A method for cooperative control of rotating speeds of a magnetic suspension motor and a working medium pump

Abstract

The application provides a kind of magnetic suspension motor and working medium pump's rotational speed collaborative control method, it is related to control technical field.The method includes: obtaining the first operating parameter of the current time magnetic suspension motor;According to the first operating parameter, predict the target motor speed of the next time magnetic suspension motor and the target working medium pump speed of working medium pump, target motor speed is associated with target working medium pump speed;In the next time, the rotational speed of magnetic suspension motor is adjusted to target motor speed, and the rotational speed of working medium pump is adjusted to target working medium pump speed.The magnetic suspension motor and working medium pump's rotational speed collaborative control method provided by the application, by the rotational speed of magnetic suspension motor and working medium pump real-time correlation prediction and collaborative control, solve the problem that magnetic suspension motor and working medium pump rotational speed cannot be adjusted in traditional control, improve the response speed of magnetic suspension motor and working medium pump when working condition changes, avoid the energy consumption problem caused by magnetic suspension motor overspeed and working medium pump rotational speed not following up adjustment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of control, in particular to a kind of magnetic suspension motor and working medium pump's rotating speed coordination control method. BACKGROUND

[0002] Magnetic suspension motor is more and more widely used in the field of new energy power generation due to its low friction, high efficiency and other advantages.In the magnetic suspension power generation system, magnetic suspension motor and working medium pump as key components, its rotating speed coordination is crucial to system performance.

[0003] In related technologies, the rotating speed control of magnetic suspension motor and working medium pump is often independent of each other, without fully considering the coupling relationship between them, resulting in low system efficiency, and it is difficult to respond quickly when working condition changes, affecting the stability and reliability of power generation system.For example, when the load changes suddenly, due to the inability of magnetic suspension motor and working medium pump to adjust the rotating speed coordinately, there will be problems such as large power generation power fluctuation and working medium flow imbalance, which not only reduces energy utilization, but also may cause damage to power generation equipment.Therefore, it is of great practical significance to develop a strategy that can realize the rotating speed coordination control of magnetic suspension motor and working medium pump. SUMMARY

[0004] To solve the problems in related technologies, the present application provides a kind of rotating speed coordination control method of magnetic suspension motor and working medium pump, the method comprises:

[0005] obtain the first operating parameter of the magnetic suspension motor at the current time;

[0006] According to the first operating parameter, predict the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next time, the target motor speed is associated with the target working medium pump speed;

[0007] At the next time, the rotating speed of the magnetic suspension motor is adjusted to the target motor speed, and the rotating speed of the working medium pump is adjusted to the target working medium pump speed.

[0008] In some embodiments of the present application, the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next time are predicted according to the first operating parameter, comprising:

[0009] According to the first operating parameter and prediction model, the target motor speed is predicted;

[0010] The target working medium pump speed is obtained by processing the target motor speed using rolling optimization algorithm.

[0011] In some embodiments of the present application, the method further comprises:

[0012] acquire a second running parameter of the working medium pump at the current time;

[0013] the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next time are predicted according to the first running parameter, including:

[0014] a speed ratio of the magnetic suspension motor and the working medium pump is determined according to the first running parameter and the second running parameter;

[0015] the target motor speed is predicted according to the first running parameter and a prediction model;

[0016] the target working medium pump speed is predicted according to the target motor speed and the speed ratio.

[0017] In some embodiments of the present application, the first running parameter includes the current motor speed and the rotor temperature change amount of the magnetic suspension motor, and the second running parameter includes the working medium pressure change amount of the working medium pump; the speed ratio of the magnetic suspension motor and the working medium pump is determined according to the first running parameter and the second running parameter, including:

[0018] a product of a first coefficient and the current motor speed is taken as a first parameter, a product of a second coefficient and the rotor temperature change amount is taken as a second parameter, and a product of a third coefficient and the working medium pressure change amount is taken as a third parameter;

[0019] a sum of the first parameter, the second parameter and the third parameter is determined as the speed ratio.

[0020] In some embodiments of the present application, the target working medium pump speed is predicted according to the target motor speed and the speed ratio, including:

[0021] a ratio of the target motor speed to the speed ratio is determined as the target working medium pump speed.

[0022] In some embodiments of the present application, the method further includes:

[0023] a target temperature of the magnetic suspension motor at the next time is predicted according to the first running parameter and a second running parameter of the working medium pump.

[0024] In some embodiments of the present application, the method further includes:

[0025] the target motor speed is corrected according to the target temperature;

[0026] the speed of the magnetic suspension motor is adjusted to the target motor speed and the speed of the working medium pump is adjusted to the target working medium pump speed at the next time, including:

[0027] adjust the rotational speed of the magnetic suspension motor to the corrected target motor rotational speed at the next moment.

[0028] In some embodiments of the application, the target motor rotational speed and the target working medium pump rotational speed of the magnetic suspension motor at the next moment are predicted according to the first operating parameter, comprising:

[0029] the target working medium pump rotational speed is determined according to the corrected target motor rotational speed; and / or,

[0030] the target motor rotational speed is corrected according to the target temperature, comprising:

[0031] a correction coefficient is determined according to the target temperature;

[0032] the target motor rotational speed is corrected by the correction coefficient.

[0033] In some embodiments of the application, the method further comprises:

[0034] a first correction rotational speed of the rotational speed of the magnetic suspension motor is determined according to the first operating parameter;

[0035] the target motor rotational speed is corrected by the first correction rotational speed;

[0036] adjusting the rotational speed of the magnetic suspension motor to the target motor rotational speed and the rotational speed of the working medium pump to the target working medium pump rotational speed at the next moment, comprising:

[0037] adjust the rotational speed of the magnetic suspension motor to the corrected target motor rotational speed at the next moment.

[0038] In some embodiments of the application, the first operating parameter comprises the current motor rotational speed of the magnetic suspension motor; the first correction rotational speed of the rotational speed of the magnetic suspension motor is determined according to the first operating parameter, comprising:

[0039] a predicted motor rotational speed of the magnetic suspension motor at the current moment is determined;

[0040] the difference between the current motor rotational speed and the predicted motor rotational speed is determined as the first correction rotational speed;

[0041] the target motor rotational speed is corrected by the first correction rotational speed, comprising:

[0042] the target motor rotational speed is superimposed with the first correction rotational speed.

[0043] The magnetic suspension motor and working medium pump rotating speed cooperative control method provided by the application can predict the target motor rotating speed of the magnetic suspension motor and the target working medium pump rotating speed of the working medium pump at the next moment by acquiring the first operating parameter of the magnetic suspension motor in real time, and adjust the rotating speed of the magnetic suspension motor to the target motor rotating speed and the rotating speed of the working medium pump to the target working medium pump rotating speed at the next moment. That is, by predicting and cooperatively controlling the rotating speed of the magnetic suspension motor and the working medium pump in real time, the problem that the rotating speed of the magnetic suspension motor and the working medium pump cannot be cooperatively adjusted in the traditional control is solved, the response speed of the magnetic suspension motor and the working medium pump when the working condition changes is improved, and the problem of energy waste caused by the over-speed of the magnetic suspension motor and the failure of the working medium pump to follow up and adjust is avoided.

[0044] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory and are not restrictive of the application. BRIEF DESCRIPTION OF DRAWINGS

[0045] The accompanying drawings incorporated in and forming a part of the specification illustrate embodiments of the application and, together with the description, serve to explain the principles of the embodiments of the application. In the drawings, like reference numerals are used to indicate like elements. The accompanying drawings are of some, but not necessarily all, embodiments of the application. Other drawings can be derived from these drawings by persons of skill in the art without paying creative effort.

[0046] Figure 1 A magnetic suspension motor and working medium pump rotating speed cooperative control method flow chart for a first exemplary embodiment of the application;

[0047] Figure 2 A magnetic suspension motor and working medium pump rotating speed cooperative control method flow chart for a second exemplary embodiment of the application;

[0048] Figure 3 A magnetic suspension motor and working medium pump rotating speed cooperative control method flow chart for a third exemplary embodiment of the application;

[0049] Figure 4 A magnetic suspension motor and working medium pump rotating speed cooperative control method flow chart for a fourth exemplary embodiment of the application. DETAILED DESCRIPTION

[0050] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application. It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other at will.

[0051] In the magnetic suspension power generation system, the magnetic suspension motor and the working medium pump as key components, the speed coordination is crucial to the system performance.

[0052] In the related art, the speed control of the magnetic suspension motor and the working medium pump is often independent of each other, and the coupling relationship between them is not fully considered, resulting in low system operation efficiency, and it is difficult to respond quickly when the working condition changes, affecting the stability and reliability of the power generation system. For example, when the load changes suddenly, due to the inability of the magnetic suspension motor and the working medium pump to adjust the speed in coordination, problems such as large power generation power fluctuation and working medium flow imbalance occur, which not only reduces the energy utilization rate, but also may cause damage to the power generation equipment. Therefore, it is of great practical significance to develop a strategy that can realize the speed coordination control of the magnetic suspension motor and the working medium pump.

[0053] In order to solve the above technical problems, the present application provides a speed coordination control method for magnetic suspension motor and working medium pump, by real-time acquisition of the first running parameter of the magnetic suspension motor to predict the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next moment, and adjust the speed of the magnetic suspension motor to the target motor speed and the speed of the working medium pump to the target working medium pump speed at the next moment, that is, by real-time correlation prediction and coordinated control of the speed of the magnetic suspension motor and the working medium pump, the problem of unable to adjust the speed of the magnetic suspension motor and the working medium pump in coordination in traditional control is solved, the response speed of the magnetic suspension motor and the working medium pump when the working condition changes is improved, and the problem of energy waste caused by the magnetic suspension motor running too fast and the working medium pump speed not following up is avoided.

[0054] The embodiment of the present application provides a speed coordination control method for magnetic suspension motor and working medium pump, as shown in Figure 1 The method comprises the following steps:

[0055] S100, acquiring the first running parameter of the magnetic suspension motor at the current moment.

[0056] S200, according to the first running parameter, predicting the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next moment, the target motor speed and the target working medium pump speed are associated.

[0057] S300, adjust the rotating speed of the magnetic suspension motor to the target motor rotating speed and adjust the rotating speed of the working medium pump to the target working medium pump rotating speed at the next moment.

[0058] In this embodiment, the target motor rotating speed of the magnetic suspension motor and the target working medium pump rotating speed of the working medium pump at the next moment are predicted by acquiring the first operating parameters of the magnetic suspension motor in real time, and the rotating speed of the magnetic suspension motor is adjusted to the target motor rotating speed and the rotating speed of the working medium pump is adjusted to the target working medium pump rotating speed at the next moment, that is, the rotating speeds of the magnetic suspension motor and the working medium pump are predicted and controlled in real time in association, the problem that the rotating speeds of the magnetic suspension motor and the working medium pump cannot be adjusted in association in the traditional control is solved, the response speed of the magnetic suspension motor and the working medium pump when the working condition changes is improved, and the problem of energy waste caused by the over-speed of the magnetic suspension motor and the failure of the working medium pump to follow up and adjust is avoided.

[0059] In an embodiment, as shown in Figure 2 the step of predicting the target motor rotating speed of the magnetic suspension motor and the target working medium pump rotating speed of the working medium pump at the next moment according to the first operating parameters in the step S200 comprises:

[0060] S201, predict the target motor rotating speed according to the first operating parameters and a prediction model.

[0061] For example, the first operating parameters can include the motor rotating speed n m (k) at the current moment (for example, the k moment), the time change Δt, the electromagnetic torque T e (k) at the current moment, the moment of inertia J of the magnetic suspension motor, and the motor temperature T L (k) at the current moment. The time change Δt can be the time difference between the current moment and the previous moment (for example, the k-1 moment), or the time difference between the next moment (for example, the k+1 moment) and the current moment, wherein the time change Δt can be 1s, 5s, 30s, and can also be 1min, 5min, 10min, etc., which are not limited in the present application. The prediction model can be represented by the following formula (1):

[0062] n m (k+1)= n m (k)+ (T e (k)- T L (k)) (1)

[0063] wherein n m (k+1) is the target motor rotating speed.

[0064] In this embodiment, according to the prediction model and the first operating parameter of the magnetic suspension motor obtained in real time, the target motor speed of the magnetic suspension motor at the next moment can be predicted, so as to facilitate adjustment of the speed of the magnetic suspension motor to the target motor speed at the next moment.

[0065] S202, the target motor speed is processed by using a rolling optimization algorithm to obtain a target working medium pump speed.

[0066] The target motor speed is associated with the target working medium pump speed. After the target motor speed is predicted according to the first operating parameter and the prediction model in step S201, the target working medium pump speed can be predicted in association with the target motor speed, that is, the target motor speed is processed by using a rolling optimization algorithm to obtain the target working medium pump speed, wherein the rolling optimization algorithm can be represented by the following formula (2):

[0067] (2)

[0068] Wherein, N p is the prediction time domain (the number of steps of future prediction), N c is the control time domain (the number of steps of optimization control instruction), n ref is the working medium pump reference speed (the working medium pump speed at the last moment), n m (k+i) is the motor speed at k+i moment, n p (k+i) is the working medium pump speed at k+i moment, ΔV d (k+i) is the d-axis voltage of the magnetic suspension motor at k+i moment, and λ is the weight coefficient of the working medium pump energy consumption. Wherein, N p may be 1-5, for example, can be 1, 3 or 5, N c may be 1-5, for example, can be 1, 3 or 5, λ can be 3-9, for example, can be 3, 6.5 or 9. When the target working medium pump speed n p (k+1) at k+1 moment is needed, then the value of i is 1. The target motor speed n m (k+1) is processed by the rolling optimization algorithm of formula (2), and the target working medium pump speed n p (k+1) at k+1 moment is calculated.

[0069] In this embodiment, the error of the prediction model is compensated in real time by the rolling optimization algorithm (such as model predictive control (MPC) algorithm), so as to ensure that the predicted target motor speed and target working medium pump speed are strongly coupled.

[0070] In one embodiment, the speed cooperative control method of the magnetic suspension motor and the working medium pump further comprises:

[0071] Obtaining the second operating parameter of the working medium pump at the current moment.

[0072] As Figure 3 shown, the step S200 of predicting the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump according to the first operating parameter includes:

[0073] S210, determining the speed ratio of the magnetic suspension motor and the working medium pump according to the first operating parameter and the second operating parameter.

[0074] The first operating parameter includes the current motor speed n m and the rotor temperature change amount ΔT, and the second operating parameter includes the working medium pressure change amount ΔP. As Figure 4 shown, the step S210 of determining the speed ratio of the magnetic suspension motor and the working medium pump according to the first operating parameter and the second operating parameter includes:

[0075] S211, taking the product of the first coefficient and the current motor speed as the first parameter, the product of the second coefficient and the rotor temperature change amount as the second parameter, and the product of the third coefficient and the working medium pressure change amount as the third parameter. The rotor temperature change amount can refer to the rotor temperature difference between the current time and the previous time, or the rotor temperature difference between the next time and the current time. The working medium pressure change amount can be the working medium pressure difference between the current time and the previous time, or the working medium pressure difference between the next time and the current time.

[0076] S212, determining the sum of the first parameter, the second parameter and the third parameter as the speed ratio, as shown in the following formula (3):

[0077] K target= α n m + β ΔT + γ ΔP (3)

[0078] wherein K target is the speed ratio, α is the first coefficient, β is the second coefficient, γ is the third coefficient, n m is the current motor speed, ΔT is the rotor temperature change amount, and ΔP is the working medium pressure change amount. The first coefficient α, the second coefficient β and the third coefficient γ are working condition adaptive coefficients. The range of the first coefficient α can be 10 -5 ~10 -3 (rpm) -1 , for example, 0.00001 (rpm) -1 , 0.00032 (rpm) -1Or 0.001 (rpm) -1 The range of the second coefficient β can be 10. -3 ~10 -1 (°C) -1 For example, it could be 0.001 (°C). -1 0.075 (°C) -1 Or 0.1 (°C) -1 The range of the third coefficient γ can be 10. -3 ~2 10 -1 (MPa) -1 For example, it could be 0.001 (MPa) -1 0.11 (MPa) -1 Or 0.2 (MPa) -1 n m The range of ΔT can be 0~30000 rmp, for example, 0, 1000 rmp, 10000 rmp or 30000 rmp. The range of ΔT can be 3~10 ℃, for example, 3 ℃, 5 ℃, 8 ℃ or 10 ℃. The range of ΔP can be 0~0.8 MPa, for example, 0, 0.2 MPa, 0.5 MPa or 0.8 MPa.

[0079] The speed ratio K is calculated by weighted fusion of motor speed (mechanical state), rotor temperature (thermal state), and working fluid pressure (fluid state). target The effect of these three factors on the speed ratio K can be quantified. target The contribution of this technology allows for the prediction of the target motor speed and the target working fluid pump speed based on the real-time operating status of the magnetic levitation motor and the working fluid pump, thus ensuring the accuracy of the prediction.

[0080] S220. Based on the first operating parameters and the prediction model, predict the target motor speed.

[0081] The prediction model can be represented by the above formula (1).

[0082] S230. Predict the target working fluid pump speed based on the target motor speed and speed ratio.

[0083] Step S230, which predicts the target working fluid pump speed based on the target motor speed and speed ratio, includes:

[0084] The ratio of the target motor speed to the speed ratio is determined as the target working fluid pump speed, as expressed by the following formula (4):

[0085] n p (k+1) (4)

[0086] wherein, n p (k+1) is the target working fluid pump rotating speed.

[0087] In this embodiment, the target working fluid pump rotating speed is determined by taking the target motor rotating speed and the rotating speed ratio as a ratio, which ensures the linear correspondence between the target working fluid pump rotating speed and the target motor rotating speed in the prediction process, thereby ensuring the prediction accuracy.

[0088] In this embodiment, when predicting the target motor rotating speed and the target working fluid pump rotating speed, the first operating parameter of the magnetic suspension motor and the second operating parameter of the working fluid pump are introduced, and the dynamic rotating speed ratio of the magnetic suspension motor and the working fluid pump is determined according to the first operating parameter of the magnetic suspension motor and the second operating parameter of the working fluid pump, thereby strengthening the coupling of the predicted target motor rotating speed and the target working fluid pump rotating speed.

[0089] In an embodiment, the rotating speed cooperative control method of the magnetic suspension motor and the working fluid pump further comprises:

[0090] predicting the target temperature of the magnetic suspension motor at the next moment according to the first operating parameter and the second operating parameter of the working fluid pump.

[0091] For example, the first operating parameter can include the motor temperature T(k) at the current moment, the time variation Δt, and the second operating parameter of the working fluid pump can include the temperature dynamic correction coefficient C of the working fluid pump, the heat dissipation Q(k) of the working fluid pump at the current moment, and the target temperature T(k+1) of the magnetic suspension motor at the next moment can be predicted by the following formula (5): cool

[0092] T(k+1)= T(k)+Δt C Q cool (k) (5)

[0093] In this embodiment, the target temperature of the magnetic suspension motor at the next moment is predicted based on the first operating parameter of the magnetic suspension motor and the second operating parameter of the working fluid pump, which can identify the overheating risk in advance, actively reduce the speed before the temperature of the magnetic suspension motor exceeds the limit (for example, exceeds the preset threshold), avoid the emergency shutdown caused by the traditional “after protection”, and improve the equipment reliability. In addition, the prediction result of the target temperature of the magnetic suspension motor at the next moment can also be involved in the prediction of the target motor rotating speed and the target working fluid pump rotating speed, so as to realize the optimization and coordination of the heat dissipation demand and the power generation efficiency of the equipment.

[0094] In an embodiment, the rotating speed cooperative control method of the magnetic suspension motor and the working fluid pump further comprises:

[0095] correcting the target motor rotating speed according to the target temperature. ​

[0096] For example, a temperature threshold is set, and the target temperature is subtracted from the temperature threshold. When the result of the target temperature minus the temperature threshold is positive, it means that the target temperature is greater than the temperature threshold, the target temperature of the magnetic suspension motor is overheated, and the target motor speed needs to be reduced. At this time, the target motor speed needs to be reduced and corrected. Conversely, when the result of the target temperature minus the temperature threshold is negative, it means that the target temperature is less than the temperature threshold, the target temperature of the magnetic suspension motor is not overheated, and the target motor speed can be increased to improve the power generation efficiency. At this time, the target motor speed needs to be increased and corrected. In this way, the speed of the magnetic suspension motor can be increased to ensure the safety of the equipment while improving the power generation efficiency under the condition that the temperature of the magnetic suspension motor does not exceed the limit.

[0097] In an embodiment, the step S300 of adjusting the speed of the magnetic suspension motor to the target motor speed and adjusting the speed of the working medium pump to the target working medium pump speed at the next time includes:

[0098] The speed of the magnetic suspension motor is adjusted to the corrected target motor speed at the next time.

[0099] After the target motor speed is corrected, for example, after the target motor speed is corrected according to the target temperature, the speed of the magnetic suspension motor is adjusted to the corrected target motor speed at the next time, which can avoid overheating and out-of-control of the equipment and shorten the temperature adjustment time.

[0100] In an embodiment, the step S200 of predicting the target motor speed of the magnetic suspension motor and the target working medium pump speed of the working medium pump at the next time according to the first operating parameter includes:

[0101] The target working medium pump speed is determined according to the corrected target motor speed.

[0102] In this embodiment, the target working medium pump speed is determined according to the corrected target motor speed, that is, the corrected target motor speed and the target working medium pump speed are associated and predicted and controlled cooperatively, which solves the problem that the speed of the magnetic suspension motor and the working medium pump cannot be adjusted cooperatively in traditional control, improves the response speed of the magnetic suspension motor and the working medium pump when the working condition changes suddenly, and avoids the problem that the speed of the magnetic suspension motor is too high or overheated while the speed of the working medium pump is not adjusted.

[0103] In an embodiment, the step of correcting the target motor speed according to the target temperature includes:

[0104] A correction coefficient is determined according to the target temperature.

[0105] The target motor speed is corrected by the correction coefficient.

[0106] For example, a temperature threshold is set, the target temperature is subtracted from the temperature threshold, and a correction coefficient is determined according to the obtained temperature difference value, which can be any value between 0.8 and 1.2. When the result of subtracting the target temperature from the temperature threshold is positive, it means that the target temperature is greater than the temperature threshold, the target temperature of the predicted magnetic suspension motor is overheated, and the target motor speed needs to be reduced. At this time, the correction coefficient can be a number between 0.8 and 1, and the greater the result of subtracting the target temperature from the temperature threshold, the smaller the value of the correction coefficient should be, so that the correction degree of the correction coefficient to the target motor speed is greater. Conversely, when the result of subtracting the target temperature from the temperature threshold is negative, it means that the target temperature is less than the temperature threshold, the target temperature of the predicted magnetic suspension motor does not overheat, and the target motor speed can be increased to improve the power generation efficiency. At this time, the correction coefficient can be a number between 1 and 1.2, and the greater the result of subtracting the target temperature from the temperature threshold, the greater the value of the correction coefficient should be, so that the correction degree of the correction coefficient to the target motor speed is greater.

[0107] In an embodiment, the method for cooperative control of the rotation speeds of the magnetic suspension motor and the working medium pump further comprises:

[0108] According to the first operation parameter, a first corrected rotation speed of the magnetic suspension motor is determined.

[0109] The target motor speed is corrected by the first corrected rotation speed.

[0110] The first operation parameter can include the current motor rotation speed (k), and the first corrected rotation speed e(k) can be determined according to the current motor rotation speed (k) and the predicted motor rotation speed (k) at the current time (predicted at the previous time), that is, represented by the following formula (6):

[0111] e(k)= (k)- (k) (6)

[0112] The target motor speed n m (k+1) is corrected by the first corrected rotation speed e(k), and the corrected target motor speed n m (k+1) can be represented by the following formula (7):

[0113] m (k+1)= n m (k+1)+ e(k) (7)

[0114] In this embodiment, the first correction speed of the speed of the magnetic suspension motor is determined through the real-time motor speed measurement value, and the predicted motor speed is corrected with the first correction speed, so that the actual speed of the magnetic suspension motor can quickly and stably track the target motor speed.

[0115] In an embodiment, the step S300 of adjusting the speed of the magnetic suspension motor to the target motor speed and adjusting the speed of the working fluid pump to the target working fluid pump speed at the next moment comprises:

[0116] The speed of the magnetic suspension motor is adjusted to the corrected target motor speed at the next moment.

[0117] The first correction speed of the speed of the magnetic suspension motor is determined through the real-time motor speed measurement value, and the target motor speed is corrected with the first correction speed, and the speed of the magnetic suspension motor is adjusted to the corrected target motor speed at the next moment. In addition, the corrected target working fluid pump speed can also be determined according to the corrected target motor speed, and the speed of the working fluid pump is adjusted to the corrected target working fluid pump speed at the next moment. In this way, continuous real-time correction can be performed in the speed prediction process of the magnetic suspension motor and the working fluid pump, thereby improving the prediction accuracy.

[0118] In an embodiment, the speed cooperative control method of the magnetic suspension motor and the working fluid pump further comprises:

[0119] The second correction speed of the speed of the working fluid pump is determined according to the second operating parameter of the working fluid pump.

[0120] The target working fluid pump speed is corrected with the second correction speed.

[0121] The second operating parameter can include the working fluid pump speed (k) at the current moment, and the second correction speed e p (k) can be determined according to the working fluid pump speed (k) at the current moment and the predicted working fluid pump speed (k) at the current moment (predicted at the previous moment), that is, represented by the following formula (8):

[0122] e p (k)= (k)- (k) (8)

[0123] The target working fluid pump speed n p (k+1) is corrected with the second correction speed e p (k), to obtain the corrected target working fluid pump speed p (k+1) can be expressed by the following formula (9):

[0124] p (k+1)= n p (k+1)+ e p (k) (9)

[0125] In this embodiment, the second correction speed of the speed of the working fluid pump is determined through the real-time working fluid pump speed measurement value, and the target working fluid pump speed is corrected with the second correction speed, so that the actual speed of the working fluid pump can quickly and stably track the target working fluid pump speed.

[0126] In an embodiment, the step S300 of adjusting the speed of the magnetic suspension motor to the target motor speed and adjusting the speed of the working fluid pump to the target working fluid pump speed at the next time comprises:

[0127] adjusting the speed of the working fluid pump to the corrected target working fluid pump speed at the next time.

[0128] The second correction speed of the speed of the working fluid pump is determined through the real-time working fluid pump speed measurement value, and the target working fluid pump speed is corrected with the second correction speed, and then the speed of the working fluid pump is adjusted to the corrected target working fluid pump speed at the next time. In this way, continuous real-time correction can be performed in the speed prediction process of the working fluid pump, and the prediction accuracy is improved.

[0129] In an embodiment, the first operating parameter comprises the current motor speed of the magnetic suspension motor. The step of determining the first correction speed of the speed of the magnetic suspension motor according to the first operating parameter comprises:

[0130] determining the predicted motor speed of the magnetic suspension motor at the current time.

[0131] determining the difference between the current motor speed and the predicted motor speed as the first correction speed.

[0132] The first correction speed e(k) can be expressed by the above formula (6).

[0133] In an embodiment, the step of correcting the target motor speed with the first correction speed comprises:

[0134] superimposing the target motor speed on the first correction speed.

[0135] corrected target motor speed m (k+1) can be expressed by the above formula (7).

[0136] In an embodiment, the second operating parameter comprises a current working fluid pump rotating speed of the working fluid pump. The step of determining, according to the second operating parameter of the working fluid pump, a second corrected rotating speed of the working fluid pump from the rotating speed of the working fluid pump comprises:

[0137] determining a predicted working fluid pump rotating speed of the working fluid pump at the current time.

[0138] determining a difference between the current working fluid pump rotating speed and the predicted working fluid pump rotating speed as the second corrected rotating speed.

[0139] the second corrected rotating speed e p (k) can be represented by formula (8) as follows.

[0140] In an embodiment, the step of correcting the target working fluid pump rotating speed by the second corrected rotating speed comprises:

[0141] superimposing the target working fluid pump rotating speed on the second corrected rotating speed.

[0142] the corrected target working fluid pump rotating speed p (k+1) can be represented by formula (9) as follows.

[0143] In an embodiment, the driving device of the magnetic suspension motor and the working fluid pump adjusts the output voltage and frequency of itself according to the rotating speed instruction issued by the controller, so as to realize fast tracking and adjustment of the rotating speed of the magnetic suspension motor and the working fluid pump. In the adjustment process, the rotating speed deviation is corrected in real time, so as to ensure that the actual rotating speed of the magnetic suspension motor and the working fluid pump can quickly and stably track the target rotating speed.

[0144] The rotating speed cooperative control method of the magnetic suspension motor and the working fluid pump provided in the above embodiments of the application cooperatively controls the rotating speeds of the magnetic suspension motor and the working fluid pump, so that the system can maintain the best operating state under different working conditions, effectively improves the power generation efficiency of the magnetic suspension power generation system, reduces the energy consumption by 15% to 25%, and improves the comprehensive energy efficiency of the system by 12% to 18%. When the load suddenly changes or other working conditions change, the rotating speed cooperative control method of the magnetic suspension motor and the working fluid pump provided in the above embodiments of the application can quickly respond, the response time is shortened by 60%, the rotating speeds of the magnetic suspension motor and the working fluid pump are timely adjusted, the power generation power is prevented from greatly fluctuating and the working fluid flow is prevented from being unbalanced, and the stability and reliability of the system are significantly enhanced. In addition, the method reduces the impact and vibration of the magnetic suspension motor and the working fluid pump in the running process through accurate rotating speed cooperative control, reduces the wear and fatigue of the equipment, prolongs the service life of the equipment, and reduces the maintenance cost.

[0145] The above description can be implemented alone or in various combinations, and these variants are within the protection scope of the application.

[0146] It should be noted that, in the present text, the terms "comprises", "comprising", or any other variant thereof, are intended to cover the non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0147] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same. Although the present application has been described in detail with reference to the foregoing examples, it should be understood by those of ordinary skill in the art that modifications can be made to the technical solutions described in the foregoing examples, or equivalent replacements can be made to some of the technical features; and such modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for coordinated speed control of a magnetic levitation motor and a working fluid pump, characterized in that, The method includes: Obtain the first operating parameters of the magnetic levitation motor at the current moment; Based on the first operating parameters, the target motor speed of the magnetic levitation motor and the target working fluid pump speed of the working fluid pump are predicted at the next moment, and the target motor speed and the target working fluid pump speed are related. At the next moment, the rotational speed of the magnetic levitation motor is adjusted to the target motor speed, and the rotational speed of the working fluid pump is adjusted to the target working fluid pump speed; The step of predicting the target motor speed of the magnetic levitation motor and the target working fluid pump speed of the working fluid pump at the next moment based on the first operating parameters, wherein the target motor speed and the target working fluid pump speed are correlated, includes: Obtain the second operating parameters of the working fluid pump at the current moment; The speed ratio of the magnetic levitation motor and the working fluid pump is determined based on the first operating parameter and the second operating parameter. Based on the first operating parameters and the prediction model, the target motor speed is predicted; Predict the target working fluid pump speed based on the target motor speed and the speed ratio; The first operating parameter includes the current motor speed and rotor temperature change of the magnetic levitation motor, and the second operating parameter includes the working fluid pressure change of the working fluid pump. Determining the speed ratio of the magnetic levitation motor and the working fluid pump based on the first operating parameters and the second operating parameters includes: The product of the first coefficient and the current motor speed is used as the first parameter, the product of the second coefficient and the rotor temperature change is used as the second parameter, and the product of the third coefficient and the working fluid pressure change is used as the third parameter. The sum of the first parameter, the second parameter, and the third parameter is determined as the speed ratio.

2. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to claim 1, characterized in that, The step of predicting the target working fluid pump speed based on the target motor speed and the speed ratio includes: The ratio of the target motor speed to the speed ratio is determined as the target working fluid pump speed.

3. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to any one of claims 1 or 2, characterized in that, The method further includes: Based on the first operating parameters and the second operating parameters of the working fluid pump, the target temperature of the magnetic levitation motor at the next moment is predicted.

4. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to claim 3, characterized in that, The method further includes: The target motor speed is corrected based on the target temperature; The step of adjusting the rotational speed of the magnetic levitation motor to the target motor speed and adjusting the rotational speed of the working fluid pump to the target working fluid pump speed at the next moment includes: At the next moment, the rotational speed of the magnetic levitation motor is adjusted to the corrected target motor speed.

5. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to claim 4, characterized in that, The step of predicting the target motor speed of the magnetic levitation motor and the target working fluid pump speed of the working fluid pump at the next moment based on the first operating parameters includes: The target working fluid pump speed is determined based on the corrected target motor speed; and / or, The step of correcting the target motor speed based on the target temperature includes: Determine the correction factor based on the target temperature; The target motor speed is corrected using the correction factor.

6. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to any one of claims 1 or 2, characterized in that, The method further includes: Based on the first operating parameters, a first corrected speed is determined for the rotational speed of the magnetic levitation motor; The target motor speed is corrected using the first corrected speed. The step of adjusting the rotational speed of the magnetic levitation motor to the target motor speed and adjusting the rotational speed of the working fluid pump to the target working fluid pump speed at the next moment includes: At the next moment, the rotational speed of the magnetic levitation motor is adjusted to the corrected target motor speed.

7. The method for coordinated speed control of the magnetic levitation motor and the working fluid pump according to claim 6, characterized in that, The first operating parameter includes the current motor speed of the magnetic levitation motor; The step of determining the first corrected speed of the magnetic levitation motor based on the first operating parameters includes: Determine the predicted motor speed of the magnetic levitation motor at the current moment; The difference between the current motor speed and the predicted motor speed is determined as the first corrected speed; The step of correcting the target motor speed with the first corrected speed includes: The target motor speed is superimposed with the first corrected speed.

Images