Electromagnetic design method of phase modifier

Abstract

The invention discloses an electromagnetic design method of a phase modifier. According to an existing design method, performance parameter comparison needs to be carried out in the final stage of the design process after a large amount of calculation, design optimization work is started, the size of a phase modifier is adjusted for recalculation, a satisfactory result can be achieved only by repeated calculation for multiple times, the design calculation workload is large, and the efficiency is low. According to the method, performance index requirements serve as parameters in the design process instead of being only used for judging threshold values of design results, that is, design values such as the main size of the phase modifier are solved according to the requirements of performance indexes of the phase modifier, such as direct-axis sub-transient reactance, direct-axis transient reactance, direct-axis transient short-circuit time constant and direct-axis transient open-circuit time constant; and related performance indexes of the designed phase modifier are ensured to meet or be superior to requirements, and the electromagnetic design working efficiency of the phase modifier is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of phase regulators, and in particular to an electromagnetic design method for phase regulators. Background Art

[0002] The existing electromagnetic design methods for large motors are based on the capacity, rated voltage and current of the designed motor. First, the size of the motor is selected through empirical data, and finally the various performance indicators of the motor are calculated. The biggest difference between a phase regulator and a generator is that its transient and sub-transient performance indicators have clear quantitative requirements. For example, the Technical Specifications for Fast Dynamic Response Synchronous Phase Regulators (Q / GDW 11588) and other standards give the direct axis sub-transient reactance X d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′ to meet the sub-transient and transient reactive power support capacity of the phase regulator. According to the existing design method, a large amount of calculation is required to compare the performance parameters in the final stage of the design process, and then start the design optimization work, adjust the size of the phase regulator and recalculate. It often takes many repeated calculations to achieve satisfactory results, which leads to large workload and low efficiency.

[0003] At the same time, the new distributed phase-shifters and large phase-shifters in converter stations have been used nationwide for a much shorter time than generator sets. Currently, there is no effective electromagnetic design method for phase-shifters oriented towards performance indicators. Performance indicators are always the final result of the calculation process and the target of repeated calculation and optimization, and are not integrated into the electromagnetic design process. This is also one of the main reasons for the large workload of electromagnetic design optimization of current phase-shifters. Summary of the invention

[0004] In view of this, the present invention provides an electromagnetic design method for a phase regulator. According to the specific performance requirements of the power system and users for the phase regulator, electromagnetic design calculations oriented to performance indicators are carried out to obtain the main dimensions of the phase regulator. The present invention uses the performance indicator requirements as parameters in the design process rather than only as thresholds for determining the design results. That is, the performance indicator direct-axis subtransient reactance X of the phase regulator is used to determine the main dimensions of the phase regulator. d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′, obtain the design values ​​of the main dimensions of the phase regulator, and ensure that the relevant performance indicators of the designed phase regulator meet or exceed the requirements, so as to improve the electromagnetic design efficiency of the phase regulator.

[0005] To achieve the above object, the present invention adopts the following technical solution: The present invention provides an electromagnetic design method for a phase regulator, which comprises:

[0006] Step 1) By using the performance index of the phase regulator, the direct-axis subtransient reactance X d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′, approximate solution of the direct-axis armature reaction reactance X ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs and the damping winding direct-axis reactance X ds ;

[0007] Step 2), use the armature reaction magnetomotive force F of each pole a Two calculation methods are used to calculate the direct-axis armature reaction reactance X obtained in step 1). ad , obtain the quantitative relationship between the main design dimensions of the phase regulator, and find the lower limit N of the number of series conductors per phase of the stator winding min ;

[0008] Step 3), select greater than or equal to N min The minimum value among the integer multiples of 2 is N, and the stator winding leakage reactance X obtained in step 1) is s , solve for l under the corresponding value of N t ,δandS, where S is the adjustment coefficient, l t is the calculated length of the stator core, and δ is the air gap size that needs to be retained for normal rotor disassembly and assembly;

[0009] Step 4), judge the rationality of the calculation results, if they meet the requirements, record the corresponding [N, l t , δ], return to step 3), set N = N + 2, start loop calculation, and end the loop calculation when the calculation result meets the end condition;

[0010] Step 5), for all [N, l obtained in step 4) t , δ], select a set of data with the smallest δ and determine the corresponding N and l t ;

[0011] Step 6), according to the direct axis transient open circuit time constant T d0 'Determine the number of turns per pole of the rotor excitation winding W f .

[0012] Further, in step 1), the direct axis armature reaction reactance X is solved by the following formula: ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs and the damping winding direct-axis reactance X ds :

[0013]

[0014] Where f represents the grid frequency.

[0015] Further, in step 2), two methods for calculating the armature reaction magnetomotive force Fa of each pole are as follows:

[0016] and

[0017]

[0018] Where U N ,I N F are the rated phase voltage and current of the phase regulator respectively; δ is the air gap magnetic pressure drop; K dp is the winding coefficient, whose value is less than 1; m represents the phase number of the phase regulator; p represents the number of pole pairs; K δ K is the Cartesian coefficient, which reflects the effect of core slotting on the air gap magnetic field. δ >1; B δ is the air gap magnetic flux density; f b is the waveform factor; f d is the air gap magnetic field distribution coefficient; f represents the grid frequency; the pole distance τ is equal to π(D z +2δ) / (2p), Dz is the rotor diameter.

[0019] Furthermore, in step 2), f b ·f d It is determined by the ratio r of the number of rotor slots to the number of rotor slot divisions, which is less than and close to 0.7.

[0020] Furthermore, in step 2),

[0021] Depend on Get formula (6):

[0022]

[0023] In the formula, δ min is the minimum allowable value of δ; B δmin For B δ The minimum allowed value.

[0024] Furthermore, in step 3), solve for l under the corresponding N value t The formulas for , δ and S are as follows:

[0025]

[0026] Q xs (N, l t ,δ) =SX s (7)

[0027]

[0028] Where D z is the rotor diameter; Q xs , Q xfs They are the calculation functions of stator winding leakage reactance and excitation winding leakage reactance respectively.

[0029] Furthermore, in step 4), using the line load A, the air gap magnetic flux density B δ 、Calculated length of stator core l t Step 3) The rationality of the calculation result is judged by the range of the size ratio of the pole pitch τ. If it meets the formula (9) to (14), record the corresponding [N, l t , δ]; Formula (9) to Formula (14) are as follows:

[0030]

[0031] δ ≥ δ min (12)

[0032] S<1 (13)

[0033]

[0034] In the formula, A max , A min Respectively represent the maximum and minimum permissible values ​​of line load A; δ min is the minimum allowable value of δ; B δmin For B δ The minimum allowable value of B δmax For B δ The maximum permissible value of min , max They represent the minimum and maximum permissible values ​​of the ratio of the calculated length of the stator core to the pole pitch; Q xds is the calculation function of the direct-axis reactance of the damping winding.

[0035] Furthermore, in step 4), the end condition is formula (15):

[0036]

[0037] Furthermore, in step 6), the W f is the maximum integer satisfying formula (16):

[0038]

[0039] In the formula, l F Indicates the length of each pole coil; q frepresents the cross-sectional area of ​​the rotor conductor; φ represents the magnetic flux per pole at no load,

[0040] In order to meet the requirements of transient reactive power support capacity of the phase regulator, the calculation result of the direct axis transient open circuit time constant should be less than or equal to T in the phase regulator performance index requirements. d0 ′,

[0041] Right now at the same time Obtain formula (16), l F and q f Determined by the size of the rotor coil, the number of turns per pole of the rotor excitation winding is obtained; R f Represents the resistance of the field winding.

[0042] Furthermore, the following steps are performed between step 3) and step 4): the sub-transient and transient performance of the phase shifter is improved by reducing the stator leakage reactance, thereby selecting the stator slot type, rotor diameter, number of rotor slots, ratio of the number of rotor slots to the number of rotor slot divisions and design values ​​of the rotor slot type; the stator slot type selects the minimum stator slot aspect ratio slot type that meets the corresponding requirements of the rated current; the rotor diameter selects a typical value to ensure the reliability of the rotor body under high-speed rotation; the number of rotor slots and the ratio of the number of rotor slots to the number of rotor slot divisions select the maximum allowable values ​​under the corresponding conditions; the rotor slot type selects the minimum slot aspect ratio slot type under the corresponding conditions based on the determination of the rotor diameter, the number of rotor slots and the ratio of the number of rotor slots to the number of rotor slot divisions; reducing the stator tooth height, increasing the slot width and reducing the slot mouth height are all helpful to improve the sub-transient performance of the phase shifter.

[0043] The beneficial effects of the present invention are as follows: the present invention measures the direct-axis subtransient reactance X of the phase regulator to be designed. d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′, directly find out the number of series conductors N of each phase of the stator winding and the calculated length l of the stator core t , air gap δ, number of turns per pole of rotor excitation winding W f The motor design data is selected by optimizing the performance of the phase regulator, and the stator slot type and other design data are selected to ensure that the transient and sub-transient performance of the designed phase regulator meets or exceeds the index requirements. In the present invention, the design values ​​of the phase regulator size not mentioned can be directly obtained by the standard method in the design specification guidance.

[0044] Compared with the traditional technology, the present invention directly establishes the quantitative relationship between the phase regulator size and the performance index, directly links the first step and the last step in the traditional method, avoids repeated optimization calculations, and improves the design calculation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The following is a brief introduction to the drawings required for describing the embodiments of the present invention.

[0046] Figure 1 The present invention is a flow chart of a method for electromagnetic design of a phase modulator. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0048] Example

[0049] This embodiment is an electromagnetic design method for a phase regulator. Figure 1 As shown, the steps are as follows:

[0050] 1) Through the performance index of the phase regulator, the direct-axis subtransient reactance X d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′, approximate solution of the direct-axis armature reaction reactance X ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs and the damping winding direct-axis reactance X ds .

[0051]

[0052] Where f represents the grid frequency.

[0053] Because the direct-axis armature reaction reactance X ad Much larger than the excitation winding leakage reactance X fs and the field winding resistance R f , and the direct-axis transient open-circuit time constant Therefore, equations (1)-(4) can be used to calculate an approximate solution.

[0054] 2) Two calculation methods using the armature reaction magnetomotive force Fa per pole and The direct-axis armature reaction reactance X obtained in step 1) ad , obtain the quantitative relationship between the main design dimensions of the phase regulator, and find the lower limit of the number of series conductors N per phase of the stator winding.

[0055] In the two calculation methods of Fa, U N ,I N F are the rated phase voltage and current of the phase regulator respectively; δ is the air gap magnetic pressure drop; K dpis the winding coefficient, which is less than 1 and is determined by N; m represents the phase number of the phase regulator; p represents the number of pole pairs; K δ K is the Cartesian coefficient, which reflects the effect of core slotting on the air gap magnetic field. δ >1, for a typical phase-shifting structure K δ Slightly greater than 1; B δ is the air gap magnetic flux density; fb is the waveform factor; fd is the air gap magnetic field distribution coefficient; the pole pitch τ is equal to π(D z +2δ) / (2p), lt is the calculated length of the stator core, D z is the rotor diameter.

[0056] because So we can get formula (6):

[0057]

[0058] In the formula, δ represents the air gap that needs to be retained for normal rotor disassembly and assembly; δ min is the minimum allowable value of δ; B δmin is the air gap magnetic flux density B δ The minimum allowable value, B δ It has a clear range of design specifications.

[0059] The present invention carries out electromagnetic design for the overall structure of the existing typical phase regulator. b ·f d It is determined by the ratio r of the number of rotor slots to the number of rotor slot divisions. The number of rotor slots is a positive integer multiple of 4. The design specification guidance requires that r is less than and close to 0.7.

[0060] 3) According to formula (6), N is a positive integer multiple of 2, and a value greater than or equal to And it is the minimum value among the integer multiples of 2 (if Nmin is 2, then N is 2; if Nmin is 3, then N is 4), the stator winding leakage reactance X obtained in step 1) s , solve for l under the corresponding value of N t , δ and S, where S is the adjustment coefficient.

[0061]

[0062] Q xs (N, l t ,δ) =SX s (7)

[0063]

[0064] In the formula, Q xs , Q xfs They are the calculation functions of stator winding leakage reactance and excitation winding leakage reactance, that is, the standard calculation method.

[0065] According to the principle of phase shifter performance optimization, the lower the direct-axis subtransient reactance and direct-axis transient reactance of the phase shifter, the better the subtransient and transient performance of the phase shifter. The values ​​of direct-axis subtransient reactance and direct-axis transient reactance are mainly determined by the stator leakage reactance. The subtransient and transient performance of the phase shifter can be improved by reducing the stator leakage reactance, thereby selecting the design values ​​of the stator slot type, rotor diameter, number of rotor slots, ratio of the number of rotor slots to the number of rotor slot divisions, rotor slot type, etc. The stator slot type is selected to meet the rated current I N Corresponding to the minimum required stator slot aspect ratio slot type, rotor diameter D z Typical values ​​are selected to ensure the reliability of the rotor body under high-speed rotation. The number of rotor slots and r (the ratio of the number of rotor slots to the number of rotor slot divisions) are selected as the maximum allowable values ​​under the corresponding circumstances. The rotor slot type is selected based on the rotor diameter, the number of rotor slots, r, etc. The minimum slot height-to-width ratio slot type under the corresponding circumstances is selected; reducing the stator tooth height, increasing the slot width, and reducing the slot mouth height are all helpful to reduce the stator leakage reactance and improve the sub-transient performance of the phase regulator.

[0066] Step 1) X ad and X s The calculation accuracy is higher, but the calculation methods of formula (1) to (4) will overestimate X ad / X fs The ratio of will cause X in step 1) fs If the calculated result is too low, to ensure X d ′ meets the requirements and guarantees the transient performance of the phase regulator, so the adjustment coefficient S is set and X is taken ad , X s and S are solved simultaneously for different values ​​of N.

[0067] 4) Using line load A and air gap magnetic flux density B δ 、Calculated length of stator core l t The rationality of the calculation results can be judged by the data such as the range of the ratio of the size of the pole pitch τ. If it meets the formulas (9), (10), (11), (12), (13), and (14), the corresponding [N, l t , δ], return to step 3), set N = N + 2, start the loop calculation, and end the loop calculation when the calculation result satisfies formula (15).

[0068]

[0069] δ ≥ δ min (12)

[0070] S<1 (13)

[0071]

[0072]

[0073] In the formula, A max , A min Respectively represent the maximum and minimum permissible values ​​of line load; δ min is the minimum allowable value of δ; B δmin For B δ The minimum allowable value of B δmax For B δ The maximum permissible value of min , max They represent the minimum and maximum permissible values ​​of the ratio of the calculated length of the stator core to the pole pitch; Q xds is the calculation function of the direct-axis reactance of the damping winding.

[0074] For conventional phase-converter structure, the rotor excitation winding leakage reactance X fs Greater than the excitation resistance R f , X calculated in step 1) s Slightly larger, X ad Slightly smaller, so the adjustment coefficient S is required to be less than 1. At the same time, the reduction of the stator winding leakage reactance is beneficial to the improvement of the transient and sub-transient performance of the phase regulator. In equations (7) and (8), S·X s Rather than X s The joint solution can ensure that the relevant performance of the final design result is better than the index requirements.

[0075] 5) For all [N, l obtained in step 4) t , δ], select a set of data with the smallest δ and determine the corresponding N and l t .

[0076] From step 2) in equation (5), it can be found that the direct-axis armature reaction reactance X ad When δ is a fixed value, the smaller N 2 l t The smaller, the lower the cost, and at the same time through Q xds From the calculation formula in the design specification guidance, it can be seen that combined with the selection of design values ​​such as slot type in step 3), to ensure X ds To meet the performance index of the phase regulator X d ″、X d ′、T d ′ and T d0 ’The minimum value required.

[0077] 6) According to the direct axis transient open circuit time constant T d0 'Determine the number of turns per pole of the rotor excitation winding W f , W f is the maximum integer that satisfies equation 16).

[0078]

[0079] In the formula, l F Indicates the length of each pole coil; q f represents the cross-sectional area of ​​the rotor conductor; φ represents the magnetic flux per pole at no load,

[0080] In order to meet the requirements of transient reactive power support capacity of the phase shifter, the calculation result of the direct axis transient open circuit time constant in the electromagnetic design scheme should be less than or equal to T in the phase shifter performance index requirements. d0 ′, at the same time Then we can get formula (16), F and q f Determined by the size of the rotor coil, the number of turns per pole of the rotor excitation winding is W f .

[0081] Application Examples

[0082] It is necessary to design a phase regulator with a rated capacity of 300Mvar, three phases, a pole pair of 1, a rated voltage of 20kV, a double-layer winding in the stator slot, and a stator winding parallel branch number of 2 (this is a typical structure of a 300Mvar phase regulator for a converter station). Its performance indicators are as follows: direct-axis subtransient reactance X d ″ is 9.65%, the direct axis transient reactance X d ' is 14.75%, the direct axis transient short circuit time constant T d ' is 0.75s, the direct axis transient open circuit time constant T d0 ′ is 7.46s. The lower the values ​​of the above four performance indicators are, the better the transient and transient performance of the phase regulator is.

[0083] The electromagnetic design method of the above phase regulator is designed as follows:

[0084] 1. Approximately calculate the direct-axis armature reaction reactance X ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs , Damping winding direct axis reactance X ds , where X ad and X s The calculation accuracy is high, and these two data are used to carry out design calculations.

[0085] 2. Use two calculation methods of the armature reaction magnetomotive force per pole to obtain the quantitative relationship between the main design dimensions of the phase regulator.

[0086] 3. Calculate the lower limit of N:

[0087] 4. Select greater than or equal to And the minimum value among the integer multiples of 2 is N. Find l under the corresponding value of Nt , δ and S.

[0088] 5. According to the principle of phase shifter performance optimization, select the stator slot type, rotor diameter, number of rotor slots, ratio of the number of rotor slots to the number of rotor slot divisions, rotor slot type and other design values, reduce the stator tooth height, increase the slot width, and reduce the slot height, which are all helpful to improve the transient performance of the phase shifter. The stator slot type is selected to meet the rated current I N Corresponding to the minimum required stator slot aspect ratio slot type, rotor diameter D z Typical values ​​are selected to ensure the reliability of the rotor body under high-speed rotation. The number of rotor slots and r are selected to have the maximum allowable values ​​under the corresponding circumstances. The rotor slot type is selected to have the minimum slot height-to-width ratio under the corresponding circumstances based on the rotor diameter, number of rotor slots, r, etc.

[0089] 6. Use line load A and air gap magnetic density B δ 、Calculated length of stator core l t The rationality of the calculation result in step 4) is judged by the range of the ratio of the size of the pole pitch τ, and if it meets the following formula, record the corresponding [N, l t , δ], return to step 4, set N = N + 2, and start the loop calculation, where Qxds is the calculation function of the damping winding direct axis reactance, that is, the standard method of obtaining. For conventional phase-converting structure, the rotor excitation winding leakage reactance Xfs is greater than the excitation resistance R f , Xs calculated in step 1) is slightly larger and Xad is slightly smaller, so the adjustment coefficient S is required to be less than 1. At the same time, reducing the value of stator winding leakage reactance is beneficial to improving the transient and sub-transient performance of the phase regulator.

[0090] 7. When the calculation result of step 4) meets the following conditions, the loop calculation ends.

[0091]

[0092] 8. For all obtained [N, l t , δ], select a set of data with the smallest δ and determine N and l t , where the number of series conductors N in each phase of the stator winding is 16, and the number of stator slots is 48. From the calculation formula in step 2), it can be found that in the direct axis armature reaction reactance X ad When δ is a fixed value, the smaller N 2 l t The smaller it is, the lower the cost.

[0093] 9. In order to meet the requirements of transient reactive power support capacity of the phase shifter, the calculation result of the direct axis transient open circuit time constant in the electromagnetic design scheme should be less than or equal to T in the phase shifter performance index requirements. d0 ', and the number of turns per pole of the rotor excitation winding is determined by this f , W fis the largest integer that satisfies the following equation.

[0094]

[0095] In the method of the present invention, the design values ​​such as motor size not mentioned can be directly obtained by the standard method in the design specification guidance. Through the calculation of electromagnetic design results, the direct axis subtransient reactance is less than 9.65%, the direct axis transient reactance is less than 14.75%, the direct axis transient short circuit time constant is less than 0.75s, and the direct axis transient open circuit time constant is less than 7.46s. The design results are better than the performance index requirements.

[0096] Compared with the traditional technology, the present invention directly establishes the quantitative relationship between the motor size and the performance index, directly links the first step and the last step in the traditional method, avoids repeated optimization calculations, and improves the design calculation efficiency.

[0097] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the protection scope of the present invention.

Claims

1. An electromagnetic design method for a phase regulator, characterized in that: include: Step 1) By using the performance index of the phase regulator, the direct-axis subtransient reactance X d ″、Direct axis transient reactance X d ', direct axis transient short circuit time constant T d ′ and direct axis transient open circuit time constant T d0 ′, approximate solution of the direct-axis armature reaction reactance X ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs and the damping winding direct-axis reactance X ds ; Step 2), use the armature reaction magnetomotive force F of each pole a Two calculation methods are used to calculate the direct-axis armature reaction reactance X obtained in step 1). ad , obtain the quantitative relationship between the main design dimensions of the phase regulator, and find the lower limit N of the number of series conductors per phase of the stator winding min ; Step 3), select greater than or equal to N min The minimum value among the integer multiples of 2 is N, and the stator winding leakage reactance X obtained in step 1) is s , solve for l under the corresponding value of N t ,δandS, where S is the adjustment coefficient, l t is the calculated length of the stator core, and δ is the air gap size that needs to be retained for normal rotor disassembly and assembly; Step 4), judge the rationality of the calculation results, if they meet the requirements, record the corresponding [N, l t , δ], return to step 3), set N = N + 2, start loop calculation, and end the loop calculation when the calculation result meets the end condition; Step 5), for all [N, l obtained in step 4) t , δ], select a set of data with the smallest δ and determine the corresponding N and l t ; Step 6), according to the direct axis transient open circuit time constant T d0 'Determine the number of turns per pole of the rotor excitation winding W f .

2. The electromagnetic design method of a phase regulator according to claim 1, characterized in that: In step 1), the direct-axis armature reaction reactance X is solved by the following formula: ad , stator winding leakage reactance X s , excitation winding leakage reactance X fs and the damping winding direct-axis reactance X ds : Where f represents the grid frequency.

3. The electromagnetic design method of a phase regulator according to claim 1, characterized in that: In step 2), two methods for calculating the armature reaction magnetomotive force Fa of each pole are as follows: and Where U N ,I N F are the rated phase voltage and current of the phase regulator respectively; δ is the air gap magnetic pressure drop; K dp is the winding coefficient, whose value is less than 1; m represents the phase number of the phase regulator; p represents the number of pole pairs; K δ K is the Cartesian coefficient, which reflects the effect of core slotting on the air gap magnetic field. δ >1; B δ is the air gap magnetic flux density; f b is the waveform factor; f d is the air gap magnetic field distribution coefficient; f represents the grid frequency; the pole distance τ is equal to π(D z +2δ) / (2p), Dz is the rotor diameter.

4. The electromagnetic design method of a phase regulator according to claim 3, characterized in that: In step 2), f b ·f d It is determined by the ratio r of the number of rotor slots to the number of rotor slot divisions, which is less than and close to 0.

7.

5. The electromagnetic design method of a phase modulator according to claim 3, characterized in that: In step 2), Depend on Get formula (6): In the formula, δ min is the minimum allowable value of δ; B δmin For B δ The minimum allowed value.

6. The electromagnetic design method of a phase regulator according to claim 3, characterized in that: In step 3), solve for l under the corresponding N value t The formulas for , δ and S are as follows: Q xs (N、l t 、d) =SX s (7) Where D z is the rotor diameter; Q xs , Q xfs They are the calculation functions of stator winding leakage reactance and excitation winding leakage reactance respectively.

7. The electromagnetic design method of a phase regulator according to claim 6, characterized in that: In step 4), use the line load A and air gap magnetic flux B δ 、Calculated length of stator core l t The size ratio range of the pole pitch τ determines the rationality of the calculation result in step 3). If it complies with equations (9) to (14), record the corresponding [N, l t , δ]; Formula (9) to Formula (14) are as follows: δ≥δ min (12) S＜1 (13) In the formula, A max , A min Respectively represent the maximum and minimum permissible values ​​of line load A; δ min is the minimum allowable value of δ; B δmin For B δ The minimum allowable value of B δmax For B δ The maximum permissible value of λ min , max They represent the minimum and maximum permissible values ​​of the ratio of the calculated length of the stator core to the pole pitch; Q xds is the calculation function of the direct-axis reactance of the damping winding.

8. The electromagnetic design method of a phase modulator according to claim 7, characterized in that: In step 4), the end condition is formula (15):

9. The electromagnetic design method of a phase modulator according to claim 3, characterized in that: In step 6), the W f is the maximum integer satisfying formula (16): In the formula, l F Indicates the length of each pole coil; q f represents the cross-sectional area of ​​the rotor conductor; φ represents the magnetic flux per pole at no load, In order to meet the requirements of transient reactive power support capacity of the phase regulator, the calculation result of the direct axis transient open circuit time constant should be less than or equal to T in the phase regulator performance index requirements. d0 ′, Right now at the same time Obtain formula (16), l F and q f Determined by the size of the rotor coil, the number of turns per pole of the rotor excitation winding is obtained; R f Represents the resistance of the field winding.

10. The electromagnetic design method of a phase regulator according to claim 1, characterized in that: The following steps are also performed between step 3) and step 4): the sub-transient and transient performance of the phase shifter is improved by reducing the stator leakage reactance, thereby selecting the stator slot type, rotor diameter, number of rotor slots, ratio of the number of rotor slots to the number of rotor slot divisions and design value of the rotor slot type; the stator slot type selects the minimum stator slot aspect ratio slot type that meets the corresponding requirements of the rated current; the rotor diameter selects a typical value to ensure the reliability of the rotor body under high-speed rotation; the number of rotor slots and the ratio of the number of rotor slots to the number of rotor slot divisions select the maximum allowable values ​​under the corresponding conditions; the rotor slot type selects the minimum slot aspect ratio slot type under the corresponding conditions based on the determination of the rotor diameter, the number of rotor slots and the ratio of the number of rotor slots to the number of rotor slot divisions; reducing the stator tooth height, increasing the slot width and reducing the slot mouth height are all helpful to improve the sub-transient performance of the phase shifter.

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