CN111740455B - 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 PDF

Info

Publication number
CN111740455B
CN111740455B CN202010708708.8A CN202010708708A CN111740455B CN 111740455 B CN111740455 B CN 111740455B CN 202010708708 A CN202010708708 A CN 202010708708A CN 111740455 B CN111740455 B CN 111740455B
Authority
CN
China
Prior art keywords
current
voltage
alternating
value
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.)
Active
Application number
CN202010708708.8A
Other languages
Chinese (zh)
Other versions
CN111740455A (en
Inventor
任春光
赵多
贾燕冰
韩肖清
孟润泉
王磊
孔健生
郭东鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Taiyuan University of Technology
Original Assignee
Taiyuan University of Technology
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Taiyuan University of Technology filed Critical Taiyuan University of Technology
Priority to CN202010708708.8A priority Critical patent/CN111740455B/en
Publication of CN111740455A publication Critical patent/CN111740455A/en
Application granted granted Critical
Publication of CN111740455B publication Critical patent/CN111740455B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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 of an alternating current-direct current hybrid micro-grid bus interface converter and electric energy quality control, 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 coupling of the double frequency fluctuation power between the AC and DC subnetworks under the condition of unbalanced voltage. The main circuit consists of an AC/DC sub-network and a bidirectional interface converter connected with 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 negative sequence voltage by utilizing the power margin transmitted by the converter; the direct current side is introduced into a boost chopper circuit, and the pulsating voltage of the direct current bus is stabilized by a power compensation principle. The invention realizes the purpose of compensating AC/DC voltage simultaneously by controlling the bus interface converter, improves the utilization rate of the bidirectional interface converter and ensures the running reliability of the micro-grid.

Description

Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage
Technical Field
The invention relates to the field of hybrid micro-grid AC/DC bus interface converter control and hybrid micro-grid power quality control, in particular to a bus interface converter control method for uniformly compensating AC unbalanced voltage and DC pulsating voltage.
Background
Along with the continuous rise of the permeability of new energy, the AC/DC hybrid micro-grid gradually becomes the trend of future development of the micro-grid due to the fact that the AC micro-grid and the DC micro-grid can be effectively combined. The actual AC/DC hybrid micro-grid is often positioned at the tail end of the power distribution network, the self capacity of the power distribution network is relatively small, when an asymmetric fault occurs in a large power grid or unbalance occurs in a load, negative sequence components can occur in the voltage, the current or the load voltage and the current of the power grid, so that the voltage at the PCC is unbalanced, and DC voltage pulsation is further caused. Meanwhile, some single-phase alternating current loads with high requirements on the electric energy quality are often connected into a direct current micro-grid through an inverter, and direct current bus voltage double frequency pulsation can be caused, so that alternating current harmonic pollution is further caused. The alternating current unbalanced voltage and the direct current double frequency pulsating voltage not only influence the normal operation of the alternating current/direct current sub-network and the bidirectional interface converter, but also cause other electric energy quality problems by being coupled to the other side through the bidirectional AC/DC converter, and influence the safe and stable operation of the whole hybrid micro-grid.
Currently, a large number of documents offer many solutions to the different power quality problems in hybrid micro-grids. The compensation methods for the three-phase unbalanced voltages are roughly classified into two types: 1. the series or parallel connection of the power quality regulator has obvious defects because additional devices are needed to be added and the cost is increased; 2. the three-phase unbalanced voltage is compensated by using a distributed energy source or an energy storage converter and the like. The dc voltage ripple control strategies can also be divided into two categories: 1. the passive or active filter circuit is introduced, the method can effectively inhibit the direct current ripple voltage, but the cost problem caused by introducing additional devices is also existed; 2. and the double frequency pulsating voltage is indirectly eliminated through an impedance remodeling control method. However, the control targets of the prior art are single, and few researches relate to a method for uniformly controlling the quality of the alternating-current and direct-current voltages of the hybrid micro-grid.
Disclosure of Invention
The invention designs a bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage, aiming at the defects of the prior art, aiming at solving the problem of different voltage qualities caused by coupling of double frequency fluctuation power between alternating current and direct current subnetworks under the condition of unbalanced voltage.
The technical scheme of the invention is as follows: a bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage comprises a hybrid micro-grid main circuit, wherein the hybrid 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, the bidirectional interface converter comprises a three-phase full-bridge circuit and a boost chopper circuit, a direct current 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 inductance L is adopted on an alternating current side for filtering, the boost chopper circuit is a fluctuating power compensation circuit and comprises an inductance L ac Capacitance C ac And a group of bridge arms composed of IGBTs connected in series with each other, an inductance L ac One end of the capacitor C is connected with the upper bridge arm of the direct current side of the three-phase full-bridge circuit, and the other end of the capacitor C is connected with the middle of the bridge arm of the compensation circuit ac One end of (C) is connected with the upper bridge arm of the compensation circuit, C ac The other end of the compensation circuit is connected with the lower bridge arm of the direct current side of the three-phase full-bridge circuit; the bidirectional interface converter is connected with an alternating-current micro-grid in an alternating-current side, a direct-current side and a direct-current micro-grid in a direct-current side, a main circuit is connected with a large power grid through a public grid connection point PCC, a hybrid micro-grid 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.
In the control method, an alternating current side positive sequence controller obtains an alternating current positive sequence current reference value i + αβ_ref The negative sequence controller obtains an alternating negative sequence current reference value i - αβ_ref Ac positive sequence current reference i + αβ_ref Ac negative sequence current reference value i - αβ_ref Synthesizing a total current reference value, comparing the total current reference value with an alternating current total actual value, inputting the total current reference value into a PR controller, outputting a trigger pulse through PWM modulation to control a three-phase full-bridge circuit, and obtaining a second harmonic current value i by a direct current side direct current controller according to the input alternating current side voltage current and direct current micro-grid direct current load voltage current 2rd Then by a given AC capacitor C ac Voltage reference and actualThe capacitor voltage is compared and PI control is carried out to obtain a current reference signal, and the current reference signal is added with a second harmonic current value i 2rd And obtaining a final inductor current reference value, wherein the inductor current reference value is compared with the actual inductor current in the compensation circuit, and after the obtained error signal is compensated by the PI controller, a series of trigger pulse control fluctuation power compensation circuits with adjustable duty ratio are output through PWM modulation.
The control method of the bus interface converter for uniformly compensating the alternating current unbalanced voltage and the direct current pulsating voltage is characterized in that a mathematical model of a bidirectional AC/DC converter under an alpha beta coordinate system is established at an alternating current side, the fundamental wave power and positive sequence current of the converter are controlled through bidirectional power flow and a Proportional Resonance (PR) algorithm, and the negative sequence voltage is compensated by utilizing the power allowance 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 is enabled to absorb double frequency fluctuation power at the two sides of alternating current and direct current simultaneously through a power compensation principle, so that a method for eliminating alternating current negative sequence voltage and direct current pulsation voltage simultaneously is finally realized. The method is specifically developed as follows:
step one: detecting output voltage u of alternating current side of three-phase full-bridge circuit abc And output current i abc Transforming the alpha-beta coordinates to obtain each quantity u in the alpha-beta coordinate system αβ 、i αβ For u αβ And i αβ Positive and negative sequence separation is carried out to obtain positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ － ；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step one is calculated αβ + Coordinate transformation is carried out, and positive sequence voltage amplitude U under abc coordinate system is extracted ac Then collecting the DC capacitor voltage of the three-phase full bridge circuit
Figure BDA0002595697160000031
And filtering the double frequency component through a wave trap to obtain a direct current average value U dc The positive sequence voltage amplitude U ac And DC voltage average value U dc Respectively carrying out normalization treatment to obtain U ac_norm And U dc_norm Then, difference is made between the two normalized scalar quantities, and the difference value delta U norm And a power reference value P ref 、Q ref Multiplying to control power bi-directional flow, and adding DeltaU norm 、P ref 、Q ref U αβ + The input reference current calculation module calculates the reference current to obtain an alternating positive sequence current reference value i + αβ_ref ；
Step three: in the negative sequence controller, first, for each axis component i of the current in the alpha-beta coordinate system α 、i β Root mean square value is obtained, and then a larger value and the rated current I of the converter are selected max (rated current I) max Representing the rated power of the converter, which can be set by the user 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 one is processed αβ － Multiplying the negative sequence voltage compensation coefficient to obtain an alternating negative sequence current reference value i - αβ_ref The method comprises the steps of carrying out a first treatment on the surface of the Finally, the reference value i of the alternating current positive sequence current obtained in the step two is compared with the reference value i of the alternating current positive sequence current obtained in the step two + αβ_ref Subtracting to obtain a total current reference value, and then the total current reference value is combined with an alternating current total actual value i αβ After 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 above steps achieve the purpose of eliminating the negative sequence component of the ac voltage, but still cannot completely eliminate the double frequency fluctuation power, so that the dc side fluctuation power compensation circuit needs to be controlled. In the DC controller, the positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ － Input into an alternating current fluctuation power calculation module, and calculate and obtain the alternating current output alternating current side double frequency fluctuation power p of the converter according to the instantaneous power theory 1 Simultaneously collecting direct-current load voltage and current U of direct-current micro-grid ac_L 、i ac_L Input to a DC power calculation moduleIn the block, the direct-current side frequency doubling fluctuating power p is extracted through a band-pass filter 2 Ac side double frequency fluctuation power p 1 And direct-current side double frequency fluctuation power p 2 Adding to obtain the active power secondary fluctuation value
Figure BDA0002595697160000041
The active power secondary fluctuation value +.>
Figure BDA0002595697160000042
Input the double frequency current calculation module and divide by the direct current voltage U dc Obtaining a second harmonic current value i which needs to be absorbed by the compensation circuit 2rd ；
Step five: given ac capacitance C ac Voltage reference value u ref ac_c And the actual capacitance voltage u ac_c The current reference signal i is obtained after comparison through PI control ref ac_c Adding the second harmonic current value i obtained in the step four 2rd Obtaining the final inductor current reference value and the actual inductor current i in the compensation circuit ac_c Compared with the prior art, the obtained error signal is compensated by the PI controller and then is subjected to PWM modulation to output a series of trigger pulse control fluctuation power compensation circuits with adjustable duty ratio.
The bus interface converter control method for uniformly compensating the alternating current unbalanced voltage and the direct current pulsating voltage has the advantages compared with the prior art that: (1) When the AC/DC hybrid micro-grid is in an unbalanced working condition, the purpose of compensating the AC negative sequence voltage and the DC pulsating voltage simultaneously can be achieved, the utilization rate of the bidirectional AC/DC converter is improved, and the micro-grid can be ensured to operate optimally and stably. (2) The boost type fluctuation power compensation circuit is introduced, so that the secondary fluctuation of active power is effectively restrained under the condition of not adding an additional device, the capacity of a direct current bus capacitor can be greatly reduced, the investment and the operation cost of a micro-grid are reduced, and the space of the micro-grid is saved.
Drawings
FIG. 1 is a diagram of a bus interface converter for uniformly compensating an AC unbalanced voltage and a DC pulsating voltage according to the present invention;
fig. 2 is a schematic diagram of unified compensation of ac unbalanced voltage and dc pulsating voltage of a bus interface converter according to the present invention.
Detailed Description
A bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage comprises a hybrid micro-grid main circuit, an alternating current micro-grid and a direct current micro-grid, wherein the hybrid micro-grid main circuit comprises a bidirectional interface converter, 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, the three-phase full-bridge circuit comprises three groups of bridge arms which are mutually connected in parallel, each group of bridge arms comprises two IGBTs which are mutually connected in series, each IGBT comprises a power tube and an anti-parallel diode, a direct current capacitor of the three-phase full-bridge circuit is connected in parallel to two sides of the bridge arm of the full-bridge circuit, an alternating current side adopts inductance L for filtering, and the boost chopper circuit is a fluctuation power compensation circuit and comprises an inductance L ac Capacitance C ac And a group of bridge arms composed of IGBTs connected in series with each other, an inductance L ac One end of the capacitor C is connected with the upper bridge arm of the direct current side of the three-phase full-bridge circuit, and the other end of the capacitor C is connected with the middle of the bridge arm of the compensation circuit ac One end of (C) is connected with the upper bridge arm of the compensation circuit, C ac The other end of the compensation circuit is connected with the lower bridge arm of the direct current side of the three-phase full-bridge circuit; the bidirectional interface converter is connected with an alternating-current micro-grid in an alternating-current side, a direct-current side and a direct-current micro-grid in a direct-current side, a main circuit is connected with a large power grid through a public grid connection point PCC, a hybrid micro-grid 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.
The method for uniformly compensating the alternating-current unbalanced voltage and the direct-current pulsating voltage of the hybrid micro-grid bus interface converter based on the boost power compensation circuit comprises the following specific implementation steps:
step one: detecting output voltage u at AC side of bidirectional AC/DC converter abc And output current i abc Transforming the alpha-beta coordinates to obtain each quantity u in the alpha-beta coordinate system αβ 、i αβ And to u αβ And i αβ Positive and negative sequence separation is carried out to obtain positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ - ；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step one is calculated αβ + Coordinate transformation is carried out, and positive sequence voltage amplitude U under abc coordinate system is extracted ac Then collecting the DC capacitor voltage of the three-phase full bridge circuit
Figure BDA0002595697160000061
And filtering the double frequency component through a wave trap to obtain a direct current average value U dc Respectively carrying out normalization processing on the voltages at the alternating current side and the direct current side to obtain U ac_norm And U dc_norm Then, difference is carried out on the two scalar quantities, and the difference value delta U norm And a power reference value P ref 、Q ref Multiplying to control power bi-directional flow, and adding DeltaU norm 、P ref 、Q ref U αβ + The input reference current calculation module calculates the reference current to obtain an alternating positive sequence current reference value i + αβ_ref ；
Step three: in the negative sequence controller, firstly, root mean square value is calculated for each axis component of current under an alpha-beta coordinate system, a larger value is selected to be compared with rated current of the converter, and an error signal is input into the proportional controller to obtain a negative sequence voltage compensation coefficient; secondly, the negative sequence voltage u obtained in the step one is processed αβ － Multiplying the negative sequence voltage compensation coefficient to obtain an alternating negative sequence current reference value i - αβ_ref The method comprises the steps of carrying out a first treatment on the surface of the Finally, the reference value i of the alternating current positive sequence current obtained in the step two is compared with the reference value i of the alternating current positive sequence current obtained in the step two + αβ_ref Subtracting, comparing with the actual value of the alternating current positive sequence current, tracking a current reference value by adopting a PR controller, and outputting trigger pulse to control a three-phase PWM converter through PWM modulation;
step four: in the DC controller, the positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ － Input into an alternating current fluctuation power calculation module, and calculate and obtain the alternating current output alternating current side double frequency fluctuation power p of the converter according to the instantaneous power theory 1 Simultaneously collecting direct-current load voltage and current U of direct-current micro-grid ac_L 、i ac_L Inputting into a DC power calculation module, and extracting DC side double frequency fluctuation power p by a band-pass filter 2 Ac side double frequency fluctuation power p 1 And direct-current side double frequency fluctuation power p 2 Adding to obtain the active power secondary fluctuation value
Figure BDA0002595697160000062
The active power secondary fluctuation value +.>
Figure BDA0002595697160000063
Dividing the input double frequency current calculation module by the direct current voltage to obtain a second harmonic current value i which needs to be absorbed by the compensation circuit 2rd ；
Step five: given the ac capacitor voltage reference u ref ac_c And the actual capacitance voltage u ac_c The current reference signal i is obtained after comparison through PI control ref ac_c Adding the second harmonic current value i obtained in the step four 2rd Obtaining the final inductor current reference value and the actual inductor current i in the compensation circuit ac_c Compared with the prior art, the obtained error signal is compensated by the PI controller and then is subjected to PWM modulation to output a series of trigger pulse control fluctuation power compensation circuits with adjustable duty ratio.

Claims (1)

1. A bus interface converter control method for uniformly compensating alternating current unbalanced voltage and direct current pulsating voltage is characterized in that a hybrid 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, the bidirectional interface converter comprises a three-phase full-bridge circuit and a boost chopper circuit, a direct current 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 inductance L is adopted on an alternating current side for filtering, the boost chopper circuit is a fluctuating power compensation circuit and comprises an inductance L ac Capacitance C ac And a group of bridge arms composed of IGBTs connected in series with each other, an inductance L ac One end of the capacitor C is connected with the upper bridge arm of the direct current side of the three-phase full-bridge circuit, and the other end of the capacitor C is connected with the middle of the bridge arm of the compensation circuit ac One end of (C) is connected with the upper bridge arm of the compensation circuit, C ac The other end of the compensation circuit is connected with the lower bridge arm of the direct current side of the three-phase full-bridge circuit; the alternating current of the bidirectional interface converter is connected with an alternating current micro-grid, the direct current is connected with a direct current micro-grid, and the main circuit is connected with a large power grid through a public grid connection 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 alternating current side positive sequence controller obtains an alternating current positive sequence current reference value i + αβ_ref The negative sequence controller obtains an alternating negative sequence current reference value i - αβ_ref Ac positive sequence current reference i + αβ_ref Ac negative sequence current reference value i - αβ_ref Synthesizing 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 a trigger pulse to control a three-phase full-bridge circuit through PWM modulation; the DC-side DC controller obtains AC-DC two-side fluctuation power according to the input AC-side voltage and current of the interface converter and the DC micro-grid load-side voltage and current, and obtains a second harmonic current value i through double frequency current calculation 2rd Then by a given AC capacitor C ac The voltage reference value is compared with the actual capacitor voltage and then PI control is carried out to obtain a current reference signal, and the current reference signal is added with a second harmonic current value i 2rd Obtaining a final inductance current reference value, wherein the inductance current reference value is compared with the actual inductance current in the compensation circuit, and after the obtained error signal is compensated by the PI controller, a series of trigger pulse control fluctuation power compensation circuits with adjustable duty ratio are output through PWM modulation;
the method comprises the following steps:
step one: detecting output voltage u of alternating current side of three-phase full-bridge circuit abc And output current i abc It is subjected to an alpha-beta coordinate transformation,obtaining the respective quantities u in the alpha-beta coordinate system αβ 、i αβ For u αβ And i αβ Positive and negative sequence separation is carried out to obtain positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ － ；
Step two: in the positive sequence controller, the positive sequence voltage u obtained in the step one is calculated αβ + Coordinate transformation is carried out, and positive sequence voltage amplitude U under abc coordinate system is extracted ac Then collecting the DC capacitor voltage of the three-phase full bridge circuit
Figure FDA0004238979740000023
And filtering the double frequency component through a wave trap to obtain a direct current average value U dc For positive sequence voltage amplitude U ac And DC voltage average value U dc Respectively carrying out normalization treatment to obtain U ac_norm And U dc_norm Then, difference is made between the two normalized scalar quantities, and the difference value delta U norm And a power reference value P ref 、Q ref Multiplying to control power bi-directional flow, and adding DeltaU norm 、P ref 、Q ref U αβ + The input reference current calculation module calculates the reference current to obtain an alternating positive sequence current reference value i + αβ_ref ；
Step three: in the negative sequence controller, first, for each axis component i of the current in the alpha-beta coordinate system α 、i β Root mean square value is obtained, and then a larger value and the rated current I of the converter are selected max Comparing, namely 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 one is processed αβ － Multiplying the negative sequence voltage compensation coefficient to obtain an alternating negative sequence current reference value i - αβ_ref The method comprises the steps of carrying out a first treatment on the surface of the Finally, the reference value i of the alternating current positive sequence current obtained in the step two is compared with the reference value i of the alternating current positive sequence current obtained in the step two + αβ_ref Subtracting to obtain a total current reference value, and then the total current reference value is combined with an alternating current total actual value i αβ After comparison, the current reference is tracked by the PR controllerThe value is modulated by PWM to output trigger pulse to control a three-phase full bridge circuit;
step four: the step achieves the aim of eliminating the negative sequence component of the alternating voltage, but the double frequency fluctuation power still cannot be completely eliminated, so that a direct current side fluctuation power compensation circuit is required to be controlled; in the DC controller, the positive sequence voltage u αβ + Positive sequence current i αβ + And negative sequence voltage u αβ － Negative sequence current i αβ － Input into an alternating current fluctuation power calculation module, and calculate and obtain the alternating current output alternating current side double frequency fluctuation power p of the converter according to the instantaneous power theory 1 Simultaneously collecting direct-current load voltage and current U of direct-current micro-grid ac_L 、i ac_L Inputting into a DC power calculation module, and extracting DC side double frequency fluctuation power p by a band-pass filter 2 Ac side double frequency fluctuation power p 1 And direct-current side double frequency fluctuation power p 2 Adding to obtain the active power secondary fluctuation value
Figure FDA0004238979740000021
The active power secondary fluctuation value +.>
Figure FDA0004238979740000022
Input the double frequency current calculation module and divide by the direct current voltage U dc Obtaining a second harmonic current value i which needs to be absorbed by the compensation circuit 2rd ；
Step five: given ac capacitance C ac Voltage reference value u ref ac_c And the actual capacitance voltage u ac_c The current reference signal i is obtained after comparison through PI control ref ac_c Adding the second harmonic current value i obtained in the step four 2rd Obtaining the final inductor current reference value and the actual inductor current i in the compensation circuit ac_c Compared with the prior art, the obtained error signal is compensated by the PI controller and then is subjected to PWM modulation to output a series of trigger pulse control fluctuation power compensation circuits with adjustable duty ratio.
CN202010708708.8A 2020-07-22 2020-07-22 Bus interface converter control method for uniformly compensating alternating-current unbalanced voltage and direct-current pulsating voltage Active CN111740455B (en)

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 CN111740455A (en) 2020-10-02
CN111740455B true 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)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113517724B (en) * 2021-04-09 2022-11-25 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
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
CN113541515B (en) * 2021-06-07 2022-11-22 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
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
CN113964877B (en) * 2021-12-21 2022-03-18 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
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

Citations (5)

* Cited by examiner, † Cited by third party
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

Patent Citations (5)

* Cited by examiner, † Cited by third party
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)

* Cited by examiner, † Cited by third party
Title
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;刘龙峰;韩肖清;任春光;王鹏;张佰富;李胜文;;高电压技术(第12期);全文 *

Also Published As

Publication number Publication date
CN111740455A (en) 2020-10-02

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
CN108448660B (en) Circulating current suppression method for parallel converter of hybrid micro-grid based on hierarchical control
CN109067154A (en) A kind of active filter and the method for eliminating train DC bus secondary resonance
CN106786485B (en) Voltage ripple suppression method for direct-current micro-grid under unbalanced load
CN109217687A (en) Power distribution network electric power electric transformer and its control method based on MMC
CN106411161B (en) Three-Phase PWM Converter and its optimal control method under the conditions of a kind of Voltage unbalance
CN110943469B (en) Single-stage energy storage converter and control method thereof
CN108173288A (en) Inhibit the voltage-type impedance adapter control method of multi-inverter grid-connected system resonance
CN208971375U (en) It is a kind of for eliminating the DC side active filter of train DC bus secondary resonance
CN105071390B (en) Control method of H-bridge three-level active power filter and system
CN106849708B (en) A kind of PFC fairing
CN111030131B (en) MMC-STATCOM circulating current suppression device based on negative sequence virtual impedance
CN111049201B (en) Coordination control method for AC/DC power grid hybrid high-power interface converter
CN104578883A (en) Inverter and control method thereof
CN102025146A (en) Double-switch direct current active power filter and control method thereof
CN106998067B (en) AC active filter for compensating characteristic harmonic wave of high-voltage DC transmission system
CN113507123B (en) Bidirectional interface converter optimization control method suitable for alternating current-direct current hybrid microgrid
CN106877674B (en) Mode of resonance DC/DC inverter power balance control method and control system
CN113114033B (en) Direct-current-side secondary ripple suppression device for traction transmission system and control method
CN106208059B (en) Adjustable impedance formula distributed photovoltaic power generation cluster resonance inhibiting system and suppressing method
CN201994667U (en) Device for removing voltage harmonics in electric power system
CN110855157B (en) Airplane ground static variable power supply direct-current bus control method based on active rectification
CN104333206A (en) Photovoltaic micro-grid inverter output voltage control method

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