Motor parameter inversion method based on circuit breaker vector control system and related device

Abstract

The invention relates to a circuit breaker vector control system-based motor parameter inversion method and a related device. The method comprises the following steps: configuring inversion operation parameters of a circuit breaker motor operating mechanism, and enabling the motor operating mechanism to be relatively static in an inversion process; generating a control signal according to the inversion operation parameter, and controlling a motor operating mechanism to be in a voltage dynamic equal state based on the control signal; collecting the bus voltage in the state that the voltage is dynamically equal, and determining the actual voltage of each winding according to the bus voltage and the control signal; actual current of the three-phase winding is collected, a current curve of the motor operating mechanism in the inversion process is fitted according to the actual current, and curve parameters of the current curve are determined; and constructing a function relation model containing motor inversion parameters, and solving and obtaining the motor inversion parameters of the corresponding phase windings based on each group of curve parameters and each winding. Compared with the prior art, additional structures and circuits do not need to be added, the operation is simple, the reliability is high, and the accuracy of inversion results is high.

Description

Technical Field

[0001] The present application relates to the technical field of high-voltage circuit breakers, and in particular to a motor parameter inversion method based on a circuit breaker vector control system and a related device. Background Art

[0002] As an important device in the power system, the circuit breaker has an important impact on the control and protection of the power grid. When the current of the power grid is too large, the circuit breaker can quickly break, thereby ensuring the safety of the power system and reducing financial losses. Therefore, the reliability of the circuit breaker plays a vital role in the safe operation of the power grid. Traditional operating mechanisms can be divided into electromagnetic, spring, pneumatic and hydraulic types according to the energy source. In the application scenario of high-voltage circuit breakers, due to the large number of mechanical parts and complex structure of traditional operating mechanisms, the reliability requirements of each part will be increased, and the hydraulic and other operating mechanisms use liquids and other substances to transfer energy. The response speed of traditional operating mechanisms may not be as expected, and there is a problem of transmission medium leakage. The traditional operating mechanism is composed of multiple connecting rods, locks, etc., with many links, large cumulative motion tolerance, slow response, poor controllability, low efficiency, and unable to adjust and control the operating process. Therefore, high-voltage circuit breakers cannot achieve maximum performance in these types of operating mechanisms. Statistics show that many circuit breaker failures occur due to operating mechanism failure.

[0003] In recent years, with the development of digital control technology and the improvement of the performance of power electronic devices, the rotary motor operating mechanism using closed-loop control technology has gradually become the focus of research and application. The motor operating mechanism drives the circuit breaker to open and close by coordinating the movement of the motor and the connecting rod. Because it integrates modern power electronic technology and advanced control theory, it can realize the dynamic regulation of the moving contact movement process, so that it can open or close according to the ideal movement process. It has the characteristics of high reliability and controllability, which greatly improves the working performance of the circuit breaker. Compared with the traditional circuit breaker operating mechanism, the motor operating mechanism uses the rotation of the motor main shaft to drive the circuit breaker contact, so as to realize the opening and closing of the circuit breaker. It has the characteristics of simple transmission mechanism, strong controllability, higher reliability and long mechanical life. Studying the motor resistance and inductance inversion method of the motor operating mechanism is conducive to timely detection of faults and further improving the reliability of the operating mechanism.

[0004] Existing inversion methods usually include direct measurement methods, artificial intelligence-based inversion methods, etc. For direct measurement methods, additional equipment and operations are required for direct measurement during the operation of the motor, and the measurement accuracy is limited by the accuracy of the measurement equipment and the stability of the motor's operating state; while the artificial intelligence-based inversion method relies on a large amount of training data to train the model. The quality and quantity of the data have a great impact on the accuracy performance of the model, and if the training data is not comprehensive or representative enough, the generalization ability of the model will be greatly limited, resulting in reduced accuracy of the inversion results. Summary of the invention

[0005] Based on this, it is necessary to provide a motor parameter inversion method and related device based on a circuit breaker vector control system that is implemented based on the original vector control system of the circuit breaker and has high accuracy of inversion results in order to solve the above technical problems.

[0006] In a first aspect, the present application provides a motor parameter inversion method based on a circuit breaker vector control system, the method comprising:

[0007] Configuring inversion operation parameters of the circuit breaker motor operating mechanism so that the motor operating mechanism is relatively stationary during the inversion process; the inversion operation parameters include the inversion current of the motor operating mechanism during the inversion process and the expected voltage of each phase winding and its polarity, the expected voltage of one phase winding of the three-phase winding of the motor operating mechanism is zero, and the expected voltages of the remaining two phase windings are determined based on the inversion current;

[0008] Generate a control signal according to the inversion operation parameter, and control the motor operating mechanism to be in a voltage dynamic equal state based on the control signal;

[0009] collecting the bus voltage under the voltage dynamic equal state, and determining the actual voltage of each winding according to the bus voltage and the control signal;

[0010] Collecting the actual current of the three-phase winding, fitting the current curve of the motor operating mechanism during the inversion process according to the actual current, and determining the curve parameters of the current curve;

[0011] Returning to the step of configuring the inversion operation parameters of the circuit breaker motor operating mechanism, respectively configuring the expected voltage of one phase of the two non-zero phase windings to be zero and determining the expected voltages of the other two phase windings based on the inversion current, until multiple sets of current curves and their corresponding curve parameters are obtained;

[0012] A functional relationship model including motor inversion parameters is constructed, and the functional relationship model is solved based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

[0013] In a second aspect, the present application further provides a motor parameter inversion device based on a circuit breaker vector control system, the device comprising:

[0014] A parameter configuration module, configured to configure the inversion operation parameters of the circuit breaker motor operating mechanism in response to the configuration signal, so that the motor operating mechanism is relatively stationary during the inversion process; the inversion operation parameters include the inversion current of the motor operating mechanism during the inversion process and the expected voltage of each phase winding and its polarity, the expected voltage of one phase winding of the three-phase winding of the motor operating mechanism is zero, and the expected voltages of the remaining two phase windings are determined based on the inversion current;

[0015] A control signal generating module, used for generating a control signal according to the inversion operation parameter, and controlling the motor operating mechanism to be in a voltage dynamic equal state based on the control signal;

[0016] A voltage acquisition and calculation module, used for acquiring the bus voltage when the voltage is dynamically equal, and determining the actual voltage of each winding according to the bus voltage and the control signal;

[0017] A curve generating module, used for collecting the actual current of the three-phase winding, fitting the current curve of the motor operating mechanism in the inversion process according to the actual current, and determining the curve parameters of the current curve;

[0018] An execution loop module is used to determine whether the number of current curves and their curve parameters meets the preset conditions, and if so, an end signal is generated, otherwise, the configuration signal is generated and the parameter configuration module is jumped until multiple sets of current curves and their corresponding curve parameters are obtained;

[0019] The parameter calculation module is used to construct a functional relationship model including motor inversion parameters in response to the end signal, and solve the functional relationship model based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

[0020] In a third aspect, the present application further provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the method described above when executing the computer program.

[0021] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0022] In the motor parameter inversion method based on the circuit breaker vector control system, according to the mechanical structure of the circuit breaker operating mechanism, by configuring the inversion operation parameters of the circuit breaker motor operating mechanism, combined with the spring reaction force when the motor operating mechanism is closed and the self-closing force characteristics when the motor operating mechanism is opened, the motor operating mechanism is made relatively static during the inversion process to prevent the faulty motor from causing damage to the power system; then, after generating a control signal according to the inversion operation parameters to control the motor operating mechanism to be in a voltage dynamic equal state, the bus voltage is collected, and the actual voltage of each winding is determined according to the bus voltage and the control signal, and the three-phase winding voltage is collected. The actual current is obtained by fitting the current curve of the motor operating mechanism during the inversion process according to the actual current, and the curve parameters of the current curve are determined. Finally, a functional relationship model including the motor inversion parameters is constructed, and the functional relationship model is solved based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding. The whole process is based on the original vector control system of the operating mechanism and adopts an open-loop PWM control method. There is no need to add additional structures and circuits. The operation is simple and the reliability is high. In addition, based on the solution of the curve parameters, the accuracy of the resistance and inductance inversion of the final motor is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a flow chart of a motor parameter inversion method based on a circuit breaker vector control system in one embodiment;

[0025] Figure 2 is a flow chart of step S101 in one embodiment;

[0026] Figure 3 is a flow chart of step S102 in one embodiment;

[0027] Figure 4 is a flow chart of step S104 in one embodiment;

[0028] Figure 5 is a flow chart of step S106 in one embodiment;

[0029] Figure 6 is a hardware structure diagram of a circuit breaker motor operating mechanism in one embodiment;

[0030] Figure 7 A control principle diagram of a circuit breaker vector control system in one embodiment;

[0031] Figure 8 Schematic diagram of the principle of a motor parameter inversion method based on a circuit breaker vector control system in one embodiment;

[0032] Fig. 9 A schematic diagram of the current flow direction of the stator winding of a motor in a collection cycle in one embodiment;

[0033] Fig.10 is a current waveform diagram of a stator winding of a motor in one embodiment;

[0034] Fig.11 is a current waveform diagram of a first-order circuit composed of an inversion resistor and an inversion inductor in one embodiment;

[0035] Fig.12 The structure block diagram of a motor parameter inversion device based on a circuit breaker vector control system in one embodiment. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0037] In one embodiment, Figure 1 As shown, a motor parameter inversion method based on a circuit breaker vector control system is provided. This embodiment takes the application of this method to a terminal as an example for explanation. It can be understood that this method can also be applied to a server, and can also be applied to a system including a terminal and a server, and is implemented through the interaction between the terminal and the server. In this embodiment, the motor parameters that need to be inverted (hereinafter referred to as "motor inversion parameters") mainly include the resistance and inductance of the motor operating mechanism (hereinafter also referred to as "motor" or "operating mechanism"). By inverting and calculating the inductance and resistance of the motor, the values ​​and changes of the resistance and inductance can be grasped in time, which is conducive to timely detection of motor faults, thereby improving the reliability of the motor operating mechanism.

[0038] Specifically, the method of this embodiment includes the following steps S101 to S106. Among them:

[0039] Step S101, configuring the inversion operation parameters of the circuit breaker motor operating mechanism so that the motor operating mechanism is relatively stationary during the inversion process.

[0040] Among them, the circuit breaker motor operating mechanism is used to operate the high-voltage circuit breaker to achieve closing and opening operations of the high-voltage circuit breaker to ensure the stable and safe operation of the circuit; and the internal characteristic inversion of the circuit breaker motor operating mechanism can infer various characteristic parameters inside the motor to obtain the accurate values ​​or change laws of these parameters, thereby providing strong support for the design, optimization and fault diagnosis of the circuit breaker.

[0041] Among them, the inversion operation parameters refer to the operation parameters of the circuit breaker motor operating mechanism during the inversion process. By configuring the inversion operation parameters, the motor operating mechanism can be relatively still during the inversion process, thereby preventing the faulty motor from causing further damage to the operating mechanism. Based on the motor inversion parameters that need to be inverted in this embodiment, the inversion operation parameters include but are not limited to the inversion current of the motor during the inversion process and the expected voltage and polarity of each phase winding (three-phase stator winding); it can be understood that in some other embodiments, according to different motor inversion parameters, the inversion operation parameters can also include electromotive force, electric power, running time, etc.

[0042] Among them, the inversion current refers to the running current of the motor during the inversion process, which is used to determine the size of the expected voltage of each phase winding; the expected voltage of each phase winding refers to the expected voltage of each winding on the three-phase winding of the motor during the inversion process, which is used to adjust the electromagnetic torque of the motor; the polarity of the expected voltage refers to the positive and negative direction of the voltage on each winding, which is used to determine the direction of current flow to control the operating mechanism to remain stationary during the inversion process.

[0043] Among them, the relative stillness of the motor operating mechanism means that the rotation direction of the motor operating mechanism is the direction of the limit block of the motor operating mechanism. The limit block of the motor operating mechanism is set based on the self-maintaining requirements of the mechanism to achieve the opening position and reduce the impact of the mechanism overshoot on the arc extinguishing chamber, so that the operating mechanism cannot continue to move after reaching the closing and opening positions, so as to limit the movement range of the motor operating mechanism, prevent it from exceeding the set safety range, and extend the service life of the arc extinguishing chamber. By setting the size of the inversion current, a suitable expected voltage can be obtained, and then the electromagnetic torque of the motor is adjusted according to the expected voltage. When the two are equal and opposite in direction, when the motor operating mechanism moves and contacts the limit block, the limit block will generate a reaction force to prevent the further movement of the motor, so that the electromagnetic torque of the motor and the reaction force generated by the limit block reach a state of equilibrium, and the two forces will offset each other, thereby achieving static stability of the motor operating mechanism.

[0044] Specifically, the inversion current of the circuit breaker motor operating mechanism during the inversion process and the expected voltage and polarity of each phase winding are configured according to the operating characteristics of the motor operating mechanism, so that the rotation direction of the motor operating mechanism is the direction of the limit block of the motor operating mechanism, and the motor operating mechanism is ensured to be stationary during the inversion process. When configuring the expected voltage and polarity, the expected voltage of one phase winding of the three-phase winding of the motor is zero, and the expected voltages of the remaining two phase windings are determined based on the inversion current, such as configuring the expected voltage of the A phase winding to zero and determining the expected voltages of the B and C phase windings according to the inversion current, and configuring the polarity of the expected voltage of the B and C phases so that the rotation direction of the motor operating mechanism is the direction of the limit block of the motor operating mechanism. In this process, no current flows on the A phase winding, so that the corresponding parameter relationship between B and C can be determined in the subsequent processing and analysis process.

[0045] Step S102, generating a control signal according to the inversion operation parameter, and controlling the circuit breaker motor operating mechanism to be in a voltage dynamic equal state based on the control signal.

[0046] Among them, the control signal is a PWM control signal, which is used to control the winding action of the motor operating mechanism. The PWM control signal carries information such as the comparison value and duty cycle of the PWM control signal, which is used to control and adjust the operation of the motor operating mechanism.

[0047] The voltage dynamic equal state is defined as the equivalent voltage of each phase winding of the circuit breaker motor operating mechanism being equal to the expected voltage of the corresponding phase under the dynamic control of the control signal. The equivalent voltage of each phase winding refers to the average voltage on the equivalent winding of the motor operating mechanism, and the equivalent winding of the motor operating mechanism refers to the motor winding controlled by the PWM control signal, and the magnetic field generated by it corresponds to the expected magnetic field. In this way, the equivalent voltage of the motor operating mechanism can be dynamically equal to the expected voltage by dynamically adjusting the control signal, thereby ensuring that the operating parameters of the motor operating mechanism during the inversion process can be accurately collected and analyzed.

[0048] Specifically, according to the expected voltage of each phase determined in step S101 (i.e., the voltage of each phase of the three-phase winding), a PWM control signal of each phase is generated based on the control system of the circuit breaker motor operating mechanism, and the motor operating mechanism is controlled according to the PWM control signal, so that the equivalent voltage of each phase winding of the circuit breaker motor operating mechanism is equal to the expected voltage of the corresponding phase under the dynamic control of the PWM control signal.

[0049] Step S103, collecting the bus voltage under the voltage dynamic equal state, and determining the actual voltage of each winding according to the bus voltage and the control signal.

[0050] The bus voltage refers to the voltage at the input end of the inverter (see the description of the "inverter module" below) in the structure of the circuit breaker operating mechanism, and is also the basic voltage used for modulation during the PWM control process, and is used to determine the actual voltage of each winding.

[0051] The actual voltage of each winding refers to the voltage actually applied to each winding when the motor operating mechanism works under the control of the PWM control signal (that is, during the inversion process).

[0052] Specifically, when the equivalent voltage of each phase winding is equal to the expected voltage of the corresponding phase under the dynamic control of the PWM control signal, the bus voltage of the motor operating mechanism is collected to obtain the bus voltage, and the actual voltage of each phase winding is determined and temporarily stored according to the bus voltage and the duty cycle carried in the PWM control signal corresponding to each phase winding for subsequent analysis and processing. In specific implementation, the bus voltage can be measured by a voltage sensor, a multimeter, and other equipment.

[0053] Step S104, collecting the actual current of the three-phase winding, fitting the current curve in the motor inversion process according to the actual current, and determining the curve parameters of the current curve.

[0054] The actual current of the three-phase winding refers to the current actually flowing through each phase winding when the motor actuator is working under the control of the PWM control signal (that is, during the inversion process).

[0055] Among them, the current curve refers to the curve representing the change of current over time obtained by fitting the actual current on each phase winding; the curve parameters corresponding to the current curve can be obtained by fitting and solving the current curve. The current parameters include the steady-state current value and time constant at which the current curve tends to be stable at a certain moment.

[0056] Specifically, the actual current of the three-phase winding is collected, and the current curve of the motor in the inversion process is obtained by fitting the actual current of each phase, and the steady-state current value and time constant corresponding to the current curve are obtained by solving the current curve. In specific implementation, the actual current of the three-phase winding can be measured by current sensors, multimeters and other equipment; when fitting and solving the current curve, one or more methods including but not limited to interpolation, least squares method, polynomial fitting and maximum likelihood estimation can be used.

[0057] Step S105, returning to the step of configuring the inverse operating parameters of the motor of the circuit breaker motor operating mechanism, respectively configuring the expected voltage of one phase of the two non-zero phase windings to zero and determining the expected voltages of the other two phase windings based on the inverse current until multiple sets of current curves and their corresponding curve parameters are obtained.

[0058] Since the motor operating mechanism of this embodiment is a three-phase motor with a three-phase winding, during the inversion process, in order to construct the parameter relationship between the phases of the motor operating mechanism during the inversion process, a relationship model is constructed to obtain the motor inversion parameters on each winding; in the process of configuring the inversion operation parameters, the status of different phases participating in the operation needs to be considered to ensure that accurate motor inversion parameters are obtained.

[0059] Specifically, return to step S101, reconfigure the expected voltage and polarity of each phase winding according to the operating characteristics of the motor operating mechanism, so that the rotation direction of the motor operating mechanism is the direction of the limit block of the motor operating mechanism, and repeat steps S102 to S104 until three different sets of current curves and their corresponding curve parameters are obtained. In the process of returning to reconfigure the expected voltage and its polarity, if the expected voltage of the A-phase winding is first configured to zero and the expected voltage of the B-phase and C-phase windings is determined according to the inversion current, then after returning, the expected voltage of the B-phase or C-phase winding is configured to zero and the expected voltage of the other A-phase and C-phase or A-phase and B-phase windings is determined according to the inversion current, until three different sets of current curves and their corresponding curve parameters are determined, and three sets of corresponding parameter relationships are obtained.

[0060] Step S106, constructing a functional relationship model including motor inversion parameters, and solving the functional relationship model based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

[0061] Among them, the functional relationship model of the motor inversion parameters is constructed based on the three groups of corresponding parameter relationships determined in step S105, and the three groups of parameter relationships respectively include the parameter relationship between AB phases, the parameter relationship between BC phases, and the parameter relationship between AC phases; the functional relationship model of the motor inversion parameters contains the motor inversion parameters to be solved, and the motor inversion parameters of phases A, B, and C on the motor operating mechanism can be obtained respectively by solving the functional relationship model of the motor inversion parameters with each group of curve parameters and the actual voltage corresponding to each winding.

[0062] Specifically, a functional relationship model of the motor inversion parameters is constructed according to the corresponding parameter relationships of the three groups, and each group of steady-state current values, time constants and the actual voltage corresponding to each winding are substituted into the functional relationship model of the motor inversion parameters to obtain the inversion resistance and inversion inductance of each phase winding.

[0063] In the motor parameter inversion method based on the circuit breaker vector control system, according to the mechanical structure of the circuit breaker operating mechanism, by configuring the inversion operation parameters of the circuit breaker motor operating mechanism, combined with the spring reaction force when the motor operating mechanism is closed and the self-closing force characteristics when the motor operating mechanism is opened, the motor operating mechanism is made relatively static during the inversion process to prevent the faulty motor from causing damage to the power system; then, after generating a control signal according to the inversion operation parameters to control the motor operating mechanism to be in a voltage dynamic equal state, the bus voltage is collected, and the actual voltage of each winding is determined according to the bus voltage and the control signal, and the three-phase winding voltage is collected. The actual current is obtained by fitting the current curve of the motor operating mechanism during the inversion process according to the actual current, and the curve parameters of the current curve are determined. Finally, a functional relationship model including the motor inversion parameters is constructed, and the functional relationship model is solved based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding. The whole process is based on the original vector control system of the operating mechanism and adopts an open-loop PWM control method. There is no need to add additional structures and circuits. The operation is simple and the reliability is high. In addition, based on the solution of the curve parameters, the accuracy of the resistance and inductance inversion of the final motor is improved.

[0064] In one embodiment, Figure 2 As shown, step S101 includes steps S201 to S204. Among them:

[0065] Step S201, obtaining normal operating parameters of the circuit breaker operating mechanism.

[0066] The normal operating parameters of the circuit breaker operating mechanism refer to the parameters of the circuit breaker operating mechanism during normal operation. The normal operating parameters include but are not limited to the peak current and the normal resistance of the motor during normal operation of the circuit breaker operating mechanism. Normally, the normal operating parameters can be obtained by referring to the relevant technical manual or the nameplate of the circuit breaker.

[0067] Step S202, configuring the inversion current according to the peak current.

[0068] Among them, the peak current refers to the maximum current that can be reached instantly when the motor operating mechanism is working. The peak current can be obtained based on the acquisition or the rated current of the motor operating mechanism.

[0069] Specifically, the peak current of the motor operating mechanism is determined, and the inversion current of the motor operating mechanism during the inversion process is configured according to the peak current. More specifically, in the specific implementation of this embodiment, the inversion current is set to 20% of the peak current, so that the current value generated by the motor operating mechanism during the inversion process is much smaller than the current when the motor operating mechanism is in normal operation, and the capacitor energy consumed is relatively small, which is beneficial to improve the safety of the inversion process. Of course, it can be understood that in some other embodiments, the ratio of the inversion current to the peak current can also be set according to actual conditions, such as setting the inversion current to 15%, 18%, 22% of the peak current or other values, and it is only necessary to ensure that the current value generated by the motor operating mechanism during the inversion process is much smaller than the current when the motor operating mechanism is in normal operation.

[0070] Step S203, configuring the expected voltage of one phase winding to be zero, and configuring the expected voltages of the other two non-zero phase windings according to the inversion current and the normal resistance of the motor actuator.

[0071] The normal resistance of the motor operating mechanism is the resistance of each phase when the motor operating mechanism works normally, and may be the rated resistance of the motor operating mechanism, which is obtained by referring to a relevant technical manual or a nameplate of a circuit breaker.

[0072] Specifically, taking phase A as an example, the expected voltage of phase A of the three-phase winding of the motor operating mechanism is set to zero, and then phase B and phase C are called non-zero phase windings. The expected voltages of phase B and phase C are determined based on Ohm's law combined with the set inversion current and the normal resistance of phase B and phase C to obtain the expected voltages of phase B and phase C. By analogy, when the expected voltages of phase B and phase C are set to zero, the expected voltages of the other two non-zero phase windings are determined in the same way as the above method, which will not be repeated here.

[0073] Step S204, performing Clark transformation and Park transformation on the non-zero phase winding and configuring the polarity of the desired voltage according to the transformation results, so that the rotation direction of the motor of the operating mechanism is limited to the direction toward the limit block of the operating mechanism and the operating mechanism is stationary during the inversion process.

[0074] Among them, the Clark transformation is used to transform the three-phase stator current (i.e., the inversion current of this embodiment) from the three-phase stationary coordinate system (i.e., the ABC coordinate system) to the two-phase stationary coordinate system (i.e., the αβ coordinate system); the Park transformation is used to transform the current component in the two-phase stationary coordinate system to the two-phase rotating coordinate system (i.e., the dq coordinate system), wherein the d-axis is consistent with the direction of the motor rotor magnetic flux, and the q-axis is perpendicular to the d-axis.

[0075] Specifically, the inversion current of each phase in the three-phase winding is subjected to Clark transformation to convert the inversion current in the three-phase stationary coordinate system into the two-phase stationary coordinate system to obtain the current components of the inversion current in each direction in the two-phase stationary coordinate system.

[0076] In an exemplary embodiment, the expression of Clark transform is as follows:

[0077]

[0078] Among them, f α ,f β are the physical quantities of the motor on the α-axis and β-axis in the αβ coordinate system, respectively. a ,f b ,f c They are the physical quantities of the motor on the A-axis, B-axis and C-axis in the ABC coordinate system, including the motor's current, voltage, magnetic flux, etc.

[0079] According to the current components of the inversion current in each direction in the two-phase stationary coordinate system obtained by Clark transformation, Park transformation is performed on the current components to transform the current components in the two-phase stationary coordinate system into the two-phase rotating coordinate system (i.e., synchronous coordinate system or dq coordinate system). Combined with the point angle of the motor actuator, the current and its direction of the inversion current in the two-phase rotating coordinate system are obtained, and the polarity of the desired voltage of the corresponding winding is determined based on the current direction, so as to adjust the polarity of the desired voltage and ensure that the rotation direction of the motor of the actuator is limited to the direction toward the limit block of the actuator.

[0080] In an exemplary embodiment, the expression of Park transformation is as follows:

[0081]

[0082] Among them, f d ,f q are the physical quantities of the motor on the d-axis and q-axis in the synchronous coordinate system or dq coordinate system, including the motor's current, voltage, flux, etc. e is the electrical angle of the motor rotor.

[0083] In this embodiment, by obtaining the normal operating parameters of the circuit breaker motor operating mechanism, configuring the inversion current according to the peak current, and then setting a suitable expected voltage according to the inversion current, and obtaining the polarity of the expected voltage of each phase winding by transforming the inversion current, the motor is controlled so that the electromagnetic torque of the motor and the reaction force of the limit block are offset, thereby maintaining the static stability of the motor operating mechanism during the inversion process and preventing the faulty motor from causing further damage to the mechanism; and the current value generated during the inversion process is much smaller than the current during the normal operation of the circuit breaker motor operating mechanism, the required capacitor energy consumption is small, and the safety is relatively high.

[0084] In one embodiment, Figure 3 As shown, step S102 includes steps S301 to S304. Among them:

[0085] Step S301, obtaining characteristic parameters of the PWM controller.

[0086] The characteristic parameters of the PWM controller include the high-level voltage, cycle and high-level duration of the PWM control signal output by the PWM controller.

[0087] Step S302, determining the duty cycle of the PWM control signal of the corresponding phase winding according to the expected voltage of each phase winding and the period and high level duration of the PWM control signal of the PWM controller, and controlling the action of the motor actuator based on the PWM control signal.

[0088] Among them, the duty cycle of the PWM control signal refers to the ratio of the duration of the high-level voltage to the entire control cycle time within a control cycle of a PWM control signal, which determines the size of the average voltage output by the PWM controller. The duty cycle can be determined by the ratio of the comparison value of the PWM control signal to the maximum value of the PWM control signal (usually the maximum count value of the PWM controller). The comparison value of the PWM control signal is the duty cycle setting value, and the duty cycle of the PWM control signal can be set in turn. By adjusting the duty cycle of the PWM control signal, the voltage level actually received by the motor winding (i.e., the equivalent voltage of each phase winding) can be adjusted, thereby controlling the action of the circuit breaker operating mechanism.

[0089] Specifically, the duty cycle of the PWM control signal of different phase windings is calculated according to the expected voltage of each phase winding determined in step S101 and the period and high-level duration of the PWM control signal obtained in step S301, and a PWM control signal with a corresponding duty cycle is generated through a PWM controller to control the motor operating mechanism based on the PWM control signal.

[0090] Step S303, determining the equivalent voltage of each phase winding of the circuit breaker operating mechanism according to the high level voltage, cycle and high level duration of the PWM control signal.

[0091] The equivalent voltage of each phase winding refers to the average voltage on the equivalent winding of the motor operating mechanism.

[0092] Specifically, the equivalent voltage of each phase winding of the circuit breaker operating mechanism is determined according to the high-level voltage, cycle and high-level duration of the PWM control signal to control the motor operating mechanism.

[0093] In an optional embodiment, the equivalent voltage is expressed as:

[0094]

[0095] Where V is the equivalent voltage, V high is the high level voltage of the PWM control signal, t is the high level duration, and T is the period of the PWM control signal.

[0096] Step S304, determining the deviation between the equivalent voltage of each phase winding of the motor operating mechanism and the expected voltage of the corresponding phase, and adjusting the duty cycle of each phase PWM signal according to the deviation to make the equivalent voltage of each phase winding of the motor operating mechanism equal to the expected voltage of the corresponding phase.

[0097] Among them, the deviation between the equivalent voltage of each phase winding of the motor operating mechanism and the expected voltage of the corresponding phase refers to the difference between the average voltage on each phase winding of the motor operating mechanism under the actual control of the PWM control signal and the expected voltage configured on the corresponding phase winding. According to the difference, the required duty cycle of the PWM signal can be calculated, and then the PWM controller is controlled to generate a PWM control signal with a corresponding duty cycle, and output it to the control end of the inverter, so as to dynamically adjust the actual operating state of the motor operating mechanism during the inversion process, so that the actual operating state of the motor operating mechanism is similar to or the same as the expected inversion process, thereby ensuring the accuracy of subsequent parameter calculations.

[0098] Specifically, the deviation between the equivalent voltage of each phase and the corresponding expected voltage is calculated based on the equivalent voltage of each phase winding of the motor operating mechanism and the expected voltage of the corresponding phase winding, and the corresponding duty cycle is calculated based on the deviation. The larger the duty cycle, the higher the corresponding equivalent voltage, and the smaller the duty cycle, the lower the corresponding equivalent voltage. Based on this, the size of the equivalent voltage of each winding can be adjusted by adjusting the size of the duty cycle, thereby reducing the deviation between the equivalent voltage of each phase and the corresponding expected voltage, so that the voltage on the equivalent winding is equal to or close to the expected voltage.

[0099] In this embodiment, the characteristic parameters of the PWM controller are obtained; a PWM control signal is generated according to the expected voltage of each phase winding and the characteristic parameters of the PWM controller to control the action of the motor operating mechanism; and the equivalent voltage of each phase winding of the motor operating mechanism is determined; the duty cycle is adjusted based on the deviation between the equivalent voltage and the expected voltage, so that the equivalent voltage of each phase winding of the motor operating mechanism is equal to the expected voltage of the corresponding phase. The whole process is implemented based on the original three-closed-loop vector control system of the circuit breaker, without adding additional hardware circuits and sensors, using open-loop control, without feedback, and the control method is simple.

[0100] In one embodiment, Figure 4 As shown, step S104 includes steps S401 to S403. Among them:

[0101] Step S401, collecting the actual current of the three-phase winding with a first preset interval as a collection period, and fitting the current curve in the motor inversion process according to the actual current of the three-phase winding.

[0102] Among them, the first preset interval is obtained based on the custom setting, and the collection period refers to the period of collecting the actual current flowing through the three-phase winding during the inversion process, so as to facilitate the fitting of the current curve during the inversion process and obtain the relationship between the actual current and time.

[0103] Specifically, a first preset interval is set and used to determine a collection period. The actual current of the three-phase winding is collected once in each collection period to obtain a series of actual current values. The current curve of the three-phase winding during the inversion process can be fitted based on the series of actual current values.

[0104] In an exemplary embodiment, the specific method of fitting the current curve during the motor inversion process is as follows:

[0105] Set an acquisition cycle; determine in sequence the first current value of the motor winding in the first stage of each acquisition cycle and the second current value in the second stage; fit each first current value to obtain a first curve and fit each second current value to obtain a second curve; determine the acquisition time of the actual current of the three-phase winding in the acquisition cycle, and determine the first curve or the second curve as the current curve of the actual current fitting motor in the inversion process of the three-phase winding according to the acquisition time.

[0106] Since the phase voltage of the non-zero phase winding of the motor operating mechanism is maintained near the desired voltage during the inversion process under the control of the PWM control signal, at this time, the resistance and inductance of the two non-zero phases are connected in series to form a first-order circuit, and cooperate with the capacitor in the circuit breaker to form a first-order charging and discharging circuit to periodically charge and discharge the inductance in the winding until the actual current region is stable.

[0107] The acquisition cycle has a first stage and a second stage, and the motor windings work alternately in the first stage and the second stage. The first stage is defined as a charging stage, in which the capacitor charges the inductors of the two non-zero phases, and the second stage is defined as a discharging stage, in which the two non-zero phases discharge through the inductors, and so on, so that the motor windings work in an alternating cycle of charging and discharging.

[0108] More specifically, since the motor windings work in alternating cycles of charging and discharging:

[0109] In the first stage of the first acquisition cycle, the capacitor charges the inductance of the two non-zero phases. During this stage, the current of the two non-zero phase windings increases from zero to a first current value. Due to the existence of the inductance, the first current value at this time has not reached stability; in the second stage of the first acquisition cycle, the inductance of the two non-zero phases discharges. During this stage, the current of the two non-zero phase windings decreases from the first current value to the first second current value. Similarly, due to the existence of the inductance, the first second current value at this time has not decreased to zero, nor has it reached stability.

[0110] In the first stage of the second acquisition cycle, the capacitor charges the inductance of the two non-zero phases again. During this stage, the current of the two non-zero phase windings increases from the first second current value to the second first current value, and the second first current value at this time has not yet reached stability; in the second stage of the second acquisition cycle, the inductance of the two non-zero phases is discharged again. During this stage, the current of the two non-zero phase windings decreases from the second first current value to the second second current value. At this time, the second second current value has not decreased to the first second current value, nor has it reached stability.

[0111] This cycle is repeated until the Kth first current value and the Kth second current value obtained in the Kth acquisition period tend to be stable, thereby obtaining a series of first current values ​​and a series of second current values.

[0112] The first current values ​​are fitted into a first curve in chronological order, and the second current values ​​are fitted into a second curve in chronological order. Since the first current values ​​represent the maximum current value that can be reached on the motor winding in the corresponding acquisition period, and the second current values ​​represent the minimum current value that can be reached on the motor winding in the corresponding acquisition period, the first curve thus fitted is the upper envelope of the current curve, and the second curve is the lower envelope of the current curve.

[0113] Determine the acquisition time of the actual current of the three-phase winding within the acquisition cycle, and determine the first curve or the second curve as the current curve of the actual current of the three-phase winding in the inversion process of the motor according to the acquisition time. For example, when the acquisition time of the actual current of the three-phase winding is the initial time of the acquisition cycle, the actual current value collected is the current value at the beginning of the first stage, and the actual current collected at this time is the second current value. The current curve obtained is similar to the second curve, and the second curve can be determined as the current curve; and when the acquisition time of the actual current of the three-phase winding is the middle of the acquisition cycle, the actual current value collected is the current value at the beginning of the second stage, and the actual current collected at this time is the first current value. The current curve obtained is similar to the first curve, and the first curve can be determined as the current curve.

[0114] Step S402 : sampling the current curve with a second preset interval as a sampling period to obtain a sampling data set including a plurality of time-current data points.

[0115] The second preset interval is obtained based on a custom setting, and the sampling period refers to the period of sampling data on the current curve during the inversion process, so as to obtain a number of time-current data points to form a sampling data set for subsequent solution.

[0116] Specifically, a second preset interval is set to determine a sampling period, and the current curve is sampled in each sampling period to obtain a series of time-current data points including the sampling moment and the current value at the moment, so as to form a sampling data set for subsequent calculations.

[0117] Step S403, defining initial values ​​of curve parameters and constructing a criterion function, iteratively solving the criterion function using a sampled data set until the criterion function meets a preset condition or reaches a maximum number of iterations, and outputting the curve parameters.

[0118] The quasi-group function is used to measure the quality of curve fitting, and the preset condition satisfied by the criterion function is whether the solution of the criterion function is within the set group minimum error range. In specific implementation, the criterion function can be one of the criterion functions including but not limited to the residual sum of squares, Bayesian information criterion, etc.

[0119] Specifically, the initial values ​​of the curve parameters are set, that is, the initial values ​​of the steady-state current value and the time constant are set, which serve as parameters to be determined in the fitting estimation process; a criterion function is constructed based on the curve parameters and the minimum error range of the criterion function is set or the maximum number of iterations is set; the value of the criterion function is solved using the time-current data points in the sampling data set; it is determined whether the solution result is within the minimum error range or whether the maximum number of iterations has been reached. If so, the curve parameters at this time are output to obtain the final steady-state current value and time parameters. If not, the curve parameters are returned and adjusted and the value of the criterion function is continued to be solved using the time-current data points in the sampling data set, and the solution result is judged. This iteration is repeated until the criterion function meets the preset conditions or the maximum number of iterations has been reached, and the curve parameters are output to obtain the final steady-state current value and time parameters.

[0120] In this embodiment, the current curve of the motor operating mechanism during the inversion process is obtained by fitting the actual current of the three-phase winding; and the current curve is sampled to obtain a sampling data set containing several time-current data points, and finally the sampling data set is used to solve the criterion function to obtain the curve parameters, which are used as the data of the subsequent model to solve the motor inversion parameters. This can reduce the impact of data abnormal points caused by individual measurement errors on the inversion results, thereby reducing the error of current curve fitting and ensuring the accuracy of the curve parameters.

[0121] In one embodiment, Figure 5 As shown, step S106 includes step S501 to step S502. Among them:

[0122] Step S501, constructing a functional relationship model including motor inversion parameters.

[0123] The functional relationship model of the motor inversion parameters is used to characterize the relationship between the motor inversion parameters and the steady-state current value, time constant and actual voltage of each winding of each current curve in the above steps. The functional relationship model includes a first functional relationship and a second functional relationship. The first functional relationship represents the equation relationship between the steady-state current value and the time voltage of each winding and the inversion resistance of each phase winding, and the inversion resistance of each phase winding can be obtained by combining them; the second functional relationship represents the equation relationship between the inversion resistance of each phase winding, the inversion voltage and the time constant of each current curve, and the inversion inductance of each phase winding can be obtained by combining them.

[0124] Specifically, a first relationship function corresponding to each phase winding is constructed based on the relationship between the steady-state current value of each current curve and the time voltage of each winding and the inversion resistance of each phase winding; a second relationship function corresponding to each phase winding is constructed based on the relationship between the inversion resistance of each phase winding, the inversion voltage and the time constant of each current curve; and a functional relationship model including the inversion resistance and inversion inductance of the motor is constructed based on each first relationship function and each second relationship function.

[0125] Step S502, solving the first functional relationship according to each group of steady-state current values ​​and the corresponding actual voltage to obtain the inversion resistance of each phase winding, and solving the second functional relationship according to each group of time constants and the inversion resistance of each phase winding to obtain the inversion inductance of each phase winding.

[0126] Specifically, the steady-state current value and time constant of each current curve determined in step S104 and the actual voltage of each phase winding determined in step S103 are substituted into the corresponding first relationship function or the second relationship function, the first relationship functions and the second relationship functions are combined, and the first relationship functions and the second relationship functions are solved to obtain the inversion resistance and inversion inductance on each phase winding.

[0127] In this embodiment, a functional relationship model is formed by constructing a first functional relationship and a second functional relationship including motor inversion parameters; the first functional relationship is solved according to each group of steady-state current values ​​and the corresponding actual voltage to obtain the inversion resistance of each phase winding, and the second functional relationship is solved according to each group of time constants and the inversion resistance of each phase winding to obtain the inversion inductance of each phase winding. During the model construction process, by controlling the conduction and working state of different phase bridge arms, pairwise related relationship equations can be constructed respectively, and the inversion resistance and inversion inductance of each phase winding can be obtained by combining all the relationships. The calculation process is simple, fast and accurate.

[0128] The motor parameter inversion method based on the circuit breaker vector control system of this embodiment is described below for the convenience of understanding by those skilled in the art. Figure 6 A hardware structure diagram of the circuit breaker motor operating mechanism is provided. The method of this embodiment is based on Figure 6 The circuit breaker motor operating mechanism shown is realized; at the same time, Figure 7 A control schematic diagram of a circuit breaker vector control system is provided. The entire process of the method of this embodiment is based on Figure 7 The circuit breaker shown is controlled by the original vector control system, without setting up additional control structure or circuit, adopting open-loop PWM control method, without feedback quantity, and the whole control process is simple and reliable.

[0129] Next, combine Figure 6 and Figure 7The specific structure and control theory in the present invention are further described by taking a specific embodiment based on a topological structure in which a single-phase resistor and an inductor are connected in series in a three-phase winding of a permanent magnet synchronous motor and the three-phase winding adopts a star connection as an example of the motor operating mechanism of the present embodiment. It should be understood that the following description is only an exemplary description and is not a specific limitation of the present application.

[0130] Please refer to Figure 6 The motor operating mechanism of this embodiment includes a storage capacitor module 601, an inverter module 602, a signal acquisition module 603, a drive module 604, a filter and signal conversion module 605, a control module 606 and a motor 607 (operating mechanism). The control module 606 is connected to a computer 609 (terminal) via a communication interface 608.

[0131] Among them, the energy storage capacitor module 601 has a rectifier circuit and a capacitor, and the capacitor provides an energy source for closing and opening the motor 607 by charging and discharging. The capacitor is connected to the inverter module 602, and the inverter module 602 includes three bridge arms respectively connected to the three-phase windings of the motor 607, each bridge arm is formed by a combination of two upper and lower IGBTs, and each bridge arm controls one phase winding of the motor respectively. The gate conduction and shutdown signals of the IGBT are generated by the control module 606 and input into the inverter module through the drive module 604 to control each phase winding. The signal acquisition module 603 uses a Hall sensor to collect capacitance, voltage and current, and uses a photoelectric encoder to collect the motor rotation angle and transmit it to the control module 606. The data such as capacitance, voltage and current are transmitted to the control module after being filtered and converted by the signal conversion module 605, so that the control module 606 can process the collected data and generate the corresponding PWM control signal. In specific implementation, the control module 606 can use the TMS320F28335 chip to implement functions such as processing of collected signals and calculation of control algorithms.

[0132] Please refer to Figure 7 The vector control system of the circuit breaker in this embodiment is a three-closed-loop vector control system. The three closed loops include a position loop, a speed loop and a torque loop from the outside to the inside. The torque loop includes two current loops of quadrature-axis current and direct-axis current.

[0133] Among them, the position loop is responsible for receiving the external position command, that is, the initial position command of the motor, and comparing the actual position of the motor with the command position, generating a position error signal and generating a corresponding speed command. The position error signal and the speed command will be used as the input of the speed loop to adjust the speed and direction of the motor, so as to achieve precise control of the motor position. The speed loop is responsible for receiving the position error command generated by the position loop and the adjusted speed command, and comparing the actual speed of the motor with the command speed, generating a speed error signal and generating a corresponding current command. The speed error signal and the current command will be used as the input of the torque loop (mainly the quadrature axis current loop, the expected input current of the direct axis current loop is zero) to adjust the current of the motor, so as to achieve precise control of the motor speed. The quadrature axis current loop is responsible for receiving the speed error signal and current command generated by the speed loop, and controlling the current of the motor to follow the current command. By accurately controlling the current of the motor, precise control of the motor torque can be achieved, thereby ensuring the stable operation of the motor.

[0134] Specifically, the quadrature-axis current loop and the direct-axis current loop are independently controlled by a PI controller respectively. The current component information of the quadrature-axis and the direct-axis is obtained by collecting the three-phase stator current (the determined inversion current in this embodiment) and transforming it through Clark transformation and Park transformation. The voltage output of the quadrature-axis and the direct-axis is output through calculation by the control module, and the voltage component in the αβ coordinate system (i.e., the expected voltage in this embodiment) is further obtained through Park inverse transformation. Finally, the space voltage vector pulse width modulation (SVPWM) module is used to generate the corresponding PWM control signal to control the conduction and shutdown of the IGBT in the inverter module, thereby driving the permanent magnet synchronous motor to rotate.

[0135] When the limit block of the motor operating mechanism is in the holding position in the open state, the control system can make the motor rotate clockwise through vector control. Similarly, the control system can make the motor rotate counterclockwise by controlling the conduction and shutdown of the six IGBTs in the drive inverter module. At this time, the motor cannot move due to the action of the limit block and is in a stalled state. The electrical angular velocity of the motor is zero, and the permanent magnet will not be able to generate back electromotive force on the stator winding of the motor, thereby keeping the motor operating mechanism stationary.

[0136] Please refer to Figure 8 , is a schematic diagram of the principle of the motor parameter inversion method based on the circuit breaker vector control system of this embodiment. Combined with the hardware structure of the circuit breaker motor operating mechanism and the circuit breaker vector control system, the steps of a specific example of the method of this embodiment are as follows:

[0137] First, the initial state parameters of the motor operating mechanism are obtained, and according to the initial state parameters of the motor operating mechanism, the desired voltages of the B-phase winding and the C-phase winding are determined based on the vector control system of the above-mentioned circuit breaker, and the desired voltage of the A-phase winding is set to zero. The control process of the desired voltages of the B-phase winding and the C-phase winding is described above and will not be repeated here.

[0138] Then, based on the operation of the vector control system of the circuit breaker, the upper IGBT and the lower IGBT of the A-phase bridge arm are kept turned off, that is, S 1 ≡0 and S 2 ≡0(where S 1 ,S 2 They are the gate switching signals of the upper IGBT and the lower IGBT of the A-phase bridge arm respectively).

[0139] Then, the vector control system outputs the corresponding PWM control signal to control the inverter module according to the expected voltage of the B-phase winding and the C-phase winding and the bus voltage, so that the equivalent voltage position of the B-phase winding and the C-phase winding is near the expected voltage of the corresponding phase. At this time, the B-phase winding and the C-phase winding cooperate to form a first-order circuit with inductance and resistance in series, and the stator current of the B-phase winding and the C-phase winding conforms to the first-order circuit characteristics.

[0140] Based on the first-order circuit composed of the above-mentioned inductor and resistor in series, when the gate signal S of the A-phase bridge arm is 1 ≡0 and S 2 ≡0,U bc >0,U c =0 (where U bc is the voltage between the B-phase winding and the C-phase winding, U c Under the condition that (is the expected voltage of the C phase winding), in one acquisition cycle, the current flow direction of the motor stator winding is as follows: Fig. 9 As shown. Since the expected voltage of phase C is zero (i.e. U c =0), so the upper IGBT of the C-phase bridge arm is turned off and the lower IGBT is turned on. Fig. 9 In (a), since the upper IGBT of the B-phase bridge arm is turned on and the lower IGBT is turned off, at this time, the capacitor, the B-phase winding and the C-phase winding form a path, and the capacitor charges the inductance of the B-phase and C-phase to form a first-order charging circuit; Fig. 9 In (b), since the upper IGBT of the B-phase bridge arm is turned off and the lower IGBT is turned on, at this time, the B-phase winding and the C-phase winding form a path and discharge through the inductor.

[0141] Thus, the motor current waveform and the control switch signal are obtained as follows: Fig.10 As shown in (b), the stator winding of the motor works in the case of alternating charging and discharging cycles. In the first stage of the first acquisition cycle (i.e., the charging stage, the charging time is t 1), the winding current (here the first current value) has not reached stability, and in the second stage of the first acquisition cycle (i.e. the discharge stage, the discharge time is t 2 ), the winding current (here the second current value) does not drop to zero, nor does it reach stability.

[0142] Therefore, in the first stage of the first acquisition cycle, the capacitor charges the inductance of the two non-zero phases, and the winding current increases from zero to a first current value.

[0143] In an optional embodiment, the first current value is expressed as:

[0144]

[0145] Among them, I 1 ' is the first current value, I s is the steady-state current value reached after long-term power-on, t 1 is the time of the first stage, i.e., the charging time, and τ is the time constant.

[0146] In the second stage of the first acquisition cycle, the inductor discharges and the winding current decreases from a first current value to a first second current value.

[0147] In an optional embodiment, the first second current value is expressed as:

[0148]

[0149] Among them, I 1 " is the first second current value, t 2 is the time of the second stage, i.e. the discharge time.

[0150] In the first stage of the second acquisition cycle, the capacitor charges the inductance of the two non-zero phases again, and the winding current increases from the first second current value to the second first current value.

[0151] In an optional embodiment, the second first current value is expressed as:

[0152]

[0153] Among them, I' 2 is the second first current value.

[0154] In the second stage of the second acquisition cycle, the inductor is discharged again, and the winding current decreases from the second first current value to the second second current value.

[0155] In an optional embodiment, the second second current value is expressed as:

[0156]

[0157] Among them, I' 2 ' is the second second current value.

[0158] In this way, in the first stage of the Kth acquisition cycle, the capacitor charges the inductance of the two non-zero phases again, and the winding current increases from the K-1th second current value to the Kth first current value.

[0159] In an optional embodiment, the Kth first current value is expressed as:

[0160]

[0161] Among them, I' K is the Kth first current value, K is the number of first current values ​​or second current values, and T' is the acquisition period.

[0162] In the second stage of the Kth acquisition cycle, the inductor is discharged again, and the winding current decreases from the Kth first current value to the Kth second current value.

[0163] In an optional embodiment, the Kth second current value is expressed as:

[0164]

[0165] Among them, I″ K is the Kth second current value.

[0166] Based on the above, the series in formula (8) is a geometric progression, and its sum is Therefore, the current increase and decrease in the Kth acquisition cycle can be expressed as:

[0167]

[0168] Combined with the above analysis, Fig.10 The upper and lower envelopes of the current curve of (a) can be expressed as:

[0169]

[0170] Among them, y 1 and 2 are the values ​​of the upper and lower envelopes of the current curve at time t' respectively.

[0171] In this embodiment, the actual current of the winding is collected once at the initial moment of each collection cycle. In this way, the final fitted current curve is approximately the lower envelope. The current curve is processed using the least squares method. The current waveform of the first-order circuit with an inductor and a resistor in series is as follows: Fig.11As shown, based on this, the resistance can be obtained as the voltage divided by the steady-state current value, and the inductance value can be obtained according to the time constant, thereby solving the steady-state current value and time constant of the current curve.

[0172] In an optional embodiment, when the current curve is processed using the least square method, the residual square sum is selected as a criterion function to estimate the steady-state current value and the time constant. In this embodiment, the criterion function is expressed as:

[0173]

[0174] Among them, J is the criterion function, y(t') is the observed value at t', f(t') is the output value at t', and f(t') contains information such as steady-state current value and time constant to achieve the estimation and solution of steady-state current value and time constant.

[0175] Finally, the relationship equation between phase B and phase C can be constructed based on the current curve of the BC phase loop and the expected voltages of phase B and phase C:

[0176]

[0177] Among them, U bc is the voltage between the B-phase winding and the C-phase winding, R b ,R c are the resistance values ​​of the inverting resistors of the B-phase and C-phase windings, L b ,L c are the inductance values ​​of the reverse inductance of the B-phase and C-phase windings respectively; τ bc is the time constant of the current curve of the BC phase loop; i bs ,i cs are the steady-state current values ​​of the B-phase and C-phase windings respectively.

[0178] Similarly, by setting the upper IGBT and the lower IGBT of the B-phase bridge arm to be always turned off and the upper IGBT and the lower IGBT of the C-phase bridge arm to be always turned off, the above process is repeated to obtain the current curve of the AC phase loop and the current curve of the AB phase loop, and the relationship equation between the A phase and the C phase and the relationship equation between the A phase and the B phase are obtained accordingly.

[0179] Among them, the relationship equation between phase A and phase C can be constructed according to the current curve of the AC phase loop and the expected voltages of phase A and phase C:

[0180]

[0181] Among them, U ac is the voltage between phase A winding and phase C winding, R a ,R care the resistance values ​​of the inverting resistors of phase A and phase C windings, L a ,L c are the inductance values ​​of the reverse inductance of the A-phase and C-phase windings respectively; τ ac is the time constant of the current curve of the AC phase loop; i bs ,i cs are the steady-state current values ​​of phase A and phase C windings respectively.

[0182] According to the current curve of the AB phase circuit and the expected voltage of phase A and phase B, the relationship equation between phase A and phase B can be constructed:

[0183]

[0184] Among them, U ab is the voltage between phase A winding and phase B winding, R a ,R b are the resistance values ​​of the inverting resistors of phase A and phase B windings, L a ,L b are the inductance values ​​of the reverse inductance of the A-phase and B-phase windings respectively; τ ab is the time constant of the current curve of the AB phase loop; i as ,i bs are the steady-state current values ​​of phase A and phase B windings respectively.

[0185] Finally, the functional relationship model of the motor inversion parameters is constructed according to the above formulas (13)(14)(15).

[0186] In an optional embodiment, the functional relationship model of the motor inversion parameters is expressed as:

[0187]

[0188] Among them, I s1 ,I s2 ,I s3 They are the current curves of the AB phase circuit, AC phase circuit and BC phase circuit respectively.

[0189] Based on the above formula (16), the inversion resistance and inversion inductance corresponding to the A-phase, B-phase and C-phase loops are obtained jointly.

[0190] In this embodiment, based on the original structure of the circuit breaker and the original vector control system, the torque fluctuation of the motor during the inversion process is small, the speed regulation range is wide, and the current control efficiency is high. In addition, the motor adopts a three-phase star-connected topology structure, combined with the characteristics of the SVPWM inverter module vector control, and controls the corresponding winding to form a first-order circuit of inductance and resistance in series during the inversion process, and obtains the corresponding first-order circuit current characteristic curve based on the desired voltage of the three-phase winding, and obtains the internal characteristics of the motor winding resistance and inductance according to the transient value and stable value of the current curve.

[0191] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0192] Based on the same inventive concept, the embodiment of the present application also provides a motor parameter inversion device based on a circuit breaker vector control system for implementing the motor parameter inversion method based on a circuit breaker vector control system involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more embodiments of the motor parameter inversion device based on a circuit breaker vector control system provided below can refer to the limitations of the motor parameter inversion method based on a circuit breaker vector control system in the above text, and will not be repeated here.

[0193] In one embodiment, Fig.12 As shown, a motor parameter inversion device based on a circuit breaker vector control system is provided, comprising: a parameter configuration module 1201, a control signal generation module 1202, a voltage acquisition and calculation module 1203, a curve generation module 1204, an execution cycle module 1205, and a parameter calculation module 1206, wherein:

[0194] The parameter configuration module 1201 is used to configure the inversion operation parameters of the circuit breaker motor operating mechanism in response to the configuration signal, so that the motor operating mechanism is relatively static during the inversion process. In specific implementation, at the beginning of the inversion process, the configuration signal is usually a signal for starting the inversion process to trigger the parameter configuration module 1201 to start parameter configuration; during the inversion process, the configuration signal is usually a configuration signal generated by the subsequent execution cycle module 1205 to ensure that the parameters corresponding to each phase winding can be obtained.

[0195] The control signal generating module 1202 is used to generate a control signal according to the inversion operation parameter, and control the motor operating mechanism to be in a voltage dynamic equal state based on the control signal.

[0196] The voltage collection and calculation module 1203 is used to collect the bus voltage under the voltage dynamic equal state, and determine the actual voltage of each winding according to the bus voltage and the control signal.

[0197] The curve generating module 1204 is used to collect the actual current of the three-phase winding, fit the current curve of the motor operating mechanism during the inversion process according to the actual current, and determine the curve parameters of the current curve.

[0198] The execution loop module 1205 is used to determine whether the number of current curves and their curve parameters meets the preset conditions. If so, an end signal is generated, otherwise a configuration signal is generated and the parameter configuration module 1201 is jumped until multiple sets of current curves and their corresponding curve parameters are obtained.

[0199] The parameter calculation module 1206 is used to construct a functional relationship model including motor inversion parameters in response to the end signal, and solve the functional relationship model based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

[0200] In an optional embodiment, the parameter configuration module 1201 is also used to obtain the normal operating parameters of the circuit breaker motor operating mechanism; configure the inversion current according to the peak current; configure the expected voltage of one of the phase windings to zero, and configure the expected voltages of the other two non-zero phase windings according to the inversion current and the normal resistance of the motor inversion mechanism; perform Clark transformation and Park transformation on the non-zero phase winding and configure the polarity of the expected voltage based on the transformation results, so that the rotation direction of the motor operating mechanism is limited to the direction toward the limit block of the motor operating mechanism so that the motor operating mechanism is stationary during the inversion process.

[0201] In an optional embodiment, the control signal generating module 1202 is also used to obtain characteristic parameters of the PWM controller; determine the duty cycle of the PWM control signal of the corresponding phase winding according to the expected voltage of each phase winding and the period and high-level duration of the PWM control signal of the PWM controller, and control the action of the motor operating mechanism based on the PWM control signal; determine the equivalent voltage of each phase winding of the motor operating mechanism according to the high-level voltage, period and high-level duration of the PWM control signal; determine the deviation between the equivalent voltage of each phase winding of the motor operating mechanism and the expected voltage of the corresponding phase, and adjust the duty cycle of each phase PWM signal according to the deviation so that the equivalent voltage of each phase winding of the motor operating mechanism is equal to the expected voltage of the corresponding phase.

[0202] In an optional embodiment, the curve generation module 1204 is also used to collect the actual current of the three-phase winding with a first preset interval as the collection period, and fit the current curve of the motor operating mechanism during the inversion process according to the actual current of the three-phase winding; sample the current curve with a second preset interval as the sampling period to obtain a sampling data set containing a number of time-current data points; define the initial values ​​of the curve parameters and construct a criterion function, use the sampling data set to iteratively solve the criterion function until the criterion function meets the preset conditions or reaches the maximum number of iterations, and output the curve parameters.

[0203] In an optional embodiment, the parameter calculation module 1206 is also used to construct a functional relationship model including motor inversion parameters; the functional relationship model includes a first functional relationship and a second functional relationship; the first functional relationship is solved according to each group of steady-state current values ​​and the corresponding actual voltage to obtain the inversion resistance of each phase winding, and the second functional relationship is solved according to each group of time constants and the inversion resistance of each phase winding to obtain the inversion inductance of each phase winding.

[0204] Each module in the motor parameter inversion device based on the circuit breaker vector control system can be implemented in whole or in part by software, hardware and a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0205] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0206] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0207] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0208] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0209] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0210] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A motor parameter inversion method based on a circuit breaker vector control system, characterized in that: The method comprises: Configuring inversion operation parameters of the circuit breaker motor operating mechanism so that the motor operating mechanism is relatively stationary during the inversion process; the inversion operation parameters include the inversion current of the motor operating mechanism during the inversion process and the expected voltage of each phase winding and its polarity, the expected voltage of one phase winding of the three-phase winding of the motor operating mechanism is zero, and the expected voltages of the remaining two phase windings are determined based on the inversion current; Generate a control signal according to the inversion operation parameter, and control the motor operating mechanism to be in a voltage dynamic equal state based on the control signal; collecting the bus voltage under the voltage dynamic equal state, and determining the actual voltage of each winding according to the bus voltage and the control signal; Collecting the actual current of the three-phase winding, fitting the current curve of the motor operating mechanism during the inversion process according to the actual current, and determining the curve parameters of the current curve; Returning to the step of configuring the inversion operation parameters of the circuit breaker motor operating mechanism, respectively configuring the expected voltage of one phase of the two non-zero phase windings to be zero and determining the expected voltages of the other two phase windings based on the inversion current, until multiple sets of current curves and their corresponding curve parameters are obtained; A functional relationship model including motor inversion parameters is constructed, and the functional relationship model is solved based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

2. The method according to claim 1, characterized in that The configuring of the inversion operation parameters of the circuit breaker motor operating mechanism so that the motor operating mechanism is relatively stationary during the inversion process includes: Acquiring normal operating parameters of the motor operating mechanism of the circuit breaker; the normal operating parameters include the peak current of the motor operating mechanism during normal operation and the normal resistance of the motor operating mechanism; configuring the inversion current according to the peak current; The desired voltage of one phase winding is configured to be zero, and the desired voltages of the other two non-zero phase windings are configured according to the inversion current and the normal resistance of the motor inversion mechanism; Clark transformation and Park transformation are performed on the non-zero phase winding and the polarity of the desired voltage is configured based on the transformation results, so that the rotation direction of the motor operating mechanism is limited to the direction toward the limit block of the motor operating mechanism and the motor operating mechanism is stationary during the inversion process.

3. The method according to claim 2, characterized in that The voltage dynamic equal state is defined as that the equivalent voltage of each phase winding of the circuit breaker motor operating mechanism is equal to the expected voltage of the corresponding phase under the dynamic control of the control signal.

4. The method according to claim 3, characterized in that Generating a control signal according to the inversion operation parameter, and controlling the motor operating mechanism to be in a voltage dynamic stable state based on the control signal comprises: Acquire characteristic parameters of the PWM controller; the characteristic parameters include a high-level voltage, a cycle, and a high-level duration of a PWM control signal output by the PWM controller; Determine the duty cycle of the PWM control signal of the corresponding phase winding according to the expected voltage of each phase winding and the period and high-level duration of the PWM control signal of the PWM controller, and control the action of the motor operating mechanism based on the PWM control signal; Determining the equivalent voltage of each phase winding of the motor operating mechanism according to the high level voltage, cycle and high level duration of the PWM control signal; Determine the deviation between the equivalent voltage of each phase winding of the motor operating mechanism and the expected voltage of the corresponding phase, and adjust the duty cycle of each phase PWM signal according to the deviation so that the equivalent voltage of each phase winding of the motor operating mechanism is equal to the expected voltage of the corresponding phase.

5. The method according to any one of claims 1 to 4, characterized in that: The collecting the actual current of the three-phase winding, fitting the current curve of the motor inversion mechanism during the inversion process according to the actual current, and determining the curve parameters of the current curve include: The actual current of the three-phase winding is collected at a first preset interval as a collection period, and the current curve of the motor operating mechanism in the inversion process is fitted according to the actual current of the three-phase winding; Sampling the current curve at a second preset interval as a sampling period to obtain a sampling data set including a plurality of time-current data points; The initial values ​​of the curve parameters are defined and a criterion function is constructed. The criterion function is iteratively solved using the sampled data set until the criterion function meets a preset condition or reaches a maximum number of iterations, and the curve parameters are output.

6. The method according to claim 5, characterized in that The collecting the actual current of the three-phase winding at a first preset interval as a collection period, and fitting the current curve of the motor operating mechanism in the inversion process according to the actual current of the three-phase winding includes: Setting a collection cycle; the collection cycle has a first stage and a second stage, and each winding of the motor inversion mechanism works alternately in the first stage and the second stage; Determine in sequence the first current value of each winding in the first phase and the second current value in the second phase of each acquisition cycle; Fitting each first current value to obtain a first curve and fitting each second current value to obtain a second curve; The acquisition time of the actual current of the winding within the acquisition period is determined, and the first curve or the second curve is determined as the current curve of the actual current of the three-phase winding fitting motor operating mechanism during the inversion process according to the acquisition time.

7. The method according to any one of claims 1 to 4, characterized in that: The constructing of a functional relationship model including motor inversion parameters, and solving the functional relationship model based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding include: Constructing a functional relationship model including motor inversion parameters; the motor inversion parameters include inversion resistance and inversion inductance of the motor actuator, the curve parameters include steady-state current values ​​and time constants corresponding to each current curve, and the functional relationship model includes a first functional relationship and a second functional relationship; The first functional relationship is solved according to each group of steady-state current values ​​and the corresponding actual voltage to obtain the inversion resistance of each phase winding, and the second functional relationship is solved according to each group of time constants and the inversion resistance of each phase winding to obtain the inversion inductance of each phase winding.

8. A motor parameter inversion device based on a circuit breaker vector control system, characterized in that: The device comprises: A parameter configuration module, configured to configure the inversion operation parameters of the circuit breaker motor operating mechanism in response to the configuration signal, so that the motor operating mechanism is relatively stationary during the inversion process; the inversion operation parameters include the inversion current of the motor operating mechanism during the inversion process and the expected voltage of each phase winding and its polarity, the expected voltage of one phase winding of the three-phase winding of the motor operating mechanism is zero, and the expected voltages of the remaining two phase windings are determined based on the inversion current; A control signal generating module, used for generating a control signal according to the inversion operation parameter, and controlling the motor operating mechanism to be in a voltage dynamic equal state based on the control signal; A voltage acquisition and calculation module, used for acquiring the bus voltage in the voltage dynamic equal state, and determining the actual voltage of each winding according to the bus voltage and the control signal; A curve generating module, used for collecting the actual current of the three-phase winding, fitting the current curve of the motor operating mechanism in the inversion process according to the actual current, and determining the curve parameters of the current curve; An execution loop module is used to determine whether the number of current curves and their curve parameters meets the preset conditions, and if so, an end signal is generated, otherwise, the configuration signal is generated and the parameter configuration module is jumped until multiple sets of current curves and their corresponding curve parameters are obtained; The parameter calculation module is used to construct a functional relationship model including motor inversion parameters in response to the end signal, and solve the functional relationship model based on each group of curve parameters and the actual voltage corresponding to each winding to obtain the motor inversion parameters of the corresponding phase winding.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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