A control method and device of a permanent magnet motor power generation system, equipment and medium

Abstract

The application provides a control method, device and equipment of a permanent magnet motor power generation system and a medium, the method comprising: obtaining a capacitance value of a support capacitor in a target permanent magnet motor power generation system, and a current input power and a current output power of the target permanent magnet motor power generation system; calculating a power difference value of the current input power and the current output power; performing integral calculation on the power difference value based on the capacitance value to obtain a voltage square value of the support capacitor; and performing feedback control on a voltage loop and a current loop of the target permanent magnet motor power generation system based on the voltage square value. The control method, device and equipment of the permanent magnet motor power generation system provided by the application take the voltage square value of the support capacitor as feedback to balance the difference between the input power and the output power and enhance the voltage stability of the direct current support capacitor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of motor control, in particular to a control method, device and equipment of a permanent magnet motor power generation system and a medium. BACKGROUND

[0002] At present, multi-legged robots with large load ratio are widely used in aerospace and other fields. In the design process, in order to meet the requirements of lightweight and compactness of multi-legged robots with large load ratio, a power generation system composed of a permanent magnet synchronous motor and a pulse width modulation (PWM) rectifier is usually used. The permanent magnet synchronous motor has the advantages of high power density and high efficiency, so the wide-speed high-quality power generation of the permanent magnet synchronous motor is studied.

[0003] In the prior art, the voltage stabilization strategy of the permanent magnet synchronous motor power generation system is to take the difference between the voltage given value and the feedback value as the input of the voltage outer loop controller, and take the current command of the current inner loop controller as the input. However, this control strategy cannot balance the input power and the output power, resulting in unstable DC support capacitor voltage. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to overcome the defect that the input power and the output power cannot be balanced in the prior art, resulting in unstable DC support capacitor voltage, so as to provide a control method, device, equipment and medium of a permanent magnet motor power generation system.

[0005] According to a first aspect, the present application provides a control method of a permanent magnet motor power generation system, the method comprising:

[0006] obtaining a capacitance value of a support capacitor in a target permanent magnet motor power generation system, and a current input power and a current output power of the target permanent magnet motor power generation system;

[0007] calculating a power difference value of the current input power and the current output power;

[0008] integrating and calculating the power difference value based on the capacitance value to obtain a voltage square value of the support capacitor;

[0009] performing feedback control on a voltage loop and a current loop of the target permanent magnet motor power generation system based on the voltage square value.

[0010] In an embodiment, the integrating and calculating the power difference value based on the capacitance value to obtain the voltage square value of the support capacitor comprises:

[0011] The voltage square value of the support capacitor is calculated according to the following formula:

[0012]

[0013] wherein P in is the current input power, P L is the current output power, C is the capacitance value of the support capacitor, u dc is the voltage of the support capacitor.

[0014] In an embodiment, the feedback control of the voltage loop and the current loop of the target permanent magnet motor power generation system based on the voltage square value comprises:

[0015] feedback control of the voltage loop of the target permanent magnet motor power generation system based on the voltage square value;

[0016] feedback control of the current loop of the target permanent magnet motor power generation system based on the feedback control result of the voltage loop of the target permanent magnet motor power generation system.

[0017] In an embodiment, before the feedback control of the current loop of the target permanent magnet motor power generation system based on the feedback control result of the voltage loop of the target permanent magnet motor power generation system, the method further comprises:

[0018] obtaining a proportional adjustment parameter, a differential adjustment parameter, a first error and a second error of the target permanent magnet motor power generation system, wherein the first error is the error between the command value of the voltage control signal target value after passing through the tracking differentiator and the observation value of the command value after passing through the extended state observer, and the second error is the error between the differential of the voltage control signal target value and the differential after passing through the extended state observation;

[0019] linearly calculating the proportional adjustment parameter, the differential adjustment parameter, the first error and the second error, and determining the linear calculation result as the voltage control amount;

[0020] feedback control of the current loop of the target permanent magnet motor power generation system based on the voltage control amount and the feedback control result of the voltage loop of the target permanent magnet motor power generation system.

[0021] In an embodiment, the determination of the voltage control amount based on the proportional adjustment parameter, the differential adjustment parameter, the first error and the second error comprises:

[0022] calculating a first product of the proportional adjustment parameter and the first error, and a second product of the differential adjustment parameter and the second error;

[0023] determining the sum of the first product and the second product as the voltage control amount.

[0024] In an embodiment, the method further comprises:

[0025] The voltage loop parameters of a target permanent magnet motor power generation system are set based on an open loop transfer function and a closed loop transfer function, the voltage loop parameters including a proportional gain and an integral gain,

[0026] The open loop transfer function is:

[0027]

[0028] wherein k1 is a control parameter, k p is the proportional gain, k i is the integral gain, ω b is a current loop control bandwidth, and C is a capacitance value of a support capacitor;

[0029] The closed loop transfer function is:

[0030]

[0031] In an embodiment, the method further comprises:

[0032] The proportional gain is calculated according to the following formula:

[0033]

[0034] wherein k1 is a control parameter, C is a capacitance value of a support capacitor, and ω vc is a desired bandwidth of a voltage loop;

[0035] The integral gain k i is calculated according to the following formula:

[0036]

[0037] wherein ω vc is a desired bandwidth of a voltage loop.

[0038] According to a second aspect, the application provides a control device for a permanent magnet motor power generation system, the device comprising:

[0039] an acquisition module configured to acquire a capacitance value of a support capacitor in a target permanent magnet motor power generation system, and a current input power and a current output power of the target permanent magnet motor power generation system;

[0040] a calculation module configured to calculate a power difference value of the current input power and the current output power;

[0041] a derivation module configured to derive a voltage square value of the support capacitor by integrating the power difference value based on the capacitance value;

[0042] a control module configured to perform feedback control on a voltage loop and a current loop of the target permanent magnet motor power generation system based on the voltage square value.

[0043] According to a third aspect, the present application provides a computer device comprising a memory and a processor, which are connected in communication with each other, and the memory stores computer instructions, and the processor executes the computer instructions to perform the control method of the permanent magnet motor power generation system according to any one of the first aspect and the optional implementation manners thereof.

[0044] According to a fourth aspect, the present application provides a computer readable storage medium storing computer instructions for causing the computer to perform the control method of the permanent magnet motor power generation system according to any one of the first aspect and the optional implementation manners thereof.

[0045] The technical scheme of the present application has the following advantages:

[0046] The embodiment of the present application provides a control method of a permanent magnet motor power generation system, which calculates a voltage square value of a support capacitor based on a target permanent magnet motor power generation system, a current input power and a current output power, takes the voltage square value of the support capacitor as feedback to balance the difference between the input power and the output power, reduces the noise introduced by differentiation, and enhances the voltage stability of the direct current support capacitor. BRIEF DESCRIPTION OF DRAWINGS

[0047] In order to more clearly illustrate the specific embodiments of the present application or the technical scheme in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0048] Figure 1 is a flow chart of a control method of a permanent magnet motor power generation system according to an embodiment of the present application;

[0049] Figure 2 is a rectifier topology diagram of a permanent magnet synchronous motor power generation system according to an embodiment of the present application;

[0050] Figure 3 is a voltage and current double-loop control block diagram based on direct current support capacitor energy feedback according to an embodiment of the present application;

[0051] Figure 4 is a nonlinear active disturbance rejection controller structure diagram based on direct current support capacitor energy feedback according to an embodiment of the present application;

[0052] Figure 5 is a schematic diagram of open loop frequency response of a voltage control system according to an embodiment of the present application;

[0053] Figure 6 is a schematic diagram of a large signal average model of a permanent magnet motor power generation system according to an embodiment of the present application;

[0054] Figure 7 is a schematic diagram of the positive direction of voltage and current in a hybrid potential function branch according to an embodiment of the present application;

[0055] Figure 8 is a structural block diagram of a control device of a permanent magnet motor power generation system according to an embodiment of the present application;

[0056] Figure 9 is a schematic diagram of a hardware structure of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0057] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0058] In order to balance the input power and output power of the permanent magnet motor power generation system and enhance the stability of the DC support capacitor voltage, a control method of a permanent magnet motor power generation system is provided in an embodiment of the present application, as shown in Figure 1 The method comprises the following steps S1 to S4.

[0059] Step S1: Obtain the capacitance value of the support capacitor in the target permanent magnet motor power generation system, and the current input power and the current output power of the target permanent magnet motor power generation system.

[0060] In the embodiment of the present application, in the wide-speed high-quality power generation process of the permanent magnet synchronous motor, the energy storage change of the DC support capacitor can directly reflect the real-time matching relationship of the input and output power of the power generation system.

[0061] Assuming that the efficiency of the target motor and the controller is η, the steady-state input power of the bus support capacitor, i.e. the current input power, is obtained as follows:

[0062]

[0063] wherein P in is the current input power, ω m is the mechanical angular velocity, T e is the electromagnetic torque, ψ f is the permanent magnet flux, i d and i q are d-q axis currents, L d and L qIt is the dq axis inductance.

[0064] Step S2: Calculate the power difference between the current input power and the current output power.

[0065] In this embodiment of the invention, the difference between the input power and the output power can reflect the differential of the DC support capacitor energy.

[0066] Step S3: Integrate the power difference based on the capacitance value to obtain the squared voltage value of the supporting capacitor.

[0067] In embodiments of the present invention, such as Figure 2 The diagram shows the topology of a traditional permanent magnet synchronous motor generator system. In the diagram, PMSG (Permanent Magnet Synchronous Generato) is a permanent magnet synchronous motor. In the traditional voltage regulation strategy, the difference between the voltage setpoint and the feedback value is used as the input of the voltage outer loop controller, and the output is the current command input of the current inner loop controller.

[0068] It is easy to see from Kirchhoff's current law that the output voltage of a fully controlled rectifier satisfies

[0069]

[0070] Multiply both sides of the equation by u dc ,get:

[0071]

[0072] The left side of the equation can be transformed into the differential form of the DC-supported capacitor energy, while the right side is expressed in terms of input power and load power.

[0073]

[0074] Performing the inverse operation of the above equation, and integrating the power difference based on the capacitance value, yields the squared voltage value u of the supporting capacitor. 2 dc Among them, u dc To support the voltage value of the capacitor, P L The current output power is given by C, where C is the capacitance of the supporting capacitor, and E is the capacitance of the supporting capacitor. c For the energy stored in a capacitor, i dc The current value to support the capacitor.

[0075] Step S4: Perform feedback control on the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage.

[0076] In embodiments of the present invention, such as Figure 3 As shown, assuming the mechanical angular velocity ω of the motor m The control remains unchanged within a control cycle, using "i"d =0” control, let η=1, based on u 2 dc Feedback control is applied to the outer voltage loop and inner current loop of the target motor.

[0077] The voltage outer loop control strategy is as follows:

[0078]

[0079] Where, k p For proportional gain, k i For integral gain;

[0080] The current inner loop control strategy is as follows:

[0081]

[0082] Where, ω b This is the bandwidth for the current loop control.

[0083] Through the above embodiments, the square voltage value of the supporting capacitor is calculated based on the capacitor value of the target permanent magnet motor power generation system, the current input power, and the current output power. The square voltage value of the supporting capacitor is used as differential feedback to balance the difference between the input power and the output power, reduce the noise introduced by the differential, and enhance the stability of the DC supporting capacitor.

[0084] Specifically, in one embodiment, step S103 above involves integrating the power difference based on the capacitance value to obtain the squared voltage value of the supporting capacitor, which specifically includes the following steps:

[0085] Calculate the square of the voltage across the supporting capacitor using the following formula:

[0086]

[0087] In this embodiment of the invention, the differential of the DC support capacitor energy reflects the difference between the input power and the output power. Therefore, introducing differential feedback of the support capacitor energy can quickly balance the difference between the input and output power, i.e., maintain the stability of the voltage across the DC support capacitor. To reduce the noise introduced by the differential, u is used here. 2 dc feedback.

[0088] Specifically, in one embodiment, the feedback control of the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage in step S104 includes the following steps:

[0089] Step S1041: Feedback control is performed on the voltage loop of the target permanent magnet motor power generation system based on the square value of the voltage.

[0090] Step S1042: Feedback control is performed on the current loop of the target permanent magnet motor power generation system based on the feedback control results of the voltage loop of the target permanent magnet motor power generation system.

[0091] In this embodiment of the invention, compared to the traditional voltage regulation strategy which uses the difference between the voltage setpoint and the feedback value as the input of the voltage outer loop controller, this embodiment first performs feedback control on the voltage loop based on the voltage square value, which can quickly balance the difference between input power and output power. Then, based on the feedback control result of the voltage loop, feedback control is performed on the current loop of the target permanent magnet motor power generation system, thus constructing a dual-loop closed-loop control of the voltage outer loop and the current inner loop to achieve control of the permanent magnet synchronous motor power generation system.

[0092] Specifically, in one embodiment, before performing step S1042 above, the control method of the permanent magnet motor power generation system provided in this embodiment further includes the following steps:

[0093] The proportional control parameters, derivative control parameters, first error, and second error of the target permanent magnet motor power generation system are obtained. The first error is the error between the command value of the control signal target value after passing through the tracking differentiator and the observed value after passing through the extended state observer. The second error is the error between the derivative of the control signal target value and the derivative after the extended state observation.

[0094] Linear calculations are performed on the proportional control parameter, the derivative control parameter, the first error, and the second error, and the linear calculation results are determined as the voltage control quantity.

[0095] Feedback control of the current loop of the target permanent magnet motor generator system is performed based on the feedback control results of the voltage control quantity and the voltage loop of the target permanent magnet motor generator system.

[0096] In this embodiment of the invention, a voltage loop active disturbance rejection controller is designed based on DC-supported capacitor energy feedback, such as... Figure 4 As shown, the tracking differentiator, extended state observer and error feedback are designed independently, and then combined to form a complete voltage loop active disturbance rejection controller. The design method of the active disturbance rejection controller is existing technology and will not be described in detail here.

[0097] This involves using a nonlinear function, and the parameters that need to be designed include r, h, and β. 01 β 02 β 03 The parameters α1, δ1, α2, δ2, r1, h1, b, and c are numerous and difficult to tune. Let a1 = a2 = 1, then fal(e, 1, δ) = e, yielding a simplified formula for calculating the parameters of the active disturbance rejection controller as follows:

[0098]

[0099] The fhan function is the fastest control synthesis function. Further detailed calculations of the fhan function can be found in existing techniques and will not be elaborated here. x1* is the command value after passing through the tracking differentiator, y* is the target value of the control signal, e is the error, and β... 01 β 02 and β 03 Here are the parameters of the observer: e1 is the first error, which is the error between the command value of the voltage control signal target value after passing through the tracking differentiator and the observed value of its command value after passing through the extended state observer; e2 is the second error, which is the error between the derivative of the voltage control signal target value and the derivative of its derivative after passing through the extended state observer; and x2* is the derivative of the control signal. and To extend the system state variables and disturbances observed by the state observer, b is the control parameter (related to the gain of the controlled system), and u is the control quantity.

[0100] Let b = 3ω e ψ f / C, the commonly used empirical formula is as follows:

[0101]

[0102] Where, ω e Let ψ be the electric angular velocity. f denoted as permanent magnet flux linkage, r as rotor radius, and h as sampling time.

[0103] Specifically, in one embodiment, the feedback control of the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage in step S104 includes the following steps:

[0104] Calculate the first product of the proportional adjustment parameter and the first error, and the second product of the derivative adjustment parameter and the second error;

[0105] The sum of the first and second products is determined as the voltage control quantity.

[0106] In this embodiment of the invention, u0 = k pa e1+k da e2, where u0 is the voltage control quantity, k pa k is the proportional adjustment parameter. da This is the differential adjustment parameter.

[0107] Specifically, in one embodiment, let the load disturbance P L =0, the control method of the permanent magnet motor power generation system provided in this embodiment further includes the following steps:

[0108] The voltage loop parameters of the target permanent magnet motor generator system are tuned based on the open-loop and closed-loop transfer functions. The voltage loop parameters include proportional gain and integral gain.

[0109] The open-loop transfer function is:

[0110]

[0111] Where k1 is the control parameter, k p For proportional gain, k i For the integral gain, ω b For the current loop control bandwidth, k1 = 1.5ω e ψ f ;

[0112] The closed-loop transfer function is:

[0113]

[0114] In this embodiment of the invention, the transfer function is the ratio of the Laplace transform of the linear system response to the Laplace transform of the excitation under initial conditions. The open-loop transfer function is the functional relationship between the ratio of the output to the input of the open-loop system and the frequency, i.e., the frequency domain characteristic of the system.

[0115] The open-loop frequency response Bode plot of the power generation system is as follows: Figure 5 As shown, the slope can be divided into three parts, from low frequency to high frequency, with slopes of -40dB / dec, -20dB / dec, and -40dB / dec. In the low-frequency region, the scaling factor is ignored, and the current loop is below ω... b The frequency is modeled as unity gain with a slope of -40dB / dec, derived from the integral coefficient k of the voltage regulator. p k i The integral characteristic of the capacitor, 2k1 / (Cs), is composed of / s and the integral characteristic of the capacitor; the second part is derived from the cutoff frequency ω of the voltage regulator. p =k i Starting from the current loop control bandwidth ω b In conclusion, within this frequency range, the integral coefficient can be ignored, the current loop is still modeled as unity gain, and the slope is determined by the proportional gain k of the voltage regulator. p The integral characteristic of the capacitor is composed of 2k1 / (Cs); when it is greater than the current loop control bandwidth ω b After the frequency is adjusted, the voltage regulator functions only as a proportional element, and the current regulator functions only as an integral element. The slope of the third part is determined by the integral element ω of the current regulator. b / s and the integral characteristic of capacitance 2k1 / (C s )composition.

[0116] Specifically, in one embodiment, the desired bandwidth of the voltage loop is set to ω. vc,

[0117] Calculate the proportional gain using the following formula:

[0118]

[0119] Calculate the integral gain k using the following formula. i :

[0120]

[0121] Where, ω vc This represents the expected bandwidth of the voltage loop.

[0122] In this embodiment of the invention, the above-mentioned formulas for calculating proportional gain and integral gain can be used as design formulas for the PI parameters of the voltage loop based on the DC support capacitor energy feedback. The proportional gain changes in real time according to the speed of the permanent magnet synchronous motor, thereby improving the power generation performance of the permanent magnet synchronous motor for multi-legged robots with large load ratios over a wide speed range.

[0123] In one embodiment, considering the negative impedance characteristics of the constant power load and the rapid change in load power, the control method of the permanent magnet motor power generation system provided in this embodiment further includes large-signal stability analysis of the permanent magnet synchronous motor power generation system.

[0124] Specifically, as the sole high-voltage power source, the stability of the permanent magnet synchronous motor power generation system is crucial. A certain type of high-load-ratio multi-legged robot platform has six powered legs. In its walking state, it uses two groups (each group of three legs, consisting of forelegs, midlegs, and hind legs) to alternate movements. The robot's gait can be divided into two-gait on flat ground, three-gait on flat ground, six-gait on flat ground, 45° vertical slope gait, and 35° horizontal slope gait. In the gait walking operation mode, the high-voltage electrical equipment has 6×6 inverter-controlled drive motors. The power requirements of various gait walking states are different, exhibiting periodicity on a long time scale and pulse characteristics on a short time scale.

[0125] Converters that operate stably on their own over a large operating range may become unstable when cascaded. For a permanent magnet synchronous motor generator system, the 36 converters can be viewed as a linear combination of adjustable power constant power loads (CPL), equivalent to a cascaded system of two converters.

[0126] In permanent magnet synchronous motor generator units and loads, the negative impedance characteristic of constant power loads is the main reason why rectifiers that are stable when operating independently become unstable when under load. There are two theoretical methods for analyzing stability: small-signal stability theory, which studies the stability problem after applying small disturbances near the equilibrium point; and large-signal stability theory, which studies the stability problem that arises during the establishment of a new equilibrium point when large-signal disturbances such as load power switching occur. While the method of proving system stability based on small-signal linearization and solving for eigenvalues ​​effectively solves the modeling difficulty caused by the strong nonlinearity of the controller's power devices, it can only determine the stability near the equilibrium point and cannot characterize the stability under large-signal disturbances with large-range fluctuations in the operating point, let alone determine the stability domain.

[0127] In one embodiment, considering the negative impedance characteristics of the constant power load and the rapid change in load power, the control method of the permanent magnet motor power generation system provided in this embodiment further includes the hybrid potential function of the permanent magnet synchronous motor power generation system.

[0128] Using the state-space averaging method, the state equations of the PWM rectifier are averaged. Treating the 36 converters as a constant-power load with adjustable power, and employing equal-amplitude coordinate transformation, the large-signal average model of the permanent magnet synchronous motor generator system is obtained as follows: Figure 6 As shown. Figure 6 The flow from the controller to the motor is in the positive direction, D d0 D q0 The duty cycle of the dq axis equivalent power device.

[0129] Hybrid potential function theory is a nonlinear stability criterion theory. Combining circuit topology and component characteristics, it constructs an energy function and uses corresponding stability criteria to analyze the stability of nonlinear circuits containing components with negative impedance characteristics.

[0130] According to Tellegen's theorem, the sum of the powers in all branches of a circuit is always equal to zero, that is:

[0131]

[0132] The first term in the formula is the sum of the potential functions of all inductor branches in the circuit, the second term is the sum of the potential functions of all capacitor branches, and the third term is the sum of the potential functions of all non-energy storage components except inductors and capacitors. Rewriting the second term using integration by parts, we get:

[0133]

[0134] The mixed potential function of the system is then defined as:

[0135]

[0136] Essentially, the mixed potential function is a Lyapunov function, composed of a current potential function and a voltage potential function, ∫u μ di μ Represents the current potential function, ∫i μ du μ This represents the voltage potential function.

[0137] Figure 7 The positive directions of voltage and current in a mixed potential function branch are defined. By using the circuit topology diagram composed of branches and nodes and the branch voltage and current, Kirchhoff's voltage and current laws can accurately describe the relationship between voltage and current in the circuit.

[0138] When there is only one capacitor (the sum of all controller capacitors), that is... The terminal voltage is u dc The currents in the d-axis and q-axis inductors of the two inductive branches are i. d0 i q0 Besides capacitor C and d-axis and q-axis inductance L d L q In addition, by calculating and summing the current potential functions of each independent component, we obtain:

[0139]

[0140] The first row represents the current potential function of non-energy storage components outside the d-axis inductor; the second row represents the current potential function of non-energy storage components outside the q-axis inductor; and the third row represents the current potential function of the equivalent current source and the constant power load.

[0141] in,

[0142] Rewriting the third line using integration by parts, we get:

[0143]

[0144] The energy of the bus capacitor is:

[0145]

[0146] Adding the above formula to the capacitor energy formula, we obtain the hybrid potential function of the permanent magnet synchronous motor generator system:

[0147]

[0148] The general expression for the mixed potential function is:

[0149] P(i,u)=-A(i)+B(u)+(i,u)

[0150] Where A(i) represents the current potential function of the non-energy storage element in the circuit; B(u) represents the voltage potential function of the non-energy storage element in the circuit; and (i, u) represents the product of the current in each branch and the voltage of the capacitor in the loop where the branch is located.

[0151] for Figure 6 The topology shown has only one capacitor with a terminal voltage of u. dc ,

[0152] That is (i, u) = u dc *i dc -u dc *i cap -u dc *i L =0, thus obtaining the expression for the current potential function of the non-energy storage element in the hybrid potential function of the permanent magnet synchronous motor generator system:

[0153]

[0154] The voltage potential function expression for non-energy storage elements:

[0155]

[0156] Differentiating the hybrid potential function of the permanent magnet synchronous motor generator system with respect to the dq-axis current and bus voltage respectively, we obtain:

[0157]

[0158] The correctness of the established hybrid potential function of the permanent magnet synchronous power generation system was verified.

[0159] In one embodiment, considering the negative impedance characteristics of the constant power load and the rapid change in load power, the control method of the permanent magnet motor power generation system provided in this embodiment further includes stability boundary calculation based on the hybrid potential function.

[0160] A dual-loop control structure based on a DC-supported capacitor energy feedback voltage outer loop and a decoupled current inner loop is adopted to obtain the decoupled d q The expression for shaft voltage is:

[0161]

[0162] get

[0163] A(i) = a 11 (i)+a 22 (i)

[0164]

[0165] in,

[0166]

[0167] According to the third stability theorem of mixed potential function theory, we have:

[0168]

[0169] but

[0170]

[0171] Then C = C.

[0172]

[0173] get:

[0174]

[0175] Where μ1 and μ2 represent the smallest eigenvalues ​​of the matrix, since L d ≤L q The criterion for the stability of large signals in the system is:

[0176]

[0177] And when |u|+|i|→∞, we have:

[0178]

[0179] The conditions for stable large signals in the system are:

[0180]

[0181] It can be seen that the larger the controller output capacitor, the higher the output voltage; under the same power step condition, the smaller the value on the right side of the inequality, the larger the large-signal stability range of the system; the bandwidth ω of the current loop b The higher the value, the greater the bandwidth ω of the voltage loop. vc The higher the value, the larger the value on the left side of the inequality, and the larger the stable range of the system under large signals. If the generator's initial speed is high and the current is low, the value of the first term on the left side of the inequality is much larger than the second term. Substituting the motor parameters—controller capacitor 2200uF, output voltage 900Vdc, MTPA angle 33°, current loop control bandwidth 200Hz, voltage loop bandwidth 20Hz, motor speed 3800 rpm—under a step transition from 0kW to 550kW rated power, if the voltage drop is higher than 445V, the system will remain asymptotically stable; otherwise, the system will become uncontrollable. When the controller capacitor is 1100uF, the corresponding voltage drop to 629V will cause the system to become unstable.

[0182] Based on the same inventive concept, the present invention also provides a control device for a permanent magnet motor power generation system.

[0183] Figure 8 This is a structural block diagram of a control device for a permanent magnet motor power generation system according to an exemplary embodiment. (See diagram below.) Figure 8 As shown, the device includes:

[0184] The acquisition module 101 is used to acquire the capacitance value of the supporting capacitor in the target permanent magnet motor power generation system, as well as the current input power and current output power of the target permanent magnet motor power generation system. For details, please refer to the relevant description of step S101 above, which will not be repeated here.

[0185] The calculation module 102 is used to calculate the power difference between the current input power and the current output power. For details, please refer to the relevant description of step S102 above, which will not be repeated here.

[0186] Module 103 is obtained, which is used to perform integral calculation on the power difference based on the capacitance value to obtain the square value of the voltage across the supporting capacitor. For details, please refer to the relevant description of step S103 above, which will not be repeated here.

[0187] The control module 104 is used to perform feedback control on the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage. For details, please refer to the relevant description of step S104 above, which will not be repeated here.

[0188] The control device for the permanent magnet motor power generation system provided in this embodiment of the invention calculates the square voltage value of the supporting capacitor based on the capacitance value of the target motor, the current input power, and the current output power. The square voltage value of the supporting capacitor is used as feedback to balance the difference between the input power and the output power, thereby reducing the noise introduced by the derivative and enhancing the voltage stability of the DC supporting capacitor.

[0189] The specific limitations and beneficial effects of the control device based on the permanent magnet motor power generation system described above can be found in the limitations of the control method for the permanent magnet motor power generation system mentioned above, and will not be repeated here. Each of the above modules can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0190] Figure 9 This is a schematic diagram of the hardware structure of a computer device according to an exemplary embodiment. For example... Figure 9 As shown, the device includes one or more processors 1310 and a memory 1320, the memory 1320 including persistent memory, volatile memory, and a hard disk. Figure 9 Taking a processor 1310 as an example, the device may also include an input device 1330 and an output device 1340.

[0191] The processor 1310, memory 1320, input device 1330, and output device 1340 can be connected via a bus or other means. Figure 9 Taking the example of a connection between China and Israel via a bus.

[0192] Processor 1310 can be a Central Processing Unit (CPU). Processor 1310 can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0193] The memory 1320, as a non-transitory computer-readable storage medium, includes persistent memory, volatile memory, and a hard disk. It can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the business management method in the embodiments of this application. The processor 1310 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions, and modules stored in the memory 1320, thereby implementing the control method of any of the above-mentioned permanent magnet motor power generation systems.

[0194] The memory 1320 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data that is needed and required. Furthermore, the memory 1320 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 1320 may optionally include memory remotely located relative to the processor 1310, and these remote memories may be connected to the data processing device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0195] Input device 1330 can receive input digital or character information, and generate key signal inputs related to user settings and function control. Output device 1340 may include display devices such as a display screen.

[0196] One or more modules are stored in memory 1320, and when executed by one or more processors 1310, they perform actions such as... Figure 1 The control method of the permanent magnet motor power generation system shown.

[0197] The above-described product can execute the method provided in the embodiments of the present invention, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in [reference 1]. Figure 1 The relevant descriptions in the illustrated embodiments.

[0198] This invention also provides a non-transitory computer storage medium storing computer-executable instructions that can execute the methods described in any of the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium may also include combinations of the above types of memory.

[0199] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A control method for a permanent magnet motor power generation system, characterized in that, The method includes: Obtain the capacitance value of the supporting capacitor in the target permanent magnet motor power generation system, as well as the current input power and current output power of the target permanent magnet motor power generation system; Calculate the power difference between the current input power and the current output power; The voltage square value of the supporting capacitor is obtained by integrating the power difference based on the capacitance value. Feedback control is performed on the voltage loop and current loop of the target permanent magnet motor power generation system based on the squared voltage value; The feedback control of the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage includes: Feedback control is performed on the voltage loop of the target permanent magnet motor power generation system based on the squared voltage value; Feedback control is performed on the current loop of the target permanent magnet motor power generation system based on the feedback control results of the voltage loop of the target permanent magnet motor power generation system. Before performing feedback control on the current loop of the target permanent magnet motor power generation system based on the feedback control results of the voltage loop of the target permanent magnet motor power generation system, the method further includes: The proportional control parameters, derivative control parameters, first error, and second error of the target permanent magnet motor power generation system are obtained. The first error is the error between the command value of the voltage control signal target value after passing through the tracking differentiator and the observed value of the command value after passing through the extended state observer. The second error is the error between the derivative of the voltage control signal target value and the derivative of the derivative after passing through the extended state observer. The proportional adjustment parameter, the derivative adjustment parameter, the first error, and the second error are linearly calculated, and the linear calculation result is determined as the voltage control quantity. Feedback control is performed on the current loop of the target permanent magnet motor power generation system based on the voltage control quantity and the feedback control result of the voltage loop of the target permanent magnet motor power generation system.

2. The method according to claim 1, characterized in that, The step of integrating the power difference based on the capacitance value to obtain the squared voltage value of the supporting capacitor includes: Calculate the square of the voltage across the supporting capacitor using the following formula: ， in, The current input power, This is the current output power. To support the capacitance value of the capacitor, To support the voltage of the capacitor.

3. The method according to claim 1, characterized in that, The voltage control quantity determined based on the proportional adjustment parameter, the derivative adjustment parameter, the first error, and the second error includes: Calculate the first product of the proportional adjustment parameter and the first error, and the second product of the differential adjustment parameter and the second error; The sum of the first product and the second product is determined as the voltage control quantity.

4. The method according to claim 1, characterized in that, The method further includes: The voltage loop parameters of the target permanent magnet motor generator system are tuned based on the open-loop and closed-loop transfer functions. These voltage loop parameters include proportional gain and integral gain. The open-loop transfer function is: ， in, For control parameters, For proportional gain, For integral gain, For the current loop control bandwidth, The capacitance value is used to support the capacitor; The closed-loop transfer function is: 。 5. The method according to claim 4, characterized in that, The method further includes: The proportional gain is calculated using the following formula: ， in, For control parameters, To support the capacitance value of the capacitor, This represents the desired bandwidth of the voltage loop. The integral gain is calculated according to the following formula. : ， in, This represents the expected bandwidth of the voltage loop.

6. A control device for a permanent magnet motor power generation system, characterized in that, The device includes: The first acquisition module is used to acquire the capacitance value of the supporting capacitor in the target permanent magnet motor power generation system, as well as the current input power and current output power of the target permanent magnet motor power generation system; The first calculation module is used to calculate the power difference between the current input power and the current output power; The module is used to perform an integral calculation on the power difference based on the capacitance value to obtain the squared voltage value of the supporting capacitor; The first control module is used for feedback control of the voltage loop and current loop of the target permanent magnet motor power generation system based on the square value of the voltage; The first control module is specifically used for: performing feedback control on the voltage loop of the target permanent magnet motor power generation system based on the square value of the voltage; and performing feedback control on the current loop of the target permanent magnet motor power generation system based on the feedback control result of the voltage loop of the target permanent magnet motor power generation system. The device further includes: The second acquisition module is used to acquire the proportional control parameters, differential control parameters, first error and second error of the target permanent magnet motor power generation system. The first error is the error between the command value of the voltage control signal target value after passing through the tracking differentiator and the observed value of the command value after passing through the extended state observer. The second error is the error between the differential of the voltage control signal target value and the differential after the extended state observer. The second calculation module is used to perform linear calculations on the proportional adjustment parameter, the derivative adjustment parameter, the first error and the second error, and to determine the linear calculation result as the voltage control quantity. The second control module is used to perform feedback control on the current loop of the target permanent magnet motor power generation system based on the voltage control quantity and the feedback control result of the voltage loop of the target permanent magnet motor power generation system.

7. A computer device, characterized in that, The system includes a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the control method of the permanent magnet motor power generation system according to any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the control method of the permanent magnet motor power generation system according to any one of claims 1-5.

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