CN112994496A - Modular multilevel converter with constant-speed and voltage-sharing functions under any active working condition - Google Patents
Modular multilevel converter with constant-speed and voltage-sharing functions under any active working condition Download PDFInfo
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- CN112994496A CN112994496A CN202110443643.3A CN202110443643A CN112994496A CN 112994496 A CN112994496 A CN 112994496A CN 202110443643 A CN202110443643 A CN 202110443643A CN 112994496 A CN112994496 A CN 112994496A
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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
- H02M7/42—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
- H02M7/483—Converters with outputs that each can have more than two voltages levels
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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
- H02M7/42—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
- H02M7/53873—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 digital control
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Abstract
The invention provides a modular multilevel converter with constant-rate voltage sharing under any active working condition, which comprises: the device comprises a direct current side circuit, an alternating current side circuit, a modular multilevel conversion device main circuit, a conditioning unit, a Hall unit and a control unit; the direct current side circuit and the alternating current circuit are both electrically connected with the main circuit; the main circuit is electrically connected with the control unit through an optical fiber; the control unit is electrically connected with the conditioning unit; the Hall unit and the control unit are electrically connected with the conditioning unit; the control unit executes a loop control algorithm, so that decoupling of the voltage-sharing dynamic characteristic of the independent loop and active transmission is realized, robustness of control parameters is greatly improved, and the problem that the voltage-sharing dynamic performance of the modular multilevel converter is poor when the modular multilevel converter operates under a low-active working condition is solved.
Description
Technical Field
The invention relates to the field of electronic circuits, in particular to a modular multilevel converter with constant-rate voltage sharing under any active working condition.
Background
Modular Multilevel Converters (MMC) have been proposed since, because of their characteristics such as good expansibility, lower device switching frequency, higher output waveform quality, etc., they have been widely used in high-voltage application occasions such as voltage source Converter stations, flexible direct current transmission, medium-low voltage distribution networks, electric power drive, etc. In addition, the modular multilevel converter has various derivative topologies with application prospects, such as a hybrid modular multilevel conversion topology and the like, due to the existence of the sub-modules.
For MMC, because it contains numerous suspended sub-capacitors, and the quality of output waveform is directly related to the voltage level of suspended sub-capacitors, therefore submodule capacitor voltage-sharing problem belongs to the important technical field in the MMC technique. Existing mainstream technical paths are mainly divided into two main categories: firstly, a capacitor voltage sequencing algorithm; and secondly, independent loop control of the sub-modules. The former is mainly used in high-voltage occasions, while the latter is widely used in medium-low voltage application occasions due to the advantages of fixed switching frequency characteristic, good voltage-sharing effect, simple realization and the like, and is generally combined with a PWM method to generate switching signals in practical use.
Among many PWM modulation techniques, Phase-Shifted Carrier PWM (CPS-PWM) is widely used in a multilevel conversion topology due to a high symmetry characteristic between switching signals corresponding to respective carriers. Most of the existing sub-module independent loop control strategies are based on CPS-PWM modulation. For the independent loop control of the sub-module, because of the simplicity of the structure, a plurality of existing independent loop control strategies have high repeatability in principle. For the existing independent loop control method, under a normal working condition, the MMC device has a good steady-state voltage-sharing characteristic. However, under the condition that the active power of the system is low, the voltage-sharing dynamic characteristic of the traditional submodule independent loop control method is greatly influenced, and if obvious submodule capacitor deviation occurs at the moment, the voltage-sharing control loop can hardly enable the system to return to a normal working state in a short time. This makes the related art technology to be limited in this condition.
In summary, the existing modular multilevel converter adopting the sub-module independent loop control technology has the defects of poor sub-module voltage-sharing capability and poor voltage-sharing dynamic characteristic under the low active working condition.
Disclosure of Invention
In view of the above, the present invention provides a modular multilevel converter with constant rate voltage sharing under any active working condition, which specifically includes the following:
the device comprises a direct current side circuit, an alternating current side circuit, a main circuit of a modular multilevel conversion device, a conditioning unit, a Hall unit and a control unit; the direct current side circuit and the alternating current circuit are both electrically connected with the main circuit; the main circuit is electrically connected with the control unit through an optical fiber; the control unit is electrically connected with the conditioning unit; the Hall unit and the control unit are electrically connected with the conditioning unit; the control unit adopts a loop control method.
Furthermore, the main circuit has three phases, and each phase comprises two bridge arms which are respectively an upper bridge armSM pi And a lower bridge armSM ni (ii) a Each bridge arm consists of N half-bridge submodules and a bridge arm inductorLComposition is carried out;ithe half-bridge arms are numbered and,i=1，2，3…,N。
further, the half-bridge sub-module specifically includes: the first switch tube, the second switch tube, the first switch tube and the second switch tube respectively correspond to the anti-parallel diode and the suspension capacitor.
Further, the control unit includes:
a system control link;
the three adders are respectively a first adder, a second adder and a third adder;
the two multipliers are respectively a first multiplier and a second multiplier;
a proportional controller, a limiting link and a normalizing and modulating link.
Further, the loop control method specifically comprises:
s101: according to the actual system electrical quantity acquired by the Hall unit and output after filtering processing of the conditioning circuit, an output voltage instruction required by the modular multilevel conversion device to operate in the current working condition is obtained through the system control link
(ii) a The system actual electrical quantity includes: DC side bus voltageE、Capacitance voltage measurement of target half-bridge sub-moduleV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodule belongs
Bridge arm current corresponding to target half-bridge type sub-modulei arm ；
S102: the output voltage instruction of the system control link
And a DC side bus voltageEAnd forming a control signal of the control unit by a first adderV ref ，Such as formula (1)：
In the formula (1), "-" is the situation that the corresponding control target half-bridge type sub-module is in the upper bridge arm of the current phase; "+" is the situation of the lower bridge arm of the corresponding control target half-bridge type submodule in the current phase;
s103: obtaining the capacitance voltage measured value of the target half-bridge type submodule through a second adderV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodules belong
Difference of (2)
As shown in formula (2):
s104: output of the second adder
Gain factor of proportional controllerK p Multiplying and passing through a first multiplier to obtain bridge arm current corresponding to the target half-bridge type submodulei arm After multiplying the reciprocal of the signal, sending the signal to an amplitude limiting link;
s105: adding the output of the amplitude limiting link with a constant 1 through a third adder to obtain an output signal of the third adder;
s106: the output signal of the third adder is compared with the control signal in step S101V ref Multiplying by a second multiplier to obtain a final output voltage instruction of the control unit
；
S107: final output voltage command
Obtaining a switching signal of a target half-bridge type submodule through a normalization and modulation link;
s108: and the target half-bridge submodule completes constant-speed voltage sharing of the target half-bridge submodule according to the switching signal in the step S106.
Further, the amplitude limiting absolute value of the amplitude limiting linkqLess than or equal to 0.05.
The final output voltage command
The value range is as follows:
。
the invention has the beneficial effects that: the decoupling of the voltage-sharing dynamic characteristic of the independent loop and active transmission is realized, the robustness of control parameters is greatly improved, and the problem that the voltage-sharing dynamic performance of the modular multilevel converter is poor under the low-active working condition is solved.
Drawings
FIG. 1 is a block diagram of a constant rate voltage-sharing modular multilevel converter according to the present invention under any active condition;
FIG. 2 is a schematic diagram of the main circuit of the present invention;
FIG. 3 is a schematic diagram of a half-bridge sub-module of the present invention;
FIG. 4 is a control block diagram of the loop control method of the present invention;
FIG. 5 is a graph showing the relationship between the output command of the clipping segment and the bridge arm current according to the present invention;
fig. 6 is a voltage-sharing dynamic waveform under a high active power condition (modulation ratio M =0.8, resistive load) of the present invention;
fig. 7 is a voltage-sharing dynamic waveform under a low active power condition (modulation ratio M =0.4, resistive load) of the present invention;
fig. 8 is a voltage sharing dynamic waveform when a larger independent voltage sharing control parameter is taken (proportional control parameter = 0.3) according to the present invention;
fig. 9 is a voltage grading dynamic waveform when taking a smaller independent voltage grading control parameter (proportional control parameter = 0.05) according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be further described with reference to the accompanying drawings.
Referring to fig. 1, a constant rate voltage-sharing modular multilevel converter device under any active working condition includes the following:
the device comprises a direct current side circuit, an alternating current side circuit, a main circuit of a modular multilevel conversion device, a conditioning unit, a Hall unit and a control unit; the direct current side circuit and the alternating current circuit are both electrically connected with the main circuit; the main circuit is electrically connected with the control unit through an optical fiber; the control unit is electrically connected with the conditioning unit; the Hall unit and the control unit are electrically connected with the conditioning unit; the control unit adopts a loop control method.
The signal transmission direction between each part in fig. 1 is the same as the direction pointed by the arrow; the specific content of each signal is given by the reference number: the method comprises the steps of 1, 2, 3, 4, 5, a regulated analog signal 6, wherein the direct current side voltage and the direct current side current 1, the switching signal 2, the submodule voltage and the bridge arm current, the alternating current side voltage and the alternating current side current, and the various collected original electric quantities. The control unit generally adopts a signal processor (DSP) and a Field Programmable Gate Array (FPGA) control framework, in the embodiment of the invention, a control algorithm is executed by the DSP, and pulse generation and other auxiliary functions are executed by the FPGA.
The main circuit collects initial voltage and current information through the Hall unit, and the output end of the Hall unit is connected with the conditioning unit; the modulation unit carries out filtering and simple operation processing on initial voltage and current information collected by the Hall unit and then outputs the initial voltage and current information to the control unit, and the control unit executes a loop control algorithm based on the output quantity of the modulation unit to obtain a switching signal of a switching tube in the main circuit and transmits the switching signal to the main circuit of the modular multilevel converter through an optical fiber.
The main circuit can be connected with corresponding active or passive circuits (namely a direct current side and an alternating current side in the figure 1) at an alternating current output end and a direct current end according to actual use working conditions, including an inversion working condition and a rectification working condition, and comprises a load;
referring to fig. 2, fig. 2 is a schematic structural diagram of a main circuit according to the present invention;
the main circuit has three phases, each phase comprises two bridge arms which are upper bridge arms respectivelySM pi And a lower bridge armSM ni (ii) a Each bridge arm consists of N half-bridge submodules and a bridge arm inductorLComposition is carried out; the half-bridge type sub-module is connected with the bridge arm inductor in series;ithe half-bridge arms are numbered and,i=1, 2, 3 …, N. The upper bridge arm and the lower bridge arm are connected in series through two bridge arm inductors; an alternating current side circuit is connected between the two bridge arm inductors; the direct current side circuit is electrically connected with the half-bridge type sub-module;
referring to fig. 3, fig. 3 is a schematic structural diagram of a half-bridge submodule; the half-bridge submodule specifically comprises: the first switch tube, the second switch tube, the first switch tube and the second switch tube respectively correspond to the anti-parallel diode and the suspension capacitor.
A suspension capacitor is connected in series between the collector of the first switch tube and the emitter of the second switch tube; the positive electrode of the suspension capacitor is electrically connected with the collector electrode of the first switching tube; the base electrodes of the first switch tube and the second switch tube are electrically connected with the control unit; the emitter of the first switching tube and the emitter of the second switching tube are connected to the direct-current side circuit;
through the above framework, the invention specially designs a loop control algorithm to realize the decoupling of the voltage-sharing dynamic characteristic and the active transmission of the independent loop; the following loop control algorithm is summarized as follows:
(1) acquiring actual voltages of all the sub-module suspension capacitors of the upper bridge arm of the current phase, and calculating to obtain the sub-module average voltage of the current bridge arm according to the actual voltages;
(2) collecting bridge arm current of an upper bridge arm of a current phase;
(3) for a certain submodule of the current bridge arm, obtaining a sub-capacitor voltage deviation value according to the actual voltage of the certain submodule and the average voltage of the submodule of the current bridge arm;
(4) obtaining an additional control instruction after the sub-capacitor voltage deviation value is subjected to gain adjustment and bridge arm current decoupling operation;
(5) adding the additional control instruction and an output instruction of a system control link to be used as a final control instruction of the submodule;
(6) sending the control instruction to a carrier phase shift modulation unit to obtain a switch pulse signal corresponding to the submodule;
(7) repeating the steps (3) to (6) for other sub-modules in the bridge arm;
(8) repeating the steps (1) to (7) for the other bridge arm in the phase;
(9) repeating the steps (1) - (8) for other phases.
Referring to fig. 4, fig. 4 is a control block diagram of a loop control method according to the present invention;
the invention provides an embodiment of a loop control method;
the control unit comprises the following:
a system control link; the system control link can be compatible with a plurality of existing related technical means, can be flexibly selected according to actual conditions, and the specific type of the adopted technical means does not influence the implementation of subsequent steps.
The three adders are respectively a first adder, a second adder and a third adder;
the two multipliers are respectively a first multiplier and a second multiplier;
a proportional controller, a limiting link and a normalizing and modulating link.
Before describing the specific implementation steps of the control method, the control variables included are described:
capacitance voltage measurement of target sub-moduleV Ci ；
Target submodule SM i Submodule average voltage of affiliated bridge arm
；
Average voltage of sub-modules of bridge arm to which module belongs
Capacitance voltage measurement with target sub-moduleV Ci Difference of (2)
(ii) a Gain factor of proportional controllerK p ；
Output voltage command from system control elementV AC *(ii) a The loop control algorithm provided by the invention is performed based on the system control link, the system control link is the global control of the device and is necessary for all conversion devices, and the execution of the loop control algorithm cannot be influenced no matter what existing scheme is adopted. That is, the loop control algorithm of the present invention only uses the output quantity of the system control linkV AC *So that this necessary part is contained in the control unit, butV AC *How is specifically obtained, the control algorithm is not concerned and is not the focus of the present invention;
DC side bus voltage measurementE；
Output voltage command from system controlV AC *And from the measured value of the upper DC side bus voltageEAndV rel ；
absolute value of amplitude limit linkq；
Final output voltage command of control loop
。
The loop control method for the embodiment specifically includes:
s101: according to the actual system electrical quantity acquired by the Hall unit and output after filtering processing of the conditioning circuit, an output voltage instruction required by the modular multilevel conversion device to operate in the current working condition is obtained through the system control link
(ii) a The system actual electrical quantity includes: DC side bus voltageE、Capacitance voltage measurement of target half-bridge sub-moduleV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodule belongs
Eyes of HemuBridge arm current corresponding to standard half-bridge type sub-modulei arm ；
S102: the output voltage instruction of the system control link
And a DC side bus voltageEAnd forming a control signal of the control unit by a first adderV ref ，Such as formula (1)：
In the formula (1), "-" is the situation that the corresponding control target half-bridge type sub-module is in the upper bridge arm of the current phase; "+" is the situation of the lower bridge arm of the corresponding control target half-bridge type submodule in the current phase;
s103: obtaining the capacitance voltage measured value of the target half-bridge type submodule through a second adderV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodules belong
Difference of (2)
As shown in formula (2):
s104: output of the second adder
Gain factor of proportional controllerK p Multiplying and passing through a first multiplier to obtain bridge arm current corresponding to the target half-bridge type submodulei arm After multiplying the reciprocal of the signal, sending the signal to an amplitude limiting link;
s105: adding the output of the amplitude limiting link with a constant 1 through a third adder to obtain an output signal of the third adder;
s106: the output signal of the third adder is compared with the control signal in step S101V ref Multiplying by a second multiplier to obtain a final output voltage instruction of the control unit
；
S107: final output voltage command
Obtaining a switching signal of a target half-bridge type submodule through a normalization and modulation link;
s108: and the target half-bridge submodule completes constant-speed voltage sharing of the target half-bridge submodule according to the switching signal in the step S106.
And repeating the steps S101 to S108 for other sub-modules until all the sub-modules of the modular multilevel converter reach the expected balance state.
When the pressure equalizing process is finished and the system operation reaches a steady state, the steps can be continuously repeated, and the normal operation of the whole device cannot be influenced. In addition, for the control method provided by the invention, the amplitude limiting absolute value of the amplitude limiting linkqGenerally not more than 0.05;
in the existing independent loop control scheme, the clipping element usually exists, but is not necessary, because the output of the controller in the existing control scheme gradually approaches zero along with the elimination of the voltage unbalance of the capacitor, and the clipping element only works in the situation of large voltage deviation and is used for avoiding overmodulation caused by overlarge output, thereby affecting the normal operation of the system. In the control structure provided by the invention, the amplitude limiting link is necessary because when the bridge arm current approaches zero, no matter whether the capacitor voltage is balanced or not, the controller outputs a control quantity approaching infinity, and therefore the amplitude limiting link is required to limit.
For convenience of understanding the necessity of the clipping element, please refer to fig. 5, where fig. 5 is a schematic diagram illustrating a relationship between an output of the clipping element and a quantity of the bridge arm current;
the upper part of the graph in fig. 5 shows the theoretical output value of the clipping element (dashed line) and the actual output of the clipping element (solid line); the lower part of the curve is a bridge arm current waveform. When the bridge arm current approaches zero, the absolute value of the reciprocal of the bridge arm current approaches infinity, as shown by a dotted line, and the theoretical output value approaches plus infinity or minus infinity. However, because of the existence of the amplitude limiting link, when the absolute value of the theoretical output value is larger than the set amplitude limiting value of the amplitude limiting link, the actual output will be saturated. In the figure, the area 1 represents the saturated output area of the clipping element, and the area 2 represents the unsaturated output area of the clipping element.
Please refer to fig. 6, which shows the voltage-sharing waveform under the high active power condition (M =0.8, resistive ac load). When the control parameter is fixed, the invention can quickly control the capacitance-voltage balance of the sub-module under the working condition of high active power.
Fig. 7 shows a voltage-sharing waveform under a low active power condition (M =0.4, resistive ac load) according to the present invention. When the control parameter is fixed, the invention can quickly control the voltage balance of the sub-module capacitor under the working condition of low active power, and compared with the situation under the working condition of high active power, the time required by the voltage-sharing process is only increased by a very small margin, and the dynamic characteristic can be approximately considered to be kept unchanged.
Referring to fig. 8-9, fig. 8 and 9 are respectively voltage-sharing dynamic waveforms when a larger independent loop control parameter (proportional control parameter = 0.3) and a smaller independent loop control parameter (proportional control parameter = 0.1) are taken according to the present invention. Compared with the existing independent voltage-sharing technical route, the method has better loop control parameter robustness, and the control parameter setting process of the device in practical engineering application is simplified.
The invention has the beneficial effects that: the decoupling of the voltage-sharing dynamic characteristic of the independent loop and active transmission is realized, the robustness of control parameters is greatly improved, and the problem that the voltage-sharing dynamic performance of the modular multilevel converter is poor under the low-active working condition is solved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (7)
1. The utility model provides a many level of modularization conversion equipment of constant speed voltage-sharing under arbitrary active operating mode which characterized in that: the method comprises the following steps: the device comprises a direct current side circuit, an alternating current side circuit, a main circuit of a modular multilevel conversion device, a conditioning unit, a Hall unit and a control unit; the direct current side circuit and the alternating current circuit are both electrically connected with the main circuit; the main circuit is electrically connected with the control unit through an optical fiber; the control unit is electrically connected with the conditioning unit; the Hall unit and the control unit are electrically connected with the conditioning unit; the control unit adopts a loop control method.
2. The modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 1, wherein: the main circuit has three phases, each phase comprises two bridge arms which are upper bridge arms respectivelySM pi And a lower bridge armSM ni (ii) a Each bridge arm consists of N half-bridge submodules and a bridge arm inductorLComposition is carried out;ithe half-bridge arms are numbered and,i=1，2，3…,N。
3. the modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 2, wherein: the half-bridge submodule specifically comprises: the first switch tube, the second switch tube, the first switch tube and the second switch tube respectively correspond to the anti-parallel diode and the suspension capacitor.
4. The modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 1, wherein: the control unit includes:
a system control link;
the three adders are respectively a first adder, a second adder and a third adder;
the two multipliers are respectively a first multiplier and a second multiplier;
a proportional controller, a limiting link and a normalizing and modulating link.
5. The modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 4, wherein: the loop control method specifically comprises the following steps:
s101: according to the actual system electrical quantity acquired by the Hall unit and output after filtering processing of the conditioning circuit, an output voltage instruction required by the modular multilevel conversion device to operate in the current working condition is obtained through the system control link
(ii) a The system actual electrical quantity includes: DC side bus voltageE、Capacitance voltage measurement of target half-bridge sub-moduleV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodule belongs
Bridge arm current corresponding to target half-bridge type sub-modulei arm ；
S102: the output voltage instruction of the system control link
And a DC side bus voltageEAnd forming a control signal of the control unit by a first adderV ref ，Such as formula (1)：
In the formula (1), "-" is the situation that the corresponding control target half-bridge type sub-module is in the upper bridge arm of the current phase; "+" is the situation of the lower bridge arm of the corresponding control target half-bridge type submodule in the current phase;
s103: through the secondThe adder obtains the capacitance voltage measured value of the target half-bridge sub-moduleV Ci The average voltage of the submodules of the bridge arms to which the target half-bridge type submodules belong
Difference of (2)
As shown in formula (2):
s104: output of the second adder
Gain factor of proportional controllerK p Multiplying and passing through a first multiplier to obtain bridge arm current corresponding to the target half-bridge type submodulei arm After multiplying the reciprocal of the signal, sending the signal to an amplitude limiting link;
s105: adding the output of the amplitude limiting link with a constant 1 through a third adder to obtain an output signal of the third adder;
s106: the output signal of the third adder is compared with the control signal in step S101V ref Multiplying by a second multiplier to obtain a final output voltage instruction of the control unit
；
S107: final output voltage command
Obtaining a switching signal of a target half-bridge type submodule through a normalization and modulation link;
s108: and the target half-bridge submodule completes constant-speed voltage sharing of the target half-bridge submodule according to the switching signal in the step S106.
6. The modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 5, wherein: the amplitude limiting absolute value of the amplitude limiting linkqLess than or equal to 0.05.
7. The modular multilevel converter for constant rate voltage sharing under any active working condition as claimed in claim 6, wherein: the final output voltage command
The value range is as follows:
。
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN202872383U (en) * | 2012-10-24 | 2013-04-10 | 无锡清源电气科技有限公司 | Modular multi-level wind energy converter controlled by direct power |
| JP2014018028A (en) * | 2012-07-11 | 2014-01-30 | Toshiba Corp | Semiconductor power conversion equipment |
| CN103701350A (en) * | 2014-01-13 | 2014-04-02 | 清华大学 | Modular multi-level converter capacitor voltage fluctuation inhibition method under low-frequency working condition |
| CN106533229A (en) * | 2016-12-09 | 2017-03-22 | 西安理工大学 | MMC apparatus sub-module capacitor voltage balance method by adopting model predictive control |
| CN109713922A (en) * | 2018-11-30 | 2019-05-03 | 国网江苏省电力有限公司泰州供电分公司 | The voltage-equalizing control circuit and method of DC capacitor in multi-level converter |
-
2021
- 2021-04-23 CN CN202110443643.3A patent/CN112994496B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014018028A (en) * | 2012-07-11 | 2014-01-30 | Toshiba Corp | Semiconductor power conversion equipment |
| CN202872383U (en) * | 2012-10-24 | 2013-04-10 | 无锡清源电气科技有限公司 | Modular multi-level wind energy converter controlled by direct power |
| CN103701350A (en) * | 2014-01-13 | 2014-04-02 | 清华大学 | Modular multi-level converter capacitor voltage fluctuation inhibition method under low-frequency working condition |
| CN106533229A (en) * | 2016-12-09 | 2017-03-22 | 西安理工大学 | MMC apparatus sub-module capacitor voltage balance method by adopting model predictive control |
| CN109713922A (en) * | 2018-11-30 | 2019-05-03 | 国网江苏省电力有限公司泰州供电分公司 | The voltage-equalizing control circuit and method of DC capacitor in multi-level converter |
Non-Patent Citations (2)
| Title |
|---|
| 刘波峰等: "低频工况下MMC电容电压波动抑制研究", 《控制工程》 * |
| 周国梁等: "适用于多工况优化设计与重复仿真的MMC快速仿真平台", 《中国电力》 * |
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