Position-sensorless control method and system for doubly salient electro-magnetic generator

Abstract

The invention discloses a position-sensorless control method and system for an electro-magnetic doubly salient generator, and belongs to the technical field of motor control. The method comprises excitation control and armature control, the excitation control maintains the DC bus voltage stable through a voltage and current regulator closed loop, and the armature control only detects A and B phase voltages; according to the method, an electric cycle is divided into three sectors, the sectors correspond to different conduction switch tubes, the sectors are judged by calculating the two-phase voltage difference value in real time and according to threshold logic, the corresponding switch tubes are triggered to be combined and conducted according to the judgment result of the sectors, and a current loop is managed by combining the diode clamping effect. Meanwhile, DC bus voltage is continuously monitored for excitation dynamic adjustment, and a sector state flag bit is utilized to ensure synchronization of rotor position tracking and switch action; according to the method, the position of the rotor sector is mapped through the two-phase voltage difference value, a position sensor and a current sampling circuit are omitted, the complexity and cost of the system are reduced, and the control precision and the anti-interference capability are both considered.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and particularly to a sensorless control method and system for an electro-excited doubly salient generator. Background Art

[0002] The electro-excited doubly salient generator is developed on the basis of the switched reluctance motor. It has neither permanent magnets nor excitation windings on the rotor, and has the advantages of simple structure, controllable excitation and high reliability. The electro-excited doubly salient generator generally adopts an uncontrolled rectifier power generation method, and only needs to control the excitation current to achieve output voltage control. It has the advantages of simple structure and no need for a position sensor, but it cannot control the armature current and has a low output power.

[0003] In recent years, in order to further improve the electromechanical energy conversion efficiency of the electro-excited doubly salient generator, the controlled rectifier power generation method has received extensive attention. It realizes further optimization of the motor performance by coordinating the control of the excitation current and the armature current at the same time. However, the controlled rectifier power generation method requires rotor position information to control the armature current, and the mechanical position sensor has the disadvantages of large volume, inconvenient installation and easy failure. Therefore, the research on the sensorless technology applicable to the electro-excited doubly salient generator is of great significance for promoting the application of the controlled rectifier power generation technology in the electro-excited doubly salient generator.

[0004] At present, the research on the sensorless technology of the electro-excited doubly salient generator is still in its infancy, and two documents have been retrieved. "Sensorless control method for electro-excited doubly salient generator based on phase current gradient" published by Zhou Xingwei et al. (patent for invention, publication number: CN 118713515A, publication date: September 27, 2024). The implementation of this method requires the use of three current sensors, which additionally increases the hardware circuit, and this method needs to calculate the current electrical angle, which will accumulate calculation errors.

[0005] "Control method and system for sensorless electro-excited doubly salient generator" published by Zhang Minghui et al. (patent for invention, announcement number: CN 115208256B, announcement date: April 21, 2023). The implementation of this method requires the use of three voltage sensors, which additionally increases the hardware circuit; this method needs to calculate the current electrical angle, which will accumulate calculation errors. Summary of the Invention

[0006] The object of the present invention is to overcome the defects in the above background art. The present invention proposes a sensorless control method and system for an electro-excited doubly salient generator. The method maps the rotor sector position through the difference between two-phase voltages, eliminating the position sensor and the current sampling circuit, reducing the system complexity and cost, and taking into account the control accuracy and anti-interference ability.

[0007] The present invention adopts the following technical solutions to solve the above technical problems:

[0008] A sensorless control method and system for an electric excitation doubly salient generator include:

[0009] A sensorless control method for an electric excitation doubly salient generator includes the following steps:

[0010] Step S1: The excitation control maintains the stability of the DC bus voltage through the closed-loop of the voltage and current regulators. The armature control detects the voltages of phases A and B to determine the sector status flag, thereby determining the sector.

[0011] Step S2: Divide the electrical cycle into three sectors and determine the conduction conditions of the switching tubes in each sector.

[0012] Step S3: Analyze the conduction interval of sector 1 and the characteristics of the phase voltage and output voltage within this interval.

[0013] Step S4: Analyze the conduction interval of sector 2 and the characteristics of the phase voltage and output voltage within this interval.

[0014] Step S5: Analyze the conduction interval of sector 3 and the characteristics of the phase voltage and output voltage within this interval.

[0015] Step S6: Obtain the sector flag based on the analysis in steps S1 to S5.

[0016] Step S7: Determine the correspondence between the sector flag, the sector, and the conduction conditions of the switching tubes.

[0017] Further, the excitation control in step S1 is specifically as follows:

[0018] In the excitation winding control link, the voltage regulator generates a reference excitation current i ref based on the error between the reference DC bus voltage U o and the rectified DC bus voltage U fref ; the excitation current regulator generates a duty cycle D based on the error between the reference excitation current i fref and the actual excitation current; then, the asymmetrical half-bridge converter is controlled through the drive signal generator.

[0019] Further, the armature control in step S1 is specifically as follows:

[0020] In the armature winding control link, the voltage value u a of phase A and the voltage value u b of phase B of the controllable bridge rectifier are detected, and the sector status flag within one electrical cycle is determined, thereby determining the sector where the rotor is currently located.

[0021] Further, the specific steps of step S2 are as follows:

[0022] Within one electrical cycle, define 0° - 120° as sector 1, 120° - 240° as sector 2, and 240° - 360° as sector 3; then the conduction logic of the electrically excited doubly salient generator controlled rectifier system within one electrical cycle is:

[0023] Within sector 1, control T2 and T3 of the controllable bridge rectifier to conduct;

[0024] Within sector 2, control T4 and T5 of the controllable bridge rectifier to conduct;

[0025] Within sector 3, control T1 and T6 of the controllable bridge rectifier to conduct.

[0026] Further, the specific steps of step S3 are as follows:

[0027] Within sector 1, θ p is the commutation angle at which the C-phase current value i c changes from negative to positive, and θ n is the commutation angle at which the B-phase current value i b changes from positive to negative; therefore, sector 1 can be divided into a [0°, θ p conduction interval, a [θ p , θ n conduction interval, and a [θ n , 120°] conduction interval; due to the small internal resistance of the armature winding, the phase voltage is approximately equal to the phase winding induced electromotive force;

[0028] Within the [0°, θ p conduction interval, the A-phase current value i a < 0, the B-phase current value i b > 0, the C-phase current value i c < 0. Although T2 and T3 are turned on, since the B-phase current value i b and the C-phase current value i c have not completed commutation, they are reverse clamped by D2 and D3; the current path is: B-phase winding → D3 → load R → D4 → A-phase winding → B-phase winding; B-phase winding → D3 → load R → D2 → C-phase winding → B-phase winding; according to Kirchhoff's voltage law, we can obtain:

[0029] u a -u b =-u o , u a -u c =0

[0030] In the formula, u p (p = a, b, c) is the phase voltage value, and u o is the output voltage value;

[0031] In the conduction interval of [θ p , θ n , the current value of phase A, i a < 0, the current value of phase B, i b > 0, the current value of phase C, i c > 0, T2 and T3 are turned on. However, since the commutation of the current value of phase B, i b has not been completed, T3 is reverse clamped by D3; the current path is: phase C winding → T2 → D4 → phase A winding → phase C winding; phase B winding → D3 → load R → D4 → phase A winding → phase B winding; according to Kirchhoff's voltage law, the voltage equation can be obtained, which is the same as that in the conduction interval of [0°, θ p ;

[0032] In the conduction interval of [θ n , 120°], the current value of phase A, i a < 0, the current value of phase B, i b < 0, the current value of phase C, i c > 0, T2 and T3 are turned on; the current path is: phase C winding → T2 → D4 → phase A winding → phase C winding; phase C winding → T2 → capacitor C → T3 → phase B winding → phase C winding; according to Kirchhoff's voltage law, the voltage equation can be obtained, which is the same as that in the conduction interval of [0°, θ p ;

[0033] Therefore, in sector 1, u a – u b = -u o < 0 always holds.

[0034] Furthermore, the specific steps of step S4 are as follows:

[0035] In sector 2, θ p is the commutation angle of the current value of phase A, i a from negative to positive, and θ n is the commutation angle of the current value of phase C, i c from positive to negative; therefore, sector 2 can be divided into the conduction intervals of [120°, 120° + θ p , [120° + θ p , 120° + θ n , and [120° + θ n , 240°];

[0036] In the conduction interval of [120°, 120° + θ p , the current value of phase A, i a < 0, the current value of phase B, i b < 0, the current value of phase C, i c> 0, although T4 and T5 are turned on, since the current value i of phase A a and the current value i of phase C c has not completed commutation yet, so they are reverse clamped by D4 and D5; the current path is: phase C winding → D5 → load R → D4 → phase A winding → phase C winding; phase C winding → D5 → load R → D6 → phase B winding → phase C winding; according to Kirchhoff's voltage law, we can get:

[0037] u a -u b = 0, u c -u a = u o

[0038] In the conduction interval of [120° + θ p , 120° + θ n , the current value i of phase A a > 0, the current value i of phase B b < 0, the current value i of phase C c > 0, T4 and T5 are turned on, but since the current value i of phase C c has not completed commutation yet, so T5 is reverse clamped by D5; the current path is: phase A winding → T4 → D6 → phase B winding → phase A winding; phase C winding → D5 → load R → D6 → phase B winding → phase C winding; according to Kirchhoff's voltage law, the voltage equation can be obtained to be the same as that in the conduction interval of [120°, 120° + θ p ;

[0039] In the conduction interval of [120° + θ n , 240°], the current value i of phase A a > 0, the current value i of phase B b < 0, the current value i of phase C c < 0, T4 and T5 are turned on; the current path is: phase A winding → T4 → D6 → phase B winding → phase A winding; phase A winding → T4 → capacitor C → T5 → phase C winding → phase A winding; according to Kirchhoff's voltage law, the voltage equation can be obtained to be the same as that in the conduction interval of [120°, 120° + θ p ;

[0040] Therefore, in sector 2, u a –u b = 0 always holds.

[0041] Furthermore, the specific steps of step S5 are as follows:

[0042] In sector 3, θ p is the commutation angle at which the current value i of phase B b changes from negative to positive, and θ n is the commutation angle at which the current value i of phase A aCommutation angle from positive to negative; thus, sector 3 can be divided into [240°, 240° + θ p conduction interval, [240° + θ p , 240° + θ n conduction interval and [240° + θ n , 360°] conduction interval;

[0043] In the [240°, 240° + θ p conduction interval, the current value i of phase A a > 0, the current value i of phase B b < 0, the current value i of phase C c < 0, although T1 and T6 are turned on, but due to the current value i of phase A a and the current value i of phase B b have not completed commutation, so they are reverse clamped by D1 and D6; the current path is: phase A winding → D1 → load R → D6 → phase B winding → phase A winding; phase A winding → D1 → load R → D2 → phase C winding → phase A winding; according to Kirchhoff's voltage law, we can get:

[0044] u a -u b =u o , u b -u c =0

[0045] In the [240° + θ p , 240° + θ n conduction interval, the current value i of phase A a > 0, the current value i of phase B b > 0, the current value i of phase C c < 0, T1 and T6 are turned on, but due to the current value i of phase A a have not completed commutation, so T1 is reverse clamped by D1; the current path is: phase B winding → T6 → D2 → phase C winding → phase B winding; phase A winding → D1 → load R → D2 → phase C winding → phase A winding; according to Kirchhoff's voltage law, the voltage equation is the same as that in the [240°, 240° + θ p conduction interval;

[0046] In the [240° + θ n , 360°] conduction interval, the current value i of phase A a < 0, the current value i of phase B b > 0, the current value i of phase C c < 0, T1 and T6 are turned on; the current path is: phase B winding → T6 → D2 → phase C winding → phase B winding; phase B winding → T6 → capacitor C → T1 → phase A winding → phase B winding; according to Kirchhoff's voltage law, the voltage equation is the same as that in the [240°, 240° + θp is the same within the conduction interval;

[0047] Therefore, within sector 3, u a –u b =u o > 0 always holds.

[0048] Furthermore, the specific steps of step S6 are as follows:

[0049] Within one electrical cycle, detect the phase A voltage value u a and the phase B voltage value u b , and then the sector status flag F p is:

[0050]

[0051] In the formula, ε is the voltage threshold. To prevent misdiagnosis, ε needs to be greater than the maximum measurement error of the voltage sensor.

[0052] Furthermore, the specific steps of step S7 are as follows:

[0053] When F p = -1, it indicates that the rotor currently enters sector 1, and control the conduction of T2 and T3 of the controllable bridge rectifier;

[0054] When F p =0, it indicates that the rotor currently enters sector 2, and control the conduction of T4 and T5 of the controllable bridge rectifier;

[0055] When F p =1, it indicates that the rotor currently enters sector 3, and control the conduction of T1 and T6 of the controllable bridge rectifier.

[0056] A sensorless control system for an electric excitation doubly salient generator, which is applied to the sensorless control method of the electric excitation doubly salient generator as described in any one of claims 1 - 9. The sensorless control system for the electric excitation doubly salient generator includes:

[0057] An asymmetrical half - bridge converter module, which converts and regulates electrical energy according to the drive signal and cooperates to achieve the overall control of the generator;

[0058] A controllable bridge rectifier module, which conducts the corresponding switching tubes according to the rotor sector, controls the commutation of the armature current, and cooperates with the diodes to construct a current loop to ensure current transmission and electromechanical energy conversion;

[0059] An excitation winding control module, where the voltage regulator generates a reference excitation current according to the bus voltage error, and the excitation current regulator generates a duty cycle based on this and the actual excitation current error to control the asymmetrical half - bridge converter and stabilize the DC bus voltage;

[0060] The armature winding control module detects the voltages of phases A and B, determines the rotor sector according to the relationship between the voltage difference and the threshold value, and cooperates with the controllable bridge rectifier to control the conduction of the switching tubes to achieve current commutation.

[0061] Compared with the prior art, the present invention adopting the above technical solution has the following beneficial effects:

[0062] 1. The sensorless control method and system for an electro-excited doubly salient generator proposed by the present invention do not require an additional current sampling circuit, and the implementation process is relatively simple.

[0063] 2. The sensorless control method and system for an electro-excited doubly salient generator proposed by the present invention only need to utilize the two-phase voltage information. Compared with the existing methods, the number of sensors is reduced, and the accuracy of position detection is high.

[0064] 3. The sensorless control method and system for an electro-excited doubly salient generator proposed by the present invention are not affected by the changes in speed and load, and have high anti-disturbance ability and stability.

[0065] 4. The sensorless control method and system for an electro-excited doubly salient generator proposed by the present invention do not need to calculate the electrical angle, have no cumulative error, and the algorithm is simple. Description of the Drawings

[0066] Figure 1 It is a block diagram of the controllable rectification system of the electro-excited doubly salient generator in the embodiment of the present invention;

[0067] Figure 2 It is a conduction logic diagram of the switching tubes in the embodiment of the present invention;

[0068] Figure 3 It is the current loop diagram of the conduction interval of [0°, θ p in the embodiment of the present invention;

[0069] Figure 4 It is the current loop diagram of the conduction interval of [θ p , θ n in the embodiment of the present invention;

[0070] Figure 5 It is the current loop diagram of the conduction interval of [θ n , 120°] in the embodiment of the present invention;

[0071] Figure 6 It is the current loop diagram of the conduction interval of [120°, 120° + θ p in the embodiment of the present invention;

[0072] Figure 7 It is the current loop diagram of the conduction interval of [120° + θp , 120° + θ n Current loop diagram of the conduction interval;

[0073] Figure 8 is the [120° + θ n , 240°] current loop diagram of the conduction interval in the embodiment of the present invention;

[0074] Figure 9 is the [240°, 240° + θ p current loop diagram of the conduction interval in the embodiment of the present invention;

[0075] Figure 10 is the [240° + θ p , 240° + θ n current loop diagram of the conduction interval in the embodiment of the present invention;

[0076] Figure 11 is the [240° + θ n , 360°] current loop diagram of the conduction interval in the embodiment of the present invention. Detailed implementation manners

[0077] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0078] A sensorless control method and system for an electro - excited doubly salient generator includes the following steps:

[0079] Step 1: As Figure 1 shown, the controllable rectifier system of the electro - excited doubly salient generator mainly consists of an asymmetrical half - bridge converter module, a controllable bridge rectifier module, an excitation winding control module, and an armature winding control module; in the excitation winding control link, the voltage regulator generates a reference excitation current i ref based on the error between the reference DC bus voltage U o and the rectified DC bus voltage U fref ; the excitation current regulator generates a duty cycle D based on the error between the reference excitation current i fref and the actual excitation current; then, the asymmetrical half - bridge converter is controlled through a drive signal generator; in the armature winding control link, the A - phase voltage value u a and the B - phase voltage value u b of the controllable bridge rectifier are detected, and the sector status flag bit within one electrical cycle is determined to determine the sector where the rotor is currently located.

[0080] Step 2: As shown in Figure 2 , within one electrical cycle, define 0° - 120° as Sector 1, 120° - 240° as Sector 2, and 240° - 360° as Sector 3. Then the conduction logic of the electro-excited doubly salient generator controlled rectifier system within one electrical cycle is as follows:

[0081] Within Sector 1, control T2 and T3 of the controllable bridge rectifier to conduct;

[0082] Within Sector 2, control T4 and T5 of the controllable bridge rectifier to conduct;

[0083] Within Sector 3, control T1 and T6 of the controllable bridge rectifier to conduct.

[0084] Step 3: Within Sector 1, θ p is the commutation angle of the C-phase current value i c from negative to positive, and θ n is the commutation angle of the B-phase current value i b from positive to negative. Therefore, Sector 1 can be divided into a [0°, θ p conduction interval, a [θ p , θ n conduction interval, and a [θ n , 120°] conduction interval. Since the armature winding internal resistance is small, the phase voltage is approximately equal to the phase winding induced electromotive force;

[0085] As Figure 3 shown, within the [0°, θ p conduction interval, the A-phase current value i a < 0, the B-phase current value i b > 0, and the C-phase current value i c < 0. Although T2 and T3 are turned on, since the B-phase current value i b and the C-phase current value i c have not completed commutation, they are reverse clamped by D2 and D3. The current path is: B-phase winding → D3 → load R → D4 → A-phase winding → B-phase winding; B-phase winding → D3 → load R → D2 → C-phase winding → B-phase winding. According to Kirchhoff's voltage law, we can obtain:

[0086] u a -u b =-u o , u a -u c =0 (1)

[0087] In the formula, u p (p = a, b, c) is the phase voltage value, and u o is the output voltage value.

[0088] As shown Figure 4 , within the conduction interval of [θ p , θ n , the current value i a of phase A < 0, the current value i b of phase B > 0, the current value i c of phase C > 0, T2 and T3 are turned on. However, since the commutation of the current value i b of phase B has not been completed, T3 is reverse-clamped by D3; the current path is: phase C winding → T2 → D4 → phase A winding → phase C winding; phase B winding → D3 → load R → D4 → phase A winding → phase B winding; according to Kirchhoff's voltage law, the voltage equation can be obtained as the same within the conduction interval of [0°, θ p , as shown in Equation (1).

[0089] As shown Figure 5 , within the conduction interval of [θ n , 120°], the current value i a of phase A < 0, the current value i b of phase B < 0, the current value i c of phase C > 0, T2 and T3 are turned on; the current path is: phase C winding → T2 → D4 → phase A winding → phase C winding; phase C winding → T2 → capacitor C → T3 → phase B winding → phase C winding; according to Kirchhoff's voltage law, the voltage equation can be obtained as the same within the conduction interval of [0°, θ p , as shown in Equation (1).

[0090] Then, within sector 1, u a – u b = -u o < 0 always holds.

[0091] Step 4: Within sector 2, θ p is the commutation angle at which the current value i a of phase A changes from negative to positive, and θ n is the commutation angle at which the current value i c of phase C changes from positive to negative; therefore, sector 2 can be divided into the conduction intervals of [120°, 120° + θ p , [120° + θ p , 120° + θ n , and [120° + θ n , 240°].

[0092] As shown Figure 6 , within the conduction interval of [120°, 120° + θ p , the current value i a of phase A < 0, the current value i b of phase B < 0, the current value i c> 0, although T4 and T5 are turned on, since the current value i of phase A a and the current value i of phase C c has not completed commutation yet, they are reverse clamped by D4 and D5; the current path is: phase C winding → D5 → load R → D4 → phase A winding → phase C winding; phase C winding → D5 → load R → D6 → phase B winding → phase C winding; according to Kirchhoff's voltage law, we can get:

[0093] u a -u b = 0, u c -u a = u o (2)

[0094] As Figure 7 shown, in the conduction interval of [120° + θ p , 120° + θ n , the current value i of phase A a > 0, the current value i of phase B b < 0, the current value i of phase C c > 0, T4 and T5 are turned on, but since the current value i of phase C c has not completed commutation yet, T5 is reverse clamped by D5; the current path is: phase A winding → T4 → D6 → phase B winding → phase A winding; phase C winding → D5 → load R → D6 → phase B winding → phase C winding; according to Kirchhoff's voltage law, the voltage equation is the same as that in the conduction interval of [120°, 120° + θ p , as shown in Equation (2).

[0095] As Figure 8 shown, in the conduction interval of [120° + θ n , 240°], the current value i of phase A a > 0, the current value i of phase B b < 0, the current value i of phase C c < 0, T4 and T5 are turned on; the current path is: phase A winding → T4 → D6 → phase B winding → phase A winding; phase A winding → T4 → capacitor C → T5 → phase C winding → phase A winding; according to Kirchhoff's voltage law, the voltage equation is the same as that in the conduction interval of [120°, 120° + θ p , as shown in Equation (2).

[0096] Then, in sector 2, u a –u b = 0 always holds.

[0097] Step 5: In sector 3, θ p is the commutation angle at which the current value i of phase B b changes from negative to positive, and θ n is the current value i of phase Aa Commutation angle from positive to negative; thus, sector 3 can be divided into a conduction interval of [240°, 240° + θ p , a conduction interval of [240° + θ p , 240° + θ n , and a conduction interval of [240° + θ n , 360°].

[0098] As Figure 9 shown, within the conduction interval of [240°, 240° + θ p , the current value of phase A, i a > 0, the current value of phase B, i b < 0, and the current value of phase C, i c < 0. Although T1 and T6 are turned on, since the current values of phase A, i a and phase B, i b have not completed commutation, they are reverse clamped by D1 and D6; the current path is: phase A winding → D1 → load R → D6 → phase B winding → phase A winding; phase A winding → D1 → load R → D2 → phase C winding → phase A winding; according to Kirchhoff's voltage law, we can obtain:

[0099] u a - u b = u o , u b - u c = 0 (3)

[0100] As Figure 10 shown, within the conduction interval of [240° + θ p , 240° + θ n , the current value of phase A, i a > 0, the current value of phase B, i b > 0, and the current value of phase C, i c < 0. Although T1 and T6 are turned on, since the current value of phase A, i a has not completed commutation, T1 is reverse clamped by D1; the current path is: phase B winding → T6 → D2 → phase C winding → phase B winding; phase A winding → D1 → load R → D2 → phase C winding → phase A winding; according to Kirchhoff's voltage law, the voltage equation is the same as that in the conduction interval of [240°, 240° + θ p , as shown in equation (3).

[0101] As Figure 11 shown, within the conduction interval of [240° + θ n , 360°], the current value of phase A, i a < 0, the current value of phase B, i b > 0, and the current value of phase C, i c<0, T1 and T6 are turned on; the current loop is: B-phase winding → T6 → D2 → C-phase winding → B-phase winding; B-phase winding → T6 → capacitor C → T1 → A-phase winding → B-phase winding; according to Kirchhoff's voltage law, the voltage equation can be obtained as the same within the conduction interval of [240°, 240°+θ p as that within the conduction interval, as shown in Equation (3).

[0102] Then, within sector 3, u a –u b =u o >0 always holds true.

[0103] Step 6: Based on the analysis in Steps 2 - 5, within one electrical cycle, detect the A-phase voltage value u a and the B-phase voltage value u b , and then the sector status flag bit F p is as follows:

[0104]

[0105] In the formula, ε is the voltage threshold; to prevent misdiagnosis, ε needs to be greater than the maximum measurement error of the voltage sensor.

[0106] When F p = -1, it indicates that the rotor currently enters sector 1, and control T2 and T3 of the controllable bridge rectifier to be turned on;

[0107] When F p =0, it indicates that the rotor currently enters sector 2, and control T4 and T5 of the controllable bridge rectifier to be turned on;

[0108] When F p =1, it indicates that the rotor currently enters sector 3, and control T1 and T6 of the controllable bridge rectifier to be turned on.

[0109] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A position sensorless control method for an electrically excited double-salient-pole generator, characterized in that: The method comprises the following steps: Step S1: Excitation control maintains DC bus voltage stability through voltage and current regulator closed loop, armature control detects A and B phase voltages, determines sector status flag, and thus determines the sector; Step S2: Divide the electrical cycle into three sectors, and determine the conduction status of the switch tube in each sector; Step S3: Analyze the conduction interval of sector 1 and the phase voltage and output voltage characteristics within the interval; Step S4: Analyze the conduction interval of sector 2 and the phase voltage and output voltage characteristics within the interval; Step S5: Analyze the conduction interval of sector 3 and the phase voltage and output voltage characteristics within the interval; Step S6: Obtaining the sector flag based on the analysis of steps S1 to S5; Step S7: Determine the corresponding relationship between the sector flag bit and the sector and switch conduction status.

2. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The excitation control in step S1 is specifically as follows: In the field winding control link, the voltage regulator is based on the reference DC bus voltage U ref and the rectified DC bus voltage U o The error between the reference excitation current i fref ; The excitation current regulator is based on the reference excitation current i fref The error between the actual excitation current and the duty cycle D; The asymmetric half-bridge converter is then controlled via a driving signal generator.

3. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The armature control in step S1 is specifically as follows: In the armature winding control link, the A phase voltage value u of the controllable bridge rectifier is detected a and B phase voltage value u b , and determine the sector status flag within an electrical cycle, thereby determining the sector in which the rotor is currently located.

4. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S2 is specifically as follows: In one electrical cycle, 0°~120° is defined as sector 1, 120°~240° is defined as sector 2, and 240°~360° is defined as sector 3; then the conduction logic of the controlled rectifier system of the electrically excited double-salient-pole generator in one electrical cycle is: In sector 1, control the controlled bridge rectifiers T2 and T3 to be turned on; In sector 2, T4 and T5 of the controlled bridge rectifier are controlled to be turned on; In sector 3, T1 and T6 of the controlled bridge rectifier are controlled to be turned on.

5. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S3 is specifically as follows: In sector 1, θ p is the C phase current value i c The commutation angle from negative to positive, θ n is the B phase current value i b Commutation angle from positive to negative; Therefore, sector 1 can be divided into [0°,θ p ] conduction interval, [θ p ,θ n ] conduction interval and [θ n ,120°] conduction interval; since the internal resistance of the armature winding is small, the phase voltage is approximately equal to the induced potential of the phase winding; In [0°,θ p ]In the conduction interval, the A phase current value i a <0, B phase current value i b >0, C phase current value i c <0, although T2 and T3 are turned on, the B phase current value i b and C phase current value i c The commutation has not been completed, so it is reverse clamped by D2 and D3; the current loop is: B phase winding → D3 → load R → D4 → A phase winding → B phase winding; B phase winding → D3 → load R → D2 → C phase winding → B phase winding; According to Kirchhoff's voltage law, we can get: in a -in b =-in o ,in a -in c =0 In the formula, u p (p=a,b,c) is the phase voltage value, u o is the output voltage value; In [θ p ,θ n ]In the conduction interval, the A phase current value i a <0, B phase current value i b >0, C phase current value i c >0, T2 and T3 are turned on, but due to the B phase current value i b The commutation has not been completed, so T3 is reverse clamped by D3; the current loop is: C phase winding → T2 → D4 → A phase winding → C phase winding; B phase winding → D3 → load R → D4 → A phase winding → B phase winding; According to Kirchhoff's voltage law, the voltage equation is [0°,θ p ]The same in the conduction interval; In [θ n ,120°] conduction interval, the A phase current value i a <0, B phase current value i b <0, C phase current value i c >0, T2 and T3 are turned on; the current loop is: C phase winding → T2 → D4 → A phase winding → C phase winding; C phase winding → T2 → capacitor C → T3 → B phase winding → C phase winding; According to Kirchhoff's voltage law, the voltage equation is [0°,θ p ]The same in the conduction interval; Therefore, in sector 1, u a –u b =-u o <0 is always true.

6. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S4 is specifically as follows: In sector 2, θ p is the current value of phase A i a The commutation angle from negative to positive, θ n is the C phase current value i c Commutation angle from positive to negative; Therefore, sector 2 can be divided into [120°, 120° + θ p ]Conduction interval, [120°+θ p ,120°+θ n ] conduction interval and [120°+θ n ,240°] conduction interval; In [120°,120°+θ p ]In the conduction interval, the A phase current value i a <0, B phase current value i b <0, C phase current value i c >0, although T4 and T5 are turned on, due to the A phase current value i a and C phase current value i c The commutation has not been completed, so it is reverse clamped by D4 and D5; the current loop is: C phase winding → D5 → load R → D4 → A phase winding → C phase winding; C phase winding → D5 → load R → D6 → B phase winding → C phase winding; According to Kirchhoff's voltage law, we can get: in a -in b =0,u c -in a =in o In [120°+θ p ,120°+θ n ]In the conduction interval, the A phase current value i a >0, B phase current value i b <0, C phase current value i c >0, T4 and T5 are turned on, but due to the C phase current value i c Commutation has not been completed, so T5 is reverse clamped by D5; the current loop is: A phase winding → T4 → D6 → B phase winding → A phase winding; C phase winding → D5 → load R → D6 → B phase winding → C phase winding; According to Kirchhoff's voltage law, the voltage equation is [120°, 120° + θ p ]The same in the conduction interval; In [120°+θ n ,240°] conduction interval, the A phase current value i a >0, B phase current value i b <0, C phase current value i c <0, T4 and T5 are turned on; the current loop is: A phase winding → T4 → D6 → B phase winding → A phase winding; A phase winding → T4 → capacitor C → T5 → C phase winding → A phase winding; According to Kirchhoff's voltage law, the voltage equation is [120°, 120° + θ p ]The same in the conduction interval; Therefore, in sector 2, u a –u b =0 is always true.

7. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S5 is specifically as follows: In sector 3, θ p is the B phase current value i b The commutation angle from negative to positive, θ n is the current value of phase A i a Commutation angle from positive to negative; Therefore, sector 3 can be divided into [240°, 240° + θ p ]Conduction interval, [240°+θ p ,240°+θ n ] conduction interval and [240°+θ n ,360°] conduction interval; In [240°,240°+θ p ]In the conduction interval, the A phase current value i a >0, B phase current value i b <0, C phase current value i c <0, although T1 and T6 are turned on, the A phase current value i a and the B phase current value i b The commutation has not been completed, so it is reverse clamped by D1 and D6; the current loop is: A phase winding → D1 → load R → D6 → B phase winding → A phase winding; A phase winding → D1 → load R → D2 → C phase winding → A phase winding; According to Kirchhoff's voltage law, we can get: in a -in b =in o ,in b -in c =0 In [240°+θ p ,240°+θ n ]In the conduction interval, the A phase current value i a >0, B phase current value i b >0, C phase current value i c <0, T1 and T6 are turned on, but due to the A phase current value i a Commutation has not been completed, so T1 is reverse clamped by D1; the current loop is: B phase winding → T6 → D2 → C phase winding → B phase winding; A phase winding → D1 → load R → D2 → C phase winding → A phase winding; According to Kirchhoff's voltage law, the voltage equation is [240°, 240° + θ p ]The same in the conduction interval; In [240°+θ n ,360°] conduction interval, the A phase current value i a <0, B phase current value i b >0, C phase current value i c <0, T1 and T6 are turned on; the current loop is: B phase winding → T6 → D2 → C phase winding → B phase winding; B phase winding → T6 → capacitor C → T1 → A phase winding → B phase winding; According to Kirchhoff's voltage law, the voltage equation is [240°, 240° + θ p ]The same in the conduction interval; Therefore, in sector 3, u a –u b =u o >0 is always true.

8. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S6 is specifically as follows: In one electrical cycle, detect the A phase voltage value u a and B phase voltage value u b , then the sector status flag F can be obtained p for: In the formula, ε is the voltage threshold. To prevent misdiagnosis, ε needs to be greater than the maximum measurement error of the voltage sensor.

9. The position sensorless control method of the electrically excited doubly salient generator according to claim 1, characterized in that: The step S7 is specifically as follows: When F p =-1, indicating that the rotor currently enters sector 1, controlling T2 and T3 of the controlled bridge rectifier to turn on; When F p =0, indicating that the rotor currently enters sector 2, and controls T4 and T5 of the controlled bridge rectifier to be turned on; When F p When =1, it indicates that the rotor currently enters sector 3, and controls T1 and T6 of the controlled bridge rectifier to be turned on.

10. A position sensorless control system for an electrically excited double-salient-pole generator, characterized in that: The position sensorless control system of the electrically excited double-salient-pole generator is applied to the position sensorless control method of the electrically excited double-salient-pole generator as claimed in any one of claims 1 to 9, and the position sensorless control system of the electrically excited double-salient-pole generator comprises: The asymmetric half-bridge converter module converts and regulates the electric energy according to the drive signal, and cooperates to realize the overall control of the generator; The controlled bridge rectifier module turns on the corresponding switch tube according to the rotor sector, controls the armature current commutation, and cooperates with the diode to build a current loop to ensure current transmission and electromechanical energy conversion; In the field winding control module, the voltage regulator generates a reference field current according to the bus voltage error, and the field current regulator generates a duty cycle based on the reference field current and the actual field current error to control the asymmetric half-bridge converter and stabilize the DC bus voltage. The armature winding control module detects the A and B phase voltages, determines the rotor sector based on the relationship between the voltage difference and the threshold, and cooperates with the controllable bridge rectifier to control the switch tube to conduct to achieve current commutation.

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