Real-time optimization control method and system for excitation system of dual-shaft excitation generator

Abstract

This invention relates to a control method and system for real-time optimization of the excitation system of a dual-shaft generator. The method establishes control parameters for the dual-shaft generator excitation system, including active power control parameters and reactive power control parameters. It also obtains the real-time response of the dual-shaft generator after disturbance, the real-time response including the active power deviation e. P Active power deviation change rate (ec) P and reactive power deviation e Q Reactive power deviation change rate (ec) Q Adjust the active power control parameters until the active power deviation e P Active power deviation change rate (ec) P The reactive power control parameters are set to zero to obtain the optimized active power control parameters; the reactive power control parameters are then adjusted until the reactive power deviation e is zero. Q Reactive power deviation change rate (ec) Q The reactive power control parameters are obtained by setting the value to zero. This invention enables real-time optimization of the excitation system parameters, improving the control effect of the excitation system and enhancing the stability of the power system.

Description

Technical Field

[0001] This invention relates to a control method and system for real-time optimization of the excitation system of a dual-shaft excitation generator. Background Technology

[0002] With the increase in single-unit capacity and the development of ultra-high voltage long-distance power transmission, the angle between the excitation electromotive force of the synchronous generator and the system voltage is getting closer and closer to the limit value, which reduces the stability of the generator and the power system.

[0003] Traditional synchronous generators have only one set of excitation windings, located on the d-axis of the rotor. This characteristic determines that their power regulation and operational stability are related to the angle between the generator's longitudinal axis magnetomotive force and the grid voltage, i.e., related to the generator's power angle, thus limiting the range of operational stability. Dual-shaft excitation generators (dual-excitation machines) have excitation windings on both the d-axis and q-axis of the rotor, with the axes of the two sets of windings perpendicular to each other. The magnitude and direction of the current in the two sets of excitation windings can be adjusted independently. By changing the ratio of the excitation currents on the d and q axes, the phase of the excitation electromotive force can be adjusted, thereby improving the stability of the power system. Dual-excitation machines can significantly improve the stability of power systems. In addition to adding excitation windings to the rotor, a complete excitation control system that can fully utilize the generator's operating performance is also essential.

[0004] The control effect of an excitation system based on a specific operating point or a specific disturbance is affected by the parameters of the dual-exciter motor, the operating point, and the type and magnitude of the disturbance. Poor control effect of the excitation system results in a long dynamic process time and large oscillation amplitude of the dual exciter, which is detrimental to the stable operation of the power system. Summary of the Invention

[0005] The purpose of this invention is to provide a control method and system for real-time optimization of the excitation system of a dual-shaft excitation generator, which can optimize the parameters of the excitation system in real time, improve the control effect of the excitation system, and enhance the stability of the power system.

[0006] Based on the same inventive concept, this invention has two independent technical solutions:

[0007] 1. A control method for real-time optimization of the excitation system of a dual-shaft excitation generator, characterized by comprising the following steps:

[0008] Step 1: Establish the control parameters of the dual-shaft generator excitation system, including active power control parameters and reactive power control parameters;

[0009] Step 2: Obtain the real-time response of the dual-shaft generator after disturbance, the real-time response including the active power deviation e P Active power deviation change rate (ec) P and reactive power deviation e QReactive power deviation change rate (ec) Q ;

[0010] Step 3: Adjust the active power control parameters until the active power deviation e P Active power deviation change rate (ec) P The reactive power control parameters are set to zero to obtain the optimized active power control parameters; the reactive power control parameters are then adjusted until the reactive power deviation e is zero. Q Reactive power deviation change rate (ec) Q The value is zero, thus obtaining the optimized reactive power control parameters.

[0011] In step 1, the control parameters of the dual-shaft generator excitation system are established based on the following formula:

[0012]

[0013] In the formula,

[0014] In the formula, K P M P N P K is the active power control parameter. Q M Q N Q For reactive power related parameters; K P K Q These are the proportional coefficients for active and reactive power errors, respectively, and M. P M Q These are the differential coefficients for active and reactive power errors, respectively, N. P N Q The inertia coefficient, U, is divided into active and reactive power errors. fq U fq0 U represents the rotor quadrature-axis excitation voltage and the given rotor quadrature-axis excitation voltage, respectively. fd U fd0 represents the rotor direct-axis excitation voltage and the given rotor direct-axis excitation voltage, respectively; P and P0 represent the active power and the given active power, respectively; Q and Q0 represent the reactive power and the given reactive power, respectively; r fd r fq These represent the resistances of the rotor's direct-axis and quadrature-axis excitation windings, respectively; x fd x fq represents the reactance of the rotor direct-axis and quadrature-axis excitation windings, respectively; s represents the differential operator, that is, differentiating the active and reactive power errors.

[0015] In step 2, the real-time response of the dual-shaft generator after disturbance is calculated using the following formula:

[0016]

[0017] Where, X = [i d i q i fd i fq i D i Q ] T ,

[0018]

[0019] F = [u d u q u fd u fq 0 0] T ,

[0020]

[0021] In the formula, i d i q i fd i fq i D i Q These represent the right-angle stator current, excitation current, and damping current, respectively; u d u q u fd u fq These represent the direct-axis stator voltage, quadrature-axis stator voltage, direct-axis excitation voltage, and quadrature-axis excitation voltage, respectively; x d x q x fd x fq x D x Q These represent the right-angle axis synchronous reactance, the right-angle axis excitation winding reactance, and the right-angle axis damping winding reactance, respectively; x ad x aq These represent the direct-axis and quadrature-axis armature reaction reactances, respectively; r a r fd r fq r D r Q These represent the stator resistance, the right-angle axis excitation winding resistance, and the right-angle axis damping winding resistance, respectively.

[0022] The active power response P is obtained by the following formula:

[0023] P = F(1)X(1) + F(2)X(2)

[0024] In the formula, F(1) and F(2) represent u d u q X(1)X(2) represents i d iq .

[0025] The reactive power response Q is obtained by the following formula:

[0026] Q = F(2)X(1) - F(1)X(2)

[0027] In the formula, F(1) and F(2) represent u d u q X(1)X(2) represents i d i q .

[0028] Active power deviation e P It is obtained through the following formula:

[0029] e P =P-P0

[0030] Active power deviation change rate (ec) P It is obtained through the following formula:

[0031]

[0032] In the formula, k is the number of samples and t is the sampling time.

[0033] reactive power deviation e Q It is obtained through the following formula:

[0034] e Q =Q-Q0

[0035] In the formula, P0 and Q0 represent the given active and reactive power after the disturbance, respectively;

[0036] reactive power deviation change rate (ec) Q It is obtained through the following formula:

[0037]

[0038] In the formula, k is the number of samples and t is the sampling time.

[0039] Step 1 also includes establishing the correspondence between the real-time response after the disturbance and the control parameters, including the active power deviation e. P Active power deviation change rate (ec) P With active power control parameter K P M P N P The correspondence between them, reactive power deviation e Q Reactive power deviation change rate (ec) Q With reactive power control parameter K Q M Q NQ The correspondence between them.

[0040] Furthermore, step 1 also includes applying a disturbance signal to the dual-shaft exciter through a disturbance application system to conduct a disturbance test and establish the correspondence between the real-time response after the disturbance and the control parameters.

[0041] Step 3 also includes, based on the active power deviation e obtained at each moment... P Active power deviation change rate (ec) P Real-time updates of active power control parameter K P M P N P The optimized value is obtained until the active power deviation e P Active power deviation change rate (ec) P It is zero; based on the reactive power deviation e obtained at each moment. Q Reactive power deviation change rate (ec) Q Real-time updates of reactive power control parameter K Q M Q N Q The optimized value is obtained until the reactive power deviation e is reached. Q Reactive power deviation change rate (ec) Q It is zero.

[0042] 2. A control system for real-time optimization of the excitation system of a dual-shaft excitation generator, comprising a processor for executing the above-described method.

[0043] The beneficial effects of this invention are as follows:

[0044] This invention establishes control parameters for a dual-shaft generator excitation system; and obtains the real-time response of the dual-shaft generator after disturbance, wherein the real-time response includes the active power deviation e. P Active power deviation change rate (ec) P and reactive power deviation e Q Reactive power deviation change rate (ec) Q Adjust the active power control parameters until the active power deviation e P Active power deviation change rate (ec) P The reactive power control parameters are set to zero to obtain the optimized active power control parameters; the reactive power control parameters are then adjusted until the reactive power deviation e is zero. Q Reactive power deviation change rate (ec) Q The reactive power control parameters are obtained by setting the value to zero. Based on the real-time response, this invention optimizes the control parameters of the dual-shaft generator excitation system in real time, improving the control effect of the excitation system, further shortening the dynamic process of the dual exciter, and enhancing the stability of the power system.

[0045] This invention establishes the control parameters of the dual-shaft generator excitation system based on the following formula:

[0046]

[0047] In the formula,

[0048] This further ensures and improves the control effect of the excitation system, shortens the dynamic process of the dual exciter, and enhances the stability of the power system.

[0049] This invention establishes in advance the correspondence between the real-time response after a disturbance and the control parameters, including the active power deviation e. P Active power deviation change rate (ec) P With active power control parameter K P M P N P The correspondence between them, reactive power deviation e Q Reactive power deviation change rate (ec) Q With reactive power control parameter K Q M Q N Q The correspondence between them further ensures rapid and real-time optimization of the control parameters of the dual-shaft generator excitation system, improves the control effect of the excitation system, and enhances the stability of the power system. Attached Figure Description

[0050] Figure 1 This is a flowchart of the control method for real-time optimization of the excitation system of the dual-shaft excitation generator according to the present invention;

[0051] Figure 2 This is a schematic diagram illustrating the real-time optimization of control parameters for the dual-shaft generator excitation system of the present invention;

[0052] Figure 3 For e P and EC P With control parameter K P The correspondence;

[0053] Figure 4 For e P and EC P With control parameter M P The correspondence;

[0054] Figure 5 For e P and EC P With control parameter N P The correspondence;

[0055] Figure 6 For e Q and EC Q With control parameter KQ The correspondence;

[0056] Figure 7 For e Q and EC Q With control parameter M Q The correspondence;

[0057] Figure 8 For e Q and EC Q With control parameter N Q The correspondence;

[0058] Figure 9 Comparison of the speed waveforms of the dual exciter before and after parameter optimization when applying torque disturbance;

[0059] Figure 10 Comparison of reactive power waveforms of dual exciters before and after parameter optimization when reactive power disturbance is applied;

[0060] Figure 11 Comparison of the speed waveforms of the dual exciter before and after parameter optimization when a sudden three-phase short circuit is applied. Detailed Implementation

[0061] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0062] Example 1:

[0063] Real-time optimization control method for excitation system of dual-shaft excitation generator

[0064] like Figure 1 As shown, a control method for real-time optimization of the excitation system of a dual-shaft excitation generator includes the following steps:

[0065] Step 1: Establish the control parameters of the dual-shaft generator excitation system, including active power control parameters and reactive power control parameters.

[0066] The control parameters for the dual-shaft generator excitation system are established based on the following formula.

[0067]

[0068] In the formula,

[0069] In the formula, K P M P N P K is the active power control parameter. QM Q N Q For reactive power related parameters; K P K Q These are the proportional coefficients for active and reactive power errors, respectively, and M. P M Q These are the differential coefficients for active and reactive power errors, respectively, N. P N Q The inertia coefficient is divided into active and reactive error. U fq U fq0 U represents the rotor quadrature-axis excitation voltage and the given rotor quadrature-axis excitation voltage, respectively. fd U fd0 P and P' represent the rotor direct-axis excitation voltage and the given rotor direct-axis excitation voltage, respectively. o represents active power and given active power, respectively; Q and Q0 represent reactive power and given reactive power, respectively; r fd r fq These represent the resistances of the rotor's direct-axis and quadrature-axis excitation windings, respectively; x fd x fq represents the reactance of the rotor direct-axis and quadrature-axis excitation windings, respectively; s represents the differential operator, that is, the differential operation on the active and reactive power errors.

[0070] A disturbance test was conducted by applying a disturbance signal to a dual-shaft exciter using a disturbance application system, establishing the correspondence between the real-time response and control parameters after the disturbance. This correspondence includes the active power deviation e. P Active power deviation change rate (ec) P With active power control parameter K P M P N P The correspondences between them are as follows: Figure 3 , Figure 4 , Figure 5 As shown, reactive power deviation e Q Reactive power deviation change rate (ec) Q With reactive power control parameter K Q M Q N Q The correspondences between them are as follows: Figure 6 , Figure 7 , Figure 8 As shown.

[0071] Step 2: Obtain the real-time response of the dual-shaft generator after disturbance, the real-time response including the active power deviation e P Active power deviation change rate (ec) P and reactive power deviation e Q Reactive power deviation change rate (ec) Q.

[0072] The real-time response of the dual-shaft generator after disturbance is calculated using the following formula.

[0073]

[0074] Where, X = [i d i q i fd i fq i D i Q ] T ,

[0075]

[0076] F = [u d u q u fd u fq 0 0] T ,

[0077]

[0078] In the formula, i d i q i fd i fq i D i Q These represent the right-angle stator current, excitation current, and damping current, respectively; u d u q u fd u fq These represent the direct-axis stator voltage, quadrature-axis stator voltage, direct-axis excitation voltage, and quadrature-axis excitation voltage, respectively; x d x q x fd x fq x D x Q These represent the right-angle axis synchronous reactance, the right-angle axis excitation winding reactance, and the right-angle axis damping winding reactance, respectively; x ad x aq These represent the direct-axis and quadrature-axis armature reaction reactances, respectively; r a r fd r fq r D r Q These represent the stator resistance, the right-angle axis excitation winding resistance, and the right-angle axis damping winding resistance, respectively.

[0079] The active power response P is obtained by the following formula:

[0080] P = F(1)X(1) + F(2)X(2)

[0081] In the formula, F(1) and F(2) represent u d u q X(1)X(2) represents i d i q .

[0082] The reactive power response Q is obtained by the following formula:

[0083] Q = F(2)X(1) - F(1)X(2)

[0084] In the formula, F(1) and F(2) represent u d u q X(1)X(2) represents i d i q .

[0085] Active power deviation e P It is obtained through the following formula:

[0086] e P =P-P0

[0087] Active power deviation change rate (ec) P It is obtained through the following formula:

[0088]

[0089] In the formula, k is the number of samples and t is the sampling time.

[0090] reactive power deviation e Q It is obtained through the following formula:

[0091] e Q =Q-Q0

[0092] In the formula, P0 and Q0 represent the given active and reactive power after the disturbance, respectively;

[0093] reactive power deviation change rate (ec) Q It is obtained through the following formula:

[0094]

[0095] In the formula, k is the number of samples and t is the sampling time.

[0096] Step 3: Adjust the active power control parameters until the active power deviation e P Active power deviation change rate (ec) P The reactive power control parameters are set to zero to obtain the optimized active power control parameters; the reactive power control parameters are then adjusted until the reactive power deviation e is zero. Q Reactive power deviation change rate (ec)Q The value is zero, thus obtaining the optimized reactive power control parameters.

[0097] The optimal values ​​of each excitation parameter are obtained based on the established correspondence, and these values ​​are applied to the excitation system. The excitation system then calculates the excitation voltage U. fd and U fq The value of is obtained and applied to the dual exciter to obtain the real-time response of the dual exciter, and then the value of e is determined. P ec P e Q and EC Q If the value is zero, the optimization ends; otherwise, the above process is repeated.

[0098] When optimizing control parameters, such as Figure 2 As shown, based on the active power deviation e obtained at each moment P Active power deviation change rate (ec) P Real-time updates of active power control parameter K P M P N P The optimized value is obtained until the active power deviation e P Active power deviation change rate (ec) P It is zero; based on the reactive power deviation e obtained at each moment. Q Reactive power deviation change rate (ec) Q Real-time updates of reactive power control parameter K Q M Q N Q The optimized value is obtained until the reactive power deviation e is reached. Q Reactive power deviation change rate (ec) Q It is zero.

[0099] Figure 9 A comparison of the speed waveforms of the dual-exciter before and after optimization of the excitation system parameters when applying torque disturbance. Figure 9 It can be seen that the speed fluctuation amplitude and oscillation time of the dual-exciter are significantly reduced after parameter optimization. Table 1 calculates the specific dynamic characteristic indicators. As can be seen from Table 1, compared with before parameter optimization, the speed fluctuation amplitude and oscillation time obtained after parameter optimization are reduced by 2.57% and 8.42%, respectively.

[0100] Table 1 Comparison of torque disturbance characteristics before and after parameter optimization

[0101]

[0102] Figure 10 A comparison of the reactive power waveforms of the dual-exciter system before and after optimization of the excitation system parameters when applying reactive power disturbance. Figure 10It can be seen that the maximum reactive power and oscillation time of the dual-exciter are significantly reduced after parameter optimization. Table 2 calculates the specific dynamic characteristic indicators, showing that compared with before parameter optimization, the maximum reactive power and oscillation time are reduced by 34.15% and 66.75%, respectively.

[0103] Table 2 Comparison of reactive power disturbance characteristics before and after parameter optimization.

[0104]

[0105] Figure 11 Table 3 shows a comparison of the dual-exciter speed waveforms before and after excitation system parameter optimization under a sudden three-phase short-circuit disturbance. Specific dynamic characteristic indices were calculated in Table 3. Figure 11 As shown in Table 3, compared with the parameters before optimization, the maximum speed, fluctuation amplitude and oscillation time obtained after parameter optimization are reduced by 0.29, 31.69% and 2.60s, respectively.

[0106] Table 3 Comparison of dynamic characteristics of sudden three-phase short circuit before and after parameter optimization

[0107]

[0108] The results above show that the oscillation amplitude and oscillation time of the dual-exciter are significantly reduced after parameter optimization. The real-time optimization method and system for dual-exciter excitation system parameters proposed in this invention can significantly improve the control effect of the excitation system and enhance the stability of the dual-exciter.

[0109] Example 2:

[0110] A control system for real-time optimization of the excitation system of a dual-shaft excitation generator.

[0111] Includes a processor for performing the method described in Embodiment 1.

[0112] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0113] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A control method for real-time optimization of an excitation system of a doubly-fed generator, characterized in that, The method comprises the following steps: Step 1: establishing control parameters of a dual-shaft generator excitation system, the control parameters comprising active power control parameters and reactive power control parameters; Step 2: Obtain real-time response of the dual-axis generator to the disturbance, including active power deviation e P , rate of change of active power deviation ec P , and reactive power deviation e Q , rate of change of reactive power deviation ec Q ; Step 3: adjusting the active power control parameter until the active power deviation e P , the active power deviation change rate ec P is zero, obtaining the optimized active power control parameter; adjusting the reactive power control parameter until the reactive power deviation e Q , the reactive power deviation change rate ec Q is zero, obtaining the optimized reactive power control parameter; In step 1, the control parameters of the dual-shaft generator excitation system are established based on the following formula, In the formulae, , wherein, K P , K Q are the proportional coefficients of active and reactive error, M P , M Q are the differential coefficients of active and reactive error, N P , N Q are the inertial coefficients of active and reactive error, U fq , U fq0 denote the rotor quadrature-axis field voltage and the given rotor quadrature-axis field voltage, respectively; U fd , U fd0 denote the rotor direct-axis field voltage and the given rotor direct-axis field voltage, respectively; P , P 0 denote the active power and the given active power, respectively; Q , Q 0 respectively represent the reactive power, the given reactive power; r fd , r fq respectively represent the rotor direct-axis field winding resistance, the rotor quadrature-axis field winding resistance; x fd , x fq respectively represent the rotor direct-axis field winding reactance, the rotor quadrature-axis field winding reactance; s denotes the differential operator, i.e. the differentiation of the active, reactive error; In step 1, further comprising: establishing a correspondence between the real-time response after the disturbance and the control parameters, including: active power deviation e P , active power deviation rate ec P and active power control parameters K P , M P , N P , reactive power deviation e Q , reactive power deviation rate ec Q and reactive power control parameters K Q , M Q , N Q . ec Step 3 includes updating the active power control parameters in real time according to the active power deviation obtained at each time instant e P , the rate of change of the active power deviation In step 1, the method further comprises: performing a disturbance test on the dual-shaft excitation generator by applying a disturbance signal through a disturbance application system, and establishing a corresponding relationship between a real-time response after disturbance and the control parameters; P Step 4 includes updating the reactive power control parameters in real time according to the reactive power deviation obtained at each time instant K P , M P , N P the optimized value of the active power deviation e P , the rate of change of the active power deviation ec P is zero; and updating the reactive power control parameters in real time according to the reactive power deviation obtained at each time instant e Q , the rate of change of the reactive power deviation ec Q Step 5 includes updating the reactive power control parameters in real time according to the reactive power deviation obtained at each time instant K Q , M Q , N Q the optimized value of the reactive power deviation e Q , the rate of change of the reactive power deviation ec Q is zero.

2. The control method of real-time optimization of an excitation system of a dual-axial field generator according to claim 1, characterized in that: ec wherein , ， ， ， wherein i d , i q , i fd , i fq , i D , i Q respectively represent direct axis stator current, quadrature axis stator current, direct axis field current, quadrature axis field current, direct axis damping current, quadrature axis damping current; u d , u q , u fd , u fq respectively represent direct axis stator voltage, quadrature axis stator voltage, direct axis field voltage, quadrature axis field voltage; x d , x q , x fd , x fq , x D , x Q respectively represent direct axis synchronous reactance, quadrature axis synchronous reactance, direct axis field winding reactance, quadrature axis field winding reactance, direct axis damping winding reactance, quadrature axis damping winding reactance; x ad , x aq respectively represent direct axis armature reaction reactance, quadrature axis armature reaction reactance; r a , r fd , r fq , r D , r Q respectively represent stator resistance, direct axis field winding resistance, quadrature axis field winding resistance, and direct axis damping winding resistance, quadrature axis damping winding resistance.

3. The control method of real-time optimization of the excitation system of a two-shaft excited generator according to claim 2, characterized in that: Active power response P This is obtained by the equation: wherein F (1), F (2) represents u d , u q , X (1) X (2) represents i d , i q .

4. The control method of real-time optimization of an excitation system of a dual-axial field generator according to claim 2, characterized in that: Reactive power response Q This is obtained by the equation: In the formula, F (1), F (2) represents u d , u q , X (1) X (2) represents i d , i q .

5. The control method of real-time optimization of an excitation system of a dual-axial field generator according to claim 3, characterized in that, Active power deviation e P This is obtained by the equation: Active power deviation change rate In step 2, the real-time response of the dual-shaft generator after disturbance is obtained through the following formula, P is obtained by the following equation: In the formula, k is the number of samples, t is the sampling time; reactive power deviation e Q is obtained by the following equation: wherein P 0 and Q 0 represent the given active and reactive power after disturbance, respectively; reactive power deviation change rate ec Q is obtained by the following equation: In the formula, k is the number of samples, t is the sampling time.

6. A control system for real-time optimization of an excitation system of a doubly-fed generator, characterized in that ec The method comprises a processor for executing the control method for real-time optimization of a dual-shaft excitation generator excitation system according to any one of claims 1 to 5.

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