CN110855166A - PWM rectifier dead-beat current prediction control method - Google Patents

PWM rectifier dead-beat current prediction control method Download PDF

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CN110855166A
CN110855166A CN201911098687.6A CN201911098687A CN110855166A CN 110855166 A CN110855166 A CN 110855166A CN 201911098687 A CN201911098687 A CN 201911098687A CN 110855166 A CN110855166 A CN 110855166A
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time
current
moment
objective function
input
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康龙云
周海兰
张健彬
赵子先
林鸿业
于玮
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South China University of Technology SCUT
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/02—Conversion of ac power input into dc power output without possibility of reversal
    • H02M7/04—Conversion of ac power input into dc power output without possibility of reversal by static converters
    • H02M7/12—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/21—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
    • H02M7/217—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M7/219—Conversion of ac power input into dc power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration

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Abstract

The invention discloses a PWM rectifier dead-beat current prediction control method, which comprises the following steps: firstly, taking a discretization mathematical model of a circuit as a prediction model of the circuit k +1 moment, and then predicting one beat in the past to obtain a prediction model of the circuit k +2 moment; then adding a zero vector in a sampling period to obtain a prediction model considering the zero vector at the moment k + 2; then, the target function is derived and the derivative is 0, and the optimal switching action time of the non-zero vector is solved; and finally, calculating the objective function value of each switch state, and selecting the switch state with the minimum objective function value as the switch state at the next moment. Compared with the traditional model prediction control method, the method has the advantages of constant frequency and low harmonic content of the current on the network side.

Description

PWM rectifier dead-beat current prediction control method
Technical Field
The invention relates to the technical field of PWM rectifier control, in particular to a PWM rectifier dead-beat current prediction control method.
Background
With the increasing energy crisis and environmental problems, research on new energy technologies is receiving more and more attention. In medium and small power occasions, the PWM rectifier is widely used. The model predictive control has the advantages of simple control structure, fast dynamic response and the like, but also has the problems of inconstant switching frequency, large calculation amount, high harmonic content of network side current and the like.
At present, a PWM rectifier has fixed-frequency prediction power control, but the method has large calculation amount and complex control, and does not consider the influence of factors such as sampling time delay and the like, so that harmonic suppression is not ideal.
Disclosure of Invention
The invention aims to solve the defects of PWM rectifier prediction control in the prior art, and provides a PWM rectifier dead-beat current prediction control method which has the advantages of fixed frequency control and small network side current harmonic wave.
The purpose of the invention can be achieved by adopting the following technical scheme:
a PWM rectifier dead beat current prediction control method includes 4 MOS tubes, a filter inductor L, a voltage stabilizing capacitor C and a resistor RLThe output side of the PWM rectifier circuit is composed of a voltage stabilizing capacitor C and a resistor RLThe control method comprises the following steps:
t1, taking a discretization mathematical equation of the column-writing PWM rectifier as a prediction model of the circuit k +1 moment, and predicting one beat in the forward direction to obtain a prediction model of the circuit k +2 moment;
t2, designing an objective function, deriving the objective function, enabling the derivative of the objective function to be equal to 0, and solving to obtain the optimal switching action time of the non-zero vector;
t3, the objective function value in each switching state is calculated, and the switching state that minimizes the objective function value is selected as the switching state at the next time.
Further, in step T1, the process of calculating the prediction model at the time of the circuit k +2 is as follows:
the first column writes the circuit differential equation as follows:
Figure BDA0002269169320000021
wherein u issIs input voltage, L is filter inductance, t is time, isFor input of current, SabRepresenting the switch state, which may take values of-1, 0, 1, vdcIs the output voltage;
discretizing the formula (A) to obtain
Figure BDA0002269169320000022
Wherein is(k) For the sample value of the input current at the present moment, is(k +1) is the predicted value of the input current at the time k +1, TsIs a sampling period, us(k) For the value of the input voltage sample at the present moment, Sab(k) Is the on-off state at time k;
reconsidering the action time of the zero vector to obtain
Figure BDA0002269169320000023
Wherein, ton(k) The action time of the non-zero vector at the moment k;
according to formula (C) to obtain
Figure BDA0002269169320000031
Wherein is(k +2) is the sample value of the input current at the time k +2, us(k +1) is the predicted value of the input voltage at the time k +1, Sab(k +1) is the switch state at time k +1, ton(k +1) is the action time of the non-zero vector at the moment k;
obtained according to formula (C) and formula (D)
Figure BDA0002269169320000032
Wherein, Δ is(k) Is the amount of current change at the k-th time, Δ is(k +1) is the current change at the k +1 th time, and the relaxation pair Δ is(k +1) constraint equal to the mean of the current differences at the k-th and k + 1-th moments, resulting in
Figure BDA0002269169320000033
Assuming equal difference between input voltages at two adjacent sampling instants, i.e.
us(k+1)-us(k)＝us(k)-us(k-1) thus obtaining
us(k+1)＝2us(k)-us(k-1) (G)
Wherein u iss(k-1) is the input voltage sample value at time k-1;
by substituting the formulae (F), (G) into the formula (E)
Figure BDA0002269169320000034
Further, in the step T2, the process of solving the optimal switching action time of the non-zero vector is as follows:
defining an objective function as
Figure BDA0002269169320000041
Wherein the content of the first and second substances,
Figure BDA0002269169320000042
is a current reference value, is(k +2) is an input current sampling value at the moment of k + 2;
the objective function is derived over time and the derivative is 0 to obtain
Figure BDA0002269169320000043
When t ison(k+1)＞TsWhen it is, let ton(k+1)＝Ts；
When t isonWhen (k +1) < 0, let ton(k+1)＝0。
Compared with the prior art, the invention has the following advantages and effects:
the traditional model predicts large current harmonic at the network side due to the fact that the control frequency is not constant, and the existing fixed-frequency power prediction needs coordinate transformation, is complex in calculation and does not consider the influence of sampling delay. The dead-beat current prediction control provided by the invention can realize fixed frequency control without coordinate transformation, takes the influence of sampling delay into consideration, and has the advantages of constant frequency and small network side current harmonic wave.
Drawings
FIG. 1 is a circuit diagram of a single-phase PWM rectifier according to an embodiment of the present invention;
FIG. 2 is a flow chart of PWM rectifier deadbeat current prediction control in an embodiment of the present invention;
FIG. 3 is a waveform diagram of a fixed frequency power predictive control experiment in an embodiment of the present invention;
FIG. 4 is a waveform diagram of a deadbeat current predictive control experiment in an embodiment of the present invention;
FIG. 5 is a harmonic plot of the constant frequency power predictive control current in an embodiment of the invention;
fig. 6 is a plot of the harmonic of the deadbeat current predictive control current in an embodiment of the invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Examples
FIG. 1 is a single phase PWM rectifier circuitThe PWM rectifier circuit comprises 4 MOS tubes, a filter inductor L, a voltage-stabilizing capacitor C and a resistor RLThe output side of the PWM rectifier circuit is composed of a voltage stabilizing capacitor C and a resistor RLAre connected in parallel.
According to the current prediction control flow chart of fig. 2, the control process can be divided into the following 3 steps:
and step T1, taking the discretization mathematical equation of the column-writing PWM rectifier as a prediction model of the circuit k +1 moment, and predicting one beat in the forward direction to obtain a prediction model of the circuit k +2 moment.
The specific method for calculating the k +2 moment prediction model of the circuit is as follows:
the first column writes the circuit differential equation as follows:
Figure BDA0002269169320000051
wherein u issIs input voltage, L is filter inductance, t is time, isFor input of current, SabRepresenting the switch state, which may take values of-1, 0, 1, vdcIs the output voltage.
Discretizing the formula (A) to obtain
Figure BDA0002269169320000052
Wherein is(k) For the sample value of the input current at the present moment, is(k +1) is the predicted value of the input current at the time k +1, TsIs a sampling period, us(k) For the value of the input voltage sample at the present moment, Sab(k) Is the switch state at time k.
Reconsidering the action time of the zero vector to obtain
Figure BDA0002269169320000061
Wherein, ton(k) The action time of the non-zero vector at time k.
According to formula (C) can be obtained
Figure BDA0002269169320000062
Wherein is(k +2) is the sample value of the input current at the time k +2, us(k +1) is the predicted value of the input voltage at the time k +1, Sab(k +1) is the switch state at time k +1, tonAnd (k +1) is the action time of the non-zero vector at the k moment.
According to formula (C) and formula (D) can be obtained
Wherein, Δ is(k) Is the amount of current change at the k-th time, Δ is(k +1) is the current change at the k +1 th time, and the relaxation pair Δ is(k +1) constraint equal to the mean of the current differences at the k-th and k + 1-th moments, resulting in
Assuming equal difference between input voltages at two adjacent sampling instants, i.e.
us(k+1)-us(k)＝us(k)-us(k-1) thus obtained
us(k+1)＝2us(k)-us(k-1) (G)
Wherein u iss(k-1) is the input voltage sample at time k-1.
By substituting the formulae (F), (G) into the formula (E)
Figure BDA0002269169320000065
And T2, designing an objective function, deriving the objective function, enabling the derivative of the objective function to be equal to 0, and solving to obtain the optimal switching action time of the non-zero vector.
The specific method for solving the optimal switching action time of the non-zero vector is as follows:
defining an objective function as
Figure BDA0002269169320000071
Wherein the content of the first and second substances,
Figure BDA0002269169320000072
is a current reference value.
The objective function is derived over time and the derivative is 0 to obtain
When t ison(k+1)＞TsWhen it is, let ton(k+1)＝Ts(ii) a When t isonWhen (k +1) < 0, let ton(k+1)＝0。
The system parameters of the experiment are shown in table 1,
TABLE 1 System parameters
Parameter(s) Value taking
Peak value of input voltage 150V
Peak value of input current 3A
AC side filter inductor L 10mH
Voltage on the direct current side 215V
Frequency of the grid 50Hz
Switching frequency 20kHz
Fig. 3 is an experimental waveform of the fixed-frequency power predictive control, and the current waveform therein is subjected to FFT analysis to obtain a current harmonic map of the fixed-frequency power predictive control of fig. 5, from which it can be seen that the current harmonic is 6.61%.
Fig. 4 is an experimental waveform of the deadbeat current predictive control, and the current waveform therein is subjected to FFT analysis to obtain a current harmonic map of the deadbeat current predictive control of fig. 6, from which it can be seen that the current harmonic is 4.42%.
From the experimental results, compared with the conventional fixed-frequency power predictive control method, the PWM rectifier fixed-frequency current predictive control method provided by the invention has a better harmonic suppression effect.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.

Claims (3)

1. A PWM rectifier dead beat current prediction control method includes 4 MOS tubes, a filter inductor L, a voltage stabilizing capacitor C and a resistor RLThe 4 MOS tubes are divided into two groups, two MOS tubes in each group are connected in series and then are connected in parallel to form a first bridge arm and a second bridge arm, one end of a filter inductor L on the input side is connected with the middle point of the first bridge arm, and the other end of the filter inductor L is connected with the middle point of the first bridge armThe other end of the input voltage is connected with the midpoint of the second bridge arm, and the output side of the PWM rectifier circuit consists of a voltage-stabilizing capacitor C and a resistor RLThe control method is characterized by comprising the following steps:
t1, taking a discretization mathematical equation of the column-writing PWM rectifier as a prediction model of the circuit k +1 moment, and predicting one beat in the forward direction to obtain a prediction model of the circuit k +2 moment;
t2, designing an objective function, deriving the objective function, enabling the derivative of the objective function to be equal to 0, and solving to obtain the optimal switching action time of the non-zero vector;
t3, the objective function value in each switching state is calculated, and the switching state that minimizes the objective function value is selected as the switching state at the next time.
2. The PWM rectifier deadbeat current predictive control method according to claim 1, wherein in step T1, the process of calculating the circuit k +2 time prediction model is as follows:
the first column writes the circuit differential equation as follows:
Figure FDA0002269169310000011
wherein u issIs input voltage, L is filter inductance, t is time, isFor input of current, SabRepresenting the switch state, which may take values of-1, 0, 1, vdcIs the output voltage;
discretizing the formula (A) to obtain
Wherein is(k) For the sample value of the input current at the present moment, is(k +1) is the predicted value of the input current at the time k +1, TsIs a sampling period, us(k) For the value of the input voltage sample at the present moment, Sab(k) Is the on-off state at time k;
reconsidering the action time of the zero vector to obtain
Figure FDA0002269169310000022
Wherein, ton(k) The action time of the non-zero vector at the moment k;
according to formula (C) to obtain
Wherein is(k +2) is the sample value of the input current at the time k +2, us(k +1) is the predicted value of the input voltage at the time k +1, Sab(k +1) is the switch state at time k +1, ton(k +1) is the action time of the non-zero vector at the moment k;
obtained according to formula (C) and formula (D)
Figure FDA0002269169310000024
Wherein, Δ is(k) Is the amount of current change at the k-th time, Δ is(k +1) is the current change at the k +1 th time, and the relaxation pair Δ is(k +1) constraint equal to the mean of the current differences at the k-th and k + 1-th moments, resulting in
Figure FDA0002269169310000025
Assuming equal difference between input voltages at two adjacent sampling instants, i.e.
us(k+1)-us(k)＝us(k)-us(k-1) thus obtaining
us(k+1)＝2us(k)-us(k-1) (G)
Wherein u iss(k-1) is the input voltage sample value at time k-1;
by substituting the formulae (F), (G) into the formula (E)
Figure FDA0002269169310000031
3. The PWM rectifier deadbeat current predictive control method according to claim 2, wherein said step T2 is characterized in that the process of solving for the optimal switching action time of the non-zero vector is as follows:
defining an objective function as
Wherein the content of the first and second substances,
Figure FDA0002269169310000033
is a current reference value, is(k +2) is an input current sampling value at the moment of k + 2;
the objective function is derived over time and the derivative is 0 to obtain
Figure FDA0002269169310000034
When t ison(k+1)＞TsWhen it is, let ton(k+1)＝Ts；
When t isonWhen (k +1) < 0, let ton(k+1)＝0。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115118171A (en) * 2022-06-30 2022-09-27 福州大学 Dead-beat control method with time delay compensation for three-phase rectifier

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080186044A1 (en) * 2007-02-06 2008-08-07 Singh Deepak K Integrated circuit failure prediction
CN106849705A (en) * 2017-03-24 2017-06-13 三峡大学 A kind of current predictive control method based on single-phase Vienna rectifiers
CN110045610A (en) * 2019-04-18 2019-07-23 中国地质大学（武汉） Inverter modified multistep model predictive control method, equipment and storage equipment
CN110086383A (en) * 2019-05-30 2019-08-02 清华大学 The model predictive control method and device of ten two phase displacement systems
CN110165924A (en) * 2019-05-16 2019-08-23 天津大学 A kind of improvement dead-beat control method of Single-phase PWM Rectifier
CN110224647A (en) * 2019-04-26 2019-09-10 江苏方天电力技术有限公司 A kind of novel magneto alternator current control method

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080186044A1 (en) * 2007-02-06 2008-08-07 Singh Deepak K Integrated circuit failure prediction
CN106849705A (en) * 2017-03-24 2017-06-13 三峡大学 A kind of current predictive control method based on single-phase Vienna rectifiers
CN110045610A (en) * 2019-04-18 2019-07-23 中国地质大学（武汉） Inverter modified multistep model predictive control method, equipment and storage equipment
CN110224647A (en) * 2019-04-26 2019-09-10 江苏方天电力技术有限公司 A kind of novel magneto alternator current control method
CN110165924A (en) * 2019-05-16 2019-08-23 天津大学 A kind of improvement dead-beat control method of Single-phase PWM Rectifier
CN110086383A (en) * 2019-05-30 2019-08-02 清华大学 The model predictive control method and device of ten two phase displacement systems

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
杨立永，等: "单相 PWM 整流器改进无差拍电流预测控制方法", 《中国电机工程学报》 *
蒋蔚，等，: "单相级联多电平H 桥整流器有限集模型预测电流控制", 《电工电能新技术》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115118171A (en) * 2022-06-30 2022-09-27 福州大学 Dead-beat control method with time delay compensation for three-phase rectifier

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