CN115224967A - Two-level grid-connected inverter multi-vector finite control set model prediction control method - Google Patents
Two-level grid-connected inverter multi-vector finite control set model prediction control method Download PDFInfo
- Publication number
- CN115224967A CN115224967A CN202210986222.XA CN202210986222A CN115224967A CN 115224967 A CN115224967 A CN 115224967A CN 202210986222 A CN202210986222 A CN 202210986222A CN 115224967 A CN115224967 A CN 115224967A
- Authority
- CN
- China
- Prior art keywords
- voltage vector
- vector
- voltage
- suboptimal
- axis
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000013598 vector Substances 0.000 title claims abstract description 261
- 238000000034 method Methods 0.000 title claims abstract description 31
- 238000005070 sampling Methods 0.000 claims abstract description 4
- 150000001875 compounds Chemical class 0.000 claims description 7
- 238000013178 mathematical model Methods 0.000 claims description 6
- 230000007547 defect Effects 0.000 abstract 1
- 230000004044 response Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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
- H02M7/42—Conversion of dc power input into ac power output without possibility of reversal
- H02M7/44—Conversion of dc power input into ac power output without possibility of reversal by static converters
- H02M7/48—Conversion of dc power input into ac power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/53—Conversion of dc power input into ac 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
- H02M7/537—Conversion of dc power input into ac 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, e.g. single switched pulse inverters
- H02M7/5387—Conversion of dc power input into ac 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, e.g. single switched pulse inverters in a bridge configuration
- H02M7/53871—Conversion of dc power input into ac 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, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current
- H02M7/53875—Conversion of dc power input into ac 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, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output
- H02M7/53876—Conversion of dc power input into ac 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, e.g. single switched pulse inverters in a bridge configuration with automatic control of output voltage or current with analogue control of three-phase output based on synthesising a desired voltage vector via the selection of appropriate fundamental voltage vectors, and corresponding dwelling times
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
-
- 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
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a model predictive control method for a multi-vector finite control set of a two-level grid-connected inverter, which is used for controlling the grid-connected inverter and comprises the following steps: step S1, collecting direct current bus voltage, network side three-phase current and network side three-phase voltage; step S2, acquiring a phase angle of the power grid; obtaining net side currentdShaft andqa step S3 of calculating a given value of a voltage vector by using the shaft given value; s4, determining an optimal voltage vector and a suboptimal voltage vector; and S5, calculating the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector and obtaining control signals of the switching tubes of the bridge arms of each phase. By using the method, a plurality of vectors, namely two active vectors and two zero vectors, can act in one sampling period, thereby greatly improving the current control precision, realizing the fixation of the switching frequency and overcoming the defects of the traditional modeThe steady-state performance of the model predictive control is insufficient, and the switching frequency is not fixed.
Description
Technical Field
The invention belongs to the field of power electronic application, and particularly relates to a model prediction control method for a two-level grid-connected inverter.
Background
With the increasing weight of energy crisis and environmental crisis, new energy power generation and related research thereof have received unprecedented attention. Particularly for a grid-connected new energy power generation system, the two-level grid-connected inverter is widely applied, and has the advantages of high efficiency, high reliability and the like. In order to control the phase and frequency of the output current of the inverter to meet the grid-connected requirement, scholars at home and abroad propose various control schemes, such as hysteresis current control, vector control and model prediction control. The model predictive control has the advantages of simple control idea, quick dynamic response, easy realization of multi-target control and the like.
In recent years, a large amount of research is carried out by scholars at home and abroad aiming at the prediction control of a limited control set model, and the research focuses on how to improve the steady-state performance, how to solve the problem of weight coefficient setting, how to reduce the calculated amount and the like. Particularly in the aspect of how to improve steady-state performance, the core idea of the existing finite control set model predictive control algorithm is mainly to apply two or more vectors in one control cycle, such as a zero vector + a non-zero vector, a non-zero vector + a non-zero vector, a plurality of non-zero vectors, and the like, however, calculating the duty ratio of two (or more) vectors will bring a great calculation burden to the controller. Furthermore, little research has been focused on the problem of the finite control set model predictive control algorithm switching frequency not being fixed.
Disclosure of Invention
The technical problem is as follows: aiming at the prior art, the method for predicting and controlling the model of the multi-vector finite control set of the two-level grid-connected inverter is provided, so that the steady-state performance of a system can be improved, and the switching frequency can be fixed.
The technical scheme is as follows: the model predictive control method for the multi-vector finite control set of the two-level grid-connected inverter comprises the following steps:
step S1: collecting direct-current bus voltage, network side three-phase current and network side three-phase voltage;
step S2: obtaining a power grid phase angle theta by utilizing a phase-locked loop according to the three-phase voltage at the grid side;
and step S3: obtaining the given values of d axis and q axis of grid side current
Calculating a given value of a voltage vector;
and step S4: determining an optimal voltage vector and a suboptimal voltage vector;
step S5: and calculating the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio, and obtaining control signals of the switching tubes of the bridge arms of each phase.
Further, step S3 includes the following specific steps:
step S31: calculating a d-axis given value of the grid-side current according to the given value of the grid-connected power;
step S32: giving a given value of a q-axis of a network side current;
step S33: calculating a given voltage vector value according to an inverter model, which specifically comprises the following steps:
the mathematical model of the inverter in the dq coordinate system is as follows:
wherein L is the inductance value of the filter inductor at the network side, R is the internal resistance of the filter inductor at the network side, omega is the angular frequency of the voltage of the power grid, i d And i q The values of the grid side current d-axis and q-axis, e d And e q The values of the grid side voltage d-axis and q-axis, u d And u q Respectively are input voltage vector d-axis and q-axis values;
the discretization form of the mathematical model shown in formula (1) is:
in the formula, T s To sample frequency, i d (k) And i q (k) Sampling values i of the values of the d axis and q axis of the grid side current at the moment k d (k + 1) and i q (k + 1) are predicted values of grid side current d-axis and q-axis values at the moment of (k + 1) respectively; according to the dead-beat control idea, if the current value of the next period reaches a given value, the input voltage vector is the given value of the voltage vector, namely:
in the formula (I), the compound is shown in the specification,
respectively setting values of a d axis and a q axis of an input voltage vector;
the alpha axis and beta axis components of the given voltage vector value are as follows:
in the formula (I), the compound is shown in the specification,
the alpha and beta components of the given value of the voltage vector are given.
Further, step S4 includes the following specific steps:
step S41: determining two adjacent non-zero voltage vectors according to the given voltage vector value, specifically comprising:
the angle δ of the given value of the voltage vector is calculated using equation (6):
when the space vector distribution of the two-level inverter is more than or equal to 0 and delta<At pi/3, the two adjacent non-zero voltage vectors are u 1 And u 2 Corresponding to a switch state of [100 ]]And [110 ]](ii) a When pi/3 is less than or equal to delta<At 2 pi/3, the two adjacent non-zero voltage vectors are u 2 And u 3 Corresponding to a switch state of [110 ]]And [010 ]](ii) a When 2 pi/3 is not more than delta<When is pi, the two adjacent non-zero voltage vectors are u 3 And u 4 Corresponding to the switch state being [010]And [011 ]](ii) a When pi is less than or equal to delta<At 4 pi/3, the two adjacent non-zero voltage vectors are u 4 And u 5 Corresponding to a switch state of [011 ]]And [001 ]](ii) a When 4 pi/3 is not more than delta<At 5 pi/3, the two adjacent non-zero voltage vectors are u 5 And u 6 Corresponding to the switch state being [001 ]]And [101 ]](ii) a When 5 pi/3 is not more than delta<At 2 π, the two phasesAdjacent non-zero voltage vector is u 6 And u 1 Corresponding to the switch state being [101 ]]And [100 ]]；
Step S42: respectively calculating the value function values corresponding to the two adjacent non-zero voltage vectors; wherein the cost function is:
g＝[u * -u(k)] 2 (7)
in the formula (I), the compound is shown in the specification,
a vector representation form of a given value of a voltage vector; u (k) is a voltage vector acting at the moment k;
step S43: comparing the value function values corresponding to the two adjacent non-zero voltage vectors, wherein the voltage vector corresponding to the smaller value function value is the optimal voltage vector u opt The other is a sub-optimal voltage vector u sub 。
Further, step S5 includes the following specific steps:
step S51: calculating the value of the corresponding value function g (u) of the zero vector 0 )；
Step S52: according to the value function values of the optimal voltage vector, the suboptimal voltage vector and the zero vector, the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector is calculated by using a Lagrange multiplier method, and the method specifically comprises the following steps:
if a voltage vector u is applied in one cycle opt 、u sub The duty ratio of the zero vector and the three is d opt 、d sub And d 0 Then the cost function is expressed as:
the duty cycle d opt 、d sub And d 0 The following constraints are satisfied:
the extreme value of the constraint following formula (8) of the formula (9) is solved by applying a Lagrange multiplier method to obtain the optimal solution of the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio
Comprises the following steps:
step S53: determining control signals of the switching tubes of the bridge arms of each phase according to the optimal voltage vector, the suboptimal voltage vector, the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio, and specifically comprising the following steps:
recording the duty ratios of three-phase bridge arms as d a 、d b And d c ：
If the optimal voltage vector is u 1 The suboptimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 2 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 2 The suboptimal voltage vector is u 3 Then, then
If the optimal voltage vector is u 3 The suboptimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 3 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 4 The suboptimal voltage vector is u 3 Then, then
If the optimal voltage vector is u 4 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 6 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 1 The suboptimal voltage vector is u 6 Then, then
In the formula u 1 ～u 6 And voltage vectors corresponding to the switch states of the two-level inverter.
Has the advantages that: 1) A plurality of voltage vectors, namely two active voltage vectors and two zero vectors, are acted in one control period, so that the steady-state performance of the system is improved;
2) The multi-vector-based PWM generation scheme can realize fixed switching frequency and is beneficial to the design of a filter;
3) The advantages of fast dynamic response and high tracking precision of the traditional model predictive control algorithm are reserved;
4) The stability performance can be improved without adding any extra hardware, and the system cost is favorably reduced.
Drawings
FIG. 1 is a flow chart of a multi-vector finite control set model predictive control method of the present invention;
FIG. 2 is a schematic diagram of a two-level grid-connected inverter circuit configuration of the present invention;
FIG. 3 shows a grid side A-phase voltage power grid e of the multi-vector finite control set model predictive control method of the present invention a Output current i a And i b Waveform, d-axis Current given i d * Is 10A;
FIG. 4 shows a grid side A-phase voltage power grid e of the multi-vector finite control set model prediction control method of the present invention a Output current i a And i b Waveform, d-axis Current given i d * Switch from 10A to 15A at 0.15 s;
fig. 5 is a switching frequency waveform of the multi-vector finite control set model predictive control method of the present invention.
Detailed Description
As shown in fig. 1 and fig. 2, an embodiment of the present invention provides a multi-vector finite control set model prediction control method, which is applied to a two-level grid-connected inverter, and includes the following steps:
step S1: collecting DC bus voltage V dc Network side three-phase current i a 、i b And i c And the grid side three-phase voltage e a 、e b And e c 。
Step S2: and (5) obtaining a power grid phase angle theta by utilizing a phase-locked loop according to the three-phase voltage of the power grid side acquired in the step (S1).
And step S3: and obtaining the given values of the d axis and the q axis of the current on the network side, and calculating the given value of the voltage vector. The method specifically comprises the following steps:
step S31: calculating a given value of a d-axis of current at the grid side according to the given value of the grid-connected power;
step S32: giving a given value of a q-axis of a network side current;
step S33: and calculating a given voltage vector value according to the inverter model.
Step S33 specifically includes:
fig. 2 shows that the mathematical model of the grid-connected inverter in the dq coordinate system is:
wherein L is the inductance value of the filter inductor at the network side, R is the internal resistance of the filter inductor at the network side, omega is the angular frequency of the voltage of the power grid, i d And i q The values of the grid side current d-axis and q-axis, e d And e q The values of the grid side voltage d-axis and q-axis, u d And u q The values of the input voltage vector are the d-axis and q-axis, respectively.
The discretization form of the mathematical model shown in formula (1) is:
in the formula, T s To adoptSample frequency i d (k) And i q (k) Sampling values i of the values of the d axis and q axis of the grid side current at the moment k d (k + 1) and i q (k + 1) are predicted values of grid side current d-axis and q-axis values at the moment of (k + 1) respectively; . According to the dead-beat control idea, if the current value of the next period reaches a given value, the following steps are carried out:
then the input voltage vector is the given value of the voltage vector, namely:
in the formula (I), the compound is shown in the specification,
respectively setting values of a d axis and a q axis of an input voltage vector;
the α -axis and β -axis components of the given voltage vector value can be obtained by the following equation:
in the formula (I), the compound is shown in the specification,
the alpha and beta components of the given value of the voltage vector are given.
And step S4: the method for determining the optimal voltage vector and the suboptimal voltage vector comprises the following specific steps:
step S41: two adjacent non-zero voltage vectors are determined from the voltage vector set-point. Specifically, first, two adjacent non-zero voltage vectors are determined according to the given voltage vector value calculated by equation (5), and the angle δ of the given voltage vector value is calculated as:
when the space vector distribution of the two-level inverter is more than or equal to 0 and delta<At pi/3, two adjacent non-zero voltage vectors are u 1 And u 2 Corresponding to a switch state of [100 ]]And [110 ]](ii) a When pi/3 is less than or equal to delta<At 2 pi/3, two adjacent non-zero voltage vectors are u 2 And u 3 Corresponding to a switch state of [110 ]]And [010 ]](ii) a When 2 pi/3 is not more than delta<At pi, two adjacent non-zero voltage vectors are u 3 And u 4 Corresponding to the switch state being [010]And [011 ]](ii) a When pi is less than or equal to delta<At 4 pi/3, two adjacent non-zero voltage vectors are u 4 And u 5 Corresponding to a switch state of [011 ]]And [001 ]](ii) a When 4 pi/3 is not more than delta<At 5 pi/3, two adjacent non-zero voltage vectors are u 5 And u 6 Corresponding to the switch state being [001 ]]And [101 ]](ii) a When 5 pi/3 is not more than delta<At 2 π, the two adjacent non-zero voltage vectors are u 6 And u 1 Corresponding to the switch state being [101 ]]And [100 ]]. The summary is shown in table 1.
TABLE 1
Step S42: respectively calculating the value function values corresponding to the two adjacent non-zero voltage vectors determined in the table 1, wherein the value function is as follows:
g＝[u * -u(k)] 2 (7)
in the formula u * ＝[u d * u q * ] T A vector expression form which is a given value of a voltage vector; u (k) is the applied voltage vector.
Step S43: comparing the value function values corresponding to two adjacent non-zero voltage vectors, wherein the voltage vector corresponding to the smaller value function value is the optimal voltage vector u opt And the other is a suboptimal voltage vector u sub 。
Step S5: and calculating the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector, and obtaining control signals of the switching tubes of the bridge arms of each phase. The method specifically comprises the following specific steps:
step S51: the value of the value g (u) corresponding to the zero vector is calculated by using the formula (7) 0 )。
Step S52: and calculating the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector by using a Lagrange multiplier method according to the value function values of the optimal voltage vector, the suboptimal voltage vector and the zero vector. The specific method for calculating the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector comprises the following steps:
if a voltage vector u is applied in one cycle opt 、u sub Zero vector (u) 0 And u 7 The two have the same action effect) and the duty ratios of the three are respectively d opt 、d sub And d 0 Then the cost function can be further expressed as:
duty ratio d opt 、d sub And d 0 The following constraints must be satisfied:
at this time, the extreme value of the constraint following formula (8) of the formula (9) needs to be solved, and the Lagrange multiplier method is applied to solve to obtain the optimal solution of the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio
Comprises the following steps:
step S53: based on the optimal voltage vector, the suboptimal voltage vector andand determining the control signal of each phase of bridge arm switching tube by the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio. Specifically, the duty ratios of the three-phase bridge arms are recorded as d a 、d b And d c If the optimum voltage vector is u 1 The suboptimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 2 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 2 The sub-optimal voltage vector is u 3 Then, then
If the optimal voltage vector is u 3 The suboptimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 3 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 4 The suboptimal voltage vector is u 3 Then, then
If it is the most importantThe optimal voltage vector is u 4 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 6 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 1 The suboptimal voltage vector is u 6 Then, then
Current given i in d-axis d * Under the condition of 10A, the multi-vector finite control set model predictive control method disclosed by the invention is implemented, and the A-phase voltage power grid e at the grid side a Output current i a And i b The waveforms are shown in fig. 3, it can be seen that the grid side voltage and the current are substantially in phase, and the system operates at unity power factor, achieving the desired effect.
When d-axis current gives i d * Under the condition that 0.25s is suddenly changed from 10A to 15A, the multi-vector finite control set model prediction control method disclosed by the invention is implemented, and the A-phase voltage power grid e at the grid side a Output current i a And i b The waveform is shown in fig. 4, and it can be seen that the output current is in phase with the network side voltage before and after the current is given to change suddenly, and the dynamic response speed is high and the current tracking is rapid.
The waveform of the system switching frequency is shown in fig. 5, and it can be seen that the system switching frequency is stable at 10kHz, which verifies that the multi-vector finite control set model predictive control method disclosed by the invention can realize the switching frequency fixation.
The above description of the present invention is intended to be illustrative. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.
Claims (4)
1. The model predictive control method for the multi-vector finite control set of the two-level grid-connected inverter is characterized by comprising the following steps of:
step S1: collecting direct-current bus voltage, network side three-phase current and network side three-phase voltage;
step S2: obtaining a power grid phase angle theta by utilizing a phase-locked loop according to the three-phase voltage at the grid side;
and step S3: obtaining the given values of d axis and q axis of grid side current
Calculating a given value of a voltage vector;
and step S4: determining an optimal voltage vector and a suboptimal voltage vector;
step S5: and calculating the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio, and obtaining control signals of the switching tubes of the bridge arms of each phase.
2. The two-level grid-connected inverter multi-vector finite control set model prediction control method according to claim 1, wherein the step S3 comprises the following specific steps:
step S31: calculating a given value of a d-axis of current at the grid side according to the given value of the grid-connected power;
step S32: giving a given value of a q-axis of a network side current;
step S33: calculating a given voltage vector value according to an inverter model, which specifically comprises the following steps:
the mathematical model of the inverter in the dq coordinate system is as follows:
wherein L is the inductance value of the filter inductor at the network side, R is the internal resistance of the filter inductor at the network side, omega is the angular frequency of the network voltage, i d And i q The values of the grid side current d-axis and q-axis, e d And e q The values of the grid side voltage d-axis and q-axis, u d And u q Respectively are input voltage vector d-axis and q-axis values;
the discretization form of the mathematical model shown in equation (1) is:
in the formula, T s To sample frequency, i d (k) And i q (k) Sampling values i of the grid side current d-axis and q-axis values at the time k d (k + 1) and i q (k + 1) are predicted values of grid side current d-axis and q-axis values at the moment of (k + 1) respectively; according to the dead-beat control idea, if the current value of the next period reaches a given value, the input voltage vector is the given value of the voltage vector, namely:
in the formula (I), the compound is shown in the specification,
respectively setting values of a d axis and a q axis of an input voltage vector;
the alpha axis and beta axis components of the given voltage vector value are as follows:
in the formula (I), the compound is shown in the specification,
the alpha and beta components of the given value of the voltage vector are given.
3. The two-level grid-connected inverter multi-vector finite control set model prediction control method according to claim 1, wherein the step S4 comprises the following specific steps:
step S41: determining two adjacent non-zero voltage vectors according to the given voltage vector value, specifically comprising:
the angle δ of the given value of the voltage vector is calculated using equation (6):
when the space vector distribution of the two-level inverter is more than or equal to 0 and delta<At pi/3, the two adjacent non-zero voltage vectors are u 1 And u 2 Corresponding to a switch state of [100 ]]And [110 ]](ii) a When pi/3 is less than or equal to delta<At 2 pi/3, the two adjacent non-zero voltage vectors are u 2 And u 3 Corresponding to a switch state of [110 ]]And [010 ]](ii) a When 2 pi/3 is not more than delta<When is pi, the two adjacent non-zero voltage vectors are u 3 And u 4 Corresponding to the switch state being [010]And [011 ]](ii) a When pi is less than or equal to delta<At 4 pi/3, the two adjacent non-zero voltage vectors are u 4 And u 5 Corresponding to a switch state of [011 ]]And [001 ]](ii) a When 4 pi/3 is not more than delta<At 5 pi/3, the two adjacent non-zero voltage vectors are u 5 And u 6 Corresponding to the switch state being [001 ]]And [101 ]](ii) a When 5 pi/3 is not more than delta<At 2 π, the two adjacent non-zero voltage vectors are u 6 And u 1 Corresponding to the switch state being [101 ]]And [100 ]]；
Step S42: respectively calculating the value function values corresponding to the two adjacent non-zero voltage vectors; wherein the cost function is:
g＝[u * -u(k)] 2 (7)
in the formula u * ＝[u d * u q * ] T A vector representation form of a given value of a voltage vector; u (k) is a voltage vector acting at the moment k;
step S43: comparing the value function values corresponding to the two adjacent non-zero voltage vectors, wherein the voltage vector corresponding to the smaller value function value is the optimal voltage vector u opt And the other is a suboptimal voltage vector u sub 。
4. The two-level grid-connected inverter multi-vector finite control set model prediction control method according to claim 1, wherein the step S5 comprises the following specific steps:
step S51: calculating the value of the corresponding value function g (u) of the zero vector 0 )；
Step S52: according to the value function values of the optimal voltage vector, the suboptimal voltage vector and the zero vector, the duty ratio of the optimal voltage vector, the suboptimal voltage vector and the zero vector is calculated by using a Lagrange multiplier method, and the method specifically comprises the following steps:
if a voltage vector u is applied in one cycle opt 、u sub The duty ratio of the zero vector and the three is d opt 、d sub And d 0 Then the cost function is expressed as:
the duty cycle d opt 、d sub And d 0 The following constraints are satisfied:
the extreme value of the constraint following formula (8) of the formula (9) is solved by applying a Lagrange multiplier method to obtain the optimal solution of the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio
Comprises the following steps:
step S53: determining control signals of the switching tubes of the bridge arms of each phase according to the optimal voltage vector, the suboptimal voltage vector, the optimal voltage vector, the suboptimal voltage vector and the zero vector duty ratio, and specifically comprising the following steps:
recording the duty ratios of three-phase bridge arms as d a 、d b And d c ：
If the optimal voltage vector is u 1 The suboptimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 2 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 2 The suboptimal voltage vector is u 3 Then, then
If the optimal voltage vector is u 3 The sub-optimal voltage vector is u 2 Then, then
If the optimal voltage vector is u 3 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 4 The suboptimal voltage vector is u 3 Then, then
If the optimal voltage vector is u 4 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 4 Then, then
If the optimal voltage vector is u 5 The suboptimal voltage vector is u 6 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 5 Then, then
If the optimal voltage vector is u 6 The suboptimal voltage vector is u 1 Then, then
If the optimal voltage vector is u 1 The suboptimal voltage vector is u 6 Then, then
In the formula u 1 ～u 6 And voltage vectors corresponding to the switch states of the two-level inverter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210986222.XA CN115224967A (en) | 2022-08-17 | 2022-08-17 | Two-level grid-connected inverter multi-vector finite control set model prediction control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210986222.XA CN115224967A (en) | 2022-08-17 | 2022-08-17 | Two-level grid-connected inverter multi-vector finite control set model prediction control method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115224967A true CN115224967A (en) | 2022-10-21 |
Family
ID=83616455
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210986222.XA Pending CN115224967A (en) | 2022-08-17 | 2022-08-17 | Two-level grid-connected inverter multi-vector finite control set model prediction control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115224967A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105897030A (en) * | 2016-06-08 | 2016-08-24 | 江苏固德威电源科技股份有限公司 | Dead beat fixed frequency model forecast control method, device and system |
| CN110198130A (en) * | 2019-05-24 | 2019-09-03 | 武汉大学 | More vector optimization control systems and method under the conditions of a kind of unbalanced power grid |
| CN111541267A (en) * | 2020-04-07 | 2020-08-14 | 南通大学 | Multi-vector model prediction control method for two-level grid-connected inverter |
-
2022
- 2022-08-17 CN CN202210986222.XA patent/CN115224967A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105897030A (en) * | 2016-06-08 | 2016-08-24 | 江苏固德威电源科技股份有限公司 | Dead beat fixed frequency model forecast control method, device and system |
| CN110198130A (en) * | 2019-05-24 | 2019-09-03 | 武汉大学 | More vector optimization control systems and method under the conditions of a kind of unbalanced power grid |
| CN111541267A (en) * | 2020-04-07 | 2020-08-14 | 南通大学 | Multi-vector model prediction control method for two-level grid-connected inverter |
Non-Patent Citations (1)
| Title |
|---|
| 谢鹰，等: "电动汽车用V2G 并网逆变器改进型MPC 算法研究", 《电源学报》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110034690B (en) | Vienna rectifier model prediction virtual flux linkage control method | |
| CN109412482B (en) | Unified predictive control method for quasi-Z-source inverter-permanent magnet synchronous motor system | |
| CN112737444B (en) | Double three-phase permanent magnet synchronous motor control method for alternatively executing sampling and control programs | |
| CN109038673B (en) | Model prediction optimization control method of photovoltaic power generation system | |
| CN112653342B (en) | Complex vector current loop decoupling control device and method under static coordinate system | |
| CN109004849B (en) | PWM rectifier fast response control method for electric servo loading system | |
| CN113991739A (en) | Simplified vector fixed-frequency prediction current control method for grid-connected inverter | |
| CN111262460B (en) | Five-level rectifier sliding mode PIR control method based on coupling inductor | |
| CN111541267A (en) | Multi-vector model prediction control method for two-level grid-connected inverter | |
| CN111049201B (en) | Coordination control method for AC/DC power grid hybrid high-power interface converter | |
| CN102611339A (en) | Current control method for three-phase rectifying device | |
| CN115224967A (en) | Two-level grid-connected inverter multi-vector finite control set model prediction control method | |
| CN110165954A (en) | A kind of dual feedback wind power generation system generator-side converter wear model predictive control method | |
| CN115622421A (en) | Control method of battery simulator based on multi-sampling technology | |
| CN111756261B (en) | PWM rectifier control method and device | |
| CN112467776B (en) | Current source type converter system, control method and space vector modulation method | |
| CN110676860B (en) | Fast prediction unbalance control method based on extended instantaneous active theory | |
| CN115065092A (en) | Frequency coupling adjustment control method for single-phase grid-connected converter | |
| CN114785166A (en) | T-shaped rectifier three-vector model prediction control method based on sliding mode control | |
| CN110048466B (en) | Prediction control method for grid-side converter model of double-fed wind power generation system | |
| CN113992095A (en) | Low-complexity direct power control method for dual three-phase permanent magnet synchronous generator PMSG model prediction | |
| CN110867864A (en) | Off-grid operation control method for active third harmonic injection matrix converter | |
| CN113992093B (en) | Double subspace duty cycle model prediction current control method for double three-phase permanent magnet synchronous generator | |
| CN109412438B (en) | Current control method based on complex vector proportion complex number integral controller cPCI | |
| CN114157170B (en) | T-shaped three-level rectifier model prediction power control method based on sliding mode control |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |