CN111740455A - Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage - Google Patents
Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage Download PDFInfo
- Publication number
- CN111740455A CN111740455A CN202010708708.8A CN202010708708A CN111740455A CN 111740455 A CN111740455 A CN 111740455A CN 202010708708 A CN202010708708 A CN 202010708708A CN 111740455 A CN111740455 A CN 111740455A
- Authority
- CN
- China
- Prior art keywords
- current
- voltage
- power
- controller
- reference value
- 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.)
- Granted
Links
Images
Classifications
-
- 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
- H02J4/00—Circuit arrangements for mains or distribution networks not specified as ac or dc
-
- 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
- H02J3/18—Arrangements for adjusting, eliminating or compensating reactive power in networks
- H02J3/1821—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators
- H02J3/1835—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control
- H02J3/1842—Arrangements for adjusting, eliminating or compensating reactive power in networks using shunt compensators with stepless control wherein at least one reactive element is actively controlled by a bridge converter, e.g. active filters
-
- 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
- H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
- H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
- H02M7/72—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/79—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with 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
- H02M7/797—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/30—Reactive power compensation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Abstract
The invention relates to the field of control and power quality control of a bus interface converter of an alternating current-direct current hybrid microgrid, in particular to a bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage. The invention effectively solves the problem of different voltage qualities caused by the coupling of double-frequency wave power between the AC and DC subnets under the condition of unbalanced voltage. The main circuit consists of an AC sub-network, a DC sub-network and a bidirectional interface converter for connecting the two sub-networks; the control circuit consists of an alternating current part and a direct current part. The alternating current side controls the converter through bidirectional power flow and a proportional resonance algorithm, and compensates the negative sequence voltage by using the power margin transmitted by the converter; and a boost chopper circuit is introduced at the direct current side, and the pulsating voltage of the direct current bus is stabilized through a power compensation principle. The invention realizes the purpose of simultaneously compensating the AC and DC voltages by controlling the bus interface converter, improves the utilization rate of the bidirectional interface converter and ensures the reliability of the operation of the micro-grid.
Description
Technical Field
The invention relates to the field of hybrid microgrid alternating current-direct current bus interface converter control and hybrid microgrid power quality control, in particular to a bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage.
Background
With the continuous rise of new energy permeability, the alternating current-direct current hybrid microgrid gradually becomes a trend of future development of the microgrid because the alternating current-direct current hybrid microgrid can effectively combine respective advantages of the alternating current microgrid and the direct current microgrid. An actual alternating current-direct current hybrid micro-grid is often located at the tail end of a power distribution network and has relatively small capacity, when an asymmetric fault occurs in a large power grid or a load is unbalanced, negative sequence components can occur in voltage and current of the power grid or the load voltage and current, voltage at a PCC (point of common coupling) is unbalanced, and direct current voltage pulsation is further caused. Meanwhile, some single-phase ac loads with high requirements on power quality are often connected to a dc microgrid through an inverter, and double-frequency ripple of dc bus voltage is also caused, which further causes ac harmonic pollution. The alternating-current unbalanced voltage and the direct-current double-frequency pulsating voltage not only influence the normal operation of the alternating-current and direct-current subnetworks and the bidirectional interface converter, but also bring other electric energy quality problems by coupling the bidirectional AC/DC converter to the other side, and influence the safe and stable operation of the whole hybrid micro-grid.
At present, a great deal of literature gives many solutions to different power quality problems in hybrid micro-grids. Compensation methods for three-phase unbalanced voltages are roughly classified into two types: the series or parallel connection of the power quality regulators needs additional devices, increases the cost and has obvious defects; and secondly, compensating the three-phase unbalanced voltage by utilizing distributed energy or an energy storage converter and the like. The control strategies for the direct current voltage pulsation can also be divided into two categories: firstly, a passive or active filter circuit is introduced, the method can effectively inhibit direct-current ripple voltage, but the cost problem caused by introducing an additional device also exists; and secondly, indirectly eliminating the double-frequency pulsating voltage by an impedance remodeling control method. However, the control target in the prior art is single, and few researches relate to a method for uniformly treating the quality of alternating current and direct current voltages of a hybrid micro-grid.
Disclosure of Invention
The invention aims to solve the problem of different voltage qualities caused by the fact that double-frequency fluctuating power is coupled between an alternating current sub-network and a direct current sub-network under the condition of unbalanced voltage, and designs a bus interface converter control method for uniformly compensating the unbalanced alternating current voltage and the direct current pulsating voltage aiming at the defects of the prior art.
The technical scheme of the invention is as follows: a bus interface converter control method for uniformly compensating an alternating-current unbalanced voltage and a direct-current pulsating voltage is characterized in that a mixed micro-grid main circuit comprises an alternating-current micro-grid, a direct-current micro-grid and a bidirectional interface converter connected with the alternating-current micro-grid and the direct-current micro-grid, the bidirectional interface converter comprises a three-phase full-bridge circuit and a boost chopper circuit, direct-current capacitors of the three-phase full-bridge circuit are connected to two sides of a bridge arm of the full-bridge circuit in parallel, an inductor L is adopted on an alternating-current side for filtering, and theacCapacitor CacAnd a set of bridge arms consisting of IGBTs connected in series, an inductor LacOne end of the capacitor is connected with the upper bridge arm on the direct current side of the three-phase full-bridge circuit, the other end of the capacitor is connected with the middle of the bridge arm of the compensating circuit, and the capacitor CacOne end of the capacitor C is connected with an upper bridge arm of the compensation circuitacThe other end of the compensation circuit is connected with a lower bridge arm on the direct current side of the three-phase full-bridge circuit, and the lower bridge arm of the compensation circuit is connected with the lower bridge arm on the direct current side of the three-phase full-bridge circuit; the AC side of the bidirectional interface converter is connected with an AC microgrid, the DC side is connected with a DC microgrid, a main circuit is connected with a large power grid through a public point of connection PCC, a hybrid microgrid control circuit comprises an AC controller and a DC controller, and the AC controller comprisesPositive sequence controller, negative sequence controller and PR controller.
In the control method, an AC side positive sequence controller obtains an AC positive sequence current reference value i+ αβ_refThe negative sequence controller obtains a reference value i of the AC negative sequence current- αβ_refReference value i of AC positive sequence current+ αβ_refReference value i of AC negative sequence current- αβ_refSynthesizing a total current reference value, comparing the total current reference value with an AC current total actual value, inputting the total current reference value with a PR controller, modulating the total current reference value with PWM, outputting a trigger pulse to control a three-phase full-bridge circuit, and obtaining a secondary harmonic current value i by a DC-side DC controller according to an input AC-side voltage current and a DC micro-grid DC load voltage current2rdThen, the AC capacitance C is givenacComparing the voltage reference value with the actual capacitor voltage, performing PI control to obtain a current reference signal, and adding the current reference signal and a second harmonic current value i2rdAnd obtaining a final inductance current reference value, comparing the inductance current reference value with the actual inductance current in the compensation circuit, compensating the obtained error signal by a PI controller, and modulating and outputting a series of trigger pulses with adjustable duty ratios by PWM to control the fluctuation power compensation circuit.
The above method for controlling a bus interface converter with unified compensation of AC unbalanced voltage and DC pulsating voltage includes establishing a mathematical model of a bidirectional AC/DC converter in an a β coordinate system at an AC side, controlling a fundamental power and a positive sequence current of the converter through a bidirectional power flow and Proportional Resonance (PR) algorithm, and compensating a negative sequence voltage by using a power margin transmitted by the converter; a boost type fluctuation power compensation circuit is introduced at the direct current side, and the boost type fluctuation power compensation circuit absorbs double-frequency fluctuation power at the two sides of alternating current and direct current simultaneously through a power compensation principle, so that the method for eliminating the alternating current negative sequence voltage and the direct current ripple voltage simultaneously is finally realized. The method is specifically developed as follows:
the method comprises the following steps: detecting output voltage u at AC side of three-phase full-bridge circuitabcAnd an output current iabcthen, α - β coordinate is transformed to obtain each quantity u in α - β coordinate systemαβ、iαβTo u, to uαβAnd iαβCarrying out positive and negative sequence separation to obtain positive sequence voltage uαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ －；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step oneαβ +Performing coordinate transformation, and extracting positive sequence voltage amplitude U in abc coordinate systemacThen collecting the DC capacitor voltage of the three-phase full-bridge circuit
Filtering out the double frequency components by a wave trap to obtain the average value U of the DC voltagedcPositive sequence voltage amplitude UacAnd the mean value U of DC voltagedcRespectively carrying out normalization processing to obtain Uac_normAnd Udc_normAnd then the difference is made between the two normalization processing scalars, the difference value delta UnormAnd a power reference value Pref、QrefMultiply to control power bi-directional flow, will be Δ Unorm、Pref、QrefAnd uαβ +The input reference current calculation module obtains an alternating current positive sequence current reference value i through reference current calculation+ αβ_ref；
in the negative controller, firstly, each axial component i of the current under the alpha- β coordinate systemα、iβCalculating the root mean square value, and selecting the larger value and the rated current I of the convertermax(rated current I)maxRepresenting rated power of the converter, which can be set by self according to the capacity of the converter), and inputting an error signal into a proportional controller to obtain a negative sequence voltage compensation coefficient; secondly, the negative sequence voltage u obtained in the step oneαβ －Multiplying the negative sequence voltage compensation coefficient to obtain an alternating negative sequence current reference value i- αβ_ref(ii) a Finally, the reference value i is compared with the AC positive sequence current obtained in the step two+ αβ_refSubtracting to obtain a total current reference value, and comparing the total current reference value with the total actual value i of the alternating currentαβAfter comparison, the signals are input into a PR controller, and the PR controller is adopted to track the electricityThe current reference value is output to trigger a pulse control three-phase full-bridge circuit through PWM modulation;
step four: the above steps achieve the purpose of eliminating the negative sequence component of the alternating voltage, but the double frequency fluctuating power still cannot be completely eliminated, so the direct current side fluctuating power compensation circuit needs to be controlled. In a DC controller, a positive sequence voltage u is appliedαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ －Inputting the power into an alternating current fluctuating power calculation module, and calculating according to an instantaneous power theory to obtain frequency doubling fluctuating power p at an alternating current output alternating current side of the converter1And simultaneously acquires the DC load voltage and current U of the DC microgridac_L、iac_LInputting the power into a DC power calculation module, and extracting the frequency doubling fluctuation power p at the DC side through a band-pass filter2Frequency-doubled fluctuating power p on the AC side1And the DC side frequency doubling fluctuation power p2Adding to obtain the second fluctuation value of the active power
Will have the active power fluctuate for two times
Input frequency doubling current calculation module and divide by direct current voltage UdcTo obtain the second harmonic current value i to be absorbed by the compensation circuit2rd；
Step five: given AC capacitance CacReference value u of voltageref ac_cAnd the actual capacitor voltage uac_cAfter comparison, a current reference signal i is obtained through PI controlref ac_cAdding the second harmonic current value i obtained in the fourth step2rdObtaining the final reference value of the inductive current and the actual inductive current i in the compensation circuitac_cCompared with the prior art, the obtained error signal is compensated by the PI controller and then modulated by the PWM to output a series of trigger pulses with adjustable duty ratios to control the fluctuation power compensation circuit.
Compared with the prior art, the bus interface converter control method for the unified compensation of the alternating-current unbalanced voltage and the direct-current pulsating voltage has the advantages that: (1) when the alternating current-direct current hybrid micro-grid is in an unbalanced working condition, the purpose of simultaneously compensating alternating current negative sequence voltage and direct current pulsating voltage can be realized, the utilization rate of the bidirectional AC/DC converter is improved, and the micro-grid can be ensured to be optimally and stably operated. (2) The boost type fluctuation power compensation circuit is introduced, secondary fluctuation of active power is effectively inhibited under the condition that no additional device is added, the capacitance capacity of a direct current bus can be greatly reduced, the investment and the operation cost of the micro-grid are reduced, and the space of the micro-grid is saved.
Drawings
Fig. 1 is a structural diagram of a bus interface converter for uniformly compensating an unbalanced ac voltage and a pulsating dc voltage according to the present invention;
fig. 2 is a schematic diagram of the bus interface converter for uniformly compensating the ac unbalanced voltage and the dc pulsating voltage according to the present invention.
Detailed Description
A bus interface converter control method for uniformly compensating an AC unbalanced voltage and a DC pulsating voltage is characterized in that a mixed micro-grid main circuit comprises a bidirectional interface converter, an AC micro-grid and a DC micro-grid, the bidirectional interface converter comprises a three-phase full-bridge circuit and a boost chopper circuit, wherein the three-phase full-bridge circuit comprises three groups of bridge arms which are connected in parallel, each group of bridge arms comprises two IGBTs which are connected in series, each IGBT comprises a power tube and an anti-parallel diode, a DC capacitor of the three-phase full-bridge circuit is connected in parallel with two sides of the bridge arms of the full-bridge circuit, an AC side adopts an inductor L for filtering, and the boost chopper circuit is a fluctuation poweracCapacitor CacAnd a set of bridge arms consisting of IGBTs connected in series, an inductor LacOne end of the capacitor is connected with the upper bridge arm on the direct current side of the three-phase full-bridge circuit, the other end of the capacitor is connected with the middle of the bridge arm of the compensating circuit, and the capacitor CacOne end of the capacitor C is connected with an upper bridge arm of the compensation circuitacThe other end of the compensation circuit is connected with a lower bridge arm at the direct current side of the three-phase full-bridge circuit, and the lower bridge arm of the compensation circuit and the three-phase full-bridge circuitThe lower bridge arm on the direct current side of the bridge circuit is connected; the alternating current side of the bidirectional interface converter is connected with an alternating current microgrid, the direct current side of the bidirectional interface converter is connected with a direct current microgrid, a main circuit is connected with a large power grid through a public grid-connected point PCC, a hybrid microgrid control circuit comprises an alternating current controller and a direct current controller, and the alternating current controller comprises a positive sequence controller, a negative sequence controller and a PR controller.
For example, the method for uniformly compensating the ac unbalanced voltage and the dc pulsating voltage of the hybrid microgrid bus interface converter based on the boost power compensation circuit is specifically implemented as follows:
the method comprises the following steps: detecting output voltage u of AC side of bidirectional AC/DC converterabcAnd an output current iabcthen, α - β coordinate is transformed to obtain each quantity u in α - β coordinate systemαβ、iαβAnd are paired with uαβAnd iαβCarrying out positive and negative sequence separation to obtain positive sequence voltage uαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ -；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step oneαβ +Performing coordinate transformation, and extracting positive sequence voltage amplitude U in abc coordinate systemacThen collecting the DC capacitor voltage of the three-phase full-bridge circuit
Filtering out the double frequency components by a wave trap to obtain the average value U of the DC voltagedcRespectively carrying out normalization processing on the AC-DC side voltage to obtain Uac_normAnd Udc_normThen, the difference between the two scalars is madenormAnd a power reference value Pref、QrefMultiply to control power bi-directional flow, will be Δ Unorm、Pref、QrefAnd uαβ +The input reference current calculation module obtains an alternating current positive sequence current reference value i through reference current calculation+ αβ_ref；
in the negative control unit, the current axes under α - β coordinate system are dividedCalculating a root mean square value, selecting a larger value to compare with the rated current of the converter, and inputting an error signal into a proportional controller to obtain a negative sequence voltage compensation coefficient; secondly, the negative sequence voltage u obtained in the step oneαβ －Multiplying the negative sequence voltage compensation coefficient to obtain the AC negative sequence current reference value i- αβ_ref(ii) a Finally, the reference value i is compared with the AC positive sequence current obtained in the step two+ αβ_refSubtracting, comparing with the actual value of the AC positive sequence current, tracking the current reference value by adopting a PR controller, and outputting a trigger pulse to control a three-phase PWM converter through PWM modulation;
step four: in a DC controller, the positive sequence voltage uαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ －Inputting the power into an alternating current fluctuating power calculation module, and calculating according to an instantaneous power theory to obtain frequency doubling fluctuating power p at an alternating current output alternating current side of the converter1And simultaneously acquires the DC load voltage and current U of the DC microgridac_L、iac_LInputting the power into a DC power calculation module, and extracting the frequency doubling fluctuation power p at the DC side through a band-pass filter2Frequency-doubled fluctuating power p on the AC side1And the DC side frequency doubling fluctuation power p2Adding to obtain the second fluctuation value of the active power
Will have the active power fluctuate for two times
The input frequency doubling current calculation module divides the direct current voltage to obtain a second harmonic current value i which needs to be absorbed by the compensation circuit2rd；
Step five: given AC capacitor voltage reference uref ac_cWith the actual capacitor voltage uac_cAfter comparison, a current reference signal i is obtained through PI controlref ac_cAdding the second harmonic current value i obtained in the fourth step2rdObtaining the final reference value of the inductor current, and compensating circuitMiddle real inductor current iac_cCompared with the prior art, the obtained error signal is compensated by the PI controller and then modulated by the PWM to output a series of trigger pulses with adjustable duty ratios to control the fluctuation power compensation circuit.
Claims (2)
1. A bus interface converter control method for uniformly compensating an AC unbalanced voltage and a DC pulsating voltage is characterized in that a main circuit of a hybrid micro-grid comprises an AC micro-grid, a DC micro-grid and a bidirectional interface converter connected with the AC micro-grid and the DC micro-grid, the bidirectional interface converter comprises a three-phase full-bridge circuit and a boost chopper circuit, a DC capacitor of the three-phase full-bridge circuit is connected in parallel with two sides of a bridge arm of the full-bridge circuit, an AC side adopts an inductor L for filtering, and the boost chopper circuit is a fluctuation power compensation circuit and comprises an inductor LacCapacitor CacAnd a set of bridge arms consisting of IGBTs connected in series, an inductor LacOne end of the capacitor is connected with the upper bridge arm on the direct current side of the three-phase full-bridge circuit, the other end of the capacitor is connected with the middle of the bridge arm of the compensating circuit, and the capacitor CacOne end of the capacitor C is connected with an upper bridge arm of the compensation circuitacThe other end of the compensation circuit is connected with a lower bridge arm on the direct current side of the three-phase full-bridge circuit, and the lower bridge arm of the compensation circuit is connected with the lower bridge arm on the direct current side of the three-phase full-bridge circuit; the alternating current side of the bidirectional interface converter is connected with an alternating current microgrid, the direct current side of the bidirectional interface converter is connected with a direct current microgrid, and a main circuit is connected with a large power grid through a public grid-connected point PCC; the bidirectional interface converter control circuit comprises an alternating current controller and a direct current controller, wherein the alternating current controller comprises a positive sequence controller, a negative sequence controller and a PR controller; in the control method, an AC side positive sequence controller obtains an AC positive sequence current reference value i+ αβ_refThe negative sequence controller obtains a reference value i of the AC negative sequence current- αβ_refReference value i of AC positive sequence current+ αβ_refReference value i of AC negative sequence current- αβ_refSynthesizing an alternating current total current reference value, comparing the alternating current total current reference value with an alternating current total current actual value, inputting the alternating current total current reference value into a PR controller, and outputting trigger pulses to control a three-phase full-bridge circuit through PWM modulation; the DC-side DC controller is obtained according to the input AC-side voltage and current of the interface converter and the load-side voltage and current of the DC microgridThe second harmonic current value i is obtained by calculating the fluctuating power on both sides of the alternating current and the direct current through double frequency current2rdThen, the AC capacitance C is givenacComparing the voltage reference value with the actual capacitor voltage, performing PI control to obtain a current reference signal, and adding the current reference signal and a second harmonic current value i2rdAnd obtaining a final inductance current reference value, comparing the inductance current reference value with the actual inductance current in the compensation circuit, compensating the obtained error signal by a PI controller, and modulating and outputting a series of trigger pulses with adjustable duty ratios by PWM to control the fluctuation power compensation circuit.
2. The method for controlling the bus interface converter for the unified compensation of the unbalanced alternating current voltage and the pulsating direct current voltage according to claim 1, comprising the following steps:
the method comprises the following steps: detecting output voltage u at AC side of three-phase full-bridge circuitabcAnd an output current iabcthen, α - β coordinate is transformed to obtain each quantity u in α - β coordinate systemαβ、iαβTo u, to uαβAnd iαβCarrying out positive and negative sequence separation to obtain positive sequence voltage uαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ －；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step oneαβ +Performing coordinate transformation, and extracting positive sequence voltage amplitude U in abc coordinate systemacThen collecting the DC capacitor voltage of the three-phase full-bridge circuit
Filtering out the double frequency components by a wave trap to obtain the average value U of the DC voltagedcPositive sequence voltage amplitude UacAnd the mean value U of DC voltagedcRespectively carrying out normalization processing to obtain Uac_normAnd Udc_normAnd then the difference is made between the two normalization processing scalars, the difference value delta UnormAnd a power reference value Pref、QrefMultiply controlled power bi-directional flowWill be Δ Unorm、Pref、QrefAnd uαβ +The input reference current calculation module obtains an alternating current positive sequence current reference value i through reference current calculation+ αβ_ref；
in the negative controller, firstly, each axial component i of the current under the alpha- β coordinate systemα、iβCalculating the root mean square value, and selecting the larger value and the rated current I of the convertermaxComparing, inputting the error signal into a proportional controller to obtain a negative sequence voltage compensation coefficient; secondly, the negative sequence voltage u obtained in the step oneαβ －Multiplying the negative sequence voltage compensation coefficient to obtain an alternating negative sequence current reference value i- αβ_ref(ii) a Finally, the reference value i is compared with the AC positive sequence current obtained in the step two+ αβ_refSubtracting to obtain a total current reference value, and comparing the total current reference value with the total actual value i of the alternating currentαβAfter comparison, the current is input into a PR controller, the PR controller is adopted to track a current reference value, and a trigger pulse is output through PWM modulation to control a three-phase full-bridge circuit;
step four: the steps achieve the purpose of eliminating the negative sequence component of the alternating voltage, but the double-frequency fluctuation power can not be completely eliminated, so that the direct current side fluctuation power compensation circuit needs to be controlled; in a DC controller, a positive sequence voltage u is appliedαβ +Positive sequence current iαβ +And negative sequence voltage uαβ －Negative sequence current iαβ －Inputting the power into an alternating current fluctuating power calculation module, and calculating according to an instantaneous power theory to obtain frequency doubling fluctuating power p at an alternating current output alternating current side of the converter1And simultaneously acquires the DC load voltage and current U of the DC microgridac_L、iac_LInputting the power into a DC power calculation module, and extracting the frequency doubling fluctuation power p at the DC side through a band-pass filter2Frequency-doubled fluctuating power p on the AC side1And the DC side frequency doubling fluctuation power p2Adding to obtain the second fluctuation value of the active power
Will have the active power fluctuate for two times
Input frequency doubling current calculation module and divide by direct current voltage UdcTo obtain the second harmonic current value i to be absorbed by the compensation circuit2rd；
Step five: given AC capacitance CacReference value u of voltageref ac_cAnd the actual capacitor voltage uac_cAfter comparison, a current reference signal i is obtained through PI controlref ac_cAdding the second harmonic current value i obtained in the fourth step2rdObtaining the final reference value of the inductive current and the actual inductive current i in the compensation circuitac_cCompared with the prior art, the obtained error signal is compensated by the PI controller and then modulated by the PWM to output a series of trigger pulses with adjustable duty ratios to control the fluctuation power compensation circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010708708.8A CN111740455B (en) | 2020-07-22 | 2020-07-22 | Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010708708.8A CN111740455B (en) | 2020-07-22 | 2020-07-22 | Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111740455A true CN111740455A (en) | 2020-10-02 |
| CN111740455B CN111740455B (en) | 2023-07-07 |
Family
ID=72657199
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010708708.8A Active CN111740455B (en) | 2020-07-22 | 2020-07-22 | Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111740455B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113410829A (en) * | 2021-05-08 | 2021-09-17 | 新天绿色能源股份有限公司 | True bipolar direct-current micro-grid bus voltage balancing device and control method thereof |
| CN113517724A (en) * | 2021-04-09 | 2021-10-19 | 国网山西省电力公司电力科学研究院 | Method for suppressing voltage ripple on direct current side of alternating current-direct current hybrid micro-grid |
| CN113541515A (en) * | 2021-06-07 | 2021-10-22 | 国网福建省电力有限公司泉州供电公司 | Control method and terminal for AC/DC bus interface converter |
| CN113964877A (en) * | 2021-12-21 | 2022-01-21 | 中国电力科学研究院有限公司 | Method and system for improving grid-connected capacity of wind turbine generator under voltage imbalance |
| CN114123203A (en) * | 2021-10-28 | 2022-03-01 | 国网山西省电力公司电力科学研究院 | Direct-current bus voltage ripple suppression strategy during voltage unbalance of alternating-current power grid |
| CN116014820A (en) * | 2023-03-28 | 2023-04-25 | 南昌科晨电力试验研究有限公司 | Asymmetric fault low-voltage ride-through control method and system based on super capacitor |
| CN117254704A (en) * | 2023-09-22 | 2023-12-19 | 中南大学 | Grid-connected voltage type rectifier frequency division analog resistance control method under unbalanced power grid |
| CN117914108A (en) * | 2024-03-07 | 2024-04-19 | 江苏康众数字医疗科技股份有限公司 | Arbitrary current generation system and method based on H-bridge state feedback |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012067167A1 (en) * | 2010-11-17 | 2012-05-24 | 富士電機株式会社 | Ac-ac converter |
| CN102891614A (en) * | 2012-10-26 | 2013-01-23 | 河南师范大学 | Improved dead-beat control method for pulse width modulation (PWM) rectifier at unbalance of voltage of power grid |
| CN106411161A (en) * | 2016-08-06 | 2017-02-15 | 太原理工大学 | Three-phase PWM converter in voltage unbalance condition and optimal control method of three-phase PWM converter |
| CN107947623A (en) * | 2017-11-24 | 2018-04-20 | 太原理工大学 | The multi-modal autonomous progress control method of two-way AC/DC converters under the conditions of a kind of laod unbalance |
| CN108879765A (en) * | 2018-07-02 | 2018-11-23 | 太原理工大学 | Prevent the bidirectional power converter control method of micro-capacitance alternating current bus current distortion |
-
2020
- 2020-07-22 CN CN202010708708.8A patent/CN111740455B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012067167A1 (en) * | 2010-11-17 | 2012-05-24 | 富士電機株式会社 | Ac-ac converter |
| CN102891614A (en) * | 2012-10-26 | 2013-01-23 | 河南师范大学 | Improved dead-beat control method for pulse width modulation (PWM) rectifier at unbalance of voltage of power grid |
| CN106411161A (en) * | 2016-08-06 | 2017-02-15 | 太原理工大学 | Three-phase PWM converter in voltage unbalance condition and optimal control method of three-phase PWM converter |
| CN107947623A (en) * | 2017-11-24 | 2018-04-20 | 太原理工大学 | The multi-modal autonomous progress control method of two-way AC/DC converters under the conditions of a kind of laod unbalance |
| CN108879765A (en) * | 2018-07-02 | 2018-11-23 | 太原理工大学 | Prevent the bidirectional power converter control method of micro-capacitance alternating current bus current distortion |
Non-Patent Citations (1)
| Title |
|---|
| 刘龙峰;韩肖清;任春光;王鹏;张佰富;李胜文;: "不平衡工况下混合微电网交直流母线接口变换器多模态运行控制策略", 高电压技术, no. 12 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113517724A (en) * | 2021-04-09 | 2021-10-19 | 国网山西省电力公司电力科学研究院 | Method for suppressing voltage ripple on direct current side of alternating current-direct current hybrid micro-grid |
| CN113410829A (en) * | 2021-05-08 | 2021-09-17 | 新天绿色能源股份有限公司 | True bipolar direct-current micro-grid bus voltage balancing device and control method thereof |
| CN113410829B (en) * | 2021-05-08 | 2023-05-16 | 新天绿色能源股份有限公司 | True bipolar direct current micro-grid busbar voltage balancing device and control method thereof |
| CN113541515A (en) * | 2021-06-07 | 2021-10-22 | 国网福建省电力有限公司泉州供电公司 | Control method and terminal for AC/DC bus interface converter |
| CN114123203A (en) * | 2021-10-28 | 2022-03-01 | 国网山西省电力公司电力科学研究院 | Direct-current bus voltage ripple suppression strategy during voltage unbalance of alternating-current power grid |
| CN114123203B (en) * | 2021-10-28 | 2023-08-29 | 国网山西省电力公司电力科学研究院 | DC bus voltage ripple suppression strategy during unbalanced AC grid voltage |
| CN113964877A (en) * | 2021-12-21 | 2022-01-21 | 中国电力科学研究院有限公司 | Method and system for improving grid-connected capacity of wind turbine generator under voltage imbalance |
| CN116014820A (en) * | 2023-03-28 | 2023-04-25 | 南昌科晨电力试验研究有限公司 | Asymmetric fault low-voltage ride-through control method and system based on super capacitor |
| CN116014820B (en) * | 2023-03-28 | 2023-08-29 | 南昌科晨电力试验研究有限公司 | Asymmetric fault low-voltage ride-through control method and system based on super capacitor |
| CN117254704A (en) * | 2023-09-22 | 2023-12-19 | 中南大学 | Grid-connected voltage type rectifier frequency division analog resistance control method under unbalanced power grid |
| CN117254704B (en) * | 2023-09-22 | 2024-04-19 | 中南大学 | Grid-connected voltage type rectifier frequency division analog resistance control method under unbalanced power grid |
| CN117914108A (en) * | 2024-03-07 | 2024-04-19 | 江苏康众数字医疗科技股份有限公司 | Arbitrary current generation system and method based on H-bridge state feedback |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111740455B (en) | 2023-07-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111740455B (en) | Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage | |
| CN111740454B (en) | Mixed micro-grid alternating-current and direct-current voltage unified control method based on bus interface converter | |
| CN111030152B (en) | Energy storage converter system and control method thereof | |
| CN109217687A (en) | Power distribution network electric power electric transformer and its control method based on MMC | |
| CN107093954B (en) | Two-stage three-phase four-leg inverter system with BOOST boosting function and control strategy | |
| CN108173288B (en) | Voltage type impedance adapter control method for inhibiting multi-inverter grid-connected system resonance | |
| CN110138253A (en) | A kind of photovoltaic combining inverter control method that multi-resonant PR and PI jointly controls | |
| CN110943469B (en) | Single-stage energy storage converter and control method thereof | |
| CN108879775B (en) | Power grid unbalanced photovoltaic inverter coordination control method considering current limit value | |
| CN106411161A (en) | Three-phase PWM converter in voltage unbalance condition and optimal control method of three-phase PWM converter | |
| CN105071390B (en) | Control method of H-bridge three-level active power filter and system | |
| CN104505834A (en) | Parallel resonance suppression adaptive compensation control method for capacitive load | |
| CN111814102A (en) | Harmonic parameter optimization method suitable for offshore wind power transmission system through alternating current submarine cable network | |
| CN107681892B (en) | Direct current converter | |
| CN114123203A (en) | Direct-current bus voltage ripple suppression strategy during voltage unbalance of alternating-current power grid | |
| CN111030131B (en) | MMC-STATCOM circulating current suppression device based on negative sequence virtual impedance | |
| CN106532703B (en) | Energy storage current transformation system, current transformer, control method of bidirectional current transformer and controller | |
| CN111049201B (en) | Coordination control method for AC/DC power grid hybrid high-power interface converter | |
| CN112952867A (en) | Method for suppressing output voltage unbalance of energy storage power converter under asymmetric load | |
| Ramteke et al. | Design and comparative study of filters for multilevel inverter for grid interface | |
| CN106877674B (en) | Mode of resonance DC/DC inverter power balance control method and control system | |
| CN106208059B (en) | Adjustable impedance formula distributed photovoltaic power generation cluster resonance inhibiting system and suppressing method | |
| CN113507123B (en) | Bidirectional interface converter optimization control method suitable for alternating current-direct current hybrid microgrid | |
| CN201994667U (en) | Device for removing voltage harmonics in electric power system | |
| CN114865680A (en) | Specific resonant frequency suppression method of modular multilevel converter |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |