CN110676851A - Low-voltage modular high-power electric energy management device and compensation method thereof - Google Patents
Low-voltage modular high-power electric energy management device and compensation method thereof Download PDFInfo
- Publication number
- CN110676851A CN110676851A CN201910904607.5A CN201910904607A CN110676851A CN 110676851 A CN110676851 A CN 110676851A CN 201910904607 A CN201910904607 A CN 201910904607A CN 110676851 A CN110676851 A CN 110676851A
- Authority
- CN
- China
- Prior art keywords
- current
- compensation
- compensation mode
- power
- harmonic
- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/01—Arrangements for reducing harmonics or ripples
-
- 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
- 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
- H02J3/26—Arrangements for eliminating or reducing asymmetry in polyphase networks
-
- 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
-
- 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
- Y02E40/40—Arrangements for reducing harmonics
-
- 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 provides a low-voltage modular high-power electric energy management device and a compensation method thereof, which relate to the technical field of electric energy quality management, can realize comprehensive management of electric energy quality, can automatically select a compensation mode according to the system condition, and can realize the maximum compensation function with high cost performance on the premise of meeting the capacity; the device comprises a detection unit, a control unit and a control unit, wherein the detection unit is used for collecting the current of a compensation object and transmitting the current to the control unit; the control unit is used for analyzing and processing the acquired current and selecting a compensation mode; the driving unit is used for generating corresponding driving signals according to the compensation mode selected by the control unit so as to drive the inversion unit to complete the compensation function; and the inversion unit is used for generating compensation current and realizing the compensation function under the action of the driving signal. The technical scheme provided by the invention is suitable for the process of power quality control.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to the technical field of power quality management, in particular to a low-voltage modular high-power management device and a compensation method thereof.
[ background of the invention ]
With the development of power electronics technology, the quality of electric energy has become an important issue. The appearance of the electric energy quality treatment device well solves the problems of harmonic wave, reactive power, three-phase imbalance and the like in the power grid. Common electric energy quality treatment devices comprise an Active Power Filter (APF), a Static Var Generator (SVG) and the like. However, due to the complexity of the power grid and the limitation of equipment, the existing power quality management device is difficult to meet the requirements of synchronous management of power quality problems such as harmonic waves, reactive power, unbalance and the like.
Accordingly, there is a need to develop a low voltage modular high power energy management device that addresses the deficiencies of the prior art to solve or mitigate one or more of the problems set forth above.
[ summary of the invention ]
In view of the above, the invention provides a low-voltage modular high-power electric energy management device and a compensation method thereof, which can realize comprehensive management of electric energy quality, can automatically select a compensation mode according to system conditions, and can realize the maximum compensation function with high cost performance on the premise of meeting capacity.
In one aspect, the present invention provides a low-voltage modular high-power electric energy management device, which is characterized in that the device comprises:
the detection unit is used for collecting the current of the compensation object and transmitting the current to the control unit;
the control unit is used for analyzing and processing the acquired current and selecting a compensation mode;
the method specifically comprises the following steps: respectively carrying out harmonic extraction, reactive current extraction and load current imbalance calculation on the collected current, analyzing the proportion of the current to the load, finding out a main power quality problem according to an analysis result, and selecting a corresponding compensation mode according to the main power quality problem;
the driving unit is used for generating corresponding driving signals according to the compensation mode selected by the control unit so as to drive the inversion unit to complete the compensation function;
and the inversion unit is used for generating compensation current and realizing the compensation function under the action of the driving signal.
The above-described aspect and any possible implementation manner further provide an implementation manner, when the detection unit performs current collection: the method is characterized in that a p-q operation mode based on an instantaneous reactive power theory is adopted for collection, and a C matrix formed by sine and cosine signals in the same phase with the voltage of the power grid is used for operation, so that the influence caused by voltage waveform distortion of the power grid is eliminated.
The above aspect and any possible implementation manner further provide an implementation manner, where the control unit includes an ARM, an FPGA, and a peripheral circuit, and the software program performs harmonic extraction, reactive current extraction, and load current imbalance calculation on the current collected by the detection unit, and analyzes the ratio of the three.
The above-mentioned aspects and any possible implementation manner further provide an implementation manner, wherein the driving unit performs dual carrier comparison modulation on the modulation wave according to different compensation modes, generates a pulse signal, and performs control by using a carrier-overlapping PWM method.
The above aspect and any possible implementation manner further provide an implementation manner, where the inverter unit includes a dc-side capacitor, a power conversion circuit, and an output filter, which are connected in sequence;
the direct-voltage side capacitor adopts a structure that an upper capacitor and a lower capacitor are connected in series;
the power conversion circuit comprises three bridge arms, each bridge arm comprises four IGBT (insulated gate bipolar transistor) switching tubes, four freewheeling diodes and two clamping diodes, and the freewheeling diodes are connected with the corresponding IGBT switching tubes in series; the two clamping diodes are connected in parallel with the middle two IGBT switch tubes in the four IGBT switch tubes;
the output filter adopts an LCL structure.
In another aspect, the present invention provides a method for current compensation using any one of the low-voltage modular high-power electric energy management devices, wherein the method comprises the following steps:
s1, collecting the current of the object to be compensated;
s2, separating harmonic current in the current by using a DFT method, calculating reactive current by using D-Q conversion, and calculating unbalanced current by using a symmetrical component method;
s3, calculating the proportion of harmonic, reactive and unbalanced currents, and comparing the proportion;
s4, determining the main power quality problem in the compensation object according to the comparison result in the S3;
s5, selecting a compensation mode according to the main power quality problem;
and S6, generating a command current according to the selected compensation mode, generating a PWM signal through a carrier overlapping modulation mode, and driving an inverter unit to work to realize a corresponding compensation function.
As for the above-mentioned aspect and any possible implementation manner, there is further provided an implementation manner, where the specific step of S5 includes:
s51, comparing the harmonic quantity with the device capacity when the harmonic is the main power quality problem;
if the harmonic amount is larger than the device capacity, selecting a compensation mode 1 and entering S6;
if the harmonic quantity is less than or equal to the device capacity, judging whether the reactive power quantity is greater than the allowance obtained by subtracting the harmonic quantity to be compensated from the device capacity; if yes, selecting a compensation mode 4, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
s52, comparing the reactive power of the system with the capacity of the device when the reactive power is the main power quality problem;
if the reactive power is larger than the device capacity, selecting a compensation mode 2, and entering S6;
if the reactive power is less than or equal to the device capacity, judging whether the harmonic quantity is greater than the device capacity minus the margin of the reactive power to be compensated; if yes, selecting a compensation mode 5, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
s53, comparing the unbalance amount with the device capacity when the unbalance is the main power quality problem;
if the unbalance amount is larger than the device capacity, selecting a compensation mode 3 and entering S6;
if the unbalance is less than or equal to the device capacity, judging whether the reactive power is greater than the device capacity minus the allowance of the unbalance to be compensated; if yes, selecting a compensation mode 4, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
S51-S53 have no sequence requirement.
The above-described aspects and any possible implementation further provide an implementation in which the compensation mode 1 compensates only harmonics; the compensation mode 2 only compensates reactive power; compensation mode 3 compensates for imbalance only; the compensation mode 4 compensates harmonic waves and reactive power, and the harmonic waves have priority; the compensation mode 5 compensates harmonic waves and reactive power, and the reactive power has priority; the compensation mode 6 compensates for harmonic, reactive and unbalanced; the compensation mode 7 is a load mode.
The above-described aspects and any possible implementations further provide an implementation in which the capacity output is limited to 100% of the rated capacity output when the compensation mode 1, the compensation mode 2, or the compensation mode 3 is selected for preventing overload of the apparatus.
As for the above-mentioned aspect and any possible implementation manner, there is further provided an implementation manner, where the load mode specifically is: and respectively replacing harmonic current, reactive current, a real part of negative sequence current, an imaginary part of negative sequence current, a real part of zero sequence current and/or an imaginary part of zero sequence current extracted from the collected current with given values.
Compared with the prior art, the invention can obtain the following technical effects: the invention can realize comprehensive treatment of power quality, can automatically select a compensation mode according to the system condition, and can realize the maximum compensation function with high cost performance on the premise of meeting the capacity; the compensation effect is good, and the components and parts of the compensation mode are small in size, low in cost, large in power, high in power factor and high in cost performance.
Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.
[ description of the drawings ]
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of a low-voltage modular high-power comprehensive power quality management device provided by an embodiment of the invention;
FIG. 2 is a topological diagram of a low-voltage modular high-power comprehensive power quality control device according to an embodiment of the present invention;
FIG. 3 is a compensation flow chart of a low-voltage modularized high-power electric energy quality comprehensive treatment device provided by an embodiment of the invention;
fig. 4 is a block diagram of an ip-iq current detection algorithm based on the instantaneous reactive power theory according to an embodiment of the present invention.
[ detailed description ] embodiments
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
In order to solve the defects of the prior art, the invention provides a low-voltage high-power electric energy quality treatment device, provides 7 compensation modes, and has the functions of comprehensively treating harmonic, reactive and three-phase imbalance problems such as automatic load detection, automatic compensation mode selection and the like. Meanwhile, the high cost performance of the system is realized through reasonable distribution of the device capacity.
Fig. 1 is a schematic structural diagram of a low-voltage modular high-power quality comprehensive treatment device provided by an embodiment of the invention. As shown in fig. 1, the power quality comprehensive treatment device comprises a detection unit, a control unit, a driving unit and an inversion unit.
1. And the detection unit is used for detecting the current of the system, specifically collecting the current of a compensation object (namely a load) and transmitting the current to the control unit.
The current detection method adopts a p-q operation mode based on an instantaneous reactive power theory, and a C matrix formed by sine and cosine signals with the same phase of the grid voltage participates in operation, so that the influence caused by the voltage waveform distortion of the grid is eliminated.
And calculating according to an instantaneous reactive power theory to obtain p-q, and obtaining a corresponding direct current component after passing through a Low Pass Filter (LPF). The fundamental current component is subtracted from the load current to obtain the harmonic current component of the load (including the negative sequence current when the negative sequence current exists in the load current). When the reactive current of the load needs to be detected, the q channel in fig. 4 is only needed to be disconnected.
Load current is accessed to a load current detection interface of the device through a secondary line of an external mutual inductor, is adjusted into a voltage signal through three current Hall devices with the current of 5A:2.5mA, and is sent to an AD unit of an ARM chip for processing through a TL064B operational amplifier.
2. The control unit is used for processing the detection result of the detection unit, namely analyzing and processing the acquired system current; carrying out a series of processing such as harmonic extraction, reactive current extraction, load current imbalance calculation and the like on the signals acquired by the detection unit, and solving the proportion of the three; analyzing and comparing the proportion conditions of harmonic wave, reactive power and unbalance in the system, finding out the main power quality problem in the system current, comparing the content of the main power quality problem with the capacity of the device, and selecting a compensation mode;
the control unit comprises an ARM, an FPGA and a peripheral circuit, and a software program is used for carrying out a series of analyses such as harmonic separation, reactive power extraction and unbalanced current calculation on signals acquired by the detection unit.
The harmonic extraction method of the load current is discrete Fourier transform, a real part and an imaginary part are respectively calculated and subjected to PI control; the reactive current extraction method is to carry out d-q decomposition on the load current, carry out subtraction on the reactive component and carry out PI control on the reactive component; the load current imbalance calculation adopts a symmetric component method to decompose negative sequence and zero sequence components for PI control.
3. The driving unit is used for generating a PWM signal according to the compensation mode to drive the IGBT inversion unit to complete the compensation function; the driving unit comprises a driving signal modulation part and a driving signal amplification part, the control unit gives an original driving signal by the control chip, and the original driving signal enters a driving signal amplification link after being modulated by the operational amplifier chip, and the link consists of an amplification power supply and a driving protection part. The amplifying power supply generates the gate drive voltage of the IGBT through the MOSFET and a custom made self-oscillating transformer. The drive protection is mainly provided by an ACPL-331J gate drive optocoupler.
According to different compensation modes, a modulation wave generates a pulse signal through double-carrier comparison modulation, the pulse signal is controlled by using a carrier overlapping PWM method, when carrier SPWM is used for regulation and control in a three-level inverter, offset in the vertical direction is added to two carriers to enable the two carriers to be overlapped, and the modulation strategy simultaneously considers carrier phase and offset. All devices participate in the work under any modulation system, and the utilization rate of the switching device can be optimized. The method keeps the same effect with the traditional harmonic elimination PWM method in the harmonic characteristic in a high modulation range, and has good harmonic characteristic under low modulation.
4. And the inversion unit mainly comprises a diode-clamped three-level IGBT inversion circuit and is used for generating device current, realizing a compensation function under the action of a driving signal and finishing the functions of compensating harmonic waves, idle work, unbalance and the like.
Fig. 2 is a topological structure of the power quality comprehensive treatment device, and as shown in fig. 2, the power quality comprehensive treatment device adopts an IGBT inverter circuit, wherein an IGBT module has a compensation capacity of 150A. If the compensation current required by the system is large, the capacity expansion of the device can be realized by connecting the comprehensive control device for the power quality in parallel, the parallel capacity expansion mode is simple and reliable, each device is independent, and A, B, C, N four main wiring terminals (namely 380V low-voltage power grid wiring terminals) are connected in parallel; the load current sampling lines are connected in series; the signals of starting, stopping, fault and emergency stop are connected in parallel, and the parallel capacity expansion of the device can be completed. .
The inversion unit mainly comprises a power conversion circuit, a direct current capacitor and an output filter.
The current output by the device is generated by the action of the voltage difference value of the direct-current side capacitor voltage and the three-phase power grid voltage on the reactor, the device needs to keep the sum of the direct-current side capacitor voltage unchanged, and the power exchange with a power grid system is realized by adjusting the modulation ratio. The direct-voltage side capacitor adopts a series structure of an upper capacitor and a lower capacitor, and in order to ensure the balance of the midpoint voltage, the voltage of the direct-current bus needs to be balanced and controlled through a voltage outer ring.
The power conversion circuit consists of three bridge arms, wherein a single-phase bridge arm is formed by connecting four IGBT switching tubes and freewheeling diodes thereof in series, and the middle two IGBTs are connected with two clamping diodes in parallel to realize a three-level midpoint clamping function. The output filter adopts an LCL structure and consists of a filter inductor, a filter capacitor and a connecting inductor, the filter has ideal suppression effect on high-frequency harmonic waves, and can effectively suppress high-frequency components generated in the switch modulation process.
The system includes a grid and a load.
The compensation mode of the inversion unit comprises 7 modes, namely compensation mode 1-compensation harmonic; compensation mode 2-compensation reactive; compensation mode 3-compensate for imbalance; compensation mode 4-compensation of harmonics and reactive power, harmonics first; compensation mode 5-compensation of harmonic and reactive, reactive first; compensation mode 6-compensation of harmonic reactive and unbalanced; compensation mode 7-load mode. The compensation mode selection user designates the highest priority, the mode is output after the user sets the mode, if the compensation mode selection setting is the intelligent compensation mode, the control unit analyzes and compares the proportion of harmonic waves, reactive power and unbalance in the system current and the absolute value, and then the control unit automatically selects the compensation mode according to the comparison result.
Compensation mode 1: the device only carries out harmonic compensation and carries out harmonic extraction on the load current, the extraction method is discrete Fourier transform, a real part and an imaginary part are respectively calculated and subjected to PI control, and finally the load harmonic current ih is calculated and transmitted to the FPGA.
Compensation mode 2: the device only carries out reactive compensation, carries out dq decomposition on load current and device output current respectively, carries out difference on reactive components, carries out PI control on the reactive components, and finally calculates a reactive instruction iqr and transmits the reactive instruction iqr to the FPGA.
Compensation mode 3: the device carries out unbalance compensation, the unbalance has a negative sequence and a zero sequence, the load current and the device output current are respectively decomposed, the negative sequence real part, the negative sequence imaginary part, the zero sequence real part and the zero sequence imaginary part are respectively subjected to difference with negative sequence real part feedback, negative sequence imaginary part feedback, zero sequence real part feedback and zero sequence imaginary part feedback, PI control is carried out on the negative sequence real part feedback, negative sequence imaginary part instruction, zero sequence real part instruction and zero sequence imaginary part instruction are finally calculated, and the negative sequence real part instruction, the negative sequence imaginary part instruction, the zero sequence real part instruction and.
Compensation mode 4: in this control mode, the device compensates for both harmonics and reactive power, but preferentially compensates for harmonics, and the calculations performed at this time include compensation mode 1 and compensation mode 2 as described above.
Compensation mode 5: in this control mode, the device compensates for both harmonics and reactive power, but preferentially compensates for reactive power, and the calculations performed at this time include compensation mode 1 and compensation mode 2 described above.
Compensation mode 6: in this control mode, the device compensates for harmonics, reactive and unbalance simultaneously, and the calculations done at this time are compensation mode 1, compensation mode 2 and compensation mode 4 as described above.
Compensation mode 7: under the control mode, harmonic current, reactive current, a negative sequence current real part, a negative sequence current imaginary part, a zero sequence current real part and a zero sequence current imaginary part extracted from the load current in the calculation are respectively replaced by given values, and the given values are given by a special debugging background of the device and are used for self-testing of the device or serving as load sources for other equipment, namely n times of harmonic compensation, given reactive current reference, negative sequence current real part reference, negative sequence current imaginary part reference, zero sequence current real part reference and zero sequence current imaginary part reference.
The flowchart during the specific compensation is shown in fig. 3, and the steps include:
step 1: from the current obtained by the detection unit, harmonic waves are separated by using a DFT method, the reactive power of the system is calculated by using D-Q conversion, and unbalanced current is calculated by using a symmetrical component method;
step 2: the control unit calculates the proportion of harmonic current, reactive current and unbalanced current, and compares the proportion; the proportion refers to the ratio of the effective values of the three currents in the load current;
and step 3: determining a main power quality problem in the compensation object according to the result of the step 2, selecting a compensation mode according to the result of the main power quality problem, and entering the following different steps;
and 4, step 4: when the harmonic waves are the main power quality problem, comparing the harmonic wave quantity with the device capacity, if the harmonic wave quantity is larger than the device capacity, automatically selecting a compensation mode 1, and automatically limiting the output at 100% rated capacity to prevent the device from overloading; if the harmonic amount is less than or equal to the device capacity, judging whether the reactive power is greater than the allowance obtained by subtracting the compensation harmonic amount from the device capacity, if so, selecting a compensation mode 4, otherwise, selecting a compensation mode 7; entering step 7;
and 5: when the reactive power of the system is a main power quality problem, comparing the reactive power of the system with the capacity of the device, if the reactive power is greater than the capacity of the device, automatically selecting a compensation mode 2, and automatically limiting the output at 100% rated capacity to prevent the device from overloading; if the system reactive power is less than or equal to the device capacity, judging whether the harmonic quantity is greater than the allowance obtained by subtracting the compensation reactive power from the device capacity, if so, selecting a compensation mode 5, otherwise, selecting a compensation mode 7; entering step 7;
step 6: when unbalance is the main power quality problem, comparing the unbalance amount with the device capacity, if the unbalance amount is larger than the device capacity, automatically selecting a compensation mode 3, and automatically limiting the output at 100% rated capacity to prevent the device from overloading; if the unbalance is less than or equal to the device capacity, judging whether the reactive power is greater than the allowance obtained by subtracting the unbalance from the device capacity, if so, selecting a compensation mode 4, otherwise, selecting a compensation mode 7; entering step 7;
and 7: according to the compensation mode, generating instruction current, generating PWM signals through a carrier overlapping modulation mode, driving an IGBT inversion unit to work, and realizing a corresponding compensation function.
In actual use, the required compensation capacity is determined, the number of the electric energy quality comprehensive treatment devices is determined, and then the selection of the compensation mode and the realization of the compensation function are carried out according to the compensation process.
The invention can realize the comprehensive treatment of the power quality, can automatically select the compensation mode according to the system condition, can realize the maximum compensation function with low cost and high cost performance on the premise of meeting the capacity, and effectively improves the power utilization reliability; the low cost and high cost performance are mainly embodied as follows: compared with common 100 ampere products in domestic markets, the device has the advantages that the volume is increased by 10%, the capacity is increased by 50%, the capacity of a single module is greatly increased, meanwhile, the capacity of a standard power distribution cabinet is increased to 500Kvar (the amplification is 33%), the capacity of the device is increased by 50%, the cost is increased by 15%, the unit cost is remarkably reduced, and the power density is remarkably improved; the realized compensation function is mainly embodied in that: compared with the existing products which mainly use 1 to 2 compensation modes in China, the device has 7 compensation modes, is a comprehensive power quality compensation device, has strong compensation function, and can effectively improve the power utilization reliability.
The low-voltage modular high-power electric energy management device and the compensation method thereof provided by the embodiment of the application are introduced in detail. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.
It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.
It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.
The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.
Claims (10)
1. A low-voltage modular high-power electric energy management device is characterized by comprising:
the detection unit is used for collecting the current of the compensation object and transmitting the current to the control unit;
the control unit is used for analyzing and processing the acquired current and selecting a compensation mode; the method specifically comprises the following steps: respectively carrying out harmonic extraction, reactive current extraction and load current imbalance calculation on the collected current, analyzing the proportion of the current to the load, finding out a main power quality problem according to an analysis result, and selecting a corresponding compensation mode according to the main power quality problem;
the driving unit is used for generating corresponding driving signals according to the compensation mode selected by the control unit so as to drive the inversion unit to complete the compensation function;
and the inversion unit is used for generating compensation current and realizing the compensation function under the action of the driving signal.
2. The low-voltage modular high-power electric energy management device according to claim 1, wherein when the detection unit collects the current: the method is characterized in that a p-q operation mode based on an instantaneous reactive power theory is adopted for collection, and a C matrix formed by sine and cosine signals in the same phase with the voltage of the power grid is used for operation, so that the influence caused by voltage waveform distortion of the power grid is eliminated.
3. The low-voltage modular high-power electric energy management device according to claim 1, wherein the control unit comprises an ARM, an FPGA and a peripheral circuit, and a software program is used for performing harmonic extraction, reactive current extraction and load current imbalance calculation on the current collected by the detection unit and analyzing the ratio of the current to the current.
4. The low-voltage modular high-power electric energy management device according to claim 1, wherein the driving unit performs double-carrier comparative modulation on the modulation wave according to different compensation modes to generate a pulse signal, and the control is performed by using a carrier-overlapping PWM method.
5. The low-voltage modular high-power electric energy management device according to claim 1, wherein the inverter unit comprises a direct-current side capacitor, a power conversion circuit and an output filter which are connected in sequence;
the direct-voltage side capacitor adopts a structure that an upper capacitor and a lower capacitor are connected in series;
the power conversion circuit comprises three bridge arms, each bridge arm comprises four IGBT (insulated gate bipolar transistor) switching tubes, four freewheeling diodes and two clamping diodes, and the freewheeling diodes are connected with the corresponding IGBT switching tubes in series; the two clamping diodes are connected in parallel with the middle two IGBT switch tubes in the four IGBT switch tubes;
the output filter adopts an LCL structure.
6. A method of current compensation using a low voltage modular high power electrical energy management device according to any one of claims 1 to 5, the method comprising the steps of:
s1, collecting the current of the object to be compensated;
s2, separating harmonic current in the current by using a DFT method, calculating reactive current by using D-Q conversion, and calculating unbalanced current by using a symmetrical component method;
s3, calculating the proportion of harmonic current, reactive current and unbalanced current, and comparing the proportion;
s4, determining the main power quality problem in the compensation object according to the comparison result in the S3;
s5, selecting a compensation mode according to the main power quality problem;
and S6, generating a command current according to the selected compensation mode, generating a PWM signal through a carrier overlapping modulation mode, and driving an inverter unit to work to realize a corresponding compensation function.
7. The method for compensating current of the low-voltage modular high-power electric energy management device according to claim 6, wherein the step S5 comprises:
s51, comparing the harmonic quantity with the device capacity when the harmonic is the main power quality problem;
if the harmonic amount is larger than the device capacity, selecting a compensation mode 1 and entering S6;
if the harmonic quantity is less than or equal to the device capacity, judging whether the reactive power quantity is greater than the allowance obtained by subtracting the harmonic quantity to be compensated from the device capacity; if yes, selecting a compensation mode 4, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
s52, comparing the reactive power with the device capacity when the reactive power is the main power quality problem;
if the reactive power is larger than the device capacity, selecting a compensation mode 2, and entering S6;
if the reactive power is less than or equal to the device capacity, judging whether the harmonic quantity is greater than the device capacity minus the margin of the reactive power to be compensated; if yes, selecting a compensation mode 5, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
s53, comparing the unbalance amount with the device capacity when the unbalance is the main power quality problem;
if the unbalance amount is larger than the device capacity, selecting a compensation mode 3 and entering S6;
if the unbalance is less than or equal to the device capacity, judging whether the reactive power is greater than the device capacity minus the allowance of the unbalance to be compensated; if yes, selecting a compensation mode 4, and entering S6; otherwise, selecting the compensation mode 7 and entering S6;
S51-S53 have no sequence requirement.
8. The method for current compensation of low-voltage modular high-power electric energy management device according to claim 7, wherein the compensation mode 1 compensates only harmonic waves; the compensation mode 2 only compensates reactive power; compensation mode 3 compensates for imbalance only; the compensation mode 4 compensates harmonic waves and reactive power, and the harmonic waves have priority; the compensation mode 5 compensates harmonic waves and reactive power, and the reactive power has priority; the compensation mode 6 compensates for harmonic, reactive and unbalanced; the compensation mode 7 is a load mode.
9. The method for current compensation of a low voltage modular high power energy management device of claim 8, wherein when the compensation mode 1, the compensation mode 2 or the compensation mode 3 is selected, the capacity output is limited to 100% of the rated capacity output for preventing overload of the device.
10. The method for compensating current of the low-voltage modular high-power electric energy management device according to claim 8, wherein the load mode is specifically as follows: and respectively replacing harmonic current, reactive current, a real part of negative sequence current, an imaginary part of negative sequence current, a real part of zero sequence current and/or an imaginary part of zero sequence current extracted from the collected current with given values.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910904607.5A CN110676851B (en) | 2019-09-24 | 2019-09-24 | Low-voltage modular high-power electric energy management device and compensation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910904607.5A CN110676851B (en) | 2019-09-24 | 2019-09-24 | Low-voltage modular high-power electric energy management device and compensation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110676851A true CN110676851A (en) | 2020-01-10 |
| CN110676851B CN110676851B (en) | 2020-12-04 |
Family
ID=69078613
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910904607.5A Active CN110676851B (en) | 2019-09-24 | 2019-09-24 | Low-voltage modular high-power electric energy management device and compensation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110676851B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112366723A (en) * | 2020-11-10 | 2021-02-12 | 许继电源有限公司 | Electric energy quality comprehensive treatment device and method thereof |
| CN113346525A (en) * | 2021-04-25 | 2021-09-03 | 西安交通大学 | Power quality control cluster system at tail end of power distribution network and power quality control method |
| CN115000975A (en) * | 2022-08-04 | 2022-09-02 | 杭州得诚电力科技股份有限公司 | Reactive compensation method of power distribution system and power distribution system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2821993Y (en) * | 2005-08-02 | 2006-09-27 | 西安赛博电气有限责任公司 | Active power filter for multiple circuit structure and control method |
| CN105490274A (en) * | 2015-12-28 | 2016-04-13 | 国网山东省电力公司青岛供电公司 | Electric power quality control system and method for metro power supply system |
| US20160329709A1 (en) * | 2015-05-07 | 2016-11-10 | Industry-Academic Cooperaiton Foundation, Yonsei University | Inverter-based stand-alone microgrid control system using pmu |
| US10003195B1 (en) * | 2017-02-06 | 2018-06-19 | University Of Macau | Hybrid STATCOM with wide compensation range and low DC-link voltage |
| CN108306540A (en) * | 2018-02-08 | 2018-07-20 | 武汉理工大学 | A kind of control method of the dead beat repeated controlling system of gird-connected inverter |
| CN108599165A (en) * | 2018-05-16 | 2018-09-28 | 哈尔滨理工大学 | Three level active filters, its application system and method based on Compound Control Strategy |
| CN110048432A (en) * | 2019-04-03 | 2019-07-23 | 杭州电子科技大学 | Multifunctional electric energy quality control apparatus and control method based on three-level current transformer |
-
2019
- 2019-09-24 CN CN201910904607.5A patent/CN110676851B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2821993Y (en) * | 2005-08-02 | 2006-09-27 | 西安赛博电气有限责任公司 | Active power filter for multiple circuit structure and control method |
| US20160329709A1 (en) * | 2015-05-07 | 2016-11-10 | Industry-Academic Cooperaiton Foundation, Yonsei University | Inverter-based stand-alone microgrid control system using pmu |
| CN105490274A (en) * | 2015-12-28 | 2016-04-13 | 国网山东省电力公司青岛供电公司 | Electric power quality control system and method for metro power supply system |
| US10003195B1 (en) * | 2017-02-06 | 2018-06-19 | University Of Macau | Hybrid STATCOM with wide compensation range and low DC-link voltage |
| CN108306540A (en) * | 2018-02-08 | 2018-07-20 | 武汉理工大学 | A kind of control method of the dead beat repeated controlling system of gird-connected inverter |
| CN108599165A (en) * | 2018-05-16 | 2018-09-28 | 哈尔滨理工大学 | Three level active filters, its application system and method based on Compound Control Strategy |
| CN110048432A (en) * | 2019-04-03 | 2019-07-23 | 杭州电子科技大学 | Multifunctional electric energy quality control apparatus and control method based on three-level current transformer |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112366723A (en) * | 2020-11-10 | 2021-02-12 | 许继电源有限公司 | Electric energy quality comprehensive treatment device and method thereof |
| CN112366723B (en) * | 2020-11-10 | 2023-03-14 | 许继电源有限公司 | Electric energy quality comprehensive treatment device and method thereof |
| CN113346525A (en) * | 2021-04-25 | 2021-09-03 | 西安交通大学 | Power quality control cluster system at tail end of power distribution network and power quality control method |
| CN115000975A (en) * | 2022-08-04 | 2022-09-02 | 杭州得诚电力科技股份有限公司 | Reactive compensation method of power distribution system and power distribution system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110676851B (en) | 2020-12-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110676851B (en) | Low-voltage modular high-power electric energy management device and compensation method thereof | |
| US10476261B2 (en) | Method and system for fault positioning and recovery of voltage source converter | |
| CN103475004B (en) | Suppress static reacance generator SVG and the control method of unbalanced load | |
| CN104362651A (en) | Three-phase imbalance downward cascade type H-bridge static synchronous reactive compensation device and compensation method | |
| CN111030152A (en) | Energy storage converter system and control method thereof | |
| CN110943469B (en) | Single-stage energy storage converter and control method thereof | |
| CN101534011A (en) | Control method for distribution network active filtering quiescent reactive compensation | |
| CN111740454A (en) | Hybrid microgrid alternating current-direct current voltage unified control method based on bus interface converter | |
| CN108767901A (en) | A kind of three-phase grid-connected inverter anti-backflow device and control method | |
| CN204258316U (en) | Cascade H bridge Static Synchronous reactive-load compensator under three-phase imbalance | |
| CN103259281A (en) | Energy conversion system and method with negative-sequence current compensation mechanism | |
| CN113098076B (en) | Control device and control method of alternating current-direct current power supply system and alternating current-direct current power supply system | |
| LU102204B1 (en) | Dc capacitor voltage balancing control method under single-phase grid fault | |
| CN111398685B (en) | Impedance measurement type island detection method suitable for annular flexible direct current power distribution network | |
| Rahman et al. | Transient stability analysis of grid connected fuel cell system | |
| CN107026475A (en) | A kind of distributed solar electricity generation system enters network control method | |
| CN203057066U (en) | Feedforward compensation energy-saving control converter | |
| CN107888090B (en) | Mixed three-phase rectifier with non-three-phase bridge arm symmetrical structure | |
| CN110912130A (en) | Circuit structure of double-alternating-current bus grid-connected converter and harmonic compensation method thereof | |
| CN215267652U (en) | Negative sequence and harmonic current detection and compensation device of traction substation | |
| Jamallo et al. | Sensorless virtual-flux direct power control of grid connected converters under unbalanced weak grid conditions | |
| CN114717604B (en) | Bipolar water electrolysis hydrogen production device and control method thereof | |
| Liao et al. | Small-signal Stability Analysis of Three-phase Four-wire system Integrated with Single-phase PV Inverters Considering Phase to Phase Coupling | |
| Behrouzian et al. | A novel capacitor-voltage balancing strategy for double-Y STATCOM under unbalanced operations | |
| Torán et al. | Comparative Analysis of B4 and B6 Inverter Topologies for Grid-Connected Operation |
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 |