Gas turbine variable frequency starting process barring gear simulation test circuit and simulation test method

Abstract

The present invention provides a circuit and a simulation test method for simulating barring during the variable-frequency starting process of a gas turbine. The circuit includes: a static starting frequency converter of the gas turbine to be tested is connected to one end of a synchronous generator through a switch, the other end of the synchronous generator is connected to a DC motor through a coupling, the positive output of the accompanying AC / DC converter is connected to the positive pole of a power diode, the negative pole of the power diode is connected to the positive pole of the power supply port of the DC motor, the negative output of the accompanying AC / DC converter is connected to the negative pole of the power supply port of the DC motor, the input end of the static starting frequency converter of the gas turbine to be tested is connected to a power supply through a plurality of switches, and the input end of the accompanying AC / DC converter is connected to a power supply through a plurality of switches. The laboratory simulation of the on-site low-speed barring working condition is realized, and the circuit structure is simple, the operation is convenient, the control is simple, the response speed is fast and the adaptability is strong.

Description

Technical Field

[0001] The present invention relates to the technical field of static starting frequency converters for gas turbines, and particularly to a circuit and a simulation test method for simulating barring during the frequency conversion starting process of a gas turbine. Background Art

[0002] With the development and utilization of clean energy such as natural gas, gas turbines have been widely used. Most heavy-duty gas turbines use static starting frequency converters to complete the starting process. For heavy-duty gas turbines used for power grid peak shaving, the starting frequency is high, so the requirements for starting success rate and the starting performance of the static frequency converter of the gas turbine are relatively high, and it is relatively difficult to simulate the low-speed barring process in the laboratory.

[0003] How to get out of the difficult situation of simulating the low-speed barring process in the laboratory environment is still a problem that needs to be urgently solved by those skilled in the art.

[0004] The prior art CN 114151202 A discloses a static frequency conversion starting system and its control method. The system includes at least one starting line connected to the unit. Each starting line includes an input switch, a transformer, a static frequency converter, and an output switch connected in sequence. Each gas turbine unit is respectively matched with a grounding switch and an excitation device. When there are more than two starting lines, the output switches of each starting line are bridged by a connection switch. The input switch, output switch, grounding switch, and connection switch are respectively controlled to be turned on and off. However, in this system, an excitation device is used to control the rotor of the gas turbine unit to enter the barring state, and the start and stop of the excitation device need to be controlled. When simulating the starting process of the frequency converter, multiple switches need to be operated and controlled in the whole system, making the structure of the whole system complex and the operation troublesome. Summary of the Invention

[0005] The present invention provides a circuit and a simulation test method for simulating barring during the frequency conversion starting process of a gas turbine to solve the problem of the difficulty in simulating the low-speed barring process in the laboratory environment in the prior art.

[0006] The present invention provides a circuit for simulating barring during the frequency conversion starting process of a gas turbine. The circuit includes: a static starting frequency converter of the gas turbine to be tested, a companion AC / DC converter, a power diode, a synchronous generator, a DC motor, a coupling, a plurality of switches, and a power supply. Among them,

[0007] The static start-up frequency converter of the gas turbine to be tested is connected to one end of the synchronous generator through a switch. The other end of the synchronous generator is connected to the DC motor through the coupling. The positive output of the auxiliary AC / DC converter is connected to the positive pole of the power diode. The negative pole of the power diode is connected to the positive pole of the power supply port of the DC motor. The negative output of the auxiliary AC / DC converter is connected to the negative pole of the power supply port of the DC motor. The input end of the static start-up frequency converter of the gas turbine to be tested is connected to the power supply through multiple switches. The input end of the auxiliary AC / DC converter is connected to the power supply through multiple switches.

[0008] According to a simulated test circuit for the barring gear during the variable-frequency start-up process of a gas turbine provided by the present invention, the other end of the synchronous generator is connected to the DC motor through the coupling, specifically including:

[0009] The other end of the synchronous generator is coaxially connected to the DC motor through the coupling.

[0010] According to a simulated test circuit for the barring gear during the variable-frequency start-up process of a gas turbine provided by the present invention, the input end of the static start-up frequency converter of the gas turbine to be tested is connected to the power supply through multiple switches, specifically including:

[0011] The input end of the static start-up frequency converter of the gas turbine to be tested, the second switch, the first switch, and the power supply are connected in series in sequence.

[0012] According to a simulated test circuit for the barring gear during the variable-frequency start-up process of a gas turbine provided by the present invention, the input end of the auxiliary AC / DC converter is connected to the power supply through multiple switches, specifically including:

[0013] The input end of the auxiliary AC / DC converter, the third switch, the first switch, and the power supply are connected in series in sequence.

[0014] According to a simulated test circuit for the barring gear during the variable-frequency start-up process of a gas turbine provided by the present invention, the power supply is a three-phase 6 kV power supply.

[0015] The present invention also provides a simulated test method using the simulated test circuit for the barring gear during the variable-frequency start-up process of a gas turbine as described above, including:

[0016] Step S1: When the synchronous generator and the DC motor are in a static state, power on the auxiliary AC / DC converter and the static start-up frequency converter of the gas turbine to be tested, and start the auxiliary AC / DC converter to enable the synchronous generator to finally obtain a stable barring gear rotation speed;

[0017] Step S2: An external device issues a start command to the static start frequency converter of the to-be-tested gas turbine, detects the barring speed, and enables the static start frequency converter of the to-be-tested gas turbine to drive the synchronous generator to start with the barring speed as the initial speed. During this process, the to-be-tested parameters of the static start frequency converter of the to-be-tested gas turbine are tested.

[0018] Step S3: An external device issues a stop command to the static start frequency converter of the to-be-tested gas turbine, so that the static start frequency converter of the to-be-tested gas turbine is in a hot standby state. The synchronous generator together with the DC motor decelerates until it stabilizes at the target working condition of the barring speed, and the synchronous generator is decelerated to finally obtain a stable barring speed.

[0019] According to an analog test method provided by the present invention, the accompanying AC / DC converter and the static start frequency converter of the to-be-tested gas turbine do not need to be powered on and off repeatedly. Steps S2 - S3 are repeated multiple times to cyclically test the process of the static start frequency converter of the to-be-tested gas turbine driving the synchronous generator to start with the barring speed as the initial speed.

[0020] According to an analog test method provided by the present invention, during the process of the static start frequency converter of the to-be-tested gas turbine driving the synchronous generator to start with the barring speed as the initial speed, the power diode is in a reverse off state, and the DC motor operates in a power generation state driven by the synchronous generator.

[0021] According to an analog test method provided by the present invention, the specific steps for finally obtaining a stable barring speed of the synchronous generator include:

[0022] Adjust the DC voltage output by the accompanying AC / DC converter according to the barring speed set for the barring working condition, so that the DC motor drives the synchronous generator to rotate until the synchronous generator stabilizes at the barring speed.

[0023] According to an analog test method provided by the present invention, when the static start frequency converter of the to-be-tested gas turbine is in a hot standby state, the power diode is in a forward conduction state, the DC motor is in an electric state to drive the synchronous generator to rotate, and the synchronous generator finally rotates at the barring speed.

[0024] The gas turbine variable-frequency starting process barring gear simulation test circuit and simulation test method provided by the present invention. The circuit includes: a to-be-tested gas turbine static starting frequency converter, a companion AC / DC converter, a power diode, a synchronous generator, a DC motor, a coupling, a plurality of switches, and a power supply. Among them, the to-be-tested gas turbine static starting frequency converter is connected to one end of the synchronous generator through a switch, the other end of the synchronous generator is connected to the DC motor through the coupling, the positive output of the companion AC / DC converter is connected to the positive pole of the power diode, the negative pole of the power diode is connected to the positive pole of the power supply port of the DC motor, the negative output of the companion AC / DC converter is connected to the negative pole of the power supply port of the DC motor, the input end of the to-be-tested gas turbine static starting frequency converter is connected to the power supply through a plurality of switches, and the input end of the companion AC / DC converter is connected to the power supply through a plurality of switches. The simulation test circuit and simulation test method provided by the present invention realize the laboratory simulation of the on-site low-speed barring gear working condition, have a simple circuit structure, are convenient to operate, have simple control, fast response speed, and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0026] Figure 1 It is a schematic structural diagram of the gas turbine variable-frequency starting process barring gear simulation test circuit provided by the present invention;

[0027] Figure 2 It is a schematic flow chart of the simulation test method provided by the present invention;

[0028] Figure 3 It is a power-on working flow chart of the to-be-tested gas turbine static starting frequency converter provided by the present invention;

[0029] Figure 4 It is a power-on working flow chart of the companion AC / DC converter provided by the present invention;

[0030] MARKING DESCRIPTION:

[0031] 1 - First switch, 2 - Second switch, 3 - Third switch, and 6 - Fourth switch, 4 - To-be-tested gas turbine static starting frequency converter,

[0032] 5 - Companion AC / DC converter, 7 - Power diode,

[0033] 8 - Synchronous generator, 9 - DC motor,

[0034] 10 - Coupling, 11 - Power supply. Detailed implementation mode

[0035] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0036] In the prior art, there is generally a problem that it is difficult to simulate the low - speed barring process in a laboratory environment. The following combines Figure 1 to describe the barring simulation test circuit for the variable - frequency start - up process of a gas turbine in the present invention. Figure 1 The structure diagram of the barring simulation test circuit provided for the variable - frequency start - up process of a gas turbine in the present invention is shown as Figure 1 shown. The simulation test circuit includes:

[0037] A static start - up frequency converter 4 of the gas turbine to be tested, a companion AC / DC converter 5, a power diode 7, a synchronous generator 8, a DC motor 9, a coupling 10, a first switch 1, a second switch 2, a third switch 3, a fourth switch 6 and a power supply 11. Among them,

[0038] The static start - up frequency converter 4 of the gas turbine to be tested is connected to one end of the synchronous generator 8 through the fourth switch 6. The other end of the synchronous generator 8 is connected to the DC motor 9 through the coupling 10. The positive output of the companion AC / DC converter 4 is connected to the positive pole of the power diode 7. The negative pole of the power diode 7 is connected to the positive pole of the power supply port of the DC motor 9. The negative output of the companion AC / DC converter 5 is connected to the negative pole of the power supply port of the DC motor 9. The input end of the static start - up frequency converter 4 of the gas turbine to be tested is connected to the power supply 11 through multiple switches. The input end of the companion AC / DC converter 5 is connected to the power supply 11 through multiple switches.

[0039] Specifically, first, the barring speed is described. The barring speed is a micro - rotation state (the speed is very low, such as 8 rps, 6 rps, etc.). In order to reduce the start - up faults and start - up difficulties of the static start - up frequency converter, usually, a barring device is used to make the synchronous generator drive the gas turbine to start from a static state to a micro - rotation state. Then, the static start - up frequency converter does not need to start by dragging the synchronous generator from a static state, but starts from the barring state of the synchronous generator, which can reduce the faults during the start - up of the static start - up frequency converter and reduce the start - up difficulty.

[0040] As Figure 1As shown, the simulation test circuit provided by the present invention is divided into a left branch and a right branch. The left branch drives the synchronous generator 8 to rotate by outputting alternating current through the static start frequency converter 4 of the to-be-tested gas turbine, hereinafter referred to as the AC side; the right branch drives the DC motor 9 to rotate by outputting direct current through the accompanying AC / DC converter 5 via the power diode 7, hereinafter referred to as the DC side. The synchronous generator 8 is connected to the gas turbine to be driven and started (since it is default in the simulation test system that the synchronous generator drives the gas turbine to start, so Figure 1 it is not shown in the figure). It simulates the process of the static start frequency converter 4 of the to-be-tested gas turbine driving the synchronous generator 8 to start and operate from the barring speed, that is, before the static start frequency converter 4 of the to-be-tested gas turbine is powered on and works, the synchronous generator 8 has been stably operating at the barring speed condition; and the component that enables the synchronous generator 8 to reach the barring speed before the static start frequency converter 4 of the to-be-tested gas turbine is powered on is the DC side circuit. The accompanying AC / DC converter 5 on the DC side is first powered on and works, and the output DC voltage is input to the DC motor 9 through the power diode 7, so that the DC motor 9 operates in the electric state. The DC motor 9 further drives the synchronous generator 8 to rotate through the coupling 10. The output voltage of the accompanying AC / DC converter is adjusted according to the barring speed of the target barring condition, so that the DC motor 9 drives the synchronous generator 8 to rotate and finally stabilizes at the barring speed. When the synchronous generator 8 is stable at the barring speed condition, then start the static start frequency converter 4 of the to-be-tested gas turbine, so that the synchronous generator 8 starts from the barring speed, and completes the simulation of the start process of the synchronous generator 8 starting from the stable barring speed and reaching the normal operating speed, and the relevant measurement parameters in the start process of the static start frequency converter 4 of the to-be-tested gas turbine driving the synchronous generator 8 to start from the barring speed can be measured.

[0041] It should be noted here that the function of the diode is to automatically adjust the energized or de-energized state of the DC motor 9. When the static start frequency converter 4 of the to-be-tested gas turbine is powered on and works, the negative voltage of the power diode 7 will be higher than the positive voltage, then the power diode 7 is in the reverse cut-off state, and the DC generator 9 works in the power generation state. When the static start frequency converter 4 of the to-be-tested gas turbine stops outputting, the synchronous generator 8 drives the DC generator 9 to decelerate and rotate due to the coasting effect until the negative voltage of the power diode 7 is lower than the positive voltage, then the power diode 7 is in the forward conduction state, and the DC motor 9 works in the electric state again and maintains the synchronous generator 9 stable at the barring speed set before under the barring speed condition.

[0042] Since the test AC / DC converter provided by the DC side of the simulation test circuit is in the state of output voltage or shutdown under the control of the power diode, there is no need for excessive switching control to determine whether the DC motor on the DC side is in the electric state or the generating state. At the same time, according to the conduction characteristics of the power diode, the synchronous generator can be smoothly restored autonomously from the high-speed operation state to the barring gear state, enabling the smooth switching between the start of the static start inverter of the engine under test and the stop of the output of the test AC / DC converter. Moreover, the circuit structure of the DC side is relatively simple, and a barring gear device is simulated with a simple circuit structure. Compared with the prior art, the simulation test circuit provided by the present invention simulates a barring gear device with a simple circuit structure on the DC side, and the operation of simulating the start of the static start inverter of the engine under test for this circuit structure is simple and convenient.

[0043] The simulation test circuit provided by the embodiment of the present invention includes: a static start inverter of the engine under test, a test AC / DC converter, a power diode, a synchronous generator, a DC motor, a coupling, a plurality of switches, and a power supply. Among them, the input end of the static start inverter of the engine under test is connected to one end of the synchronous generator through a switch, the other end of the synchronous generator is connected to the DC motor through the coupling, the positive output terminal of the test AC / DC converter is connected to the positive electrode of the power diode, the negative electrode of the power diode is connected to the positive electrode of the power supply port of the DC motor, the negative output terminal of the test AC / DC converter is connected to the negative electrode of the power supply port of the DC motor, the input end of the static start inverter of the engine under test is connected to the power supply through a plurality of switches, and the input end of the test AC / DC converter is connected to the power supply through a plurality of switches. The circuit provided by the present invention realizes the simulation of the working condition of low-speed barring gear on the laboratory site, has a simple circuit structure, a simple operation method for the circuit, simple control, fast response speed, and strong adaptability.

[0044] Based on the above embodiment, in the simulation test circuit, the other end of the synchronous generator is connected to the DC motor through the coupling, specifically including:

[0045] The other end of the synchronous generator is coaxially connected to the DC motor through the coupling.

[0046] Specifically, the coupling coaxially connects the synchronous generator and the DC motor, making the energy transfer efficiency higher when one of them drives the other to rotate.

[0047] Based on the above embodiment, in the simulation test circuit, the input end of the static start inverter of the engine under test is connected to the power supply through a plurality of switches, specifically including:

[0048] The input end of the static start inverter of the engine under test, the second switch 2, the first switch 1, and the power supply are connected in series in sequence.

[0049] Specifically, the structure of multiple switches through which the static start-up frequency converter of the engine under test in the circuit is connected to the power supply is further defined.

[0050] Based on the above embodiments, in this simulation test circuit, the input end of the accompanying AC / DC converter is connected to the power supply through multiple switches, specifically including:

[0051] The input end of the accompanying AC / DC converter, the third switch 3, the first switch 1, and the power supply are connected in series in sequence.

[0052] Specifically, the structure of multiple switches through which the static start-up frequency converter of the engine under test in the circuit is connected to the power supply is further defined here. It can be seen that the first switch 1 is the main switch, and the second switch 2 and the third switch 3 respectively control the static start-up frequency converter of the engine under test and the accompanying AC / DC converter. Designing the switches in the simulation test circuit in this way can achieve the purpose of controlling the static start-up frequency converter of the engine under test and the accompanying AC / DC converter with simple operations.

[0053] Based on the above embodiments, in this simulation test circuit, the power supply is a three-phase 6 kV power supply.

[0054] Specifically, it is preferable that the power supply is a three-phase 6 kV power supply to make the power supply more suitable for this simulation test circuit.

[0055] Based on the above embodiments, the embodiments of the present invention further provide a simulation test method using the simulation test method described in any of the above embodiments. Figure 2 It is a schematic flowchart of the simulation test method provided by the present invention. As Figure 2 shown, this simulation test method includes the following steps:

[0056] Step S1: When the synchronous generator and the DC motor are in a stationary state, power on the accompanying AC / DC converter and the static start-up frequency converter of the engine under test, and start the accompanying AC / DC converter so that the synchronous generator finally obtains a stable barring speed.

[0057] Step S2: Send a start command to the static start-up frequency converter of the engine under test externally, detect the barring speed, and make the static start-up frequency converter of the engine under test drive the synchronous generator to start with the barring speed as the initial speed. During this process, test the parameters to be measured of the static start-up frequency converter of the engine under test.

[0058] Step S3: Send a stop command to the static start-up frequency converter of the engine under test externally, so that the static start-up frequency converter of the engine under test is in a hot standby state, and the synchronous generator together with the DC motor decelerates until it stabilizes at the target working condition of the barring speed, and finally makes the synchronous generator decelerate to obtain a stable barring speed.

[0059] Specifically, for the static start-up frequency converter of the gas turbine to be tested, the synchronous generator needs to be dragged and started from the turning gear speed. Therefore, the synchronous generator needs to operate stably at the turning gear speed condition before the static start-up frequency converter of the gas turbine to be tested is powered on and works. Therefore, step S1 of the simulation test method is to make the DC motor in the electric state by powering on the auxiliary AC / DC converter on the DC side of the simulation test circuit, so as to drag the synchronous generator. The synchronous generator is dragged and started by the DC motor, and after accelerating to the turning gear speed, it operates stably. At this time, the synchronous generator is stable in the turning gear state, and the DC side simulates the turning gear state to complete. Then enter step S2, power on the static start-up frequency converter of the gas turbine to be tested. The static start-up frequency converter of the gas turbine to be tested will output voltage to drag the synchronous generator to continue accelerating from the turning gear speed, that is, the AC side completes the process simulation of the synchronous generator starting from the turning gear state to the initial speed. During this process, the static start-up frequency converter of the gas turbine to be tested is tested, which is the static start-up frequency converter of the gas turbine to be tested for simulating the turning gear start-up process in the laboratory environment. Finally, in step S3, an external instruction is issued to control the static start-up frequency converter of the gas turbine to be tested to stop output. The static start-up frequency converter of the gas turbine to be tested is in the hot standby state, and the synchronous generator gradually decelerates until the auxiliary AC / DC converter on the DC side outputs a voltage that meets the target turning gear working condition again, so that the synchronous generator is stable at the turning gear speed again. After the above process is completed, a set of measured parameters of the static start-up frequency converter of the gas turbine to be tested when starting in the simulated turning gear state can be tested. It should be noted here that the common measured parameters of the static start-up frequency converter of the gas turbine to be tested include the power, output voltage, output current, etc. of the static start-up frequency converter of the gas turbine to be tested during the start-up process, which are not specifically limited here.

[0060] Figure 3 The power-on working flowchart of the static start-up frequency converter of the gas turbine to be tested provided by the present invention is as Figure 3 shown. All switches in the simulation test circuit are closed. After the static start-up frequency converter of the gas turbine to be tested is powered on, it is necessary to judge whether to start working. If not, the static start-up frequency converter of the gas turbine to be tested is in the hot standby state, that is, the shutdown state. If it starts, it is necessary to detect the turning gear speed. The static start-up frequency converter of the gas turbine to be tested starts with the turning gear speed as the initial speed. During the start-up process, it always receives and judges whether the external instruction is a shutdown instruction. If it is a shutdown instruction, the static start-up frequency converter of the gas turbine to be tested stops output and returns to the hot standby state. If there is no shutdown instruction, the static start-up frequency converter of the gas turbine to be tested drags the synchronous generator to continue accelerating.

[0061] The simulation test method of the simulation test circuit provided by the present invention includes the following steps: Step S1: When the synchronous generator and the DC motor are in a stationary state, power on the companion AC / DC converter and the frequency converter for starting the engine under test at rest, and start the companion AC / DC converter to enable the synchronous generator to finally obtain a stable barring speed; Step S2: Externally send a start command to the frequency converter for starting the engine under test at rest, detect the barring speed, and enable the frequency converter for starting the engine under test at rest to drive the synchronous generator to start with the barring speed as the initial speed. During this process, test the parameters to be measured of the frequency converter for starting the engine under test at rest; Step S3: Externally send a stop command to the frequency converter for starting the engine under test at rest, so that the frequency converter for starting the engine under test at rest is in a hot standby state, and the synchronous generator together with the DC motor decelerates until it stabilizes at the target working condition of the barring speed, and finally enables the synchronous generator to decelerate to obtain a stable barring speed. The simulation test method provided by the present invention realizes the simulation of the low-speed barring working condition on the laboratory site, has simple control, fast response speed, and strong adaptability.

[0062] Based on the above embodiment, in this simulation test method, it further includes:

[0063] The companion AC / DC converter and the frequency converter for starting the engine under test at rest do not need to be powered on and off repeatedly. Repeat steps S2 - S3 multiple times to cyclically test the parameters to be measured of the frequency converter for starting the engine under test at rest during the process of driving the synchronous generator to start with the barring speed as the initial speed.

[0064] Specifically, the companion AC / DC converter and the frequency converter for starting the engine under test at rest do not need to be powered on and off repeatedly, and steps S2 - S3 can be repeated multiple times to cyclically test the parameters to be measured of the frequency converter for starting the engine under test at rest during the process of driving the synchronous generator to start with the barring speed as the initial speed. That is, multiple sets of parameters to be measured of the frequency converter for starting the engine under test at rest during the start in the simulated barring state can be tested. The more data is tested, the more accurate the analysis result obtained by mathematical statistics analysis will be, improving the accuracy of the simulation test.

[0065] Based on the above embodiment, in this simulation test method, during the process of the frequency converter for starting the engine under test at rest driving the synchronous generator to start with the barring speed as the initial speed, the power diode is in a reverse off state, and the DC motor operates in a power generation state driven by the synchronous generator.

[0066] Specifically, during the process of the static start of the engine under test, where the frequency converter drives the synchronous generator to start with the barring speed as the initial speed, the negative voltage of the power diode will be higher than the positive voltage. At this time, the power diode is in the reverse cut-off state, and the accompanying AC / DC converter stops outputting voltage. The DC motor is only driven to rotate by the synchronous generator through the coupling. Through the start operation of the static start frequency converter of the engine under test and the conduction and cut-off characteristics of the power diode on the DC side, a smooth switching between the output start of the static start frequency converter of the engine under test and the output shutdown of the accompanying AC / DC converter is achieved.

[0067] Based on the above embodiments, in this simulation test method, the step of enabling the synchronous generator to finally obtain a stable barring speed specifically includes:

[0068] Adjust the DC voltage output by the accompanying AC / DC converter according to the barring speed set for the barring condition, so that the DC motor drives the synchronous generator to rotate until the synchronous generator stabilizes at the barring speed.

[0069] Specifically, Figure 4 The flowchart of the power-on operation of the accompanying AC / DC converter provided by the present invention is as follows. As Figure 4 shown, all the switches in the simulation test circuit are closed. After the accompanying AC / DC converter is powered on, it is necessary to determine whether to start up after power-on. If not, the accompanying AC / DC converter is in the hot standby state, that is, the shutdown state. If so, the accompanying AC / DC converter starts to work after power-on. During the power-on operation, it continuously detects whether to shut down. If so, the accompanying AC / DC converter is in the hot standby state, that is, the shutdown state. If not, it is necessary to detect whether the barring speed of the currently set target barring condition needs to be modified. If so, adjust the output voltage of the accompanying AC / DC converter according to the current barring speed, so that the DC motor drives the synchronous generator to rotate until the synchronous generator stabilizes at the barring speed and operates.

[0070] Based on the above embodiments, in this test simulation method, when the static start frequency converter of the engine under test is in the hot standby state, the power diode is in the forward conduction state, the DC motor is in the electric state and drives the synchronous generator to rotate, and the synchronous generator finally rotates at the barring speed.

[0071] Specifically, when the static start-up frequency converter of the engine to be tested is in the hot standby state, the positive voltage of the power diode on the DC side is higher than the negative voltage, and the power diode is in the forward conduction state. The output voltage of the accompanying AC / DC converter drives the DC motor, and the DC motor is in the electric state to drive the synchronous generator to rotate, so that the synchronous generator finally rotates at the barring speed based on the output voltage of the accompanying AC / DC converter on the DC side in the analog test circuit, realizing the smooth switching between the shutdown of the static start-up frequency converter of the engine to be tested and the start of the output of the accompanying AC / DC converter.

[0072] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or equivalently replace some of the technical features. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A simulated test circuit for the barring gear during the variable-frequency starting process of a gas turbine, characterized in that, The circuit includes: a static start-up frequency converter of the gas turbine to be tested, a companion AC / DC converter, a power diode, a synchronous generator, a DC motor, a coupling, a plurality of switches, and a power supply. Among them, one end of the synchronous generator is connected to the static start-up frequency converter of the gas turbine to be tested through a switch, the other end of the synchronous generator is connected to the DC motor through the coupling, the positive output terminal of the companion AC / DC converter is connected to the positive electrode of the power diode, the negative electrode of the power diode is connected to the positive electrode of the power supply port of the DC motor, the negative output terminal of the companion AC / DC converter is connected to the negative electrode of the power supply port of the DC motor, the input terminal of the static start-up frequency converter of the gas turbine to be tested is connected to the power supply through a plurality of switches, and the input terminal of the companion AC / DC converter is connected to the power supply through a plurality of switches; The input terminal of the static start-up frequency converter of the gas turbine to be tested is connected to the power supply through a plurality of switches, specifically including: the input terminal of the static start-up frequency converter of the gas turbine to be tested, the second switch (2), the first switch (1), and the power supply are connected in series in sequence; The input terminal of the companion AC / DC converter is connected to the power supply through a plurality of switches, specifically including: the input terminal of the companion AC / DC converter, the third switch (3), the first switch (1), and the power supply are connected in series in sequence.

2. The simulated test circuit for the barring gear during the variable-frequency starting process of a gas turbine according to claim 1, characterized in that, The other end of the synchronous generator is connected to the DC motor through the coupling, specifically including: the other end of the synchronous generator is coaxially connected to the DC motor through the coupling.

3. The simulated test circuit for the barring gear during the variable-frequency starting process of a gas turbine according to any one of claims 1-2, characterized in that, The power supply is a three-phase 6 kV power supply.

4. A simulated test method using the simulated test circuit for the barring gear during the variable-frequency starting process of a gas turbine according to any one of claims 1-2, characterized in that, It includes: Step S1: When the synchronous generator and the DC motor are in a static state, power on the companion AC / DC converter and the static start-up frequency converter of the gas turbine to be tested, start the companion AC / DC converter, and finally make the synchronous generator obtain a stable barring speed; Step S2: Send a start command to the static start-up frequency converter of the gas turbine to be tested externally, detect the barring speed, and make the static start-up frequency converter of the gas turbine to be tested drive the synchronous generator to start with the barring speed as the initial speed. During this process, test the parameters to be measured of the static start-up frequency converter of the gas turbine to be tested; Step S3: Send a stop command to the static start-up frequency converter of the gas turbine to be tested externally, so that the static start-up frequency converter of the gas turbine to be tested is in a hot standby state, the synchronous generator together with the DC motor decelerates until it stabilizes at the target working condition of the barring speed, and finally makes the synchronous generator decelerate to obtain a stable barring speed.

5. The simulated test method according to claim 4, characterized in that, It also includes: The companion AC / DC converter and the static start-up frequency converter of the gas turbine to be tested do not need to be powered on and off repeatedly. Repeat steps S2 - S3 multiple times to cyclically test the process of the static start-up frequency converter of the gas turbine to be tested driving the synchronous generator to start with the barring speed as the initial speed.

6. The simulated test method according to claim 4, characterized in that, During the process of the static start-up frequency converter of the gas turbine to be tested driving the synchronous generator to start with the barring speed as the initial speed, the power diode is in a reverse cut-off state, and the DC motor operates in a power generation state driven by the synchronous generator.

7. The simulated test method according to claim 4, characterized in that, The process of finally achieving a stable barring speed for the synchronous generator specifically includes: Adjust the DC voltage output by the accompanying AC / DC converter according to the barring speed set for the barring condition, so that the DC motor drives the synchronous generator to rotate until the synchronous generator stabilizes at the barring speed.

8. The simulated test method according to claim 4, characterized in that, When the static start inverter of the engine under test is in the hot standby state, the power diode is in the forward conduction state, the DC motor is in the electric state to drive the synchronous generator to rotate, and the synchronous generator finally rotates at the barring speed.

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