A large current temperature rise test system for a static frequency converter and its test method

Abstract

The present invention relates to a large-current temperature rise test system for a static frequency converter and a test method thereof, comprising: a first isolation transformer, a second isolation transformer, a drive unit and a control unit; the secondary ends of the first isolation transformer and the second isolation transformer are respectively connected to the static frequency converter under test through circuit breakers; the primary ends of the first isolation transformer and the second isolation transformer are both connected to the power grid; the drive unit is used to provide thyristor drive pulses to the rectifier bridge and the inverter bridge of the static frequency converter according to the current set value provided by the control unit; the control unit is used to implement the large-current temperature rise test control of the static frequency converter based on the relevant test parameters and output the large-current temperature rise test results of the static frequency converter. Compared with the traditional large-current temperature rise test, the test time of the present invention can be shortened by half, the detection efficiency is greatly improved, and there is no need to use a high-power load, reducing the test cost.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and particularly relates to a large current temperature rise test system for a static frequency converter and a test method thereof. Background Art

[0002] In the test regulations for the starting device of the static frequency converter of a pumped storage unit, the large current temperature rise test is the item that takes the longest time in the entire test regulations of the static frequency converter product. The temperature rise test needs to be carried out according to the conditions specified in the national standard to obtain the temperature rise parameters of each part, and to judge whether the product meets the requirements of the national standard in terms of safety, reliability and usage conditions. The temperature rise test is a required item for certifying the safety of the product, and its importance is self-evident.

[0003] The traditional large current temperature rise test adopts the method of inputting voltage to the AC side of the power bridge to be tested and connecting a load to the DC side, but there are three problems: 1) The rectifier bridge and the inverter bridge need to be tested separately, and the test time is long; 2) The current is uncontrollable, and the control parameters need to be repeatedly adjusted, and the detection efficiency is low; 3) A high-power load is required, and a good heat dissipation and cooling system is equipped, and the test cost is high. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a large current temperature rise test system for a static frequency converter and a test method thereof. Compared with the traditional large current temperature rise test of a static frequency converter, the test time of this method can be shortened by half, the detection efficiency is greatly improved, and there is no need to use a high-power load, reducing the test cost.

[0005] The purpose of the present invention is achieved by the following technical solutions:

[0006] The present invention provides a large current temperature rise test system for a static frequency converter, which is improved in that the system includes: a first isolation transformer, a second isolation transformer, a driving unit and a control unit;

[0007] The secondary side of the first isolation transformer and the secondary side of the second isolation transformer are respectively connected to the static frequency converter to be tested through circuit breakers;

[0008] The primary side of the first isolation transformer and the primary side of the second isolation transformer are both connected to the power grid;

[0009] The driving unit is used to provide thyristor driving pulses to the rectifier bridge and the inverter bridge of the static frequency converter according to the current given value provided by the control unit;

[0010] The control unit is configured to obtain relevant test parameters of a static frequency converter operating under the control of thyristor drive pulses, implement control of the large-current temperature rise test of the static frequency converter based on the relevant test parameters, and output the large-current temperature rise test results of the static frequency converter.

[0011] Preferably, the relevant test parameters of the static frequency converter include: the temperature of the first isolation transformer, the temperature of the second isolation transformer, the temperature at the junction of the thyristor and the radiator of the static frequency converter, and the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter.

[0012] The present invention provides a method for the large-current temperature rise test of a static frequency converter. The improvement lies in that the method includes:

[0013] Step 1: Close the circuit breaker.

[0014] Step 2: Use the control unit of the test system to control the large-current temperature rise test process of the static frequency converter and obtain the large-current temperature rise test results of the static frequency converter.

[0015] Step 3: Open the circuit breaker.

[0016] Preferably, in Step 2, the control unit controls the large-current temperature rise test process of the static frequency converter and obtains the large-current temperature rise test results of the static frequency converter, including:

[0017] Step 2-1: Initialize i = 1, t = 1, and sort the preset rounds of tests in the large-current temperature rise test of the static frequency converter in the order of decreasing priority given values.

[0018] Step 2-2: The process controller in the control unit inputs the current given value of the i-th round of tests in the sequence to the adder of the drive unit.

[0019] Step 2-3: The first thermosensitive element, the second thermosensitive element, and the third thermosensitive element in the control unit respectively monitor the temperature of the second isolation transformer, the temperature of the first isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter at the t-th moment of the i-th round of tests.

[0020] Meanwhile, the oscillograph in the control unit monitors the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter during the i-th round of tests.

[0021] Step 2-4: The temperature rise calculator in the control unit calculates the temperature rise of the second isolation transformer, the temperature rise of the first isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter during the i-th round of tests based on the temperatures of the second isolation transformer, the first isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter at each moment during the i-th round of tests;

[0022] Step 2-5: The data analyzer in the control unit determines whether the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter are not distorted and the fluctuation ranges are all less than the preset current threshold, and whether the temperature rises of the first isolation transformer, the second isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter are all less than their respective corresponding limit temperature rises. If so, it inputs "yes" to the process controller; otherwise, it inputs "no" to the process controller;

[0023] Step 2-6: If the output information of the data analyzer is "yes" and t·Δt is less than the given value of the continuous operation time of the static frequency converter in the i-th round of tests, then let t = t + 1 and return to Step 2-3;

[0024] If the output information of the data analyzer is "yes", t·Δt is equal to the given value of the continuous operation time of the static frequency converter in the i-th round of tests, and the given value of the priority of this round of tests is the lowest, then the process controller triggers the display to output that the static frequency converter is normal and ends the large current temperature rise test of the static frequency converter;

[0025] If the output information of the data analyzer is "yes", the timing time of the i-th round of tests is equal to the preset continuous operation time of the static frequency converter in the i-th round of tests, and the given value of the priority of this round of tests is not the lowest, then let i = i + 1 and return to Step 2-2;

[0026] If the output information of the data analyzer is "no", then the process controller triggers the display to output that there is an abnormality in the internal components of the static frequency converter and it needs to be repaired, and ends the large current temperature rise test of the static frequency converter;

[0027] where i ∈ Q i , Q i is the preset number of test rounds in the large current temperature rise test of the static frequency converter, and Δt is the time interval at the moment.

[0028] Compared with the closest prior art, the beneficial effects of the present invention are:

[0029] The technical solution provided by the present invention includes: a first isolation transformer, a second isolation transformer, a driving unit, and a control unit; the secondary ends of the first isolation transformer and the second isolation transformer are respectively connected to the static frequency converter under test through circuit breakers; the primary ends of the first isolation transformer and the second isolation transformer are both connected to the power grid; the driving unit is configured to provide thyristor driving pulses to the rectifier bridge and the inverter bridge of the static frequency converter according to the current set value provided by the control unit; the control unit is configured to obtain relevant test parameters of the static frequency converter operating under the control of the thyristor driving pulses, implement the large-current temperature rise test control of the static frequency converter based on the relevant test parameters, and output the large-current temperature rise test results of the static frequency converter. This solution simultaneously tests the rectifier bridge and the inverter bridge of the static frequency converter, greatly shortening the test time. The driving unit quickly provides thyristor driving pulses to the rectifier bridge and the inverter bridge of the static frequency converter, enabling the current of the static frequency converter during the test to quickly reach the current value specified by the national standard, greatly improving the detection efficiency, and eliminating the need to use high-power loads, reducing the test cost.

[0030] The technical solution provided by the present invention can conduct a temperature rise test on the static frequency converter at any time to ensure the reliable operation of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a structural diagram of a large-current temperature rise test system for a static frequency converter;

[0032] Figure 2 is the electrical connection topology of a 6-6 pulse static frequency converter in an embodiment of the present invention;

[0033] Figure 3 is the electrical connection topology of a 12-6 pulse static frequency converter in an embodiment of the present invention;

[0034] Figure 4 is the electrical connection topology of a 12-12 pulse static frequency converter in an embodiment of the present invention;

[0035] Figure 5 is the A-phase current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter monitored by the oscillograph in Embodiment 1 of the present invention;

[0036] Figure 6 is the A-phase current waveforms at the input of the rectifier bridge and the output of the inverter bridge of the static frequency converter monitored by the oscillograph in Embodiment 2 of the present invention;

[0037] Figure 7 is a flowchart of a large-current temperature rise test method for a static frequency converter. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following further elaborates on the specific implementation manners of the present invention in conjunction with the accompanying drawings.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0040] The present invention provides a large-current temperature rise test system for a static frequency converter, as Figure 1 shown. The system includes: a first isolation transformer, a second isolation transformer, a drive unit, and a control unit;

[0041] The secondary side of the first isolation transformer and the secondary side of the second isolation transformer are respectively connected to the static frequency converter under test through circuit breakers;

[0042] The primary sides of the first isolation transformer and the second isolation transformer are both connected to the power grid;

[0043] The drive unit is used to provide thyristor drive pulses to the rectifier bridge and inverter bridge of the static frequency converter according to the current set value provided by the control unit;

[0044] The control unit is used to obtain relevant test parameters of the static frequency converter operating under the control of the thyristor drive pulses, implement large-current temperature rise test control of the static frequency converter based on the relevant test parameters, and output the large-current temperature rise test results of the static frequency converter.

[0045] Specifically, the relevant test parameters of the static frequency converter include: the temperature of the first isolation transformer, the temperature of the second isolation transformer, the temperature at the junction of the thyristor and the radiator of the static frequency converter, and the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter.

[0046] Specifically, the drive unit includes: a first voltage transformer, a second voltage transformer, a current transformer, an adder, a maximum value calculator, a first PI regulator, a second PI regulator, a first pulse width modulator, and a second pulse width modulator; this drive unit realizes the purpose of quickly reaching the current value specified by the national standard for the current of the static frequency converter during the test through double-current closed-loop control;

[0047] Among them, the first voltage transformer is used to monitor the three-phase voltage at the input of the rectifier bridge of the static frequency converter and feedback it to the first pulse width modulator;

[0048] The second voltage transformer is used to monitor the three-phase voltages at the output terminals of the inverter bridge of the static frequency converter and feedback them to the second pulse width modulator;

[0049] The current transformer is used to monitor the three-phase currents at the input terminals of the rectifier bridge of the static frequency converter;

[0050] The maximum value calculator is used to calculate the maximum current amplitude among the three-phase currents collected by the current transformer;

[0051] The adder is used to calculate the difference between the current set value provided by the process controller of the control unit and the maximum current amplitude among the three-phase currents collected by the current transformer;

[0052] The first PI regulator is used to perform PI control on the output of the adder to obtain the firing angle of the rectifier bridge of the static frequency converter and input it to the first pulse width modulator;

[0053] The second PI regulator is used to perform PI control on the output of the adder to obtain the firing angle of the inverter bridge of the static frequency converter and input it to the second pulse width modulator;

[0054] The first pulse width modulator is used to generate thyristor drive pulses for the rectifier bridge of the static frequency converter based on the three-phase voltages feedback by the first voltage transformer and the firing angle input by the first PI regulator, and use the drive pulses to control the on-off of the thyristors in the rectifier bridge of the static frequency converter;

[0055] The second pulse width modulator is used to generate thyristor drive pulses for the inverter bridge of the static frequency converter based on the three-phase voltages feedback by the second voltage transformer and the firing angle input by the second PI regulator, and use the drive pulses to control the on-off of the thyristors in the inverter bridge of the static frequency converter.

[0056] Specifically, the control unit includes: a process controller, a first thermal element, a second thermal element, a third thermal element, an oscillograph, a temperature rise calculator, a data analyzer, and a display;

[0057] The first thermal element is used to monitor the temperature of the second isolation transformer;

[0058] The second thermal element is used to monitor the temperature of the first isolation transformer;

[0059] The third thermal element is used to monitor the temperature at the junction of the thyristors and the radiator of the static frequency converter;

[0060] The temperature rise calculator is used to calculate the temperature rise of the first isolation transformer, the temperature rise of the second isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter during each round of tests respectively according to the temperatures of the first isolation transformer, the second isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter at each moment during each round of tests;

[0061] The oscillograph is used to monitor the current waveforms at the input end of the rectifier bridge, the output end of the reactor, and the output end of the inverter bridge of the static frequency converter during each round of tests;

[0062] The data analyzer is used to input "yes" to the process controller if the current waveforms at the input end of the rectifier bridge, the output end of the reactor, and the output end of the inverter bridge of the static frequency converter are all non-deformed and the fluctuation ranges are all less than the preset current threshold, and the temperature rises of the first isolation transformer, the second isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter are all less than their respective corresponding limit temperature rises, otherwise input "no" to the process controller;

[0063] The process controller is used to implement the process control of each round of tests based on the output information of the data analyzer and the given parameters of each round of tests preset in the large current temperature rise test of the static frequency converter;

[0064] Wherein, the large current temperature rise test of the static frequency converter includes at least one round of pre-test and one round of formal test, and the given parameters of each round of tests preset in the large current temperature rise test of the static frequency converter include the current given value, the static frequency converter continuous operation time given value, and the priority given value preset in the large current temperature rise test of the static frequency converter.

[0065] In the best embodiment of the present invention, the current given value preset in the pre-test can be 50% of the rated current of the static frequency converter, and the static frequency converter continuous operation time preset in the pre-test can be λ;

[0066] The current given value preset in the formal test can be the rated current of the static frequency converter, and the static frequency converter continuous operation time preset in the formal test can be β, and β is not less than 2λ;

[0067] The preset current threshold can be 20% of the rated current;

[0068] Wherein, both β and λ are positive numbers.

[0069] Further, the implementing the process control of each round of tests based on the output information of the data analyzer and the given parameters of each round of tests preset in the large current temperature rise test of the static frequency converter includes:

[0070] Sort the preset rounds of tests in the large current temperature rise test of the static frequency converter in descending order according to the given priority values, and sequentially implement the process control of each preset round of tests in the sequence;

[0071] Among them, the process control of the i-th round of tests preset in the sequence includes:

[0072] Input the current given value of the i-th round of tests preset in the sequence into the adder of the drive unit, and start the timing of this round of tests;

[0073] If the output information of the data analyzer is "yes", and the timing time of this round of tests is less than the given value of the continuous operation time of the static frequency converter in this round of tests, do not operate;

[0074] If the output information of the data analyzer is "yes", the timing time of this round of tests is equal to the given value of the continuous operation time of the static frequency converter in this round of tests, and the given priority value of this round of tests is the lowest, then trigger the display to output that the static frequency converter is normal, and end the large current temperature rise test of the static frequency converter;

[0075] If the output information of the data analyzer is "yes", the timing time of this round of tests is equal to the given value of the continuous operation time of the static frequency converter in this round of tests, and the given priority value of this round of tests is not the lowest, then implement the process control of the (i + 1)-th round of experiments in the sequence;

[0076] If the output information of the data analyzer is "no", then trigger the display to output that there is an abnormality in the internal components of the static frequency converter, which needs to be repaired, and end the large current temperature rise test of the static frequency converter;

[0077] Among them, the given priority value of the pre-test is higher than the given priority value of the formal test, i ∈ Q i , Q i is the number of preset test rounds in the large current temperature rise test of the static frequency converter.

[0078] Furthermore, if the first isolation transformer or the second isolation transformer is made of dry-type Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 60 degrees Celsius, and the limiting temperature rise of the iron core is 65 degrees Celsius;

[0079] If the first isolation transformer or the second isolation transformer is made of oil-immersed Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 65 degrees Celsius, and the limiting temperature rise of the iron core is 70 degrees Celsius;

[0080] If the first isolation transformer or the second isolation transformer is made of Class B insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 80 degrees Celsius, and the limiting temperature rise of the iron core is 85 degrees Celsius;

[0081] If the first isolation transformer or the second isolation transformer is made of class F insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 100 degrees Celsius, and the limiting temperature rise of the iron core is 105 degrees Celsius;

[0082] The limiting temperature rise at the junction of the thyristor and the radiator of the static frequency converter is 40 degrees Celsius.

[0083] Table 1

[0084]

[0085] Specifically, the static frequency converter is a 6-6 pulse static frequency converter, a 12-6 pulse static frequency converter or a 12-12 pulse static frequency converter.

[0086] In the best embodiment of the present invention, the static frequency converter mainly includes: a rectifier bridge, a reactor and an inverter bridge; Figure 2 shows the electrical connection topology of a 6-6 pulse static frequency converter, Figure 3 shows the electrical connection topology of a 12-6 pulse static frequency converter, Figure 4 shows the electrical connection topology of a 12-12 pulse static frequency converter, wherein the rectifier bridge SRN and the inverter bridge SRM are both composed of three-phase bridge arms, the three-phase bridge arms are respectively connected to three-phase currents of A, B, and C, and two thyristors are connected in series in each phase bridge arm. The upper bridge arm of the A phase of the rectifier bridge is thyristor T 11 , and the lower bridge arm is thyristor T 14 , the upper bridge arm of the B phase is thyristor T 13 , and the lower bridge arm is thyristor T 16 , the upper bridge arm of the C phase is thyristor T 15 , and the lower bridge arm is thyristor T 12 ; the upper bridge arm of the A phase of the inverter bridge is thyristor T 21 , and the lower bridge arm is thyristor T 24 , the upper bridge arm of the B phase is thyristor T 23 , and the lower bridge arm is thyristor T 26 , the upper bridge arm of the C phase is thyristor T 25 , and the lower bridge arm is thyristor T 22 , L d is the inductance value of the reactor.

[0087] Example 1: For a 3MW static frequency converter, a large current temperature rise test is carried out. The proportional term coefficient of the PI regulator corresponding to the rectifier bridge is 80, and the integral term coefficient is 10. At the same time, the proportional term coefficient of the PI regulator corresponding to the inverter bridge is 10, and the integral term coefficient is 2. The current given value I ωSet to 160A, with the duration set to 30 minutes. The oscillograph records the waveforms of the phase A voltage at the input of the rectifier bridge, the phase A current at the input of the rectifier bridge, the phase A current at the output of the reactor, and the phase A current at the output of the inverter bridge. The waveforms are as Figure 5 shown. It can be seen from the figure that by adopting the technical solution of the present invention, large-current operation can be achieved, and it has good stability.

[0088] Embodiment 2: A large-current temperature rise test is carried out on a 3MW static frequency converter. The proportional term coefficient of the PI regulator corresponding to the rectifier bridge is 80, and the integral term coefficient is 10. At the same time, the proportional term coefficient of the PI regulator corresponding to the inverter bridge is 10, and the integral term coefficient is 2. The set current given value I ω is 80A. At the t moment after running for a period of time, the current given value I ω changes from 80A to 160A. The oscillograph is used to record the waveforms of the phase A current at the input of the rectifier bridge and the phase A current at the output of the inverter bridge. The waveforms are as Figure 6 shown. It can be seen from the figure that the actual current reaches the given value within 40ms. It is proved that the technical solution of the present invention can make the current quickly reach the expected requirements and has good dynamic performance.

[0089] The present invention provides a test method for a large-current temperature rise test system, as Figure 7 shown. The method includes:

[0090] Step 1: Close the circuit breaker;

[0091] Step 2: Use the control unit of the test system to control the large-current temperature rise test process of the static frequency converter and obtain the large-current temperature rise test result of the static frequency converter;

[0092] Step 3: Open the circuit breaker.

[0093] Specifically, in step 2, the control unit controls the large-current temperature rise test process of the static frequency converter and obtains the large-current temperature rise test result of the static frequency converter, including:

[0094] Step 2-1: Initialize i = 1, t = 1, and sort the preset rounds of tests in the large-current temperature rise test of the static frequency converter in the order of the priority given value from high to low;

[0095] Step 2-2: The process controller in the control unit inputs the current given value of the i-th round of test in the sequence to the adder of the drive unit;

[0096] Step 2-3: The first thermosensitive element, the second thermosensitive element, and the third thermosensitive element in the control unit respectively monitor the temperature of the second isolation transformer, the temperature of the first isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter at the t-th moment of the i-th round of test;

[0097] Meanwhile, the oscillograph in the control unit monitors the current waveforms at the input end of the rectifier bridge, the output end of the reactor, and the output end of the inverter bridge of the static frequency converter during the i-th round of tests.

[0098] Step 2-4: The temperature rise calculator in the control unit calculates the temperature rise of the second isolation transformer, the temperature rise of the first isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter during the i-th round of tests based on the temperatures of the second isolation transformer, the first isolation transformer, and the junction of the thyristor and the radiator of the static frequency converter at each moment during the i-th round of tests.

[0099] Step 2-5: The data analyzer in the control unit determines whether the current waveforms at the input end of the rectifier bridge, the output end of the reactor, and the output end of the inverter bridge of the static frequency converter are all non-deformed and the fluctuation ranges are all less than the preset current threshold, and whether the temperature rises of the first isolation transformer, the second isolation transformer, and the junction of the thyristor and the radiator of the static frequency converter are all less than their respective corresponding limit temperature rises. If so, it inputs "yes" to the process controller; otherwise, it inputs "no" to the process controller.

[0100] Step 2-6: If the output information of the data analyzer is "yes" and t·Δt is less than the given value of the continuous operation time of the static frequency converter in the i-th round of tests, then let t = t + 1 and return to Step 2-3.

[0101] If the output information of the data analyzer is "yes", t·Δt is equal to the given value of the continuous operation time of the static frequency converter in the i-th round of tests, and the given value of the priority of this round of tests is the lowest, then the process controller triggers the display to output that the static frequency converter is normal and ends the large current temperature rise test of the static frequency converter.

[0102] If the output information of the data analyzer is "yes", the timing time of the i-th round of tests is equal to the preset continuous operation time of the static frequency converter in the i-th round of tests, and the given value of the priority of this round of tests is not the lowest, then let i = i + 1 and return to Step 2-2.

[0103] If the output information of the data analyzer is "no", then the process controller triggers the display to output that there is an abnormality in the internal components of the static frequency converter and it needs to be repaired, and ends the large current temperature rise test of the static frequency converter.

[0104] where i ∈ Q i , Q i is the preset number of test rounds in the large current temperature rise test of the static frequency converter, and Δt is the time interval at the moment.

[0105] Furthermore, the period during the i-th round of tests is the time period corresponding to the start moment of the i-th round of tests to the t-th moment of the i-th round of tests.

[0106] At the t-th moment of the i-th round of tests, the static frequency converter operates under the control of thyristor drive pulses;

[0107] The thyristor drive pulses are generated by the drive unit based on the current set value of the i-th round of tests at the t-th moment of the i-th round of tests;

[0108] The large current temperature rise test of the static frequency converter includes at least one round of preliminary tests and one round of formal tests, and the priority set value of the preliminary tests is higher than that of the formal tests.

[0109] Specifically, if the first isolation transformer or the second isolation transformer is made of dry type A-class insulation material, the limit temperature rise of the winding of the first isolation transformer or the second isolation transformer is 60 degrees Celsius, and the limit temperature rise of the iron core is 65 degrees Celsius;

[0110] If the first isolation transformer or the second isolation transformer is made of oil-immersed A-class insulation material, the limit temperature rise of the winding of the first isolation transformer or the second isolation transformer is 65 degrees Celsius, and the limit temperature rise of the iron core is 70 degrees Celsius;

[0111] If the first isolation transformer or the second isolation transformer is made of B-class insulation material, the limit temperature rise of the winding of the first isolation transformer or the second isolation transformer is 80 degrees Celsius, and the limit temperature rise of the iron core is 85 degrees Celsius;

[0112] If the first isolation transformer or the second isolation transformer is made of F-class insulation material, the limit temperature rise of the winding of the first isolation transformer or the second isolation transformer is 100 degrees Celsius, and the limit temperature rise of the iron core is 105 degrees Celsius;

[0113] The limit temperature rise at the junction of the thyristor and the radiator of the static frequency converter is 40 degrees Celsius.

[0114] Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can be implemented in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can be implemented in 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.) containing computer-usable program code.

[0115] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows 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 the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one or more flows and / or one or more blocks in the flow. Figure 1 one or more flows and / or one or more blocks Figure 1 of the functions specified in the block.

[0116] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means for implementing the functions specified in one or more flows and / or one or more blocks in the flow. Figure 1 one or more flows and / or one or more blocks Figure 1 of the functions specified in the block.

[0117] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flows and / or one or more blocks in the flow. Figure 1 one or more flows and / or one or more blocks Figure 1 of the functions specified in the block.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: It is still possible to modify the specific embodiments of the present invention or make equivalent replacements, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the protection scope of the claims of the present invention.

Claims

1. A large current temperature rise test system for a static frequency converter, characterized in that, The system includes: a first isolation transformer, a second isolation transformer, a drive unit, and a control unit; The secondary sides of the first isolation transformer and the second isolation transformer are respectively connected to the static frequency converter under test through circuit breakers; The primary sides of the first isolation transformer and the second isolation transformer are both connected to the power grid; The drive unit is configured to provide thyristor drive pulses to the rectifier bridge and the inverter bridge of the static frequency converter according to the current set value provided by the control unit; The control unit is configured to obtain relevant test parameters of the static frequency converter operating under the control of the thyristor drive pulses, implement large current temperature rise test control of the static frequency converter based on the relevant test parameters, and output the large current temperature rise test results of the static frequency converter; The drive unit includes: a first voltage transformer, a second voltage transformer, a current transformer, an adder, a maximum value calculator, a first PI regulator, a second PI regulator, a first pulse width modulator, and a second pulse width modulator; Wherein, the first voltage transformer is configured to monitor the three-phase voltage at the input end of the rectifier bridge of the static frequency converter and feedback it to the first pulse width modulator; The second voltage transformer is configured to monitor the three-phase voltage at the output end of the inverter bridge of the static frequency converter and feedback it to the second pulse width modulator; The current transformer is configured to monitor the three-phase current at the input end of the rectifier bridge of the static frequency converter; The maximum value calculator is configured to calculate the maximum current amplitude among the three-phase currents collected by the current transformer; The adder is configured to calculate the difference between the current set value provided by the process controller of the control unit and the maximum current amplitude among the three-phase currents collected by the current transformer; The first PI regulator is configured to perform PI control on the output of the adder to obtain the trigger angle of the rectifier bridge of the static frequency converter and input it to the first pulse width modulator; The second PI regulator is configured to perform PI control on the output of the adder to obtain the trigger angle of the inverter bridge of the static frequency converter and input it to the second pulse width modulator; The first pulse width modulator is configured to generate thyristor drive pulses for the rectifier bridge of the static frequency converter based on the three-phase voltage feedback by the first voltage transformer and the trigger angle input by the first PI regulator, and use the drive pulses to control the on / off of the thyristors in the rectifier bridge of the static frequency converter; The second pulse width modulator is configured to generate thyristor drive pulses for the inverter bridge of the static frequency converter based on the three-phase voltage feedback by the second voltage transformer and the trigger angle input by the second PI regulator, and use the drive pulses to control the on / off of the thyristors in the inverter bridge of the static frequency converter; The control unit includes: a process controller, a first thermosensitive element, a second thermosensitive element, a third thermosensitive element, an oscillograph, a temperature rise calculator, a data analyzer, and a display; The first thermosensitive element is configured to monitor the temperature of the second isolation transformer; The second thermosensitive element is configured to monitor the temperature of the first isolation transformer; The third thermosensitive element is configured to monitor the temperature at the junction of the thyristors and the radiator of the static frequency converter; The temperature rise calculator is used to calculate the temperature rise of the first isolation transformer, the temperature rise of the second isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter during each round of tests respectively according to the temperatures of the first isolation transformer, the second isolation transformer, and the junction of the thyristor and the radiator of the static frequency converter at each moment during each round of tests; The oscillograph is used to monitor the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter during each round of tests; The data analyzer is used to input "yes" to the process controller if the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter are not deformed and the fluctuation ranges are all less than the preset current threshold, and the temperature rises of the first isolation transformer, the second isolation transformer, and the junction of the thyristor and the radiator of the static frequency converter are all less than their respective corresponding limit temperature rises, otherwise input "no" to the process controller; The process controller is used to implement the process control of each round of tests based on the output information of the data analyzer and the given parameters of each round of tests preset in the high-current temperature rise test of the static frequency converter; Among them, the high-current temperature rise test of the static frequency converter includes at least one round of pre-test and one round of formal test, and the given parameters of each round of tests preset in the high-current temperature rise test of the static frequency converter include the current given value, the given value of the continuous operation time of the static frequency converter, and the priority given value preset in the high-current temperature rise test of the static frequency converter.

2. The system according to claim 1, wherein The relevant test parameters of the static frequency converter include: the temperature of the first isolation transformer, the temperature of the second isolation transformer, the temperature at the junction of the thyristor and the radiator of the static frequency converter, and the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter.

3. The system according to claim 1, characterized in that, The implementation of the process control of each round of tests based on the output information of the data analyzer and the given parameters of each round of tests preset in the high-current temperature rise test of the static frequency converter includes: Sorting the rounds of tests preset in the high-current temperature rise test of the static frequency converter in descending order according to the priority given value, and sequentially implementing the process control of each round of tests preset in the sequence; Among them, the process control of the round of tests preset in the sequence includes: Input the current set value of the round of test in the sequence into the adder of the drive unit, and start timing for this round of test; If the output information of the data analyzer is "yes" and the timing time of this round of test is less than the given value of the continuous operation time of the static frequency converter for this round of test, then do nothing; If the output information of the data analyzer is "yes", the timing time of this round of test is equal to the given value of the continuous operation time of the static frequency converter for this round of test, and the priority given value of this round of test is the lowest, then trigger the display to output that the static frequency converter is normal, and end the high-current temperature rise test of the static frequency converter; If the output information of the data analyzer is "yes", the timing time of this round of test is equal to the given value of the continuous operation time of the static frequency converter for this round of test, and the priority given value of this round of test is not the lowest, then implement the process control of the (i + 1)-th round of test in the sequence; If the output information of the data analyzer is "no", then trigger the display to output that there is an abnormality in the internal components of the static frequency converter and it needs to be repaired, and end the high-current temperature rise test of the static frequency converter; Among them, the priority given value of the pre-test is higher than that of the formal test. , is the preset number of test rounds in the large current temperature rise test of the static frequency converter.

4. The system according to claim 1, wherein If the first isolation transformer or the second isolation transformer is made of dry - type Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 60 degrees Celsius, and the limiting temperature rise of the iron core is 65 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of oil - immersed Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 65 degrees Celsius, and the limiting temperature rise of the iron core is 70 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of Class B insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 80 degrees Celsius, and the limiting temperature rise of the iron core is 85 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of Class F insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 100 degrees Celsius, and the limiting temperature rise of the iron core is 105 degrees Celsius; The limiting temperature rise at the junction of the thyristor of the static frequency converter and the radiator is 40 degrees Celsius.

5. The system according to claim 1, characterized in that, The static frequency converter is a 6 - 6 pulse static frequency converter, a 12 - 6 pulse static frequency converter or a 12 - 12 pulse static frequency converter.

6. The test method of the high-current temperature rise test system according to any one of claims 1-5, characterized in that, The method includes: Step 1: Close the circuit breaker; Step 2: Use the control unit of the test system to control the large - current temperature - rise test process of the static frequency converter and obtain the large - current temperature - rise test results of the static frequency converter; Step 3: Open the circuit breaker; In Step 2, the control unit controls the large - current temperature - rise test process of the static frequency converter and obtains the large - current temperature - rise test results of the static frequency converter, including: Step 2 - 1: Initialize i = 1, t = 1, and sort the preset rounds of tests in the large - current temperature - rise test of the static frequency converter in the order of decreasing priority given value; Step 2-2: The process controller in the control unit inputs the current set value of the round of tests in the sequence into the adder of the drive unit; Step 2-3: The first thermal element, the second thermal element, and the third thermal element in the control unit respectively monitor the temperature of the second isolation transformer, the temperature of the first isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter at the t-th moment of the t-th round of tests; Meanwhile, the oscillograph in the control unit monitors the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter during the ​ Step 2-4: During the round of tests, the temperature rise calculator in the control unit calculates the temperature rise of the second isolation transformer, the temperature rise of the first isolation transformer, and the temperature rise at the junction of the thyristor and the radiator of the static frequency converter at each moment based on the temperature of the second isolation transformer, the temperature of the first isolation transformer, and the temperature at the junction of the thyristor and the radiator of the static frequency converter during the round of tests; Step 2 - 5: The data analyzer in the control unit determines whether the current waveforms at the input of the rectifier bridge, the output of the reactor, and the output of the inverter bridge of the static frequency converter are not distorted and the fluctuation ranges are all less than the preset current threshold, and whether the temperature rises of the first isolation transformer, the second isolation transformer, and the junction of the thyristor of the static frequency converter and the radiator are all less than their respective limiting temperature rises simultaneously. If so, input "yes" to the process controller, otherwise input "no" to the process controller; Step 2-6: If the output information of the data analyzer is yes, and less than the given value of the continuous operation time of the static frequency converter in the nth round of tests, then let t = t + 1, and return to Step 2-3; If the output information of the data analyzer is yes, is equal to the set value of the continuous running time of the static frequency converter in the nth round of tests, and the set value of the priority of this round of tests is the lowest, then the process controller triggers the display to output that the static frequency converter is normal and ends the high-current temperature rise test of the static frequency converter; If the output information of the data analyzer is "yes", the timing time of the round of test is equal to the preset continuous operation time of the static frequency converter in the round of test, and the priority given value of this round of test is not the lowest, then let , return to step 2-2; If the output information of the data analyzer is "no", the process controller triggers the display to output that the internal components of the static frequency converter are abnormal and need to be repaired, and ends the large - current temperature - rise test of the static frequency converter; Among them, , is the preset number of test rounds in the large current temperature rise test of the static frequency converter, is the time interval at the moment.

7. The method according to claim 6, wherein Said the time period during the round of tests is from the start time of the round of tests to the time period corresponding to the t-th moment of the At the t-th moment of the n-th round of tests, the stationary frequency converter operates under the control of thyristor drive pulses; The thyristor drive pulse is the one generated by the drive unit at the t-th moment of the round of tests based on the current set value of the The large - current temperature - rise test of the static frequency converter includes at least one round of pre - test and one round of formal test, and the priority given value of the pre - test is higher than that of the formal test.

8. The method according to claim 6, wherein If the first isolation transformer or the second isolation transformer is made of dry - type Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 60 degrees Celsius, and the limiting temperature rise of the iron core is 65 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of oil - immersed Class A insulation material, the limiting temperature rise of the winding of the first isolation transformer or the second isolation transformer is 65 degrees Celsius, and the limiting temperature rise of the iron core is 70 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of Class B insulation material, the maximum temperature rise of the windings of the first isolation transformer or the second isolation transformer is 80 degrees Celsius, and the maximum temperature rise of the iron core is 85 degrees Celsius; If the first isolation transformer or the second isolation transformer is made of Class F insulation material, the maximum temperature rise of the windings of the first isolation transformer or the second isolation transformer is 100 degrees Celsius, and the maximum temperature rise of the iron core is 105 degrees Celsius; The maximum temperature rise at the junction of the thyristor of the static frequency converter and the radiator is 40 degrees Celsius.

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