CN110336511B - Six-phase motor harmonic current suppression method based on model prediction direct torque control - Google Patents
Six-phase motor harmonic current suppression method based on model prediction direct torque control Download PDFInfo
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- 239000013598 vector Substances 0.000 claims abstract description 104
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- 230000007935 neutral effect Effects 0.000 claims description 2
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P21/00—Arrangements or methods for the control of electric machines by vector control, e.g. by control of field orientation
- H02P21/24—Vector control not involving the use of rotor position or rotor speed sensors
- H02P21/28—Stator flux based control
- H02P21/30—Direct torque control [DTC] or field acceleration method [FAM]
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P27/00—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage
- H02P27/04—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage
- H02P27/06—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters
- H02P27/08—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation
- H02P27/12—Arrangements or methods for the control of AC motors characterised by the kind of supply voltage using variable-frequency supply voltage, e.g. inverter or converter supply voltage using dc to ac converters or inverters with pulse width modulation pulsing by guiding the flux vector, current vector or voltage vector on a circle or a closed curve, e.g. for direct torque control
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Abstract
The invention discloses a six-phase motor harmonic current suppression method based on model prediction direct torque control, which comprises the following steps: according to the voltage vector characteristics of the six-phase motor, the vector requirement for harmonic current suppression is analyzed; according to a vector selection rule of direct torque, considering the change conditions of torque and flux linkage, and formulating a vector selection table; selecting corresponding zero vectors according to the principle of minimum switching times, and making a zero vector corresponding table; deducing a prediction model of the motor from a mathematical model of the six-phase motor; obtaining a simplified cost function according to the characteristics of direct torque control of model prediction; the model prediction direct torque control method based on the scheme can effectively inhibit the harmonic current of the six-phase motor, is simple and easy to implement in the scheme implementation process, and can fully utilize the maximum voltage vector of the system.
Description
Technical Field
The invention relates to the technical field of six-phase motor control, in particular to a six-phase motor harmonic current suppression method based on model prediction direct torque control.
Background
The multiphase motor has the characteristics of small torque pulsation, large control freedom, low-voltage high-power output, strong fault-tolerant capability and the like, so that the multiphase motor is very suitable for systems such as electric automobiles, ship propulsion, wind power generation, full-electric airplanes and the like. The double three-phase motor is two sets of asymmetric six-phase motors with the difference of 30-degree electrical angles of three-phase windings, and in the motor, because the alpha and beta subspace voltage vectors for motor energy conversion can be projected onto the x and y harmonic subspaces at the same time, the vector and direct torque control method of the common three-phase motor both need to be modified properly, and can be suitable for being used in the double three-phase motor.
In order to eliminate harmonic components of a double three-phase motor, a method which is used for reference from a traditional three-phase motor control method comprises the following steps: a SVPWM method of four-vector synthesis, a double zero sequence injection PWM method, a three-phase decoupling PWM method and the like. In recent years, with the wide application of a model predictive control algorithm in the field of motors, documents have found that by using four voltage vectors with different amplitudes of a double three-phase motor, the voltage vectors with 2-3 amplitudes can be synthesized to generate a vector with zero voltage in the x and y subspaces and the position of the x and y harmonic subspaces, and then the motor is controlled by combining the model predictive control algorithm to suppress harmonic current and improve the efficiency of the motor. However, these methods utilize vectors of various magnitudes to perform a combined control process, which is complex and time-consuming in the vector synthesis process on one hand, and does not fully utilize the maximum voltage vector on the other hand. The six-phase motor harmonic current suppression method based on model prediction direct torque control provided by the invention fully utilizes the maximum voltage vector, realizes suppression of x and y subspace harmonic current, and is simple and easy to implement.
Disclosure of Invention
The invention aims to provide a six-phase motor harmonic current suppression method based on model prediction direct torque control, which fully utilizes a maximum voltage vector, realizes suppression of harmonic current and improves motor efficiency. The technical scheme adopted by the invention is described in detail as follows:
step 1: according to the voltage vector characteristics of the six-phase motor, the vector requirement for harmonic current suppression is analyzed;
step 2: according to a vector selection rule of direct torque, considering the change conditions of torque and flux linkage, and making a vector selection table meeting harmonic suppression;
and step 3: selecting a corresponding zero vector according to the principle of minimum switching times, and making a zero vector corresponding table;
and 4, step 4: deducing a prediction model of the motor from a mathematical model of the six-phase motor;
and 5: obtaining a simplified cost function according to the characteristics of direct torque control of model prediction;
step 6: when the motor runs, obtaining motor parameters and the current state, and substituting corresponding vectors in a vector table into a prediction model one by one to obtain a predicted value of harmonic current;
and 7: substituting the predicted value of the harmonic current into a cost function to obtain a function value;
and 8: repeating the step 6 and the step 7, and finding the voltage vector with the minimum current function value as an optimal vector;
and step 9: outputting the optimal vector to a 6-phase inverter, controlling a switching tube to execute corresponding action by the inverter according to the vector, and outputting voltage to control the motor to operate;
step 10: and (5) continuously repeating the steps 6 to 9, and continuously operating the motor.
Compared with the prior art, the invention has the advantages that: obtaining a vector selection table by utilizing the characteristic of direct torque control, and predicting at most 3 vectors according to the change conditions of torque and flux linkage; the system uses a zero vector, so that torque fluctuation can be reduced and efficiency can be improved; the maximum voltage vector of the system is fully utilized, and the voltage utilization rate of the system is improved; the implementation process of the scheme is simple and feasible, the harmonic current of the six-phase motor can be effectively inhibited, and the efficiency of the motor is improved.
Drawings
FIG. 1 Structure of a Dual three-phase neutral-point isolated six-phase Motor drive System
FIG. 2 six-phase system α, β and x, y subspace voltage vector profiles
FIG. 3 spatial distribution variation of 3 consecutive vectors in the α, β subspace in the x, y subspace
FIG. 4 model-based predictive direct torque control six-phase motor control system block diagram
Detailed Description
The following detailed description of embodiments of the invention is provided in conjunction with the accompanying drawings of FIGS. 1-4:
step 1: according to the voltage vector characteristics of the six-phase motor, the vector requirement for harmonic current suppression is analyzed;
the corresponding neutral point isolated six-phase motor drive system of the present invention is shown in fig. 1, and the vectors of the α, β and x, y subspaces of the system can be expressed as follows:
wherein a ═ ejπ/6，(Sa,Sb,Sc,Sd,Se,Sf) E (0,1) is the switching state of six arms of the inverter, such as SaWhen equal to 0, it represents the upper bridge arm switch tube Sa1Cut-off, lower bridge arm switch tube Sa2Conduction, SaThe opposite is true when 1 is true, and the other bridge arms are similar. Each of the alpha, beta and x, y subspaces has 26The vector space composed of L4, L3, L2 and L1 is shown in fig. 2, where the two numbers of subscript of each vector are the states of each switch tube expressed in 2, such as V64Representing binary numbers (110100) corresponding to six switches (S), respectivelya,Sb,Sc,Sd,Se,Sf) The switch state of (1).
Due to any two adjacent (i.e., 30 degrees apart) L4 magnitude vectors in α, β, two L1 magnitude vectors separated by 150 degrees are formed in the x, y subspace. Therefore, 3L 4 vectors of α and β, which are continuously spaced by 30 degrees, always form a 2 nd L1 vector, which is different from the 1 st and 3 rd vectors by plus or minus 150 degrees, in x and y subspaces, as illustrated in fig. 3. Each time 3 consecutive vectors of L4 in α, β are selected, they are vectors that can be made to have a composite magnitude of zero in x, y.
Step 2: according to a vector selection rule of direct torque, considering the change conditions of torque and flux linkage, and formulating a vector selection table;
the changes in torque and flux linkage Δ ψ, Δ T are taken into account in accordance with the control system block diagram shown in FIG. 4 and the vector selection rule for direct torqueeWhen the motor state is in the sector S1, the 12 large vectors of the outermost layer L4 are divided into 4 cases, and the following table can be obtained.
Table 1 vector selection table for sector S1
In the table 1 denotes a reference value ψref,
Greater than the current value psi, TeAt this time, the vector for increasing the current value needs to be selected; phase (C)The value-1 should indicate that the vector of the pre-reduction value needs to be selected, and 0 indicates that the current value remains unchanged with the zero vector. When the motor rotates counterclockwise to different sectors from S2 to S12, the vectors in the table are also in the position shown in fig. 2, and the counterclockwise rotation can obtain the corresponding vector table.
And step 3: selecting a corresponding zero sequence vector according to the principle of minimum switching times, and making a zero vector corresponding table;
since the zero vector has four types, namely V00, V77, V07 and V70, the selection of the zero vector is selected according to the principle that the switching times are the minimum when the current vector is switched to the zero vector, and the following table 2 can be obtained.
TABLE 2 corresponding zero vector for different vectors
| Current vector | V44 | V64 | V66 | V26 | V22 | V32 |
| Zero vector | V00 | V70 | V77 | V07 | V00 | V70 |
| Current vector | V33 | V13 | V11 | V51 | V55 | V45 |
| Zero vector | V77 | V07 | V00 | V70 | V77 | V07 |
And 4, step 4: deducing a prediction model of the motor from a mathematical model of the six-phase motor;
the mathematical model of the six-phase motor is shown in the following equation, where the voltage equation for the d, q space is as follows:
the voltage equation for the x, y space is as follows:
the flux linkage and torque equations for the motor are as follows:
combining the formula (3) with a first-order forward Euler discretization method, a current prediction model of an x and y space can be obtained as follows:
and 5: according to the characteristics of direct torque control of model prediction, a simple and feasible cost function is obtained;
the conventional cost function is generally:
such a cost function requires λ1,λ2,λ3The adjustment of three factors is complicated. Since the present method combines the advantages of direct torque, the voltage vectors of Table 1 have been selected with consideration
ΔTeSo the flux linkage and torque part can be removed from the cost function, and the cost function is simplified as follows:
such a cost function does not require λ1,λ2,λ3The adjustment of the three factors is very simple and easy.
Step 6: when the motor runs, firstly, motor parameters and the current state are obtained, and corresponding vectors in a vector table are substituted into a prediction model one by one to obtain a predicted value of harmonic current;
1) from the current state i of the motorabcdefθ is obtained according to the following formulad,iq,ix,iy：
2) From id,iqAnd a parameter L inherent to the motord,Lq,ψfT can be obtained from the formula (4)eThe psi value;
3) derived from PI controllers
And set psirefAnd TePhi, by hysteresis comparison to yield Δ Te,Δψ；
And 7: if Δ TeWhen it is 0, the zero vector is output as V according to the vector table 2optGo to step 9;
and 8: if Δ TeNot equal to 0, and obtaining an optimal vector V by a prediction model and a cost functionopt；
1) According to Δ TeThe value of Δ ψ and vector table 1, resulting in 3 voltage vectors being preselected;
2) combined with motor intrinsic parameters Lz,RsAnd a system sampling period TsSubstituting 3 voltage vectors into a current prediction model formula (5) one by one to obtain
3) According to the cost function (7), the voltage vector when the cost function is minimum is calculated and used as the optimal vector Vopt；
And step 9: vector V of output voltageoptFor the 6-phase inverter, the inverter controls the corresponding switching tube to be switched on or switched off according to each binary value in the vector, and outputs corresponding voltage to control the motor to operate;
step 10: and (5) continuously repeating the steps 6 to 9, and continuously operating the motor according to a set scheme to realize the suppression of harmonic current.
The six-phase motor control system implemented by the steps can effectively inhibit the motor from being driven by the motorx,iyThe formed harmonic current improves the operation efficiency of the motor.
Claims (4)
1. A six-phase motor harmonic current suppression method based on model predictive direct torque control is characterized by comprising the following steps:
1) considering the harmonic cause of the six-phase motor, according to the voltage vector characteristics of the six-phase motor and the vector selection rule of direct torque, a vector selection table of each sector is formulated, wherein non-zero vectors in the vector selection table are in a group of 3, and vectors in the group can generate a synthetic vector which enables the harmonic voltage of an x subspace and a y subspace to be zero;
2) when the motor is running, the current delta psi and delta T in a certain sectoreThe value obtains a group of vectors from a vector table, and the optimal vector is selected to control the motor by combining a cost function which minimizes harmonic current, wherein delta phi represents a stator flux linkage reference value psi of the motorrefDifference, Δ T, from the current value of flux linkageeReference value T representing motor torquee refAnd the current value TeA difference of (d);
3) at delta psi, delta TeWhen the sector value is not changed, the optimal vector is selected from the same group of vectors rapidly and continuously for control, and a required synthetic vector which enables the harmonic current to be minimum can be obtained equivalently in a sequence combination mode;
4) when the motor continuously rotates, the harmonic current suppression effect can be achieved by continuously repeating the steps 3) and 4).
2. The method for suppressing the harmonic current of the six-phase motor based on the model predictive direct torque control according to claim 1, wherein the involved motors are six-phase permanent magnet motors with two sets of three-phase windings with a difference of 30 degrees in electrical angle and isolated neutral points.
3. The method of suppressing six-phase motor harmonic current based on model predictive direct torque control of claim 1 wherein the vector selection table is as follows:
table 1 vector selection table for sector S1
When the motor rotates to different sectors counterclockwise, the vector in the table is rotated counterclockwise to obtain a corresponding vector table; the non-zero vectors of table 1 are selected from the largest 12 vectors of equal magnitude of the 64 vectors of the six-phase motor, the numbers in the vectors representing the switching states of the 6 arms of the drive.
4. The method for suppressing six-phase motor harmonic current based on model predictive direct torque control according to claim 1, wherein the cost function is:
in the formula
The harmonic current of the motor six-phase current projected in the x and y subspaces is a predicted value of the next moment obtained by the current prediction model.
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| CN111585477B (en) * | 2020-06-04 | 2021-09-28 | 福州大学 | Voltage vector preselection-based dual-motor drive system predicted torque control method |
| CN113098348B (en) * | 2021-04-09 | 2023-10-31 | 沈阳工业大学 | Predictive torque control method for double three-phase permanent magnet synchronous motor |
| CN114189184B (en) * | 2021-11-25 | 2023-12-01 | 上大电气科技(嘉兴)有限公司 | Six-phase motor model predictive control method for reducing harmonic content |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105162380A (en) * | 2015-10-13 | 2015-12-16 | 哈尔滨工业大学 | Six-phase permanent-magnet synchronous motor model predictive control method |
| CN107994832A (en) * | 2017-11-24 | 2018-05-04 | 东南大学 | A kind of multichannel permanent magnet synchronous motor mixing Direct Torque Control |
| EP3399641A1 (en) * | 2011-09-29 | 2018-11-07 | Daihen Corporation | Signal processor, filter, control circuit for power converter circuit, interconnection inverter system and pwm converter system |
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| US9614461B2 (en) * | 2014-12-02 | 2017-04-04 | Princeton Power Systems, Inc. | Bidirectional high frequency variable speed drive for CHP (combined heating and power) and flywheel applications |
| CN107565865B (en) * | 2017-09-13 | 2019-07-23 | 华中科技大学 | A kind of fault-tolerant double vector prediction control method and device of six-phase permanent-magnet motor |
| CN109217765B (en) * | 2018-09-17 | 2021-06-15 | 沈阳工业大学 | Direct torque control method for double three-phase permanent magnet synchronous motor |
| CN109379013B (en) * | 2018-11-30 | 2020-05-29 | 北京理工大学 | Torque ripple suppression method for permanent magnet synchronous motor |
| CN109951128B (en) * | 2019-04-02 | 2020-09-15 | 合肥工业大学 | Model-free current prediction control method and system for SMPMSM (Small form-factor permanent magnet synchronous motor) driving system for online optimization of inverter reference voltage vector |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3399641A1 (en) * | 2011-09-29 | 2018-11-07 | Daihen Corporation | Signal processor, filter, control circuit for power converter circuit, interconnection inverter system and pwm converter system |
| CN105162380A (en) * | 2015-10-13 | 2015-12-16 | 哈尔滨工业大学 | Six-phase permanent-magnet synchronous motor model predictive control method |
| CN107994832A (en) * | 2017-11-24 | 2018-05-04 | 东南大学 | A kind of multichannel permanent magnet synchronous motor mixing Direct Torque Control |
Non-Patent Citations (1)
| Title |
|---|
| 《基于零序平衡矢量的六相感应电动机SVPWM策略研究》;李山;《机床与液压》;20091231;388-393 * |
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