Circuit for reducing torque ripple of three-phase motor, control method thereof and related device
By using the front -stage three -phase bridge, rear -class three -phase bridge, and Class Union H bridge circuit topology in the motor drive system, the problem of rotating the rotation of the motor's rotation is solved, and higher operating stability and efficiency are achieved.
Patent Information
- Application Number
- CN202411372727.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2025-01-28
AI Technical Summary
In the prior art, the back-to-back three-phase bridge converter has torque pulsation during the motor operation, which hinders its promotion in the field of precision applications.
The circuit topology includes the front three -phase bridge, the rear -level three -phase bridge, and the High Bridge of the Class Lianlian, through the setting of the H bridge of the class, reducing the harmonic components in the circuit output voltage, thereby reducing the motor rotation pulse.
By reducing the pulse of the torque when the motor is running, the operating stability and working efficiency of the motor are improved, and it is suitable for areas with higher requirements for torque output stability.
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Figure CN119382567A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of network service failure recovery, and in particular to a circuit for reducing torque pulsation of a three-phase motor, a control method thereof, and related devices. Background Art
[0002] With the development of frequency conversion technology, multilevel converters are widely used in wind power generation, mine hoisting, steel rolling, motor drive and other fields. Back-to-back three-phase bridge converters have been widely used in motor drive applications that require four-quadrant operation due to their characteristics of bidirectional energy flow and relatively mature control technology. However, there will be torque pulsation during the operation of the motor, which to a large extent hinders its promotion in precision applications, especially in fields with high requirements for torque output stability. Therefore, how to reduce the torque pulsation during motor operation and improve the operating stability and work efficiency of the motor is a technical problem that needs to be solved. Summary of the invention
[0003] In view of this, the purpose of the present application is to propose a circuit for reducing the torque pulsation of a three-phase motor and its control method and related devices to solve or partially solve the above-mentioned technical problems.
[0004] Based on the above purpose, the present application provides a circuit for reducing torque ripple of a three-phase motor, comprising:
[0005] The front stage three-phase bridge, the rear stage three-phase bridge and the cascade H bridge;
[0006] The input end of the front-stage three-phase bridge is connected to a three-phase AC power supply, and the output end of the front-stage three-phase bridge is connected to the input end of the rear-stage three-phase bridge; the output end of the rear-stage three-phase bridge is connected to the input end of the cascade H-bridge, and the output end of the cascade H-bridge is connected to a three-phase motor;
[0007] The cascaded H-bridge includes three phases, and each phase includes a plurality of full-bridge modules connected in series.
[0008] In some embodiments, the full-bridge module includes a first capacitor and four semiconductor power devices.
[0009] In some embodiments, the semiconductor functional device is a metal oxide semiconductor field effect transistor.
[0010] In some embodiments, the semiconductor functional device is an insulated gate bipolar transistor.
[0011] In some embodiments, the four semiconductor power devices include: a first semiconductor power device, a second semiconductor power device, a third semiconductor power device and a fourth semiconductor power device; the common node of the first end of the first semiconductor power device and the first end of the second semiconductor power device is the input end of the full-bridge module, and the common node of the first end of the third semiconductor power device and the first end of the fourth semiconductor power device is the output end of the full-bridge module; the common node of the second end of the first semiconductor power device and the second end of the third semiconductor power device is connected to the first end of the first capacitor, and the common node of the second end of the second semiconductor power device and the second end of the fourth semiconductor power device is connected to the second end of the first capacitor.
[0012] In some embodiments, the front-stage three-phase bridge includes three front-stage single-phase bridges, and the front-stage single-phase bridge includes a first upper insulated gate bipolar transistor and a first lower insulated gate bipolar transistor; the common node between the first end of the first upper insulated gate bipolar transistor and the first end of the first lower insulated gate bipolar transistor is the input end of the front-stage three-phase bridge.
[0013] In some embodiments, the rear-stage three-phase bridge includes three rear-stage single-phase bridges, and the rear-stage single-phase bridge includes a second upper insulated gate bipolar transistor and a second lower insulated gate bipolar transistor; the common node between the first end of the second upper insulated gate bipolar transistor and the first end of the second lower insulated gate bipolar transistor is the output end of the rear-stage three-phase bridge.
[0014] In some embodiments, the circuit also includes a second capacitor; the common node of the second end of the first upper insulated gate bipolar transistor and the second end of the second upper insulated gate bipolar transistor is connected to the first end of the second capacitor, and the common node of the second end of the first lower insulated gate bipolar transistor and the second end of the second lower insulated gate bipolar transistor is connected to the second end of the second capacitor.
[0015] In some embodiments, each phase of the cascaded H-bridge includes the same number of full-bridge modules connected in series.
[0016] Based on the same concept, the present application also proposes a control method for a circuit for reducing torque pulsation of a three-phase motor, the method being applied to the circuit for reducing torque pulsation of a three-phase motor as described above; the method comprising:
[0017] The cascaded H-bridge is modulated by carrier phase shifting, wherein the modulation wave of the carrier phase shifting is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the subsequent three-phase bridge.
[0018] Based on the same concept, the present application also proposes a control device for a circuit for reducing torque pulsation of a three-phase motor, and the device is applied to the circuit for reducing torque pulsation of a three-phase motor as described above; the device comprises:
[0019] The adjustment module adopts carrier phase shift to modulate the cascade H bridge; wherein the modulation wave of the carrier phase shift is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the rear three-phase bridge.
[0020] Based on the same concept, the present application also proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the control method of the circuit for reducing the torque pulsation of a three-phase motor as described above is implemented.
[0021] Based on the same concept, the present application also proposes a non-transitory computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a computer to execute the control method of the circuit for reducing the torque pulsation of a three-phase motor as described above.
[0022] Based on the same concept, the present application also proposes a computer program product, which includes a computer program. The computer program is executed by one or more processors so that the processors execute the control method of the circuit for reducing the torque pulsation of a three-phase motor as described above.
[0023] From the above, it can be seen that the circuit and its control method and related devices for reducing the torque pulsation of a three-phase motor provided by the present application include a front-stage three-phase bridge, a rear-stage three-phase bridge and a cascaded H-bridge; the input end of the front-stage three-phase bridge is connected to a three-phase AC power supply, and the output end of the front-stage three-phase bridge is connected to the input end of the rear-stage three-phase bridge; the output end of the rear-stage three-phase bridge is connected to the input end of the cascaded H-bridge, and the output end of the cascaded H-bridge is connected to a three-phase motor; the cascaded H-bridge includes three phases, each phase includes a plurality of full-bridge modules connected in series, and has the characteristics of bidirectional energy flow through the combined topology of the three-phase bridge and the cascaded H-bridge. Through the setting of the cascaded H-bridge, the harmonic components in the output voltage of the circuit are reduced, the torque pulsation during motor operation is reduced, and the operating stability and working efficiency of the motor are improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] In order to more clearly illustrate the technical solutions in the present application or related technologies, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0025] Figure 1 A schematic diagram of the structure of a circuit for reducing torque ripple of a three-phase motor according to an embodiment of the present application;
[0026] Figure 2 This is a schematic structural diagram of a full-bridge module according to an embodiment of the present application;
[0027] Figure 3 A structural schematic diagram of a full-bridge module connection relationship according to an embodiment of the present application;
[0028] Figure 4 This is a schematic diagram of the structure of a control front-stage three-phase bridge according to an embodiment of the present application;
[0029] Figure 5 This is a schematic diagram of the structure of a control rear-stage three-phase bridge according to an embodiment of the present application;
[0030] Figure 6 A schematic diagram of the structure of a vector control of a three-phase motor according to an embodiment of the present application;
[0031] Figure 7 A schematic diagram of the operation of a cascaded H-bridge according to an embodiment of the present application;
[0032] Figure 8 A schematic diagram of an ideal output waveform of each single-phase module on the output side of a converter according to an embodiment of the present application;
[0033] Fig. 9 Schematic diagram of a flow chart of a control method for a circuit for reducing torque pulsation of a three-phase motor according to an embodiment of the present application.
[0034] Fig.10 This is a schematic diagram of the structure of a control device for a circuit for reducing torque pulsation of a three-phase motor according to an embodiment of the present application.
[0035] Fig.11 A schematic diagram of a specific electronic device hardware structure of an embodiment of the present application. DETAILED DESCRIPTION
[0036] It is understandable that the data involved in this technical solution (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of relevant laws, regulations and relevant provisions.
[0037] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be the usual meanings understood by people with general skills in the field to which the present application belongs. The "first", "second" and similar words used in the present application do not represent any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, which can be direct connections, indirect connections, wired connections, and wireless connections. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly. In addition, in the description of the present application, unless otherwise specified, the term "multiple" refers to two or more. The term "and / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects are in an "or" relationship.
[0038] The principles and spirit of the present application will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are provided only to enable those skilled in the art to better understand and implement the present application, and are not intended to limit the scope of the present application in any way. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.
[0039] It is understandable that before using the technical solutions of each embodiment of the present application, the type, scope of use, usage scenarios, etc. of the personal information involved will be informed to the user in an appropriate manner, and the user's authorization will be obtained.
[0040] For example, in response to receiving an active request from a user, a prompt message is sent to the user to clearly remind the user that the operation requested to be performed will require obtaining and using the user's personal information. Thus, the user can independently choose whether to provide personal information to the electronic device, application, server, storage medium or other software or hardware that performs the operation of the technical solution of the present application according to the prompt message.
[0041] As an optional but non-limiting implementation, in response to receiving the user's active request, the prompt information may be sent to the user in the form of a pop-up window, in which the prompt information may be presented in text form. In addition, the pop-up window may also carry a selection control for the user to choose "agree" or "disagree" to provide personal information to the electronic device.
[0042] It is understandable that the above notification and the process of obtaining user authorization are merely illustrative and do not constitute a limitation on the implementation method of this application. Other methods that meet relevant laws and regulations may also be applied to the implementation method of this application.
[0043] It should be understood herein that any number of elements in the drawings is for illustration rather than limitation, and any naming is only for distinction rather than having any limiting meaning.
[0044] As described in the background technology section, among the current related technologies, back-to-back three-phase bridge converters have been widely used in motor drive applications that require four-quadrant operation due to their characteristics of bidirectional energy flow and relatively mature control technology. However, there will be torque pulsation during the operation of the motor, which to a large extent hinders its promotion in precision applications, especially in fields that require high torque output stability. Therefore, how to reduce the torque pulsation during motor operation and improve the operating stability and work efficiency of the motor is a technical problem that needs to be solved.
[0045] In summary, in order to solve the above problems, the embodiment of the present application proposes a circuit for reducing the torque ripple of a three-phase motor, including:
[0046] A front-stage three-phase bridge, a rear-stage three-phase bridge and a cascaded H-bridge; the input end of the front-stage three-phase bridge is connected to a three-phase AC power supply, and the output end of the front-stage three-phase bridge is connected to the input end of the rear-stage three-phase bridge; the output end of the rear-stage three-phase bridge is connected to the input end of the cascaded H-bridge, and the output end of the cascaded H-bridge is connected to a three-phase motor; the cascaded H-bridge includes three phases, each phase includes a plurality of full-bridge modules connected in series, and has the characteristic of bidirectional energy flow through the combined topology of the three-phase bridge and the cascaded H-bridge. Through the setting of the cascaded H-bridge, the harmonic components in the output voltage in the circuit are reduced, the torque pulsation during the operation of the motor is reduced, and the operation stability and working efficiency of the motor are improved.
[0047] In some specific application scenarios, the circuit for reducing the torque pulsation of a three-phase motor of the present application can be applied to various systems and devices involving three-phase motors.
[0048] The following describes a circuit for reducing torque pulsation of a three-phase motor according to an exemplary embodiment of the present application in conjunction with a specific application scenario. It should be noted that the above application scenario is only shown to facilitate understanding of the spirit and principle of the present application, and the implementation of the present application is not limited in this regard. On the contrary, the implementation of the present application can be applied to any applicable scenario.
[0049] refer to Figure 1 , is a schematic diagram of a circuit for reducing torque ripple of a three-phase motor according to an embodiment of the present application, the circuit comprising:
[0050] The front stage three-phase bridge 01, the rear stage three-phase bridge 02 and the cascade H bridge 03;
[0051] The input end of the front-stage three-phase bridge 01 is connected to the three-phase AC power supply 05, and the output end of the front-stage three-phase bridge 01 is connected to the input end of the rear-stage three-phase bridge 02; the output end of the rear-stage three-phase bridge 02 is connected to the input end of the cascade H bridge 03, and the output end of the cascade H bridge 03 is connected to the three-phase motor 04;
[0052] The cascaded H-bridge 03 includes three phases, and each phase includes a plurality of full-bridge modules connected in series.
[0053] It should be noted that in this embodiment, due to the high distortion rate in the output voltage of the back-to-back three-phase bridge, directly connecting to the motor will cause excessive torque pulsation of the motor, so a cascaded H-bridge unit is introduced to reduce the distortion rate of the motor terminal voltage. The general cascade unit is to output active power, so the DC side of each cascade unit must be active, but the cascade unit in this embodiment outputs harmonic voltage, and the cascade unit will not bear active power, so its DC side only needs capacitors.
[0054] In some embodiments, reference Figure 2 , the full-bridge module includes a first capacitor Cd1 and four semiconductor power devices.
[0055] In some embodiments, the semiconductor functional device is a metal oxide semiconductor field effect transistor (MOSFET).
[0056] In some embodiments, the semiconductor functional device may also be an insulated gate bipolar transistor (IGBT). It should be noted that the cost of the semiconductor field effect transistor (MOSFET) is lower than that of the insulated gate bipolar transistor (IGBT), and the user may select a suitable semiconductor functional device according to the needs, and there is no limitation on this.
[0057] In some embodiments, reference Figure 1 and Figure 2The four semiconductor power devices include: a first semiconductor power device V1, a second semiconductor power device V2, a third semiconductor power device V3 and a fourth semiconductor power device V4; the common node of the first end of the first semiconductor power device V1 and the first end of the second semiconductor power device V2 is the input end of the full-bridge module, and the common node of the first end of the third semiconductor power device V3 and the first end of the fourth semiconductor power device V4 is the output end of the full-bridge module; the common node of the second end of the first semiconductor power device V1 and the second end of the third semiconductor power device V3 is connected to the first end of the first capacitor Cd1, and the common node of the second end of the second semiconductor power device V2 and the second end of the fourth semiconductor power device V4 is connected to the second end of the first capacitor Cd1.
[0058] In some embodiments, reference Figure 1 The front-stage three-phase bridge 01 includes three front-stage single-phase bridges, and the front-stage single-phase bridge includes a first upper insulated gate bipolar transistor and a first lower insulated gate bipolar transistor; the common node of the first end of the first upper insulated gate bipolar transistor and the first end of the first lower insulated gate bipolar transistor is the input end of the front-stage three-phase bridge.
[0059] In some embodiments, reference Figure 4 The front three-phase bridge adopts double closed-loop control, and its DC side output As a given input, U d and U q As the controller output, e d and e q As feedforward compensation, the current state feedback ωL is introduced s i d and ωL s i q Feedforward decoupling is performed to achieve independent control of the current. The voltage regulator is used as an outer loop to stabilize the DC output voltage, and its output is used as the current loop component i d The given input is finally modulated by SVPWM and outputs control pulses.
[0060] In some embodiments, reference Figure 1 The rear-stage three-phase bridge 02 includes three rear-stage single-phase bridges, and the rear-stage single-phase bridge includes a second upper insulated gate bipolar transistor and a second lower insulated gate bipolar transistor; the common node of the first end of the second upper insulated gate bipolar transistor and the first end of the second lower insulated gate bipolar transistor is the output end of the rear-stage three-phase bridge.
[0061] In some embodiments, reference Figure 5 The three-phase voltage U a , U b, U c and three-phase current i a 、i b 、i c After coordinate transformation, we get e d 、e q and i d 、i q The voltage regulator calculates the error between the reference voltage and the actual AC voltage and performs closed-loop control operations to generate an inner-loop current reference value. The current regulator calculates the error between the reference current and the actual AC current and performs closed-loop control operations to generate a reference voltage for SVPWM modulation. The SVPWM modulator calculates the pulse width based on the reference voltage provided by the error compensator and generates control pulses to drive the converter to work, ultimately achieving stable control of the output voltage using the voltage outer loop and control of the output current using the current inner loop.
[0062] In some embodiments, reference Figure 1 , the circuit also includes a second capacitor Cd2; the common node of the second end of the first upper insulated gate bipolar transistor and the second end of the second upper insulated gate bipolar transistor is connected to the first end of the second capacitor Cd2, and the common node of the second end of the first lower insulated gate bipolar transistor and the second end of the second lower insulated gate bipolar transistor is connected to the second end of the second capacitor Cd2.
[0063] In some embodiments, reference Figure 6 The control of the three-phase motor adopts a vector control method. The stator voltage equation on the motor side is transformed into a synchronous rotating coordinate system to obtain the shaft voltage formula output by the cascaded H bridge to the motor side:
[0064] u md = pψ d -ωψ q +R m i md ;
[0065] u mq = pψ q -ωψ d +R m i mq ;
[0066] Among them, u md 、u mq is the dq axis voltage output from the cascaded H bridge to the motor side, ψ d , q is the dq-axis flux of the motor stator, ω is the electrical angular velocity of the motor rotor, i md 、i mq is the motor stator dq axis current, R m is the stator phase winding resistance of the motor. Among them, the flux equation is:
[0067] ψ d =L md i md +M afd0 i f ;
[0068] ψ d =L md i md +M afd0 i f ;
[0069] Among them, L md , L mq are the stator dq axis self-inductance, M afd0 is the mutual inductance between the rotor excitation winding and the stator equivalent d-axis winding, i f is the rotor excitation winding current. The torque equation and motion equation are:
[0070] T em =p(ψ d i mq -ψ q i md );
[0071]
[0072] Where P is the number of pole pairs, J is the moment of inertia of the motor and load, T L is the load torque.
[0073] In some embodiments, it can be known from the above flux equation that the magnetic field of the motor can be controlled by the rotor excitation winding or by the stator current. To simplify the control structure, the stator d-axis flux is controlled only by the rotor excitation winding, the stator d-axis current is controlled to 0, and the torque is controlled by controlling the stator q-axis current, and the motor vector control diagram is obtained as shown in FIG. Figure 6 shown.
[0074] In some embodiments, each phase of the cascaded H-bridge includes the same number of full-bridge modules connected in series.
[0075] In some embodiments, the upper and lower switches of each phase of the front-stage three-phase bridge are complementary and turned on, and the upper and lower switches of the rear-stage three-phase bridge are complementary and turned on.
[0076] In some embodiments, the number of full-bridge modules connected in series in each phase of the cascaded H-bridge is equal, and the upper and lower switches in the full-bridge modules are complementary and conductive.
[0077] In some embodiments, the control of the front-stage three-phase bridge adopts dual dq closed-loop control, and the voltage controller is used as the outer loop regulation to stabilize the DC output voltage, and its output is used as the given input of the current loop component. The inner current loop is used to control the actual current on the grid side to quickly track the current instruction; the control of the rear-stage three-phase bridge also adopts dual dq closed-loop control, and the voltage controller performs error calculation and closed-loop control operation between the reference voltage and the actual voltage to generate an inner loop current reference value. The current controller performs error calculation and closed-loop control operation between the reference current and the actual current, and finally realizes the stable control of the output voltage by the voltage outer loop and the control of the output current by the current inner loop.
[0078] In some embodiments, the motor is controlled using a vector control method. By establishing a motor model, the voltage and current of the motor are converted into the voltage and current on the dq axis; independent control of the motor is achieved through current vector control; and precise control of the motor speed is achieved through speed closed-loop control.
[0079] In some embodiments, the modulation strategy of the front-stage three-phase bridge and the rear-stage three-phase bridge adopts SVPWM modulation, the basic principle of which is the average value equivalence principle, that is, by combining the basic voltage vectors in one switching cycle, the average value thereof is equal to the given voltage vector. At a certain moment, the voltage vector rotates to a certain area, which can be obtained by the different combinations of two adjacent non-zero vectors and zero vectors constituting this area in time. Compared with the traditional modulation strategy, the SVPWM modulation strategy has a smaller harmonic component of the current waveform and is easier to realize digitization.
[0080] The circuit for reducing the torque pulsation of a three-phase motor provided in the present application includes: a front-stage three-phase bridge, a rear-stage three-phase bridge and a cascaded H-bridge; the input end of the front-stage three-phase bridge is connected to a three-phase AC power supply, and the output end of the front-stage three-phase bridge is connected to the input end of the rear-stage three-phase bridge; the output end of the rear-stage three-phase bridge is connected to the input end of the cascaded H-bridge, and the output end of the cascaded H-bridge is connected to a three-phase motor; the cascaded H-bridge includes three phases, and each phase includes a plurality of full-bridge modules connected in series. Through the combined topology of the three-phase bridge and the cascaded H-bridge, it has the characteristic of bidirectional energy flow. Through the setting of the cascaded H-bridge, the harmonic components in the output voltage of the circuit are reduced, the torque pulsation during the operation of the motor is reduced, and the operation stability and working efficiency of the motor are improved.
[0081] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments, the present application also provides a control method for a circuit for reducing torque pulsation of a three-phase motor. The method is applied to the circuit of any of the above-mentioned embodiments, with reference to Fig. 9 , the method comprises the following steps:
[0082] S101, adopt carrier phase shifting to modulate the cascaded H-bridge; wherein the modulation wave of the carrier phase shifting is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the subsequent three-phase bridge.
[0083] In the specific implementation, in this embodiment, the modulation strategy of the cascaded H-bridge adopts carrier phase-shift modulation, and the modulation wave is the third, fifth, and seventh harmonics in the output voltage of the subsequent three-phase bridge. Its interaction with the fundamental current output by the subsequent three-phase bridge will only produce reactive power, thereby achieving the effect of reducing the pulsation of the motor rotation.
[0084] It should be noted that the cascaded H-bridge uses unipolar frequency-doubled carrier phase shifting technology (CPS-SPWM), which can greatly increase the equivalent switching frequency and ensure the accurate output of high-order harmonics. Unipolar frequency-doubled CPS-SPWM technology is an excellent modulation strategy suitable for high-power power electronic switching converters, which can achieve the effect of higher equivalent switching frequency at lower device switching frequency. Figure 7 , is the CPS-SPWM principle, where u s (t) is the target modulation wave, -u s (t) is the same as u s (t) The modulation wave is 180 degrees out of phase, C1(t), C2(t), C N (t) is a triangular carrier wave with different starting phases, which are 0°, 180° / N and 180°(N-1) / N respectively. The phase difference between two adjacent modulation waves is 180° / N, thus achieving a phase shift effect. Figure 3 and Figure 7 The control principle is as follows: C1(t) with an initial phase of 0° and u s The driving signal T1 obtained by comparing (t) and its complementary driving signal T2 respectively drive the switch tubes V1 and V2 of the upper and lower bridge arms of the left half bridge of the unit module 1; C1(t) with an initial phase of 0° and -u s (t) The driving signal T3 obtained by comparison and the complementary driving signal T4 drive the switch tubes V3 and V4 of the upper and lower bridge arms of the right half bridge of the unit module 1 respectively; similarly, the initial phase is C N (t) respectively with u s (t) and -u s (t) The driving signal obtained by comparison controls the on and off of the Nth unit switch tube.
[0085] The Fourier decomposition of the output waveform of the Lth unit can be obtained:
[0086]
[0087] Where: F L (t) is the output waveform, M is the modulation ratio; E is the unit direct pressure amplitude; ωc is the carrier angular frequency; is the initial phase angle of the carrier; ω s is the angular frequency of the modulation wave; is the initial phase angle of the modulation wave.
[0088] The first formula in the above formula can be expressed as:
[0089]
[0090] Where: k c is the carrier ratio.
[0091] If all unit outputs are taken into account, the total output waveform after superposition can be decomposed into:
[0092]
[0093] From the above formula, we can know that the output waveform of the cascade unit mainly includes two parts: the component with the same frequency as the modulation wave and the high-order harmonic component. Let the fundamental frequency be f0 and the fundamental-to-carrier ratio be k c0 When the modulation wave is a single harmonic, let f s =s f0, s is the harmonic order, and s≤50, then the output voltage mainly contains single harmonic components and high-order harmonic components. Through the design of the RLC filter circuit, the high-frequency switching ripple can be filtered out. After filtering, the output of the cascade inverter meets:
[0094]
[0095] Where M is the modulation ratio, E is the unit direct voltage amplitude, N is the number of full-bridge modules included in each phase of the cascaded H-bridge required for the specified harmonic output, ω s is the modulation wave angular frequency, is the initial phase angle of the modulation wave.
[0096] From the above formula, we can know that by changing the modulation wave M, f s and The fundamental wave and any harmonic of the given instruction can be output.
[0097] Under the aforementioned basic control method, harmonic voltage (third, fifth, and seventh harmonics) is emitted through the cascaded H-bridge. The harmonic voltage and the fundamental frequency current of the motor will only generate reactive power, thereby reducing the torque pulsation during motor operation and improving the operating stability and working efficiency of the motor. Figure 8It is the ideal output waveform of each single-phase module on the output side of the converter, wherein the N1 full bridge is controlled to emit the third harmonic to offset the third harmonic in the output voltage of the three-phase bridge at the next stage; the N2 full bridge is controlled to emit the fifth harmonic to offset the fifth harmonic in the output voltage of the three-phase bridge at the next stage; the N3 full bridge is controlled to emit the seventh harmonic to offset the seventh harmonic in the output voltage of the three-phase bridge at the next stage; as the harmonic content in the output voltage decreases, the amplitude of the output voltage decreases accordingly, and because the higher the harmonic number, the higher the required switching frequency, the smaller the period of the corresponding output voltage waveform. It should be noted that for each phase of the cascaded H bridge, three groups of full bridges, N1, N2, and N3, are included to offset the third, fifth, and seventh harmonics in the output voltage of the three-phase bridge at the next stage, respectively.
[0098] The control method of the circuit for reducing the torque pulsation of a three-phase motor in the above-mentioned embodiment is used to realize the corresponding circuit for reducing the torque pulsation of a three-phase motor in any of the above-mentioned embodiments, and has the beneficial effects of the corresponding circuit embodiment for reducing the torque pulsation of a three-phase motor, which will not be repeated here.
[0099] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a control device for a circuit for reducing torque pulsation of a three-phase motor. The device is applied to the circuit for reducing torque pulsation of a three-phase motor as described above, with reference to Fig.10 , the device comprises:
[0100] The adjustment module 201 adopts carrier phase shifting to modulate the cascaded H-bridge; wherein the modulation wave of the carrier phase shifting is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the subsequent three-phase bridge.
[0101] For the convenience of description, the above device is described in terms of functions divided into various modules. Of course, when implementing the present application, the functions of each module can be implemented in the same or multiple software and / or hardware.
[0102] The control device of the circuit for reducing the torque pulsation of a three-phase motor in the above-mentioned embodiment is used to implement the corresponding control method of the circuit for reducing the torque pulsation of a three-phase motor in any of the above-mentioned embodiments, and has the beneficial effects of the corresponding control method embodiment of the circuit for reducing the torque pulsation of a three-phase motor, which will not be repeated here.
[0103] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present disclosure also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the circuit for reducing the torque pulsation of the three-phase motor as described in any of the above embodiments is implemented.
[0104] It should be noted that the method of the embodiment of the present application can be performed by a single device, such as a computer or server. The method of this embodiment can also be applied to a distributed scenario and completed by multiple devices cooperating with each other. In the case of such a distributed scenario, one of the multiple devices can only perform one or more steps in the method of the embodiment of the present application, and the multiple devices will interact with each other to complete the described method.
[0105] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the above embodiments and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.
[0106] Fig.11 A more specific schematic diagram of the hardware structure of an electronic device provided in this embodiment is shown. The device may include: a processor 1010, a memory 1020, an input / output interface 1030, a communication interface 1040 and a bus 1050. The processor 1010, the memory 1020, the input / output interface 1030 and the communication interface 1040 are connected to each other in communication within the device through the bus 1050.
[0107] The processor 1010 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this specification.
[0108] The memory 1020 may be implemented in the form of ROM (Read Only Memory), RAM (Random Access Memory), static storage device, dynamic storage device, etc. The memory 1020 may store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented by software or firmware, the relevant program codes are stored in the memory 1020 and are called and executed by the processor 1010.
[0109] The input / output interface 1030 is used to connect the input / output module to realize information input and output. The input / output module can be configured in the device as a component (not shown in the figure), or it can be externally connected to the device to provide corresponding functions. The input device may include a keyboard, a mouse, a touch screen, a microphone, various sensors, etc., and the output device may include a display, a speaker, a vibrator, an indicator light, etc.
[0110] The communication interface 1040 is used to connect a communication module (not shown) to realize communication interaction between the device and the power equipment. The communication module can realize communication through a wired method (such as USB, network cable, etc.) or a wireless method (such as mobile network, WIFI, Bluetooth, etc.).
[0111] The bus 1050 includes a path that transmits information between the various components of the device (eg, the processor 1010, the memory 1020, the input / output interface 1030, and the communication interface 1040).
[0112] It should be noted that, although the above device only shows the processor 1010, the memory 1020, the input / output interface 1030, the communication interface 1040 and the bus 1050, in the specific implementation process, the device may also include other components necessary for normal operation. In addition, it can be understood by those skilled in the art that the above device may also only include the components necessary for implementing the embodiments of the present specification, and does not necessarily include all the components shown in the figure.
[0113] The electronic device of the above embodiment is used to implement the control method of the circuit for reducing the torque pulsation of the three-phase motor in any of the above embodiments, and has the beneficial effects of the corresponding method embodiment, which will not be repeated here.
[0114] Based on the same inventive concept, corresponding to any of the above-mentioned embodiment methods, the present disclosure also provides a non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the control method of the circuit for reducing the torque pulsation of a three-phase motor as described in any of the above embodiments.
[0115] The computer-readable medium of this embodiment includes permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, read-only compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device.
[0116] The computer instructions stored in the storage medium of the above embodiment are used to enable the computer to execute the control method of the circuit for reducing the torque pulsation of the three-phase motor as described in any of the above embodiments, and have the beneficial effects of the corresponding method embodiments, which will not be repeated here.
[0117] Based on the same inventive concept, corresponding to any of the above-mentioned embodiments and methods, the present application also provides a computer program product, which includes a computer program. In some embodiments, the computer program instructions can be executed by one or more processors of a computer so that the computer and / or the processor execute the control method of the circuit for reducing the torque pulsation of a three-phase motor described in the above-mentioned embodiment. Corresponding to the execution subject corresponding to each step in each embodiment of the circuit for reducing the torque pulsation of a three-phase motor, the processor that executes the corresponding step can belong to the corresponding execution subject.
[0118] To simplify the description and discussion, and in order not to make the embodiments of the present application difficult to understand, the known power supply / ground connection with the integrated circuit (IC) chip and other components may or may not be shown in the provided drawings. In addition, the device can be shown in the form of a block diagram to avoid making the embodiments of the present application difficult to understand, and this also takes into account the following fact, that is, the details of the implementation of these block diagram devices are highly dependent on the platform to be implemented in the embodiments of the present application (that is, these details should be fully within the scope of understanding of those skilled in the art). In the case of elaborating specific details (e.g., circuit) to describe exemplary embodiments of the present application, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details or when these specific details are changed. Therefore, these descriptions should be considered to be illustrative rather than restrictive.
[0119] Although the present application has been described in conjunction with specific embodiments of the present application, many replacements, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may use the embodiments discussed.
[0120] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present application (including the claims) is limited to these examples. In line with the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present application as described above, which are not provided in detail for the sake of simplicity.
[0121] The embodiments of the present application are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application should be included in the scope of protection of the present application.
Claims
1. A circuit for reducing torque ripple of a three-phase motor, characterized in that: include: The front stage three-phase bridge, the rear stage three-phase bridge and the cascade H bridge; The input end of the front-stage three-phase bridge is connected to a three-phase AC power supply, and the output end of the front-stage three-phase bridge is connected to the input end of the rear-stage three-phase bridge; the output end of the rear-stage three-phase bridge is connected to the input end of the cascade H-bridge, and the output end of the cascade H-bridge is connected to a three-phase motor; The cascaded H-bridge includes three phases, and each phase includes a plurality of full-bridge modules connected in series.
2. The circuit according to claim 1, characterized in that The full-bridge module includes a first capacitor and four semiconductor power devices.
3. The circuit according to claim 2, characterized in that The semiconductor functional device is a metal oxide semiconductor field effect transistor.
4. The circuit according to claim 2, characterized in that The semiconductor functional device is an insulated gate bipolar transistor.
5. The circuit according to claim 2, characterized in that The four semiconductor power devices include: a first semiconductor power device, a second semiconductor power device, a third semiconductor power device and a fourth semiconductor power device; the common node of the first end of the first semiconductor power device and the first end of the second semiconductor power device is the input end of the full-bridge module, and the common node of the first end of the third semiconductor power device and the first end of the fourth semiconductor power device is the output end of the full-bridge module; the common node of the second end of the first semiconductor power device and the second end of the third semiconductor power device is connected to the first end of the first capacitor, and the common node of the second end of the second semiconductor power device and the second end of the fourth semiconductor power device is connected to the second end of the first capacitor.
6. The circuit according to claim 1, characterized in that The front-stage three-phase bridge includes three front-stage single-phase bridges, and the front-stage single-phase bridge includes a first upper insulated gate bipolar transistor and a first lower insulated gate bipolar transistor; the common node of the first end of the first upper insulated gate bipolar transistor and the first end of the first lower insulated gate bipolar transistor is the input end of the front-stage three-phase bridge.
7. The circuit according to claim 6, characterized in that The rear-stage three-phase bridge includes three rear-stage single-phase bridges, and the rear-stage single-phase bridge includes a second upper insulated gate bipolar transistor and a second lower insulated gate bipolar transistor; the common node of the first end of the second upper insulated gate bipolar transistor and the first end of the second lower insulated gate bipolar transistor is the output end of the rear-stage three-phase bridge.
8. The circuit according to claim 7, characterized in that The circuit also includes a second capacitor; a common node between the second end of the first upper insulated gate bipolar transistor and the second end of the second upper insulated gate bipolar transistor is connected to the first end of the second capacitor, and a common node between the second end of the first lower insulated gate bipolar transistor and the second end of the second lower insulated gate bipolar transistor is connected to the second end of the second capacitor.
9. The circuit according to claim 1, characterized in that Each phase of the cascaded H-bridge includes the same number of full-bridge modules connected in series.
10. A control method for a circuit for reducing torque ripple of a three-phase motor, characterized in that: The method is applied to the circuit according to any one of claims 1 to 9; the method comprises: The cascaded H-bridge is modulated by carrier phase shifting, wherein the modulation wave of the carrier phase shifting is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the subsequent three-phase bridge.
11. A circuit control device for reducing torque ripple of a three-phase motor, characterized in that: The device is applied to the circuit according to any one of claims 1 to 9; the device comprises: The adjustment module adopts carrier phase shift to modulate the cascade H bridge; wherein the modulation wave of the carrier phase shift is the third harmonic, the fifth harmonic and the seventh harmonic in the output voltage of the rear three-phase bridge.
12. An electronic device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the method according to claim 10 is implemented when the processor executes the program.
13. A non-transitory computer-readable storage medium, characterized in that: The non-transitory computer-readable storage medium stores computer instructions for causing a computer to execute the method of claim 10 .
14. A computer program product, characterized in that The computer program product comprises a computer program, and the computer program is executed by one or more processors so that the processors perform the method according to claim 10 .