of a partial circuit of a valve assembly equivalent test circuit provided by the present invention;

[0046] Figure 3 A structural diagram of a valve assembly equivalent test circuit provided by the present invention;

[0047] Figure 4 A schematic diagram of a flow chart of a full-operating equivalent test method for a valve assembly provided in the present invention;

[0048] Figure 5 A flowchart of a specific use case of a full-operating equivalent test method for a valve assembly provided by the present invention;

[0049] Figure 6 A schematic diagram of the operation of an electronic device provided in the present invention application. DETAILED DESCRIPTION

[0050] The specific implementation methods of the present invention are further described in detail below with reference to the accompanying drawings.

[0051] Embodiment 1:

[0052] like Figure 2 , Figure 3 As shown, the present invention application proposes a valve assembly equivalent test circuit, comprising: a DC power supply unit, a first phase unit, a second phase unit and a common bridge arm respectively connected in parallel;

[0053] The first phase unit and the second phase unit each include two bridge arms connected in series;

[0054] The common bridge arm is electrically connected between the connection point of the two bridge arms connected in series in the first phase unit and the connection point of the two bridge arms connected in series in the second phase unit; the common bridge arm is connected in series with the modular multi-level valve assembly to be tested to form an H-bridge structure;

[0055] The DC power supply unit is used to charge the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm respectively, as a steady-state stress equivalent test circuit;

[0056] After charging is completed, the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm are all used to generate a test current for testing the modular multi-level valve assembly.

[0057] As mentioned above, the modular multi-level valve assembly can be a valve assembly in a DC transformer, a flexible DC converter or any other equipment using modular multi-level technology. There can be multiple modular multi-level valve assemblies to be tested connected in series with a common bridge arm. The DC power supply unit can be used to charge the capacitors in the first submodule and the second submodule in the test circuit, and also to supplement electric energy to each bridge arm during the operation of the test circuit.

[0058] Furthermore, the DC power supply unit includes a DC power supply E connected in series. dc Peace wave reactor L dc ;

[0059] Each bridge arm in the first phase unit and the second phase unit comprises a first auxiliary valve assembly and a first bridge arm reactor connected in series, and the first auxiliary valve assembly comprises a plurality of first submodules connected in series;

[0060] The common bridge arm includes a plurality of second auxiliary valve assemblies and a second bridge arm reactor L connected in series. 0 ; A plurality of the second auxiliary valve assemblies are connected in series with at least one of the modular multi-level valve assemblies to be tested; the second auxiliary valve assembly comprises a plurality of second sub-modules connected in series;

[0061] The modular multi-level valve assembly to be tested has a third submodule;

[0062] The first submodule is a half-bridge submodule or a full-bridge submodule, the second submodule is a half-bridge submodule or a full-bridge submodule, and the third submodule is a half-bridge submodule or a full-bridge submodule;

[0063] The first submodule, the second submodule and the third submodule contain capacitors for charging or discharging.

[0064] exist Figure 2 In this embodiment, the bridge arm of the first phase unit and the second phase unit includes an upper bridge arm and a lower bridge arm. The upper bridge arm of the first phase unit includes a first bridge arm inductor Ls and a first auxiliary valve assembly HA, and the lower bridge arm of the first phase unit includes a first bridge arm inductor Ls and a first auxiliary valve assembly LA; the upper bridge arm of the second phase unit includes a first bridge arm inductor Ls and a first auxiliary valve assembly HB, and the lower bridge arm of the second phase unit includes a first bridge arm inductor Ls and a first auxiliary valve assembly LB connected in series. The first submodule is Figure 2 The SMs in the first phase unit and the second phase unit are shown in FIG.

[0065] Among them, the first auxiliary valve components HA, LA, HB, and LB are composed of multiple first sub-modules connected in series. The number of first sub-modules contained in the four first auxiliary valve components can be designed to be the same, and the specific number of first sub-modules can be designed according to circuit parameters such as the test capacity required by the circuit, the first bridge arm inductor, and the first sub-module voltage.

[0066] Among them, the number of second auxiliary valve assemblies in the common bridge arm is not limited, and it contains at least one modular multi-level valve assembly to be tested. The type of the third submodule in the modular multi-level valve assembly to be tested is not limited, and it can be a half-bridge submodule or a full-bridge submodule. The number of third submodules in the modular multi-level valve assembly to be tested is not limited as long as it meets the relevant test standards. The number of modular multi-level valve assemblies to be tested in the common bridge arm is not limited as long as it meets the relevant test standards.

[0067] In this embodiment, the common bridge arm may include two reverse series-connected modular multi-level valve assemblies to be tested WA and WB, and at least one second bridge arm reactor. Figure 2 The middle one is SM located in the public bridge arm, L OA , L OB Both are inductance symbols.

[0068] Furthermore, the circuit further comprises:

[0069] A filter circuit is connected in parallel with the DC power supply unit, wherein the filter circuit comprises a resistor, a capacitor and a reactor connected in series.

[0070] The filter circuit is connected in parallel with the first phase unit and the second phase unit. The filter circuit can provide a path for the AC current of a specific frequency, stabilize the voltage at the DC port, and improve the accuracy of the test current control. The specific structure of the filter circuit is not limited, and can be composed of a resistor, a capacitor and a reactor connected in series. The values ​​of the resistor, capacitor and reactor can be designed according to the operating frequency of the test circuit, the voltage level of the DC power supply unit, the power transmitted between the bridge arms and other conditions.

[0071] Further, the circuit also includes: a transient electrical stress test circuit connected in parallel with the common bridge arm, the transient electrical stress test circuit including: a switch S1, an inductor L1, a thyristor V1, a diode D2, a capacitor C1, a capacitor C2, a thyristor V3, an inductor L2, a switch S2, a diode D1 and a thyristor V2; the switch S1, the inductor L1, the thyristor V1, the diode D2, the capacitor C1, the capacitor C2, the thyristor V3, the inductor L2 and the switch S2 are connected in series in sequence, the thyristor V3 is connected in parallel with the thyristor V2, the diode D2 and the capacitor C1 are connected in parallel with the diode D1, and the two ends of the common bridge arm are respectively connected to the connection point between the switch S1 and the switch S2 and the connection point between the capacitor C1 and the capacitor C2.

[0072] The test circuit of the present invention includes only one power supply, and realizes the pre-charging and energy replenishing functions at the same time, which makes the operation of the circuit simpler and reduces the circuit cost and volume; it includes a transient electrical stress test circuit in parallel with the modular multi-level valve assembly to be tested, which can be switched with the steady-state electrical stress test circuit by switching the knife switch.

[0073] Embodiment 2:

[0074] Based on the same inventive concept, Figure 4 As shown, the present invention also proposes a full-condition equivalent test method for a valve assembly, comprising the following steps:

[0075] Step 1: Control the DC power supply unit in the valve assembly equivalent test circuit to charge the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm in the valve assembly equivalent test circuit respectively;

[0076] Step 2: After charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, and the test current is used to test the modular multi-level valve assembly connected in series with the common bridge arm.

[0077] For example, in step 1: due to the structure of the present invention, an H-bridge structure is adopted as a whole, and the test current is not mainly generated by the AC and DC energy exchange between the second auxiliary valve assembly in the common bridge arm, but is mainly generated by the first auxiliary valve assembly in the first phase unit and the second phase unit. The common bridge arm is used as a test path, which is closer to the actual operation of the modular multi-level valve assembly to be tested.

[0078] For example, in step 2: the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, which may include:

[0079] The bridge arm in the first phase unit, the second phase unit or the common bridge arm is adjusted so that the DC component of the test current reaches the target DC component, and the AC component of the test current reaches the target AC component; the target DC component and the target AC component are used to simulate the current stress to which the modular multi-level valve assembly is subjected in actual operation.

[0080] In the above, after charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, which may include:

[0081] Controlling the first auxiliary valve assembly in the first phase unit, the second phase unit and the second auxiliary valve assembly in the common bridge arm to generate a voltage for testing the modular multi-level valve assembly according to the test current; controlling the modular multi-level valve assembly to be tested to generate the test voltage;

[0082] The waveform and phase of the voltage generated by the first auxiliary valve assembly in the first phase unit and the second phase unit are adjusted so that the current flowing through the modular multi-level valve assembly to be tested in the valve assembly equivalent test circuit reaches the test current, while keeping the voltage of the capacitor of the first submodule, the second submodule, and the third submodule in the modular multi-level valve assembly to be tested stable.

[0083] In the above, after the charging is completed, after the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, after the modular multi-level valve assembly test is finished, the method may further include:

[0084] After charging is completed, the waveforms of the voltages generated by the first auxiliary valve assembly in the first phase unit and the second phase unit and the second auxiliary valve assembly in the common bridge arm are gradually adjusted until the current in the valve assembly equivalent test circuit is 0; the bridge arms and the common bridge arms in the first phase unit and the second phase unit are locked, and the DC power supply unit is disconnected to discharge the capacitors in the first submodule and the second submodule.

[0085] In the above, the step of adjusting the bridge arm in the first phase unit, the second phase unit or the common bridge arm so that the DC component of the test current reaches the target DC component and the AC component of the test current reaches the target AC component includes:

[0086] Adjusting the voltage waveform amplitudes generated by the first auxiliary valve assemblies in the first phase unit and the second phase unit, adjusting the phase angle difference between the voltage waveforms generated by the two bridge arms of the first phase unit, and adjusting the phase angle difference between the voltage waveforms generated by the two bridge arms of the second phase unit, so that the DC component of the test current reaches the target DC component;

[0087] Adjust the voltage waveform amplitude generated by the first auxiliary valve components in the first phase unit and the second phase unit, adjust the phase angle difference between the voltage waveforms generated by the first phase unit and the second phase unit, and adjust the voltage waveform generated by the common bridge arm, so that the AC component of the test current reaches the target AC component.

[0088] The above mainly realizes the regulation of the DC component and AC component of the test current.

[0089] The method described above may further include:

[0090] Close the switch S1, and the DC power supply unit in the equivalent test circuit of the control valve assembly charges the capacitor C1 and the capacitor C2 respectively;

[0091] After the capacitors C1 and C2 are completely charged, the transient electrical stress test circuit is controlled to perform an overcurrent shutdown test and a short-circuit current test on the modular multi-level valve assembly.

[0092] The current shutoff test includes: locking the first auxiliary valve assembly and the second auxiliary valve assembly, closing the switch knife S1 and the switch knife S2, triggering the thyristor V1, and the modular multi-level valve assembly discharges through the inductor L1 and the diode D1 to generate an overcurrent. After detecting that the current reaches a preset current threshold, the modular multi-level valve assembly automatically locks to complete the overcurrent shutoff test;

[0093] The short-circuit current test includes triggering thyristors V2 and V3, and discharging capacitors C1 and C2 to the modular multi-level valve assembly through inductors L1 and L2 respectively, so that the modular multi-level valve assembly is subjected to the stress of the discharged current, thereby realizing the short-circuit current test.

[0094] When the common bridge arm includes two modular multi-level valve assemblies to be tested that are connected in reverse series, a feasible control method is to control the voltage reference waves of the two modular multi-level valve assemblies to be tested to be exactly the same, so that the voltage output of the modular multi-level valve assembly to be tested in the common bridge arm will not affect the operation of the first phase unit and the second phase unit, thereby realizing decoupling control of the test current and the voltage of the modular multi-level valve assembly to be tested, reducing the control difficulty of the test circuit and improving the control flexibility.

[0095] Secondly, the common bridge arm may include two modular multi-level valve assemblies to be tested that are connected in reverse series, which means that the number of the third sub-module in the modular multi-level valve assembly to be tested will not affect the test capability of the test circuit. In addition, the currents flowing through the two modular multi-level valve assemblies to be tested are opposite, so the electrical stress of the modular multi-level valve assembly to be tested under different energy transfer directions can also be tested simultaneously.

[0096] In summary, by adjusting the voltage waveform and phase of the first auxiliary valve assembly in the first phase unit and the second phase unit, the AC and DC components of the test current can be independently adjusted, and a test current with any proportion of AC and DC components can be generated, thereby improving the equivalence of the test current; since the decoupling control between the test current and the voltage of the modular multi-level valve assembly to be tested is realized, the output voltage amplitude of the modular multi-level valve assembly to be tested and the phase difference between it and the test current can be controlled, thereby improving the flexibility of voltage and current control; by controlling the voltage waveform of each first auxiliary valve assembly and the second auxiliary valve assembly in the first phase unit, the second phase unit and the common bridge arm, the capacitor voltage of the first sub-module and the second sub-module in each bridge arm and the common bridge arm in the circuit can be more accurately stabilized near the target value during the test; the transient electrical stress test circuit can perform overcurrent shutdown tests, short-circuit current tests and other tests on the modular multi-level valve assembly, simulating various transient stresses that may be generated during the operation of the modular multi-level valve assembly or other equipment with similar principles. Therefore, the test circuit can realize accurate simulation and equivalence of various electrical stresses of DC transformers, flexible DC converters and other equipment with similar principles under all working conditions.

[0097] Embodiment 3:

[0098] Based on the same inventive concept, Figure 5 As shown, the present invention also proposes a specific use case of a full-condition equivalent test method for a valve assembly, which specifically includes the following steps:

[0099] Step S1: Control the DC power supply unit to charge each bridge arm and the common bridge arm in the test circuit until the capacitor voltage of the first submodule and the second submodule reaches the rated value;

[0100] Step S2: After charging is completed, unlock each bridge arm and the common bridge arm in the test circuit, and output voltage according to a preset voltage waveform;

[0101] Step S3: adjusting the voltage waveform and phase of the first auxiliary valve assembly of each bridge arm in the first phase unit and the second phase unit so that the test current in the test circuit reaches the target value; adjusting the voltage waveform and phase of the modular multi-level valve assembly to be tested in the common bridge arm so that the test voltage reaches the target value; adjusting the voltage waveform of the first auxiliary valve assembly and the second auxiliary valve assembly in the first phase unit, the second phase unit and the common bridge arm so that the voltage of the capacitor of the first submodule, the second submodule and the third submodule in each bridge arm in the test circuit is stable at the target value;

[0102] Step S4: After completing the running test, gradually adjust the voltage waveforms of the first phase unit, the second phase unit and the first auxiliary valve assembly and the second auxiliary valve assembly in the common bridge arm until the test current is 0; lock each bridge arm and the common bridge arm and turn off the DC power supply unit to discharge the capacitors of the first submodule and the second submodule.

[0103] In the above, step S3 in this embodiment can be implemented in the following manner:

[0104] The test current is the common bridge arm current in the test circuit, including the DC component and the AC component of the test current;

[0105] Adjusting the DC component of the test current to reach the target value includes: adjusting the voltage wave amplitude of the first auxiliary valve assembly in the first phase unit and the second phase unit and the phase angle difference between the voltage waves of the two bridge arms;

[0106] Adjusting the AC component of the test current to reach the target value includes: adjusting the voltage wave amplitude of the first auxiliary valve assembly of each bridge arm in the first phase unit and the second phase unit, the phase angle difference between the voltage waves of the first phase unit and the second phase unit, and the voltage waveform of the second auxiliary valve assembly in the common bridge arm;

[0107] In the above, step S3 in this embodiment can also be implemented in the following manner:

[0108] When the common bridge arm includes two reverse-connected modular multi-level valve assemblies to be tested, the voltage waveforms of the reverse-connected modular multi-level valve assemblies to be tested are controlled to be exactly the same, so that the voltage output of the modular multi-level valve assembly in the common bridge arm will not affect the operation of the first phase unit and the second phase unit in the test circuit.

[0109] Based on the common bridge arm, when the common bridge arm contains multiple modular multilevel valve assemblies to be tested that are connected in reverse series, the currents flowing through the multiple modular multilevel valve assemblies are opposite, and the electrical stress of the modular multilevel valve assemblies under test in different energy transfer directions can be subjected to equivalent tests at the same time, and the output voltages of the multiple modular multilevel valve assemblies connected in reverse series are controlled to offset each other, thereby realizing decoupling control between the test current and the voltage of the modular multilevel valve assembly to be tested.

[0110] Embodiment 4:

[0111] Based on the same inventive concept, Figure 6 As shown, the present invention also provides an electronic device, which may be a computer device, a single-chip device, an intelligent mobile device, etc. The electronic device in this embodiment may include a processor, a memory, a transceiver component, etc. The memory, the processor, and the transceiver component are connected via a bus; the memory may be used to store an execution program, and an exemplary execution program may include instructions; the processor is used to execute the instructions stored in the memory. The memory may also be used to store data, which may be called and / or modified when the instructions are executed.

[0112] The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, which is suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in a storage medium to implement the corresponding method flow or corresponding functions, so as to realize the steps of a full-condition equivalent test method for a valve assembly in the above-mentioned embodiment.

[0113] Embodiment 5:

[0114] Based on the same inventive concept, the present invention also provides a readable storage medium, specifically an electronic device readable storage medium (Memory), which is a memory device in the electronic device for storing programs and data. It can be understood that the storage medium here can include both the built-in storage medium in the electronic device and the extended storage medium supported by the electronic device. The storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more execution programs (including program codes). It should be noted that the storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. The processor loads and executes one or more instructions stored in the storage medium, which can implement the steps of a full-condition equivalent test method for a valve assembly in the above-mentioned embodiment.

[0115] Those skilled in the art will appreciate that the embodiments of the present invention application can be provided as methods, systems, or computer program products. Therefore, the present invention application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present invention application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0116] The present invention application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present invention application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0117] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0118] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention application rather than to limit its protection scope. Although the present invention application is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that after reading the present invention application, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the application, but these changes, modifications or equivalent substitutions are all within the protection scope of the claims to be approved.

Claims

1. A valve assembly equivalent test circuit, characterized in that: include: A DC power supply unit, a first phase unit, a second phase unit and a common bridge arm connected in parallel respectively; The first phase unit and the second phase unit each include two bridge arms connected in series; The common bridge arm is electrically connected between the connection point of the two bridge arms connected in series in the first phase unit and the connection point of the two bridge arms connected in series in the second phase unit; the common bridge arm is connected in series with the modular multi-level valve assembly to be tested; The DC power supply unit is used to charge the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm respectively; After charging is completed, the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm are all used to generate a test current for testing the modular multi-level valve assembly.

2. The circuit according to claim 1, characterized in that The DC power supply unit includes a DC power supply and a smoothing reactor connected in series; Each bridge arm in the first phase unit and the second phase unit comprises a first auxiliary valve assembly and a first bridge arm reactor connected in series, and the first auxiliary valve assembly comprises a plurality of first submodules connected in series; The common bridge arm comprises a plurality of second auxiliary valve assemblies connected in series and a second bridge arm reactor; a plurality of the second auxiliary valve assemblies are connected in series with at least one of the modular multi-level valve assemblies to be tested; the second auxiliary valve assembly comprises a plurality of second sub-modules connected in series; The modular multi-level valve assembly to be tested has a third submodule; The first submodule is a half-bridge submodule or a full-bridge submodule, the second submodule is a half-bridge submodule or a full-bridge submodule, and the third submodule is a half-bridge submodule or a full-bridge submodule; The first submodule, the second submodule and the third submodule contain capacitors for charging or discharging.

3. The circuit according to claim 1, characterized in that Also includes: A filter circuit is connected in parallel with the DC power supply unit, wherein the filter circuit comprises a resistor, a capacitor and a reactor connected in series.

4. The circuit according to claim 1, characterized in that Also includes: A transient electrical stress test circuit connected in parallel with the common bridge arm, the transient electrical stress test circuit comprising: a switch S1, an inductor L1, a thyristor V1, a diode D2, a capacitor C1, a capacitor C2, a thyristor V3, an inductor L2, a switch S2, a diode D1 and a thyristor V2; the switch S1, the inductor L1, the thyristor V1, the diode D2, the capacitor C1, the capacitor C2, the thyristor V3, the inductor L2 and the switch S2 are sequentially connected in series, the thyristor V3 is connected in parallel with the thyristor V2, the diode D2 and the capacitor C1 are connected in parallel with the diode D1, and two ends of the common bridge arm are respectively connected to a connection point between the switch S1 and the switch S2 and a connection point between the capacitor C1 and the capacitor C2.

5. A full-condition equivalent test method for a valve assembly, characterized in that: include: The DC power supply unit in the control valve assembly equivalent test circuit respectively charges the two bridge arms in the first phase unit, the two bridge arms in the second phase unit and the common bridge arm in the valve assembly equivalent test circuit; After charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly in the valve assembly equivalent test circuit, and the test current is used to test the modular multi-level valve assembly connected in series with the common bridge arm.

6. The method according to claim 5, characterized in that After the charging is completed, the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, including: Controlling the first auxiliary valve assembly in the first phase unit, the second phase unit and the second auxiliary valve assembly in the common bridge arm to generate a voltage for testing the modular multi-level valve assembly according to the test current; controlling the modular multi-level valve assembly to be tested to generate the test voltage; The waveform and phase of the voltage generated by the first auxiliary valve assembly in the first phase unit and the second phase unit are adjusted so that the current flowing through the modular multi-level valve assembly to be tested in the valve assembly equivalent test circuit reaches the test current, while keeping the voltage of the capacitors of the first submodule, the second submodule in the valve assembly equivalent test circuit and the third submodule in the modular multi-level valve assembly to be tested stable.

7. The method according to claim 5, characterized in that The first phase unit, the bridge arm in the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, including: The bridge arm in the first phase unit, the second phase unit or the common bridge arm is adjusted so that the DC component of the test current reaches the target DC component, and the AC component of the test current reaches the target AC component; the target DC component and the target AC component are used to simulate the current stress to which the modular multi-level valve assembly is subjected in actual operation.

8. The method according to claim 6, characterized in that After the charging is completed, after the bridge arms in the first phase unit, the second phase unit and the common bridge arm generate a test current for testing the modular multi-level valve assembly, the method further includes: After charging is completed, the waveforms of the voltages generated by the first auxiliary valve assembly in the first phase unit and the second phase unit and the second auxiliary valve assembly in the common bridge arm are gradually adjusted until the current in the valve assembly equivalent test circuit is 0; the bridge arms and the common bridge arms in the first phase unit and the second phase unit are locked, and the DC power supply unit is disconnected to discharge the capacitors in the first submodule and the second submodule.

9. The method according to claim 7, characterized in that: The step of adjusting the bridge arm in the first phase unit, the second phase unit or the common bridge arm so that the DC component of the test current reaches a target DC component and the AC component of the test current reaches a target AC component includes: Adjust the voltage waveform amplitudes generated by the first auxiliary valve assemblies in the first phase unit and the second phase unit, adjust the phase angle difference between the voltage waveforms generated by the two bridge arms of the first phase unit, and adjust the phase angle difference between the voltage waveforms generated by the two bridge arms in the second phase unit, so that the DC component of the test current reaches the target DC component; Adjust the voltage waveform amplitude generated by multiple first auxiliary valve assemblies in the first phase unit and the second phase unit, adjust the phase angle difference between the voltage waveforms generated by the first phase unit and the second phase unit, and adjust the voltage waveform generated by the second auxiliary valve assembly in the common bridge arm, so that the AC component of the test current reaches the target AC component.

10. The method according to any one of claims 5 to 9, characterized in that: Also includes: Close the switch S1, and the DC power supply unit in the equivalent test circuit of the control valve assembly charges the capacitor C1 and the capacitor C2 respectively; After the capacitors C1 and C2 are fully charged, the transient electrical stress test circuit in the valve assembly equivalent test circuit is controlled to perform an overcurrent shutdown test and a short-circuit current test on the modular multi-level valve assembly; The current shutoff test includes: locking the first auxiliary valve assembly and the second auxiliary valve assembly, closing the switch knife S1 and the switch knife S2, triggering the thyristor V1, and the modular multi-level valve assembly discharges through the inductor L1 and the diode D1 to generate an overcurrent. After detecting that the current reaches a preset current threshold, the modular multi-level valve assembly automatically locks to complete the overcurrent shutoff test; The short-circuit current test includes triggering thyristors V2 and V3, and discharging capacitors C1 and C2 to the modular multi-level valve assembly through inductors L1 and L2 respectively, so that the modular multi-level valve assembly is subjected to the stress of the discharged current, thereby realizing the short-circuit current test.

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