Feedforward excitation current determining method, and aircraft three-stage electric excitation power generation system

Abstract

The present application relates to the technical field of avionics, and provides a feedforward excitation current determining method, a device, and a storage medium, which can enable current inner loops to directly and rapidly respond to load changes rather than only relying on voltage outer loops for adjustment, thereby improving the dynamic performance of aircraft variable-frequency alternating-current power generation systems. The method is applied to an aircraft three-stage electric excitation power generation system. The system comprises a main generator, a main exciter, a permanent magnet generator, a rotating rectifier, a generator controller, and a feedforward excitation current determining apparatus. The feedforward excitation current determining apparatus is used for: acquiring load power, an engine rotating speed and a given reference voltage of the main generator; calculating an excitation current required by the current load and a no-load excitation current on the basis of the load power, the engine rotating speed and the given reference voltage of the main generator, motor parameters of the main generator, and motor parameters of the main exciter; and determining a feedforward excitation current on the basis of the excitation current required by the current load and the no-load excitation current.

Description

Method for determining feedforward excitation current and aircraft three-stage electric excitation generation system Technical Field

[0001] The present application relates to the field of aviation electrical technology, and in particular to a method for determining a feedforward excitation current and an aircraft three-stage electric excitation power generation system. Background Art

[0002] Three-stage electromagnetic generators are widely used in aviation high-power AC power systems. These systems consist of a main generator, a main exciter, a permanent magnet exciter, a rotating rectifier, and a generator controller.

[0003] In the traditional three-stage electric excitation generator voltage regulation process, the controller needs to detect signals such as the voltage output by the main generator and the excitation current of the main exciter, and change the magnitude of the excitation current of the main exciter through the voltage regulation program to achieve the purpose of controlling the excitation current of the main generator, thereby realizing the output voltage regulation of the main generator.

[0004] Currently, a current feedforward method has been proposed to improve the dynamic characteristics of the motor when switching high-power loads by selecting different typical operating points of the power generation system through experimental means. The functional relationship between the excitation current and load power of a three-stage brushless synchronous motor at a certain speed is fitted based on the experimental data. However, this method is labor-intensive, and the fitted function is not applicable to different speeds. In addition, the experimental data is affected by different test conditions, which is prone to experimental errors.

[0005] Summary of the Invention

[0006] The embodiment of the present application provides a method for determining the feedforward excitation current, which enables the current inner loop to directly respond quickly to load changes instead of just adjusting through the voltage outer loop, thereby improving the dynamic performance of the motor aircraft variable frequency AC power generation system.

[0007] An embodiment of the present invention provides a method for determining a feedforward excitation current. The method is applied to a three-stage electric excitation power generation system of an aircraft. The system includes a main generator, a main exciter, a permanent magnet generator, a rotating rectifier, a generator controller, and a device for determining a feedforward excitation current. The device for determining a feedforward excitation current is configured to execute the method for determining a feedforward excitation current. The method includes:

[0008] Obtain the load power, engine speed and given reference voltage of the main generator;

[0009] Calculating the excitation current and no-load excitation current required by the current load according to the load power, engine speed and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter;

[0010] The feedforward excitation current is determined according to the excitation current required by the current load and the no-load excitation current.

[0011] An embodiment of the present invention provides a three-stage electric excitation power generation system for an aircraft. The system includes a main generator, a main exciter, a permanent magnet generator, a rotating rectifier, a generator controller, and a device for determining a feedforward excitation current. The device for determining the feedforward excitation current includes:

[0012] A sampling module is used to obtain the load power, engine speed and given reference voltage of the main generator;

[0013] a calculation module, configured to calculate the excitation current required by the current load and the no-load excitation current according to the load power, engine speed and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter;

[0014] The determination module is used to determine the feedforward excitation current according to the excitation current required by the current load and the no-load excitation current.

[0015] A computer program product includes a computer program, and when the computer program is executed by a processor, the computer program implements the above-mentioned method for determining the feedforward excitation current.

[0016] The present invention provides a method for determining a feedforward excitation current. The method first obtains the load power, engine speed, and given reference voltage of a main generator. The method then calculates the excitation current required for the current load and the no-load excitation current based on the load power, engine speed, and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter. Finally, the feedforward excitation current is determined based on the excitation current required for the current load and the no-load excitation current. The method calculates the feedforward excitation current by taking into account the effects of the main generator's load power, engine speed, and given reference voltage on the excitation current. This feedforward excitation current is added to the traditional dual closed-loop control of voltage and excitation current. By introducing feedforward excitation current compensation, the inner current loop can directly and quickly respond to load changes, rather than simply adjusting through the outer voltage loop. Consequently, the method can improve the dynamic performance of a variable-frequency AC generator system for an electric aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a control block diagram of a three-stage electric excitation power generation system for an aircraft provided by the present application;

[0018] FIG2 is a flow chart of a method for determining a feedforward excitation current provided by the present application;

[0019] FIG3 is an example diagram of the excitation current simulation curve provided in this application

[0020] FIG4 is an example diagram of an output voltage simulation curve provided by the present application;

[0021] FIG5 is a schematic structural diagram of a device for determining a feedforward excitation current provided in the present application. DETAILED DESCRIPTION

[0022] In order to better understand the above technical solution, the technical solution of the embodiment of the present application is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiment of the present application and the specific features in the embodiment are detailed descriptions of the technical solution of the embodiment of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiment of the present application and the technical features in the embodiment can be combined with each other.

[0023] Figure 1 shows a control block diagram of a three-stage electrically excited generator system for aircraft, according to an embodiment of the present invention. This control block diagram includes a main generator, a main exciter, a rotating rectifier, a generator controller, and a device for determining a feedforward excitation current. The generator controller includes a voltage loop PI controller, a current loop PI controller, and a controller excitation circuit.

[0024] As shown in FIG1 , the feedforward excitation current determination device in this embodiment includes three input quantities and one output quantity. Among them, the three input quantities refer to the load power P of the power generation system. out 、Main generator speed Ω m And given reference voltage U ref , 1 output is the feedforward excitation current Δi ef In Figure 1, the input of the voltage outer loop is the given reference voltage U output by the main generator. ref , given reference voltage U ref And the effective value of the main generator output voltage U rms After making the difference, the voltage loop PI controller outputs the excitation current given value Excitation current set value and the controller's excitation current i ef1 Make the difference and add the feedforward excitation current Δi ef After passing through the current loop PI controller, the excitation modulation duty cycle D is output and sent to the field programmable gate array (FPGA) processor. Inside the FPGA, duty cycle D is compared with the carrier signal, PWM modulation is performed, and the PWM modulated wave is output to control the controller's excitation circuit.

[0025] Among them, the generator output voltage U rmsThe acquisition method is as follows: the AC voltage signal at the voltage regulating point of the power generation system is collected and first divided by a resistor. This voltage signal is then input into an A / D converter chip for conversion, converting the AC voltage signal into a digital signal. After the conversion is completed, the digital signal output by the A / D converter chip is transmitted to the microprocessor in the generator controller. In the microprocessor, the Clarke transform and Park transform are used in combination with the electrical angle of the generator to calculate the transient effective value of the generator output voltage U. rms .

[0026] The excitation current signal i of the main exciter ef The voltage signal is converted into a digital signal through a sampling resistor, filtered by a second-order low-pass filter, and then sent to the A / D conversion chip to be converted into a digital signal. The digital signal output by the A / D conversion chip is then sent to the microprocessor.

[0027] In conjunction with the content disclosed in FIG1 , this embodiment provides a method for determining a feedforward excitation current. This method is applied to the above-mentioned device for determining a feedforward excitation current. FIG2 is a flow chart of a method for determining a feedforward excitation current provided in this embodiment. The steps performed by this method include:

[0028] S201, obtain the load power, engine speed and given reference voltage of the main generator.

[0029] In an optional embodiment provided in the present application, the load power P of the main generator is calculated by multiplying the effective value of the voltage at the load end and the effective value of the current at the load end. out Specifically, the current signal output by the generator is converted into a voltage signal through a sampling resistor, filtered by a second-order low-pass filter, and then sent to the A / D conversion chip to convert it into a digital signal. The digital signal output by the A / D conversion chip is then sent to the microprocessor, and the current effective value is calculated through Clarke transformation and Park transformation. The effective value of the output current of the generator and the effective value of the output voltage U rms Multiplying them, we can calculate the output power P of the power generation system out .

[0030] In an optional embodiment provided in the present application, since the engine and the main generator are coaxial, the speed Ω of the main generator can be obtained by differentiating the position signal fed back by the sensor on the engine bearing. m .

[0031] S202: Calculate the excitation current required by the current load and the no-load excitation current according to the load power, engine speed and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter.

[0032] In the electric excitation three-stage power generation system, the load power P outThe effective value of the voltage at the load end, U rms and the effective value of the current at the load end I rms The target effective phase voltage U at the output is calculated by multiplying. ref is the reference voltage set in the controller and is a known quantity.

[0033] Motor parameters of the main generator: armature winding resistance R s , direct-axis inductance L d , armature excitation mutual inductance L md , Excitation winding resistance R f , number of pole pairs p g It is a known quantity and is determined during motor design.

[0034] Motor parameters of the main exciter: armature winding resistance R es , direct-axis inductance L ed , armature excitation mutual inductance L emd , Excitation winding resistance R esf , number of pole pairs p eg It is a known quantity and is determined during motor design.

[0035] Engine speed Ω m It is calculated by the differential sampling of the position sensor and is a known quantity.

[0036] Specifically, the excitation current required by the current load is calculated using the following formula, which represents the relationship between the main exciter excitation current of the three-stage electrically excited power generation system and the load power of the power generation system, the engine speed, and the target phase voltage of the main generator:

[0037] Among them, i ef is the excitation current required by the current load, L emd The armature excitation mutual inductance of the main exciter, L md The armature excitation mutual inductance of the main generator, U ref For a given reference voltage, p g The number of pole pairs of the main generator, Ω m The engine speed of the main generator, P out is the load power of the main generator, L d is the direct-axis inductance of the main generator, R f The excitation winding resistance of the main generator, p eg The number of pole pairs of the main exciter, L ed The direct-axis inductance of the main exciter.

[0038] The generator does not output power under no-load condition, so the load power P out According to the above formula, the excitation current expression under no-load condition can be obtained:

[0039] Among them, i ef0 is the no-load excitation current.

[0040] S203: Determine a feedforward excitation current according to the excitation current required by the current load and the no-load excitation current.

[0041] In the present invention, in order to improve the system's responsiveness to load changes, the feedforward quantity is the change in excitation current, that is, the difference between the excitation current required by the current load power and the no-load excitation current. The feedforward excitation current formula can be obtained by subtracting the excitation current required by the current load from the no-load excitation current:

[0042] The excitation current derivation formula simplified from the above formula deviates from the actual excitation current, so an error compensation coefficient k is introduced into the above formula. The relationship expression can be simplified as: Δi ef =f(P out ,Ω m ,U ref )

[0043] in,

[0044] The relationship between the excitation current of the main exciter of the three-stage electric excitation power generation system and the load power of the power generation system, the engine speed and the target phase voltage of the main generator.

[0045] In this embodiment, a functional relationship between generator output power, motor speed, a given reference voltage, and excitation current is established through parameter selection and theoretical derivation, eliminating the need to construct a physical test environment to establish an approximate fitting curve for the relationship between generator output voltage, motor speed, a given reference voltage, and excitation current. This embodiment takes into account the effects of generator output power, motor speed, and a given reference voltage on the excitation current. By incorporating feedforward excitation current compensation into the traditional dual closed-loop control of voltage and excitation current, the inner current loop can directly respond to load changes, rather than simply regulating through the outer voltage loop, thereby improving the dynamic performance of the variable-frequency AC generator system for electric aircraft.

[0046] An embodiment of the present invention provides a method for determining a feedforward excitation current. The method first obtains the load power, engine speed, and given reference voltage of a main generator. The method then calculates the excitation current required for the current load and the no-load excitation current based on the load power, engine speed, and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter. Finally, the method determines the feedforward excitation current based on the excitation current required for the current load and the no-load excitation current. The method calculates the feedforward excitation current by taking into account the effects of the main generator's load power, engine speed, and given reference voltage on the excitation current. This feedforward excitation current is added to the traditional dual closed-loop control of voltage and excitation current. By introducing feedforward excitation current compensation, the inner current loop can directly and quickly respond to load changes, rather than simply adjusting through the outer voltage loop. Consequently, the method can improve the dynamic performance of a variable-frequency AC generator system for an electric aircraft.

[0047] The following is the feedforward excitation current Δi ef Derivation process of calculation formula:

[0048] The output voltage of the aircraft three-stage generator is controlled by the excitation current of the main exciter. The permanent magnet exciter is an uncontrollable part and can be regarded as the power supply of the generator controller. The mathematical model of the electromagnetic generator undergoes Clarke transformation and Parker transformation, and its flux equation and voltage equation are shown as (1) and (2):

[0049] Among them, i in the magnetic flux equation (1) d 、i q 、i0、i f 、i D 、i Q They are direct-axis current, quadrature-axis current, zero-axis current, excitation current, direct-axis damping winding current, and quadrature-axis damping winding current; ψ d , ψ q , ψ0, ψ f , ψ D , ψ Q is the direct-axis flux, quadrature-axis flux, zero-axis flux, excitation flux, direct-axis damping winding flux, and quadrature-axis damping winding flux; L d 、L q , L0, L f 、L D 、L Q 、L df 、L dD 、L fD 、L qQThey are: direct-axis inductance, quadrature-axis inductance, zero-axis inductance, excitation inductance, direct-axis damping winding inductance, quadrature-axis damping winding inductance, mutual inductance between direct-axis winding and excitation winding, mutual inductance between direct-axis winding and direct-axis damping winding, mutual inductance between excitation winding and damping winding, and mutual inductance between quadrature-axis winding and damping winding.

[0050] In the voltage equation (2), p is the time differential factor, ω is the electrical angular velocity, and u is d 、u q 、u0、u f are the direct-axis voltage, quadrature-axis voltage, zero-axis voltage and excitation winding voltage, r, r f 、r D 、r Q are the armature winding resistance, field winding resistance, direct-axis damping winding resistance, and quadrature-axis damping winding resistance.

[0051] In the dq coordinate system, its zero-axis component is usually 0, and the damping winding on the rotor only generates an induced electromotive force during the motor starting process. During synchronous rotation, the damping winding does not cut the magnetic field. If only the system response of the electromagnetic generator during synchronous rotation is observed, the damping winding can be ignored. Therefore, the zero-axis component and the damping winding component in the flux equation (1) and the voltage equation (2) can be ignored after starting. The simplified flux equation and voltage equation are shown in (3) and (4):

[0052] This application uses the load power P of the main generator out , engine mechanical speed Ω m And the main generator given reference voltage U ref Combining formulas (3) and (4), the required excitation current value under the current steady-state operating condition can be derived in detail. The difference between the required excitation current value under the current load and the excitation current value under no-load is used as the feedforward excitation current. This application takes into account the effects of the generator output power, motor speed, and a given reference voltage on the excitation current.

[0053] First, we need to establish the voltage equation. The voltage equation of the main generator can be obtained according to equations (3) and (4):

[0054] Equation (5) is the transient voltage expression of the main generator. The aircraft three-stage power generation system will only operate at high speeds, and the inductive reactance of the armature winding is significantly greater than the resistive reactance ω. g L>>R s , so the armature winding resistance term can be ignored. When the generator is in a static state, the voltage and current in the dq coordinate system remain constant, then the transient part of equation (5) Can be regarded as 0. Engine speed Ω mand the number of pole pairs of the main generator p g is a known constant, and the electrical frequency ω in equation (5) g Can be obtained by p g *Ω m Item replacement.

[0055] After the above simplification steps, equation (1) can be further simplified into the following form: d =p g Ω m L q i q u q =p g Ω m (-L d i d +L md i f ) (6)

[0056] The generator output voltage is monitored and controlled by the generator controller. When the generator is in steady state, the output voltage is stable at a constant U ref , that is, a given voltage. According to the amplitude-invariant Clarke transform, the following relationship holds:

[0057] Substituting (6) into (7), we can obtain the voltage equation:

[0058] After establishing the voltage equation (8), the next step is to establish the main generator active power equation.

[0059] Equation (9) is the expression for the active power of the motor with constant amplitude. The three-phase load of the main generator is considered a resistive load, so the active power is equal to the sum of the three-phase load power. Substituting (6) into (9), the active power equation of the main generator can be derived:

[0060] The reactive power of the main generator can be expressed by the following equation:

[0061] Since the active power of the main generator is equal to the sum of the three-phase load power, the reactive power of the main generator is 0. Substituting (6) into (11), the main generator reactive power equation can be derived:

[0062] Equations (8), (10), and (12) are the main generator voltage equation, the main generator active power equation, and the main generator reactive power equation, respectively. The three equations constitute the main generator equation group. d , quadrature axis current i q, excitation current i f is an unknown quantity. Solving the equations yields the following relationship between the main generator excitation current and load power:

[0063] Since both the main generator and the main exciter are electrically excited AC synchronous motors, the voltage equation of the main exciter is constructed similarly to that of the main generator: ed =p eg Ω m L eq i eq u eq =p eg Ω m (-L ed i ed +L emd i ef ) (14)

[0064] When the power generation system is in steady state, the current of the main generator remains constant under ideal conditions. Therefore, the excitation voltage of the main generator can be expressed by the product of the internal resistance of the excitation inductance and the excitation current: u f =R f i f (15)

[0065] In a three-stage electric excitation power generation system, the main generator excitation voltage is obtained by rectifying the three-phase voltage of the main exciter through a rotating rectifier. Therefore, the armature voltage of the main exciter satisfies the following equation:

[0066] Substituting (14) and (15) into (16), the following main exciter voltage equation can be further derived:

[0067] The expression of active power output by the main exciter is similar to that of the main generator:

[0068] The active power provided by the main exciter, that is, the power dissipated by the resistive reactance in the main generator excitation coil, follows the following equation:

[0069] Substituting (19) into (18), the equation for the active power of the main exciter can be established:

[0070] In the steady-state state of the power generation system, the excitation current of the main generator remains constant under ideal conditions. Only the resistive reactance in the excitation coil consumes power, that is, the reactive power of the main exciter can be regarded as 0. Therefore, the relevant equation for the reactive power of the main exciter is as follows:

[0071] Equations (17), (20), and (21) form the main exciter equation group. Solving the equation group, we can obtain the following expressions for the main exciter excitation current and the main generator excitation current:

[0072] Equation (22) reveals the relationship between the main exciter excitation current and the main generator excitation current. Substituting equation (13) into equation (22) yields the following relationship: ef =f(P out ,Ω m ,U ref ) (twenty three)

[0073] Formulas (23) and (24) illustrate the relationship between the excitation current of the main exciter and the load power of the power generation system, the engine speed, and the target phase voltage of the main generator. Here, formula (24) is a detailed expansion of formula (23). Based on the derivation of formula (24), the load power P of the power generation system fed back by the sensor can be out 、Current engine speedΩ m , and the main generator target effective phase voltage U set by the controller ref , calculate the excitation current of the main exciter in the steady state under the current working conditions.

[0074] Since there are simplified steps in the derivation of formula (24), the result of (24) will deviate from the actual excitation current. In order to compensate for the deviation between formula (24) and the actual value, a compensation coefficient k is introduced, and the excitation current formula can be expressed as:

[0075] It can be seen that under no-load conditions, P in formula (25) out If the term is 0, the excitation current required at no load can be expressed by the following equation:

[0076] In the new excitation current feedforward method proposed in this article, in order to improve the system's responsiveness to load changes, the feedforward amount is the change in excitation current, that is, the difference between the excitation current required by the current load power and the no-load excitation current. The feedforward excitation current can be obtained by subtracting formulas (25) and (26):

[0077] Figure 3 shows a comparison of the excitation current derived from Equation (27) and the simulation data at 18,000 rpm. The calculated data in Figure 3 is the excitation current data derived from Equation (27). It can be observed that the calculated excitation current is lower than the simulation data because the resistance of the motor winding is ignored in the derivation of the formula. However, once a compensation coefficient is introduced to correct the excitation current calculated by Equation (27), the resulting data is almost completely consistent with the simulation data, thus ensuring high accuracy.

[0078] Figure 4 shows a simulated output voltage curve for a system with feedforward excitation current, as the load increases from half to full load in 0.5 seconds, compared with the output voltage curve for a system without feedforward excitation current. As can be seen from the figure, feedforward excitation current technology can significantly accelerate system response, shorten the duration of undervoltage under load, and improve system performance.

[0079] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0080] In one embodiment, a device for determining a feedforward excitation current is provided. The device for determining a feedforward excitation current corresponds one-to-one with the method for determining a feedforward excitation current in the above embodiment. As shown in FIG5 , the functional modules of the device for determining a feedforward excitation current are described in detail as follows:

[0081] The sampling module 51 is used to obtain the load power, engine speed and given reference voltage of the main generator;

[0082] a calculation module 52 for calculating the excitation current required by the current load and the no-load excitation current according to the load power, engine speed and given reference voltage of the main generator, as well as the motor parameters of the main generator and the motor parameters of the main exciter;

[0083] The determination module 53 is configured to determine the feedforward excitation current according to the excitation current required by the current load and the no-load excitation current.

[0084] In an optional embodiment provided by the present invention, the calculating of the excitation current required by the current load according to the load power, engine speed, and given reference voltage of the main generator, as well as motor parameters of the main generator and motor parameters of the main exciter, includes:

[0085] Calculate the excitation current required by the current load using the following formula:

[0086] Among them, i ef is the excitation current required by the current load, L emdThe armature excitation mutual inductance of the main exciter, L md The armature excitation mutual inductance of the main generator, U ref For a given reference voltage, p g The number of pole pairs of the main generator, Ω m The engine speed of the main generator, P out is the load power of the main generator, L d is the direct-axis inductance of the main generator, R f The excitation winding resistance of the main generator, p eg The number of pole pairs of the main exciter, L ed The direct-axis inductance of the main exciter.

[0087] In an optional embodiment provided by the present invention, the no-load excitation current is calculated by the following formula:

[0088] Among them, i ef0 is the no-load excitation current.

[0089] In an optional embodiment provided by the present invention, the feedforward excitation current is calculated by the following formula:

[0090] Where k is the error compensation coefficient.

[0091] In an optional embodiment provided by the present invention, the rotational speed of the main generator is obtained by differentiating a position signal fed back by a sensor on an engine bearing.

[0092] In an optional embodiment provided by the present invention, the load power of the main generator is calculated by multiplying the effective value of the voltage at the load end and the effective value of the current at the load end.

[0093] The specific definition of the feedforward excitation current determination device can be found in the definition of the feedforward excitation current determination method described above and will not be repeated here. Each module in the above-mentioned device can be implemented in whole or in part through software, hardware, or a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the computer device in hardware form, or can be stored in the memory of the computer device in software form, so that the processor can call and execute the corresponding operations of each of the above modules.

[0094] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0095] Those skilled in the art will clearly understand that for the sake of convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0096] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for determining a feedforward excitation current, characterized in that The method is applied to a three - stage electro - excited power generation system of an aircraft. The system includes a main generator, a main exciter, a permanent - magnet generator, a rotating rectifier, a generator controller, and a device for determining the feed - forward excitation current. The device for determining the feed - forward excitation current is used to execute the method for determining the feed - forward excitation current. The method includes: Obtain the load power of the main generator, the engine speed, and the given reference voltage; Calculate the excitation current required for the current load and the no - load excitation current according to the load power of the main generator, the engine speed, the given reference voltage, the motor parameters of the main generator, and the motor parameters of the main exciter; Determine the feed - forward excitation current according to the excitation current required for the current load and the no - load excitation current.

2. The method according to claim 1, wherein The calculation of the excitation current required for the current load according to the load power of the main generator, the engine speed, the given reference voltage, the motor parameters of the main generator, and the motor parameters of the main exciter includes: Calculate the exciting current required for the current load through the following formula: where i ef is the exciting current required for the current load, L emd is the armature exciting mutual inductance of the main exciter, L md is the armature exciting mutual inductance of the main generator, U ref is the given reference voltage, p g is the number of pole pairs of the main generator, Ω m is the engine speed of the main generator, P out is the load power of the main generator, L d is the direct-axis inductance of the main generator, R f is the exciting winding resistance of the main generator, p eg is the number of pole pairs of the main exciter, L ed is the direct-axis inductance of the main exciter.

3. The method according to claim 2, wherein The calculation of the no - load excitation current according to the load power of the main generator, the engine speed, the given reference voltage, the motor parameters of the main generator, and the motor parameters of the main exciter includes: The no-load exciting current is calculated by the following formula: where i ef0 is the no-load exciting current.

4. The method according to claim 3, wherein The determination of the feed - forward excitation current according to the excitation current required for the current load and the no - load excitation current includes: Calculate the feedforward excitation current using the following formula: where k is an error compensation coefficient.

5. The method according to claim 2, characterized in that, The method further includes: Differentiate the position signal fed back by the sensor on the engine bearing to obtain the speed of the main generator.

6. The method according to claim 2, wherein The method further includes: Calculate the load power of the main generator by multiplying the effective value of the voltage at the load end and the effective value of the current at the load end.

7. A three-stage electric excitation power generation system for an aircraft, characterized in that, The system includes a main generator, a main exciter, a permanent - magnet generator, a rotating rectifier, a generator controller, and a device for determining the feed - forward excitation current. The device for determining the feed - forward excitation current includes: A sampling module for obtaining the load power of the main generator, the engine speed, and the given reference voltage; A calculation module for calculating the excitation current required for the current load and the no - load excitation current according to the load power of the main generator, the engine speed, the given reference voltage, the motor parameters of the main generator, and the motor parameters of the main exciter; A determination module for determining the feed - forward excitation current according to the excitation current required for the current load and the no - load excitation current.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for determining the feed - forward excitation current according to any one of claims 1 to 6.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for determining the feed - forward excitation current according to any one of claims 1 to 6.

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