Aviation gas turbine starter starting current limiting device, aviation gas turbine starter

Abstract

This application discloses a starting current limiting device for an aviation gas turbine starter and an aviation gas turbine starter, including a time-delay relay KT1, a main circuit on / off control contactor KM2, a shielded series resistor contactor KM3, and a resistor R. This application addresses the problem of excessive starting current during field flight testing of aircraft gas turbine starters by designing, assembling, and conducting simulation tests to verify the starting performance of a DC starter series resistance voltage reduction device. By designing a starting current limiting circuit and analyzing and calculating basic parameters, and then conducting tests according to starter speed requirements, the optimal circuit parameter configuration is determined based on the test results. This provides a suitable starting current limiting device scheme for the gas turbine starter starting system, offering a safe and simple electric starting solution for stable system operation, enhancing the reliability and adaptability of the device, and maximizing the starter's starting speed performance requirements. It has certain engineering application potential.

Description

Technical Field

[0001] This application relates to the field of aviation gas turbine starter technology, and in particular, to an aviation gas turbine starter starting current limiting device and an aviation gas turbine starter. Background Technology

[0002] In small and medium-sized aero engines, DC generators are generally used as starting power. Their advantages include lighter weight, simpler control, and the ability to be converted into a generator after starting. For example, a certain type of aero turboshaft engine uses a DC generator to complete the starting, cold run, and dummy start operations. The specific takeoff process is as follows: After the generator drives the auxiliary power unit (APU, i.e., the starter motor) to ignite successfully, it drives the aircraft engine compressor to rotate and perform work. Once the compressor reaches a certain speed, fuel is injected and ignited in the engine combustion chamber. The high-temperature exhaust gas in the combustion chamber drives the turbine to rotate, and the turbine drives the compressor to rotate at a constant speed until the aircraft engine reaches the required speed for takeoff.

[0003] The starting motor's initial output torque, torque characteristics, speed, ambient temperature, and weight all affect its compatibility with the engine. Among these, the compatibility between the motor's output torque characteristics and the engine's resistance torque characteristics is the most important. Data shows that most small and medium-sized engines in Europe and America that use electric motors for starting do not have a pressure reduction or boosting starting process. Some also use a staged starting method, involving a pressure reduction → full pressure → boosting → compound-wound to series-wound starting process. In China, to reduce helicopter load, simplify the starting procedure, and improve engine start-up capability, most engines are required to use a single-stage starting method, i.e., without intermediate pressure reduction or boosting processes, directly using full pressure starting. This allows the engine to have a high gas generator speed at the initial startup, enabling the gas turbine to perform work earlier and complete the starting process as quickly as possible.

[0004] In the design and implementation of DC starting step-down / current limiting schemes, most adopt the direct series resistor voltage divider starting method, while a few adopt the step-down to full voltage starting method by first connecting the series resistor and then disconnecting it.

[0005] In existing technologies for limiting the starting current of DC starters, most of the direct series resistor voltage divider methods cannot guarantee sufficient starting torque, reducing the work done by the electric starter and limiting its starting performance. The step-down to full-voltage starting method, which connects the resistor in series and then disconnects it, can limit the starting current and provide sufficient starting torque, but it is rarely explored through experimentation to find the appropriate series resistor size and disconnection time under specific speeds of the starter and engine. This means that the current limiting circuit cannot meet the starting speed performance requirements of the starter to the greatest extent, and its reliability is even lower in the aviation field. Summary of the Invention

[0006] A preferred embodiment of this application provides a starting current limiting device for an aviation gas turbine starter, which solves the technical problems of limited starting performance and the inability of the current limiting circuit to meet the starting speed performance requirements of the starter in the prior art of limiting the starting current of a DC starter.

[0007] The technical solution adopted in this application is as follows:

[0008] A starting current limiting device for an aviation gas turbine starter includes a time-delay relay KT1, a main circuit on / off control contactor KM2, a shielded series resistor contactor KM3, and a resistor R. Specifically: one end of the electromagnetic coil of the shielded series resistor contactor KM3 is connected to the negative terminal of the electric starter, and the other end is connected to the stationary contact circuit of the time-delay relay KT1; the moving contact of KT1 is connected to the starting current monitoring shunt circuit RS; one end of the electromagnetic coil of the time-delay relay KT1 is connected to the vehicle controller, and the other end is connected to the negative terminal of the electric starter; the main circuit on / off control contactor KM2, shielded series resistor contactor KM3, and resistor R. The moving contact of the circuit on / off control contactor KM2 is connected to the starting current monitoring shunt circuit RS. The stationary contact of the main circuit on / off control contactor KM2 is connected in sequence to the resistor R and the positive terminal of the electric starter. One end of the electromagnetic coil of the main circuit on / off control contactor KM2 is connected to the vehicle controller, and the other end is connected to the negative terminal of the electric starter. The moving contact of the shielded series resistor contactor KM3 is connected to the stationary contact of the main circuit on / off control contactor KM2. The stationary contact of the shielded series resistor contactor KM3 is connected to the positive terminal of the electric starter.

[0009] Before starting, the time delay relay KT1, the main circuit on / off control contactor KM2, and the shielded series resistor contactor KM3 are all de-energized. During starting, the vehicle controller sends a start signal, the main circuit on / off control contactor KM2 is energized, the resistor R is connected in series in the circuit, and the electric starter starts in a reduced-voltage mode. When the time delay relay KT1 reaches the preset delay time t, the shielded series resistor contactor KM3 is energized, the shielded resistor R is activated, and the electric starter switches from reduced-voltage to full-voltage starting mode. The resistance value of the resistor R and the delay time t are determined by the optimal matching value selected from the battery starting current limiting test.

[0010] Furthermore, the resistance value of the resistor R and the delay time t are determined through the following steps:

[0011] S1. Reference data for selecting the resistance value of the resistor R and the delay time t required for the current-limiting test, obtained through the unlimited current-start test of the airborne battery;

[0012] S2. By recording the battery starting current limiting test, the optimal matching value of resistor R and delay time t is obtained by referring to the selection data of the resistance value of resistor R and delay time t.

[0013] Further, step S1 specifically includes the following steps:

[0014] S11. According to the aircraft starting circuit status, the power supply is a parallel airborne battery, without a starting current limiting device, and a starter motor starting test is conducted to obtain the peak current, line resistance, electric starter internal resistance and the empirical value of delay time t, wherein the empirical value of delay time t is 1s.

[0015] S12. If the starting current within the requirements of the starter can be met, the estimated value of the resistance R can be calculated based on the starting measurement test results.

[0016] Furthermore, in step S11, when conducting the starter motor starting test, the starter motor cold run, main engine cold run (simulating engine cold run), and main engine starting (simulating engine starting) tests are conducted respectively.

[0017] Further, step S12 specifically includes the following steps:

[0018] If the starting current requirement of the starter can be met, the estimated value of the resistance R can be calculated based on the starting measurement test results using the following formula:

[0019] U E =I 峰 ×(R S +r)

[0020] U E =I 期 ×(R S +r+R).

[0021] In the formula:

[0022] U E Power supply voltage;

[0023] I 峰 Peak current;

[0024] I 期 : Expected starting current;

[0025] R S Line resistance;

[0026] r: Internal resistance of the electric starter.

[0027] Furthermore, step S2 specifically includes the following steps:

[0028] S21. Take several experimental values ​​of resistance R near the estimated value of the obtained resistance R, and take several experimental values ​​of delay time t near the empirical value of delay time t.

[0029] S22. The test values ​​of the resistor R and the test values ​​of the delay time t are arranged and combined and then sorted.

[0030] S23. Connect the starting current limiting device to the line, adjust the resistance R and delay time t of the starting current limiting device according to the arrangement and combination, set the parameters of the starting current limiting device according to the sorting order, conduct a starter motor starting test, and obtain different starter motor starting performance parameters, including the first and second current peaks and the first and second voltage peaks during the starting process, and the change curve of the APU starter motor compressor speed with time.

[0031] S24. Based on the peak values ​​of the first and second currents and the peak values ​​of the first and second voltages during the startup process, the curve of the APU starter compressor speed changing with time, and the full start time of different APU starter models, select the optimal values ​​of resistor R and delay time t from the permutation and combination of the test values ​​of the resistor R and the test values ​​of the delay time t.

[0032] Furthermore, in step S23, when conducting the starter motor starting test, the starter motor cold run, the main engine cold run (simulating engine cold run), and the main engine starting test are conducted respectively.

[0033] Further, step S24 specifically includes the following steps:

[0034] S241. Obtain the start-up delay when different resistors R and delay times t are connected, including the actual delay, the start time of the APU starter motor, and the full start time of the APU starter motor. Each time is counted from the start signal given by the controller.

[0035] S242. When the combination of the test value of the resistor R and the test value of the dry delay time t contains the following: the delay time t is greater than the APU start-up time, and similarly, when the APU starter compressor speed corresponding to the delay time t in the curve of the APU starter compressor speed change with time is within the set range of the speed after the APU is fully started, then the corresponding test value of the resistor R and the test value of the dry delay time t are taken as the optimal values ​​of the resistor R and the delay time t.

[0036] Furthermore, the setting range is 16% to 17% of the rotational speed after the APU is fully started.

[0037] Another preferred embodiment of this application provides an aviation gas turbine starter, including an airborne battery, an electric starter, a main circuit fast-acting fuse FU, a starting current monitoring shunt RS, and the aforementioned aviation gas turbine starter starting current limiting device.

[0038] Furthermore, the onboard battery is a 28V DC power supply.

[0039] Compared with the prior art, this application has the following advantages:

[0040] This application provides a starting current limiting device for an aviation gas turbine starter and an aviation gas turbine starter, including a time delay relay KT1, a main circuit on / off control contactor KM2, a shielded series resistor contactor KM3, and a resistor R. The resistance value of the resistor R and the delay time t are determined by the optimal matching value selected through battery starting current limiting tests. Existing starting current limiting devices, which use a DC motor current limiting starting technology that first reduces voltage and then switches to full voltage, are relatively crude in their circuit design and component specification selection. They do not specifically optimize the appropriate resistance value and disconnection time (i.e., delay time t) through comparative experiments to adapt to the specific speeds of the starter and engine. This fails to ensure that the current limiting circuit maximally meets the starting speed performance requirements of the starter. This application, based on the starter starting process requirements and simulating several flight states, provides a more precise and practical design for the current limiting device and selection of component parameters. It offers a safe and simple electric starting scheme for stable system operation, enhances the reliability and adaptability of the device, maximizes the starting speed performance requirements of the starter, and has certain engineering application potential.

[0041] In addition to the purposes, features, and advantages described above, this application provides other purposes, features, and advantages. The application will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0042] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0043] Figure 1 This is a schematic diagram of the principle of an existing aviation gas turbine starter.

[0044] Figure 2 This is a schematic diagram of the starting current limiting device for an aviation gas turbine starter according to a preferred embodiment of this application.

[0045] Figure 3 This is a schematic diagram of the starting current curve of the onboard battery for the starter of an existing aviation gas turbine starter.

[0046] Figure 4 This is a schematic diagram of the starting current limiting verification test current curve (20mΩ, 1.5s) of a preferred embodiment of this application.

[0047] Figure 5 This is a schematic diagram of the starting current limiting verification test current curve (25mΩ, 1.5s) of a preferred embodiment of this application.

[0048] Figure 6 This is a schematic diagram of the starting current limiting verification test current curve (30mΩ, 1.5s) of a preferred embodiment of this application.

[0049] Figure 7 This is a schematic diagram of the APU starter compressor speed Ng (rpm) curve when a 25mΩ resistor is connected in series and a delay of 1.5s is applied, according to a preferred embodiment of this application. Detailed Implementation

[0050] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0051] The starting formula for an electric starter is as follows:

[0052] I = (UC) e nφ) / R a

[0053] In the formula:

[0054] I: Starting current;

[0055] U: Power supply voltage;

[0056] C e : Electromotive force constant of electric starter;

[0057] n: Electric starter speed;

[0058] φ: Electric starter flux;

[0059] R a Total resistance of the starting circuit, including power supply resistance, line resistance, and electric starter resistance.

[0060] As can be seen from the starting formula of the electric starter, the starting current of the electric starter is related to the power supply voltage, the back EMF of the starter, and the circuit resistance. However, the onboard battery voltage is constant at 28VDC and cannot be adjusted, so the starting current can only be limited by increasing the circuit resistance.

[0061] The formula for the starting torque of an electric starter is as follows:

[0062] T = C e ·φ·I

[0063] In the formula:

[0064] T: Starting torque;

[0065] I: Starting current;

[0066] C e : Electromotive force constant of electric starter;

[0067] φ: Electric starter flux.

[0068] As can be seen from the starting torque formula of the electric starter, a decrease in starting current will lead to a decrease in starting torque, which reduces the work done by the electric starter and is detrimental to the starting of both the starter and the aircraft.

[0069] To limit the starting current while providing sufficient starting torque to ensure smooth starting of the starter and aircraft, a reduced-voltage to full-voltage starting method can be adopted. In the initial stage of starting, a starting resistor of a certain size is connected in series in the starting circuit to limit the starting current. When the back electromotive force of the electric starter reaches a certain value, the starting resistor is bypassed, allowing the electric starter to operate in full-voltage starting mode. To maximize the starting speed performance requirements of the starter, the size of the starting resistor R and the reduced-voltage starting time t are determined through experimental verification.

[0070] The original starting control principle is as follows: Figure 1 Without a starting current limiting device, the power supply is directly applied to both ends of the electric starter, and the starting process is not subject to external regulation.

[0071] The principle of current-limiting start control is as follows: Figure 2 The main components are as follows:

[0072] FU: Fast-acting fuse for main circuit;

[0073] RS: Starting current monitoring shunt;

[0074] KT1: Electric starter start-up energization delay relay;

[0075] KM2: Main circuit on / off control contactor;

[0076] KM3: Shielded series resistor contactor.

[0077] like Figure 2As shown, a preferred embodiment of this application provides a starting current limiting device for an aviation gas turbine starter, including a time-delay relay KT1, a main circuit on / off control contactor KM2, a shielded series resistor contactor KM3, and a resistor R. Specifically: one end of the electromagnetic coil of the shielded series resistor contactor KM3 is connected to the negative terminal of the electric starter, and the other end is connected to the stationary contact circuit of the time-delay relay KT1; the moving contact of KT1 is connected to the starting current monitoring shunt circuit RS; and one end of the electromagnetic coil of the time-delay relay KT1 is connected to the vehicle controller, and the other end is connected to the electric starter. The negative terminal of the motor; the moving contact of the main circuit on / off control contactor KM2 is connected to the starting current monitoring shunt circuit RS; the stationary contact of the main circuit on / off control contactor KM2 is connected in sequence to the resistor R and the positive terminal of the electric starter; one end of the electromagnetic coil of the main circuit on / off control contactor KM2 is connected to the vehicle controller, and the other end is connected to the negative terminal of the electric starter; the moving contact of the shielded series resistor contactor KM3 is connected to the stationary contact of the main circuit on / off control contactor KM2, and the stationary contact of the shielded series resistor contactor KM3 is connected to the positive terminal of the electric starter;

[0078] Connect the starting current limiting device to the starting circuit at points A, B, and C in the diagram. Before starting, the time delay relay KT1, the main circuit on / off control contactor KM2, and the shielded series resistor contactor KM3 are all de-energized. During starting, the vehicle controller sends a starting signal, the main circuit on / off control contactor KM2 is energized, and the resistor R is connected in series in the circuit. The electric starter starts in a reduced-voltage mode. When the time delay relay KT1 reaches the preset delay time t, the shielded series resistor contactor KM3 is energized, the shielded resistor R is activated, and the electric starter switches from reduced-voltage to full-voltage starting. The resistance value of the resistor R and the delay time t are determined by the optimal matching value selected from the battery starting current limiting test.

[0079] This embodiment provides a starting current limiting device for an aviation gas turbine starter and an aviation gas turbine starter, including a time delay relay KT1, a main circuit on / off control contactor KM2, a shielded series resistor contactor KM3, and a resistor R. The resistance value of the resistor R and the delay time t are determined by the optimal matching values ​​selected through battery starting current limiting tests. Existing starting current limiting devices, which use a DC motor current limiting starting technology that first reduces voltage and then switches to full voltage, are relatively crude in their circuit design and component specification selection. They do not specifically optimize the appropriate resistance value and disengagement time (i.e., delay time t) through comparative experiments to adapt to the specific speeds of the starter and engine. This fails to ensure that the current limiting circuit maximally meets the starting speed performance requirements of the starter. This embodiment, based on the starter starting process requirements and simulating several flight states, provides a more precise and practical design for the current limiting device and selection of component parameters. It offers a safe and simple electric starting scheme for stable system operation, enhances the reliability and adaptability of the device, maximizes the starting speed performance requirements of the starter, and has certain engineering application potential.

[0080] Preferably, the resistance value of the resistor R and the delay time t are determined by the following steps:

[0081] S1. Reference data for selecting the resistance value of the resistor R and the delay time t required for the current-limiting test, obtained through the unlimited current-start test of the airborne battery;

[0082] S2. By recording the battery starting current limiting test, the optimal matching value of resistor R and delay time t is obtained by referring to the selection data of the resistance value of resistor R and delay time t.

[0083] Preferably, step S1 specifically includes the following steps:

[0084] S11. According to the aircraft starting circuit status, the power supply is a parallel airborne battery, without a starting current limiting device. Perform starter cold run, main engine cold run (simulating engine cold run), and main engine start (simulating engine start) tests respectively, obtaining peak current, line resistance, starter internal resistance, and empirical values ​​for delay time t. The empirical value for delay time t is 1 second. The total voltage of the parallel airborne battery is 28VDC. The starting current curve is shown in [reference needed]. Figure 3 The starting peak current is close to 900A, which does not meet the requirement that the aircraft's starting peak current should not exceed 800A. According to Joule's law, Q = I... 2 As can be seen from Rt, when the time is the same near the peak current, the larger the peak current, the more heat is generated, and the easier it is for the fuse to burn out.

[0085] S12. If the starting current within the requirements of the starter can be met, the estimated value of the resistance R can be calculated based on the starting measurement test results.

[0086] Preferably, in step S11, when performing the starter motor starting test,

[0087] Preferably, step S12 specifically includes the following steps:

[0088] If the starting current requirement of the starter can be met, the estimated value of the resistance R can be calculated based on the starting measurement test results using the following formula:

[0089] U E =I 峰 ×(R S +r)

[0090] U E =I 期 ×(R S +r+R).

[0091] In the formula:

[0092] U E Power supply voltage;

[0093] I 峰 Peak current;

[0094] I 期 : Expected starting current;

[0095] R S Line resistance;

[0096] r: Internal resistance of the electric starter.

[0097] Take U E =28VDC, I 峰 =900A, I 期 Substituting 500A into the two formulas for calculation, we get a series resistance R of approximately 25mΩ. Therefore, the resistance selection in the current limiting test scheme can be distributed around this value.

[0098] Preferably, step S2 specifically includes the following steps:

[0099] S21. Take several experimental values ​​of resistance R near the estimated value of the obtained resistance R, and take several experimental values ​​of delay time t near the empirical value of delay time t.

[0100] S22. The test values ​​of the resistor R and the test values ​​of the delay time t are arranged and combined and then sorted (see Table 1);

[0101] Table 1. Start-up Current Limiting Verification Test Plan

[0102]

[0103] S23. Connect the starting current limiting device to the line, adjust the resistance R and delay time t of the starting current limiting device according to the arrangement and combination, and set the parameters of the starting current limiting device according to the order in Table 1. Conduct a starter motor starting test and obtain different starter motor starting performance parameters as shown in Tables 2-10, including the peak values ​​of the first and second currents and the peak values ​​of the first and second voltages during the starting process, and the curve of the APU starter motor compressor speed changing with time:

[0104] Table 2 shows the current-limiting start-up test with a 20mΩ resistor in series and a 1s delay.

[0105]

[0106] Table 3 shows the current-limiting start-up test with a 20mΩ resistor in series and a delay of 1.5s.

[0107]

[0108] Table 4 shows the current-limiting start-up test with a 20mΩ resistor in series and a 2s delay.

[0109]

[0110] Table 5 shows the current-limiting start-up test with a 25mΩ resistor in series and a 1s delay.

[0111]

[0112] Table 6 shows the current-limiting start-up test with a 25mΩ resistor in series and a delay of 1.5s.

[0113]

[0114] Table 7 shows the current-limiting start-up test with a 25mΩ resistor in series and a 2s delay.

[0115]

[0116] Table 8 shows the current-limiting start-up test with a 30mΩ resistor in series and a 1s delay.

[0117]

[0118]

[0119] Table 9 shows the current-limiting start-up test with a 30mΩ resistor in series and a delay of 1.5s.

[0120]

[0121] Table 10 shows a 30mΩ resistor in series, 2s delay current-limiting start-up test.

[0122]

[0123] in:

[0124] I 峰1 I 峰2 These refer to the first and second current peaks during the startup process, respectively.

[0125] U1 and U2 refer to the first and second voltage peaks during the startup process, respectively.

[0126] Simultaneously, the current curves during large-scale engine startup can be obtained by connecting resistors of 20mΩ, 25mΩ, and 30mΩ in series, as shown below. Figures 4-6 As shown (taking a delay of 1.5 seconds as an example)

[0127] The curve of the APU starter compressor speed Ng (rpm) with a 25mΩ series connection and a delay of 1.5s is shown below. Figure 7 As shown.

[0128] Due to the current limiting device, the APU startup time is extended. The delay when connecting three resistors of 20mΩ, 25mΩ, and 30mΩ in series during large-scale startup is shown in Table 11:

[0129] Table 11 shows partial start-up delays with different series resistors (unit: seconds).

[0130]

[0131]

[0132] In the table, all times are counted from the start signal given by the controller; the delay time refers to the time t between step-down and full-voltage conversion; the parameter acquisition period is 25ms.

[0133] S24. Based on the peak values ​​of the first and second currents and the peak values ​​of the first and second voltages during the startup process, the curve of the APU starter compressor speed changing with time, and the full start time of different APU starter models, select the optimal values ​​of resistor R and delay time t from the permutation and combination of the test values ​​of the resistor R and the test values ​​of the delay time t.

[0134] Preferably, in step S23, when performing the starter motor starting test, the starter motor cold run, the main engine cold run (simulating engine cold run), and the main engine starting test are performed respectively.

[0135] Preferably, step S24 specifically includes the following steps:

[0136] S241. Obtain the start-up delay when different resistors R and delay times t are connected, including the actual delay, the start time of the APU starter motor, and the full start time of the APU starter motor. Each time is counted from the start signal given by the controller.

[0137] S242. When the combination of the test value of the resistor R and the test value of the dry delay time t contains the following: the delay time t is greater than the APU start-up time, and similarly, when the APU starter compressor speed corresponding to the delay time t in the curve of APU starter compressor speed change with time is within 16% to 17% of the speed after the APU is fully started, then the corresponding test value of the resistor R and the test value of the dry delay time t are taken as the optimal values ​​of the resistor R and the delay time t.

[0138] The starting current curve was significantly improved after adding a series resistor and a time delay. Both the first and second current peaks met the requirement that the aircraft's starting current peak should not exceed 800A, thus achieving the goal of reducing the peak starting current. The solution is basically feasible. Based on the APU starter compressor speed results with different series resistor values ​​and different delay times, when the series resistor value was 25mΩ and the delay time was 1.5s, the speed was approximately 16-17% when resistor R was deactivated (turning to full pressure). At this point, the starter had just begun supplying fuel (as determined from the experimental fuel pressure curve). Fuel was injected into the fuel slinger, and after successful starter ignition, it smoothly drove the free turbine to perform work, causing the compressor rotor to accelerate upwards. Considering the maximum starting time of different APU starter models and the starting performance requirements of the downstream engine, a resistor value of 25mΩ and a time delay t of 1.5s for the time relay KT yielded the best starting effect.

[0139] Ground-based full-machine testing conditions were used for starting current-limiting tests. The starter's ground starting capability was unaffected, with the starting time extension remaining within an acceptable 9 seconds. T9 and Ng values ​​were normal. At the altitude and temperature conditions of high-altitude bench testing, current-limiting starting tests were conducted. Connecting a 25mΩ resistor in series for voltage reduction and a 1.5s delay had minimal impact on the starter's air-starting capability. However, considering that the starter was always in a normal temperature environment during high-altitude bench testing, the impact of extreme low-temperature conditions at high altitudes lacks experimental support and poses a certain risk. Regardless of whether a resistor was connected in series during starting, the starter maintained the same technical condition and no changes to its configuration were necessary.

[0140] Another preferred embodiment of this application provides an aviation gas turbine starter, including an airborne battery, an electric starter, a main circuit fast-acting fuse FU, and a starting current monitoring shunt RS. The airborne battery is a 28V DC power supply. The application also includes the aviation gas turbine starter starting current limiting device.

[0141] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0142] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A starting current limiting device for an aviation gas turbine starter, characterized in that, Includes time-delay relay KT1, main circuit on / off control contactor KM2, shielded series resistor contactor KM3, and resistor. R Wherein: one end of the electromagnetic coil of the shielded series resistor contactor KM3 is connected to the negative terminal of the electric starter, and the other end is connected to the stationary contact circuit of the time delay relay KT1; the moving contact of the time delay relay KT1 is connected to the starting current monitoring shunt circuit RS; one end of the electromagnetic coil of the time delay relay KT1 is connected to the vehicle controller, and the other end is connected to the negative terminal of the electric starter; the moving contact of the main circuit on / off control contactor KM2 is connected to the starting current monitoring shunt circuit RS; the stationary contact of the main circuit on / off control contactor KM2 is sequentially connected to resistors. R The electromagnetic coil of the main circuit on / off control contactor KM2 is connected to the vehicle controller at one end and to the negative terminal of the electric starter at the other end; the moving contact of the shielded series resistor contactor KM3 is connected to the stationary contact of the main circuit on / off control contactor KM2, and the stationary contact of the shielded series resistor contactor KM3 is connected to the positive terminal of the electric starter. Before starting, the time-delay relay KT1, the main circuit on / off control contactor KM2, and the shielded series resistor contactor KM3 are all de-energized. Upon starting, the vehicle controller sends a start signal, energizing the main circuit on / off control contactor KM2, and the resistor... R In series in the circuit, the electric starter starts in a reduced-voltage mode. When the time delay relay KT1 reaches the preset delay time t, the shielded series resistor contactor KM3 is energized, and the shielded resistor... R The electric starter switches from reduced voltage to full voltage starting mode, and the resistor... R The resistance value and delay time t are determined by the optimal matching value selected from the battery starting current limiting test. R The resistance value and delay time t are determined through the following steps: S1. Obtain the required resistance for the current-limiting test through an unlimited start-up test of the onboard battery. R Reference data for selecting the resistance value and delay time t; S2. Through the battery starting current limiting test, based on the aforementioned resistance... R The selection of resistance value and delay time t is based on the preferred data obtained from the resistor selection. R The optimal matching value between the delay time t and the delay time t.

2. The starting current limiting device for an aviation gas turbine starter according to claim 1, characterized in that, Step S1 specifically includes the following steps: S11. According to the aircraft starting circuit status, the power supply is a parallel airborne battery, without a starting current limiting device, and a starter motor starting test is performed to obtain the peak current, line resistance, electric starter motor internal resistance and the empirical value of delay time t, wherein the empirical value of delay time t is 1s. S12. If the starting current within the starter motor's requirements can be met, the resistance can be calculated based on the starting measurement test results. R The estimated value.

3. The starting current limiting device for an aviation gas turbine starter according to claim 2, characterized in that, In step S11, when performing the starter motor starting test, the starter motor cold run, main engine cold run, and main engine starting test are performed respectively.

4. The starting current limiting device for an aviation gas turbine starter according to claim 2, characterized in that, Step S12 specifically includes the following steps: If the starting current requirement of the starter can be met, the resistance can be calculated using the following formula based on the starting measurement test results. R Estimated value: ； ； In the formula: Power supply voltage; Peak current; : Expected starting current; Line resistance; Internal resistance of the electric starter.

5. The starting current limiting device for an aviation gas turbine starter according to claim 4, characterized in that, Step S2 specifically includes the following steps: S21, in the obtained resistor R Take several resistors near the estimated value R The experimental values ​​are obtained by taking several experimental values ​​of delay time t around the empirical value of delay time t; S22, the resistor R The experimental values ​​are arranged and combined with the experimental values ​​of several delay times t, and then sorted. S23. Connect the line to the starting current limiting device, and adjust the resistance of the starting current limiting device according to the above arrangement and combination. R The delay time t is set, and the parameters of the starting current limiting device are set according to the sorting order. The starter start test is carried out to obtain different starter start performance parameters, including the peak values ​​of the first and second currents and the peak values ​​of the first and second voltages during the start process, and the change curve of the APU starter compressor speed over time. S24. Based on the peak values ​​of the first and second currents and the peak values ​​of the first and second voltages during the starting process, the curve of the APU starter compressor speed changing with time, and the full start time of different APU starter models, from the resistor... R The resistance is selected from the permutations and combinations of the experimental values ​​and several experimental values ​​with delay time t. R The optimal value of the delay time t.

6. The starting current limiting device for an aviation gas turbine starter according to claim 5, characterized in that, In step S23, when performing the starter motor starting test, the starter motor cold run, main engine cold run, and main engine starting test are performed respectively.

7. The starting current limiting device for an aviation gas turbine starter according to claim 5, characterized in that, Step S24 specifically includes the following steps: S241, Obtain the connection of different resistors R The starting delay situation at delay time t includes the actual delay, the start time of the APU starter motor, and the full start time of the APU starter motor. Each time is counted from the start signal given by the vehicle controller. S242, when the resistor R Among the permutations and combinations of the test values ​​and several test values ​​with delay times t, there exists a situation where the delay time t is greater than the APU start-up time. When the APU starter compressor speed corresponding to the delay time t in the curve of APU starter compressor speed change over time is within the set range of the speed after the APU is fully started, then the corresponding resistor will be... R The experimental values ​​and the experimental values ​​with several delay times t are used as resistance. R The optimal value of the delay time t.

8. The starting current limiting device for an aviation gas turbine starter according to claim 7, characterized in that, The set range is 16% to 17% of the speed after the APU is fully started.

9. An aviation gas turbine starter, comprising an airborne battery, an electric starter, a main circuit fast-acting fuse FU, and a starting current monitoring shunt RS, characterized in that, It also includes a starting flow limiting device for an aviation gas turbine starter as described in any one of claims 1 to 8.

Images