A sensorless aviation three-stage motor starting control method

Abstract

The present application belongs to the field of aviation motor control technology, and particularly relates to a position sensor-free aviation three-stage motor starting control method, the method comprising: performing the initial motor starting when the motor is stationary, applying the excitation voltage according to the stationary starting voltage application method, and starting the three-stage motor through the id=0 control strategy; after the aviation three-stage motor accelerates to the set speed, the motor is decelerated; before the motor speed drops to zero, the motor starting instruction is given again, and the switching time is determined. Before the switching time arrives, the rotor position and speed required for the operation process are obtained through the mechanical position sensing system, and the rotor position and speed are estimated through the sliding mode observer. After the switching time, the rotor position and speed required for the operation process are switched to the position given by the sliding mode observer. The present application combines the mechanical position sensing system with the rotor position estimation method based on the sliding mode observer to realize the control method of position-free starting of the aviation three-stage motor in the medium and high speed sections.

Description

Technical Field

[0001] The present application belongs to the field of aviation motor control technology, and in particular relates to an aviation three-stage motor starting control method based on position sensorless technology. Background Art

[0002] With the gradual promotion of the concept of multi- / all-electric aircraft, the domestic aviation three-stage motor starting / generating function integration technology has made substantial breakthroughs. The aviation three-stage motor (hereinafter referred to as the three-stage motor) is mainly composed of a main generator, an exciter, a permanent magnet machine and a rotating rectifier. The rotor is coaxially installed with the rotating rectifier. The structural diagram of the three-stage starting and generating system when the exciter stator adopts a single-phase winding structure is shown in the figure. Figure 1 As shown. In the starting mode, the onboard battery provides AC excitation voltage for the exciter, and the AC excitation voltage induces three-phase AC in the exciter rotor. The three-phase current generated is rectified by the rotating rectifier to provide excitation current for the main generator. The excitation current interacts with the stator magnetic field of the main generator to generate power torque, which drives the engine to ignite and start. The permanent magnet machine does not participate in the starting process; in the power generation mode, the engine drives the three-stage motor to rotate, and the rotating permanent magnet machine rotor generates an induced potential in its stator winding. The three-phase voltage formed is regulated by the power generation controller and then provided by the exciter and rotating rectifier to the main generator. DC excitation, thereby realizing the power generation function of the main generator.

[0003] Due to the complex environment in which the engine is located, when the wind acts on the engine to drive the motor to rotate, or when the engine needs to be quickly restarted after a sudden stop in the air, the motor needs to start the aircraft engine when the speed is not zero. The harsh electromagnetic and space environment during the starting process puts the traditional mechanical position sensing system to the test when the motor is running at medium and high speeds. When the motor starts with speed, the traditional full-speed position-free control method based on the combination of high-frequency injection method (low speed section) and back-EMF method (medium and high speed sections) will no longer be applicable. Summary of the invention

[0004] In order to improve the stability of motor operation, it is necessary to combine the mechanical position sensing system with the rotor position estimation method, and complete the rapid switching from the mechanical position sensing system control to the position-free system control after the motor starts with speed, so as to realize the reliable operation of the three-stage motor in the medium and high speed sections. The present application proposes a control method for realizing the position-free starting of the aviation three-stage motor in the medium and high speed sections by combining a mechanical position sensing system with a rapid rotor position estimation method based on a sliding mode observer. This method reduces the electromagnetic interference of the power signal to the position sensing system by temporarily reducing the output power of the controller, and at the same time uses the sliding mode observer to quickly estimate the motor rotor position. When the rotor position estimation is completed, the controller runs at full capacity, and controls the motor to drag the aircraft engine to the disengagement speed through the id=0 control algorithm based on the position-free sensor to complete the engine ignition and start.

[0005] The present application provides an aviation three-stage motor starting control method based on a position sensorless system, which mainly includes:

[0006] Step S1, when the motor is in a stationary state, a motor start command is given to start the motor for the first time, an excitation voltage is applied according to the stationary starting voltage application method, and the three-stage motor is started by the id=0 control strategy. The stator voltage and current of the main generator required in the starting control process are respectively collected in real time by the voltage sensor and the current sensor. The rotor position and speed required in the low-speed operation process are obtained by the mechanical position sensor system. The rotor position and speed required in the medium-high speed operation process are given by the sliding mode observer. The low-speed section and the medium-high speed section are given by the given speed n. ed distinguish;

[0007] Step S2, after the aviation three-stage motor is accelerated to a set speed, a motor stop start instruction is given to decelerate the motor;

[0008] Step S3, before the motor speed drops to zero, the motor start command is given again, the motor is started for the second time, and the switching time is determined. Before the switching time is reached, the rotor position and speed required for the operation process are obtained through the mechanical position sensing system, and the rotor position and speed are estimated by the sliding mode observer. After the switching time, the rotor position and speed required for the operation process are switched to those given by the sliding mode observer. During the second starting process, the excitation voltage is applied in a dynamic starting voltage application manner, and the integral is initialized by the set q-axis current PI regulator integral initial value.

[0009] Preferably, determining the rotor position and speed by the sliding mode observer comprises:

[0010] Step S11, construct a sliding mode observer as shown below:

[0011]

[0012] in, To estimate the speed, R s is the stator phase resistance of the main generator, L d , L q are the d-axis and q-axis inductances of the main generator stator, The estimated current of α and β axes in the αβ coordinate system of the main generator stator, u α 、u α is the equivalent terminal voltage of α and β axes in the αβ coordinate system of the main generator stator, To estimate the back EMF of the α and β axes of the main generator stator in the αβ coordinate system, the αβ coordinate system is obtained by CALRK transformation of the ABC coordinate system. α 、f β is the switching function, and its expression is as follows:

[0013]

[0014]

[0015] Among them, k α , k β is the constant coefficient, Δi is the error control range;

[0016] Step S12: Integrate the variables on both sides of the constructed sliding mode observer to obtain the estimated current of the α and β axes in the αβ coordinate system.

[0017] Step S13: Subtract the estimated current value of the α and β axes in the αβ coordinate system from the actual current value, and bring the difference into the switching function in step S11 Perform calculations and perform low-pass filtering on the calculation results to obtain the estimated back EMF of the α and β axes in the αβ coordinate system.

[0018] Step S14: normalize the estimated back EMF and process the normalized estimated back EMF with a phase-locked loop to obtain an estimated rotor position. and estimated speed

[0019] Preferably, in step S1, the given speed n ed It is 200r / min.

[0020] Preferably, in step S2, the set rotation speed is 1500 r / min.

[0021] Preferably, the static starting voltage application method includes:

[0022] The voltage amplitude changes during the setting start process are as follows:

[0023]

[0024] Among them, n e1 、n e2 are the switching values ​​for different speed sections, n N is the motor disengagement speed, U meN is the maximum excitation voltage amplitude;

[0025] When the motor starts at rest, the excitation voltage of the exciter increases in a ramp manner, as shown in the following formula:

[0026]

[0027] Among them, t 1 Switch value for the first time period.

[0028] Preferably, the first time period switching value is 2s.

[0029] Preferably, the dynamic starting voltage application method includes:

[0030] The voltage amplitude changes during the setting start process are as follows:

[0031]

[0032] Among them, n e1 、n e2 are the switching values ​​for different speed sections, n N is the motor disengagement speed, U meN is the maximum excitation voltage amplitude;

[0033] When the motor is started dynamically, the excitation voltage of the exciter changes as shown in the following formula:

[0034]

[0035] Among them, t′ 1 , t′ 2 are the switching values ​​of the second time period and the third time period respectively, k me is a constant coefficient between 0 and 1.

[0036] Preferably, the switching value of the second time period is 0.7s, the switching value of the third time period is 0.75s, and k me is 0.35.

[0037] Preferably, the q-axis current PI regulator integral initial value includes:

[0038] When the motor starts from a standstill, the initial value of the integral is 0; when the motor starts with a speed, the initial value of the integral is U q_I =Umg0 +k mg U mgN n e , where k mg is a constant coefficient between 0 and 1, U mgN is the rated operating voltage of the motor, U mg0 is a constant value, n e is the real-time speed of the motor obtained by the mechanical position sensing system. The motor static start and belt speed start are determined by the given speed n ed Determine that when the motor starts with a speed, the starting speed is greater than or equal to the given speed n ed .

[0039] Preferably, in step S3, the switching time is 0.7 s.

[0040] The present application estimates the rotor position quickly by adjusting the excitation voltage and the initial value of the q-axis current PI adjustment machine integral, thereby realizing position sensorless control in the medium and high speed sections of the motor belt speed (200r / min~2000r / min), and improving the reliability of the starting control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a structural diagram of a three-stage starting and generating system when the exciter stator adopts a single-phase winding.

[0042] Figure 2 is the motor load characteristic curve.

[0043] Figure 3 It is the control block diagram of the motor starting process. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0045] The present application provides a method for controlling the starting of an aviation three-stage motor based on a position sensorless system. When the motor speed is not zero, the method combines a mechanical position sensing system with a rotor position estimation method based on a sliding mode observer to achieve a control method for starting the aviation three-stage motor in the medium and high speed sections without a position. Figure 1-Figure 3 As shown, it contains the following steps in sequence:

[0046] Step 1: Estimate the rotor position and speed of the motor in the medium and high speed range using the rotor position estimation method based on the sliding mode observer, as follows:

[0047] 1.1) The sliding mode observer is constructed as shown below:

[0048]

[0049] in, To estimate the speed, R s is the stator phase resistance of the main generator, L d , L q are the d-axis and q-axis inductances of the main generator stator, The estimated current of α and β axes in the αβ coordinate system of the main generator stator, u α 、u α is the equivalent terminal voltage of α and β axes in the αβ coordinate system of the main generator stator, To estimate the back EMF of the α and β axes of the main generator stator in the αβ coordinate system, the αβ coordinate system is obtained by CALRK transformation of the ABC coordinate system. α 、f β is the switching function, and its expression is as follows:

[0050]

[0051]

[0052] Among them, k α , k β is a constant coefficient, and Δi is the error control range.

[0053] In a specific embodiment, the stator resistance of the main generator R s =0.00954Ω, the stator d-axis and q-axis inductances of the main generator are L d =0.00047H,L q =0.00032H, constant coefficient k α =k β =250, Δi=20.

[0054] 1.2) Integrate the variables on both sides of the sliding mode observer constructed in step 1.1) to obtain the estimated current of the α and β axes in the αβ coordinate system:

[0055] 1.3) Subtract the estimated current values ​​of the α and β axes in the αβ coordinate system from the actual current values, and bring the differences into the switching function in step 1.1) Perform calculations and perform low-pass filtering on the calculation results to obtain the estimated back EMF of the α and β axes in the αβ coordinate system.

[0056] In a specific embodiment, a first-order linear low-pass filter is used for processing, and the low-pass filter coefficient used is 0.2.

[0057] 1.4) The estimated back EMF obtained in step 1.3) is normalized, and the processing process is as follows:

[0058]

[0059] 1.5) Use a phase-locked loop to process the normalized estimated back EMF obtained in step 1.4) to obtain the estimated rotor position and estimated speed

[0060] Step 2: Set the starting process relationship as follows:

[0061]

[0062] Among them, n e1 、n e2 are the switching values ​​for different speed sections, n N is the motor disengagement speed, U meN is the maximum excitation voltage amplitude.

[0063] In a specific embodiment, n e1 =2000r / min, n e2 =3428r / min, n N =4000r / min, U meN =210V.

[0064] When the motor starting mode is different, the amplitude is applied in different ways, as follows:

[0065] 2.1) When the motor starts at rest, the excitation voltage amplitude of the exciter increases in a ramp manner, as shown in the following formula:

[0066]

[0067] 2.2) When the motor is dynamically started, the excitation voltage of the exciter changes as shown in the following formula:

[0068]

[0069] Among them, t 1 , t′ 1 , t′ 2 Switching values ​​for different time periods, k me is a constant coefficient between (0,1).

[0070] In a specific embodiment, t 1 =2s, t′ 1 =0.7s, t′ 2 =0.75s, k me =0.35.

[0071] Step 3: Set the initial value of the integral of the q-axis current PI regulator during the starting process. When the motor starts from a standstill (the starting speed is less than n ed ), the initial value of the integral is 0; when the motor starts with a speed (the starting speed is greater than or equal to n ed ), the initial value of the integral is U q_I =U mg0 +k mg U mgN n e , where k mg is a constant coefficient between (0, 1), U mgN is the rated operating voltage of the motor, U mg0 is a constant value, n e is the real-time motor speed obtained through the mechanical position sensing system, n ed It is the boundary value for judging the motor starting mode.

[0072] In a specific embodiment, k mg =0.05, U mg0 =60V, U mgN =270V, n ed =200r / min.

[0073] Step 4: When the motor is stationary, give the motor start command, apply the excitation voltage to the exciter according to step 2, the excitation frequency is 200Hz, start the three-stage motor through the id=0 control strategy, and the stator voltage and current of the main generator required during the starting control process are collected in real time through the voltage sensor and the current sensor respectively. ed , for example 200r / min) the rotor position and speed required for the operation process are obtained through the mechanical position sensing system, and the medium and high speed (speed greater than or equal to n ed The rotor position and speed required for the operation of the first stage are obtained by the method described in step 1.

[0074] Step 5: When the motor accelerates to a certain speed, such as 1500r / min, a motor stop start command is given, the motor stops accelerating, and slowly decelerates under the combined effect of load inertia and friction.

[0075] Step 6: Before the motor speed drops to zero, give the motor start command again to determine the motor start speed (800r / min in this example), and give the initial value of the excitation voltage and q-axis current PI regulator integral according to the start time, as follows:

[0076] 6.1) When the starting time is less than t' 1 When, for example, 0.7s, the rotor position information is obtained through the mechanical position sensing system, and the motor rotor position is estimated according to step 1 for subsequent use. During the starting process, the excitation voltage and the initial value of the integral are given according to steps 2 and 3;

[0077] 6.2) When the starting time is greater than t' 1 During the starting process, the rotor position information is obtained according to step 1, and the excitation voltage is given according to step 2.

[0078] Step 7: Continue to obtain rotor position information according to step 1, use id=0 control strategy to complete the subsequent starting acceleration process, and drive the engine to reach the disengagement speed.

[0079] From the simulation waveforms of the estimated position and estimated speed at starting with belt speeds of 1200r / min and 2000r / min, it can be seen that the rotor position estimation error is within 0.05rad, and the speed estimation error is basically within 15r / min, which meets the rotor position accuracy and speed accuracy requirements of the three-stage motor starting stage under actual conditions.

[0080] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for starting and controlling an aviation three-stage motor based on a position sensorless system, characterized in that: include: Step S1, when the motor is in a stationary state, a motor start command is given to start the motor for the first time, an excitation voltage is applied according to the stationary starting voltage application method, and the three-stage motor is started by the id=0 control strategy. The stator voltage and current of the main generator required in the starting control process are respectively collected in real time by the voltage sensor and the current sensor. The rotor position and speed required in the low-speed operation process are obtained by the mechanical position sensor system. The rotor position and speed required in the medium-high speed operation process are given by the sliding mode observer. The low-speed section and the medium-high speed section are given by the given speed n. ed distinguish; Step S2, after the aviation three-stage motor is accelerated to a set speed, a motor stop start instruction is given to decelerate the motor; Step S3, before the motor speed drops to zero, the motor start command is given again, the motor is started for the second time, and the switching time is determined. Before the switching time is reached, the rotor position and speed required for the operation process are obtained through the mechanical position sensing system, and the rotor position and speed are estimated by the sliding mode observer. After the switching time, the rotor position and speed required for the operation process are switched to those given by the sliding mode observer. During the second starting process, the excitation voltage is applied in a dynamic starting voltage application mode, and the integral is initialized by setting the initial integral value of the q-axis current PI regulator; Wherein, determining the rotor position and speed by the sliding mode observer includes: Step S11, construct a sliding mode observer as shown below: in, To estimate the speed, R s is the stator phase resistance of the main generator, L d , L q are the d-axis and q-axis inductances of the main generator stator, The estimated current of α and β axes in the αβ coordinate system of the main generator stator, u α 、u β is the equivalent terminal voltage of α and β axes in the αβ coordinate system of the main generator stator, To estimate the back EMF of the α and β axes of the main generator stator in the αβ coordinate system, the αβ coordinate system is obtained by CALRK transformation of the ABC coordinate system. α 、f β is the switching function, and its expression is as follows: Among them, k α , k β is the constant coefficient, △i is the error control range; Step S12: Integrate the variables on both sides of the constructed sliding mode observer to obtain the estimated current of the α and β axes in the αβ coordinate system. Step S13: compare the estimated current value and the real current value i of the α and β axes in the αβ coordinate system α 、i β Make a difference and bring the difference into the switching function in step S11 Perform calculations and perform low-pass filtering on the calculation results to obtain the estimated back EMF of the α and β axes in the αβ coordinate system. Step S14: normalize the estimated back EMF and process the normalized estimated back EMF with a phase-locked loop to obtain an estimated rotor position. and estimated speed The static starting voltage application method includes: The voltage amplitude changes during the setting start process are as follows: Among them, n e1 、n e2 are the switching values ​​for different speed sections, n N is the motor disengagement speed, U meN is the maximum excitation voltage amplitude, n e The real-time speed of the motor is obtained through the mechanical position sensing system; When the motor starts at rest, the excitation voltage of the exciter increases in a ramp manner, as shown in the following formula: Among them, t1 is the switching value of the first time period, and t is the running time; The dynamic starting voltage application method includes: The voltage amplitude changes during the setting start process are as follows: Among them, n e1 、n e2 are the switching values ​​for different speed sections, n N is the motor disengagement speed, U meN is the maximum excitation voltage amplitude; When the motor is started dynamically, the excitation voltage of the exciter changes as shown in the following formula: Among them, t1′ and t2′ are the switching values ​​of the second time period and the third time period respectively, k me is a constant coefficient between 0 and 1; The q-axis current PI regulator integral initial value includes: When the motor starts from a standstill, the initial value of the integral is 0; when the motor starts with a speed, the initial value of the integral is U q_I =U mg0 +k mg U mgN n e , where k mg is a constant coefficient between 0 and 1, U mgN is the rated operating voltage of the motor, U mg0 is a constant value, the motor static start and belt speed start are determined by the given speed n ed Determine that when the motor starts with a speed, the starting speed is greater than or equal to the given speed n ed .

2. The position sensorless aviation three-stage motor starting control method according to claim 1, characterized in that: In step S1, the given speed n ed It is 200r / min.

3. The position sensorless aviation three-stage motor starting control method according to claim 1, characterized in that: In step S2, the set rotation speed is 1500r / min.

4. The position sensorless aviation three-stage motor starting control method according to claim 1, characterized in that: The switching value of the first time period is 2s.

5. The position sensorless aviation three-stage motor starting control method according to claim 1, characterized in that: The switching value of the second time period is 0.7s, and the switching value of the third time period is 0.75s. me is 0.

35.

6. The position sensorless aviation three-stage motor starting control method according to claim 1, characterized in that: In step S3, the switching time is 0.7s.

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