AU2021105482A4 - A system and method for constant switching frequency control for converter - Google Patents

A system and method for constant switching frequency control for converter Download PDF

Info

Publication number
AU2021105482A4
AU2021105482A4 AU2021105482A AU2021105482A AU2021105482A4 AU 2021105482 A4 AU2021105482 A4 AU 2021105482A4 AU 2021105482 A AU2021105482 A AU 2021105482A AU 2021105482 A AU2021105482 A AU 2021105482A AU 2021105482 A4 AU2021105482 A4 AU 2021105482A4
Authority
AU
Australia
Prior art keywords
voltage source
current
source converter
current error
switching frequency
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.)
Ceased
Application number
AU2021105482A
Inventor
S. Gawande
Bhagyashree Mudaliar
Gopal Krishnan
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.)
Yeshwantrao Chavan College of Engineering
Datta Meghe Institute of Medical Sciences
Sharad Pawar Dental College
Original Assignee
Yeshwantrao Chavan College of Engineering
Datta Meghe Institute of Medical Sciences
Sharad Pawar Dental College
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 Yeshwantrao Chavan College of Engineering, Datta Meghe Institute of Medical Sciences, Sharad Pawar Dental College filed Critical Yeshwantrao Chavan College of Engineering
Priority to AU2021105482A priority Critical patent/AU2021105482A4/en
Application granted granted Critical
Publication of AU2021105482A4 publication Critical patent/AU2021105482A4/en
Ceased legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0025—Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
    • 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
    • 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
    • H02M7/493—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 the static converters being arranged for operation in parallel
    • 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
    • H02M7/539—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 with automatic control of output wave form or frequency
    • H02M7/5395—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 with automatic control of output wave form or frequency by pulse-width modulation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/687—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices the devices being field-effect transistors
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
    • H03K19/02—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components
    • H03K19/173—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits using specified components using elementary logic circuits as components
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H02M1/0009—Devices or circuits for detecting current in a converter

Abstract

A SYSTEM AND METHOD FOR CONSTANT SWITCHING FREQUENCY CONTROL FOR CONVERTER The present disclosure relates to a system for constant switching frequency control for a voltage source converter. The system includes a comparator configured to receive a reference current and a load current, wherein the load current is received from a load associated with the voltage source converter. A processing unit operatively configured with the comparator, and configured to receive an output of the comparator. The processing unit comprising a memory for storing instructions which on execution causes the processing unit to track, using the comparator output, the reference current error by the load current. Further, current error derivative is computed from the current error. A region of operation of a voltage source converter is detected using the processing unit. The current error derivative is located, in the region of operation of the voltage source converter to minimize the current error for achieving constant switching frequency of the voltage source converter. 1/6 100 LOAD CURRENT REFERENE RATORPROCESS1ING VOLTAGE LA REFERNCE OMPAATORUNIT 4--0 CONVERTER M LA CURRENT 1E 2 z0a Figure 1 SYSTEM I0D MEMORY INTERFACE( PROCESSING ENGINES) ERRoRTRACiNG ENGINE OPERATINGEGINE 212 214 LOCATING ENGINE OTHER ENGINE(S) TABASE Figure

Description

1/6
100
LOAD CURRENT
REFERENE RATORPROCESS1ING VOLTAGE LA REFERNCE OMPAATORUNIT 4--0 CONVERTER M LA CURRENT 1E 2 z0a
Figure 1
SYSTEM I0D
MEMORY INTERFACE( PROCESSING ENGINES)
ERRoRTRACiNG ENGINE OPERATINGEGINE
212 214
LOCATING ENGINE OTHER ENGINE(S) TABASE
Figure
A SYSTEM AND METHOD FOR CONSTANT SWITCHING FREQUENCY CONTROL FOR CONVERTER
Technical field of invention:
The present disclosure relates to the field of voltage source converter. More particularly the present disclosure relates to a system and method for constant switching frequency control for the voltage source converter/Inverter.
Background of the present invention
Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
The technique for providing constant switching frequency may be used in different types of electronic devices including voltage source inverter, current source inverter, voltage source converters, and current source converters. When these inverters/converters are realized using semiconductor switches such as Metal Oxide Semiconductor Field Effect Transistor (MOSFET), Insulated Gate Bipolar Transistor (IGBT), etc possessing high switching frequency and switched using Pulse Width Modulation (PWM) or current control method, there are chances to operate these converters with variable switching frequency. When inverter/converter switching frequency is not constant, it may leads to uneven high stresses on inverter switches and also increases switching losses, which subject to develop high temperature. This further increases the rating of heat sinks, cost and circuit complexity.
Amongst different inverter/converters, voltage source inverter (VSI) is an electronics device which converts direct current (DC) into an alternating current (AC) with fixed fundamental frequency. Voltage source inverter can be used in several applications such as transmission system in the form of Flexible AC Transmission Systems (FACTS) devices like Static compensator (STATCOM), Static Synchronous Series Compensator (SSSC), unified power Flow Controller (UPFC), Interline Power Flow Controller (IPFC). VSI may be used in distribution system in the form of custom power devices like Distribution STATCOM, Dynamic Voltage Restorer (DVR), Unified Power Quality Conditioner (UPQC). Further, VSI may be used in Adjustable Speed Drives (ASDs) to control motor parameters, can be used in electric vehicles, wireless power transfer (WPT) systems and can have a major application in smart grid using device such as Electric Spring (ES) used for regulating the voltage across the critical loads.
To reduce the stress on semiconductor switches, to get reduce switching frequency and to achieve the constant switching frequency of voltage source inverter (VSI), several methods have been used. All these alternatives have made to minimize the drawbacks arises due to variable switching frequency. The ramp comparison used in carrier-based control, variable hysteresis band allows to continuously vary the hysteresis band on instant to instant basis to track the current error, phase locked loop (PLL) is used with LP filter, an optimal voltage vector based hysteresis current control, predictive current control, space vector modulation (SVM) etc. provides an attempt to achieve constant switching frequency of inverter. Amongst all, the space vector modulation is proposed to be one of the most popular PWM method and hysteresis as most beneficial and preferred current control method (HCC) due to its easy implementation, peak current limiting capability, fast dynamic response and independency on load parameters.
Therefore, there is a need of a method or system for constant switching frequency control for voltage source converter, which have advantages of both the SVM technique and the HCC.
Objective of the invention:
Some of the objects of the present disclosure, which at least one embodiment herein satisfies are as listed herein below.
It is an object of the present disclosure to provide a method for constant switching frequency control for voltage source converter.
It is an object of the present disclosure to provide a method for constant switching frequency control for voltage source converter that combines space vector modulation (SVM) and hysteresis current control (HCC).
It is an object of the present disclosure to provide a method for constant switching frequency control for voltage source converter that eliminates the limitations of the conventional hysteresis control with simultaneously retaining all the benefits of hysteresis control and space vector modulation.
It is an object of the present disclosure to provide a method for constant switching frequency control for voltage source converter able to track the reference currents with negligible response time.
Summary of the invention
The present disclosure relates to the field of voltage source converter. More particularly the present disclosure relates to a system and method for constant switching frequency control for the voltage source converter/Inverter.
An aspect of the present disclosure pertains to a system for constant switching frequency control for a voltage source converter. The system includes a comparator configured to receive a reference current and a load current, wherein the load current is received from a load associated with the voltage source converter. A processing unit operatively configured with the comparator, and configured to receive an output of the comparator. The processing unit comprising a memory for storing instructions which on execution causes the processing unit to track, using the comparator output, the reference current error by the load current. Compute a current error derivative from the current error, detect a region of operation of a voltage source converter. Locate, the current error derivative, in the region of operation of the voltage source converter to minimise the current error for achieving constant switching frequency of the voltage source converter.
In an aspect, the current error may be calculated by adding and subtracting the output of the comparator to a first hysteresis value, and a second hysteresis value. The first hysteresis value and the second hysteresis value may be hysteresis bands. The first hysteresis band may be lower than the second hysteresis band.
In an aspect, the first hysteresis band and the second hysteresis band may include a first hysteresis comparator and a second hysteresis comparator, respectively. In an aspect, the location of the current error derivative to the region of operation takes place when the current error is in the second hysteresis band. In an aspect, the region of operation of the voltage source converter may be detected on the basis of any or combination of a voltage converter output, and output of the first hysteresis comparator and the second hysteresis comparator.
In an aspect, the location of the current error in the region of operation of the load output may include changing a switching logic, on the basis of the current error and region of operation of the voltage source converter. In an aspect, the switching logic may include a sequence for operating a plurality of switches of the voltage source converter. In an aspect, the region of operation of the voltage converter may be detected by using space vector modulation technique.
In an aspect, the first hysteresis value tracks the current error in a specific band, and the second hysteresis value performs detection of the region of operation. In another aspect, the present disclosure pertains to a method for constant switching frequency control for a voltage source converter. The method includes detecting, by a processor, a current error in a load current based on a comparison between the load current and a reference current. The load current is received from a load associated with the voltage source converter. Computing, by the processor, a current error derivative from the current error. Detecting, by the processor, a region of operation of the voltage source converter. Locating, by the processor, the current error derivative in the region of operation of the voltage source converter to minimize the current error for achieving constant switching frequency of the voltage converter. Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.
Brief description of the drawings
The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure. The diagrams are for illustration only, which thus is not a limitation of the present disclosure.
In the figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label with a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.
FIG. 1 illustrates an exemplary block diagram of the system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure. FIG. 2 illustrates an exemplary module diagram for system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure. FIG. 3 illustrates detailed control circuit for system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure. FIG. 4A illustrates exemplary voltage space vector, and FIG. 4B illustrates derivative of space vector, in accordance with an embodiment of the present disclosure. FIG. 5 illustrates exemplary waveform representing switching pulses of the voltage source inverter, in accordance with an embodiment of the present disclosure. FIG. 6 illustrates exemplary equivalent circuit diagram of voltage source inverter with filter and load, in accordance with an embodiment of the present disclosure. FIG. 7 illustrates a method for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure.
Detailed description of invention
The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without some of these specific details.
The present disclosure relates to the field of voltage source converter. More particularly the present disclosure relates to a system and method for constant switching frequency control for the voltage source converter/Inverter.
[0036] FIG. 1 illustrates an exemplary block diagram of the system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure.
As illustrated, the system 100 can include a comparator 102 that can be configured to receive a reference current and a load current. The comparator can 102 include but not limited to a operational amplifier. The load current can be received from a load 108 that can be associated with the voltage source converter 106. A processing unit 104 can be operatively configured with the comparator 102, and can be configured to receive an output of the comparator 102. The output of the comparator 102 can represent a different between the reference current and the load current, and the output of the comparator 102 can also be referred as current error.
In an embodiment, the processing unit 104 can comprising a memory for storing instructions which on execution causes the processing unit to track the reference current error by the load current on the basis of the current error. Compute a current error derivative from the current error. Detect a region of operation of a voltage source converter 106 (also referred as voltage converter 106, herein). Locate, the current error derivative, in the region of operation of the voltage source converter 106 to minimize the current error for achieving constant switching frequency of the voltage source converter 106.
In an embodiment, the current error can be calculated by adding and subtracting the output of the comparator to a first hysteresis value, and a second hysteresis value. The first hysteresis value and the second hysteresis value can be hysteresis bands or hysteresis current controlled (HCC) bands. The first hysteresis band can be lower than the second hysteresis band. The first hysteresis band and the second hysteresis band can include a first hysteresis comparator and a second hysteresis comparator, respectively. The location of the current error derivative to the region of operation takes place when the current error is in the second hysteresis band only. The region of operation of the voltage source converter 106 can be detected on the basis of any or combination of a voltage source converter 106 output, and output of the first hysteresis comparator and the second hysteresis comparator. The first hysteresis band can track the current error in a specific band, and the second hysteresis band can detect the region of operation of the voltage source converter/inverter.
In an embodiment, the location of the current error in the region of operation of the load output can include changing a switching logic, on the basis of the current error and region of operation of the voltage source converter. The switching logic can be stored in the memory associated with the processing unit in the form of but without limiting to a table. The switching logic can include a sequence for operating a plurality of switches of the voltage source converter 106. A three phase voltage source converter can include two switches for each phase. The region of operation of the voltage source converter 106 can be detected by using space vector modulation technique.
FIG. 2 illustrates an exemplary module diagram for system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure. As illustrated, an exemplary module diagram of the proposed system 100 for constant switching frequency control can include a processing unit 104 that can further include one or more processor(s) 202. The one or more processor(s) 202 can be implemented as one or more microprocessors, microcomputers, microcontrollers, digital signal processors, central processing units, logic circuitries, and/or any devices that manipulate data based on operational instructions. Among other capabilities, the one or more processor(s) 202 are configured to fetch and execute computer-readable instructions stored in a memory 204 associated with the one or more processors 202. The memory 204 can store one or more computer-readable instructions or routines, which may be fetched and executed to create or share the data units over a network service. The memory 204 can include any non-transitory storage device including, for example, volatile memory such as RAM, or non-volatile memory such as EPROM, flash memory, and the like.
The system can also include an interface(s) 206. The interface(s) 206 can comprise a variety of interfaces, for example, interfaces for data input and output devices, referred to as I/O devices, storage devices, battery charging and the like. The interface(s) 206 can facilitate communication of system with the voltage source inverter 106 The interface(s) 206 can also provide a communication pathway for one or more components of the system 100. Examples of such components include, but are not limited to, processing engine(s) 208 and data 210.
The processing engine(s) 208 can be implemented as a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities of the processing engine(s) 208. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing engine(s) 208 can be processor executable instructions stored on a non-transitory machine-readable storage medium and the hardware for the processing engine(s) 208 can comprise a processing resource (for example, one or more processors), to execute such instructions. In the present examples, the machine-readable storage medium can store instructions that, when executed by the processing resource, implement the processing engine(s) 208. In such examples, the simulation test kit 102 can comprise the machine-readable storage medium storing the instructions and the processing resource to execute the instructions, or the machine-readable storage medium may be separate but accessible to the system and the processing resource. In other examples, the processing engine(s) 208 can be implemented by electronic circuitry.
The data 210 can comprise data that is either stored or generated as a result of functionalities implemented by any of the components of the processing engine(s) 208. The present disclosure relates to system for constant switching frequency control for voltage source converter 106. In order perform the above-mentioned verification, the system can include a current error tracking engine 212, which can be used to track the current error. The comparator 102 receives a reference current, and a load current from a load 108 that can be associated with the voltage source converter 106. The output of the comparator can pertain to a different between the reference current and the load current, and can be used to track the current error using the first hysteresis band and the second hysteresis band.
In an embodiment, an operating region detection engine 214 can be included to detect an operating region of the voltage source inverter 106. The proposed system detects the operating region of the voltage source inverter 106 using a spaced vector modulation (SVM) technique. The operating region of the voltage source converter 106 can be detected based on but without limiting to voltage source converter output, and output of the first hysteresis comparator and the second hysteresis comparator.
In an embodiment, a relocation engine 216 can be included to relocate the current error derivative to the detected operating region of the voltage source converter if the tracked current error is in the second hysteresis band. The current error derivative can be computed from the output of the comparator 102. The location of the current error derivative to the detected region of operation is performed to minimise the current error that can eventually facilitates a constant switching frequency for the voltage source converter.
FIG. 3 illustrates detailed control circuit for system for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure.
[0049] As illustrated, the current error derivative which is proposed by a region detector to detect the position of output voltage space vectors (also referred as output of the voltage source inverter, herein). Two hysteresis bands are used one with wider hysteresis band denoted by HAh 330 (also referred as second hysteresis value 330, herein) and the other one with lower hysteresis band HAl 320 (also referred as first hysteresis value 320, herein). The current error obtained from the comparator are fed to both the hysteresis bands. The voltage space vectors are governed according to the operating regions. When the voltage space vector is properly applied in appropriate region, then the current error will remain inside the outer higher hysteresis band. On the contrary, application of incorrect voltage vector shifts the current error out of hysteresis band. The Hah HAh also performs an important function of detection of proper region of the output voltage space vectors. The HAl with lower value of hysteresis band forms the main HCC as it is used to track the current error within the specified band. Based on the logics/output (0 or 1) of the lower and higher hysteresis bands, the region selection can be performed where the appropriate switching combinations of inverter switches are generated to obtain the desired constant switching operation of the inverter. When HAh = 1, HBh = 0 and HCh = 0, it indicates region 1.
In an embodiment, the lower hysteresis bands 320 can be used with narrower band to track the reference currents and limit the current error within the specified band. When the current error of phase -A hits the upper edge of the narrower hysteresis comparator 320 and current error of both phase B and hits the lower band, HAl= 1, HB1= 0 and HC1=0. The voltage vector VI is applied to decrease both phase B and Phase C currents. V2 is applied to increase IA and IB simultaneously when HAl = 1 and HB1 =1. In other cases, the zero vector V is applied. Whenever, outer (higher) hysteresis band 330 hits due to incorrect regions, a proper non-zero zero space vector can be always triggered to reduce the current error magnitude and the correct region can be recorded as per the switching logic table 340. The HCC generates other vectors apart from the space vectors required according to the region in the SVM technique. When the error is generated, the error signal is fed to the space vector modulated HCC control block in order to modify the switching singles. After selection of the switching signals, the switching signals are provided from the table 340 to the voltage source converter 106.
FIG. 4A illustrates exemplary voltage space vector, and FIG. 4B illustrates derivative of space vector, in accordance with an embodiment of the present disclosure.
As illustrated, the FIGs. 4A and 4B illustrates detection of the region of operation of the voltage source converter. If proper voltage space vector is located in region 1, then the current error derivative is also in region 1. The switching frequency gets lowered by using the derivative of the current error. In order to execute the task, a proper voltage space vector can be chosen which gives minimum value of derivative of current error as given in example circuit of FIG. 4B. If the desired ouput space vector Vk* is located in the region 1, then the derivative vectors of current error corresponding to pulse width modulated (PWM) phase voltage Vk will be shown in FIG. 4B. The proper discrete space vectors producing small derivatives values of current error for space vectors Vk* are VI, V2 and VO. The derivative de/dt has a vital role in diminishing the number of switching. Selecting voltage vector Vk which results in minimum value of de/dt is necessary to accomplish reduce and constant switching frequency of inverter. This technique utilises only two vectors beside the zero vector in each region, hence, line current varies with the slow slope and the number of switching can be decreased. Further, the utilisation of non-zero vectors instead of zero voltage vector give sharp slope for current error even in case of large voltage difference.
FIG. 5 illustrates exemplary waveform representing switching pulses of the voltage source inverter, in accordance with an embodiment of the present disclosure.
[0054] As illustrated, the tracking of reference currents within the specified bands as in 500. As in 500 proper region is detected therefore the reference current is within the specified higher band. The switching pulses are given in 510. In 510 there are three states in which zero state represents that there is zero voltage level VO.
FIG. 6 illustrates exemplary equivalent circuit diagram of voltage source inverter with filter and load, in accordance with an embodiment of the present disclosure.
[0056] As illustrated, the equivalent circuit of Electric spring with inverter 620 connected in series with non-critical load forming a smart load 630. The terminal voltage of the inverter module 620 can be described by the following equation:
Where, SA, SB and SC are the switching functions of inverter corresponding to each phase and VDC/2 is the DC voltage across each dc link capacitor. For positive DC voltage + VDC/2, the switch shall be located at terminal 1 and for negative DC value - VDC/2, the switch will be at terminal 0. By applying Kirchhoff's voltage law:
Where VTA, VTB, VTC are the three phase voltages at PCC and IA, IB, IC are the three phase injected currents by Electric Spring (voltage source inverter). From above two equations the system turns to be, The space vectors of currents and the voltages at the PCC can be mentioned as following: For various switching patterns, the inverter output voltage space vectors for six regions are given below: k=1,2,.....6 The six non-zero voltage vectors are shown in Fig.3B yields: The current error can be expressed as:
In order to eliminate the current error I= *, the desired output voltage vector shall be as follows: From above equation we get The above equation indicates the reference current and injected currents are tracked properly by using SVM technique. Only using the error obtained from the final equation will be more complex and tedious. Hence, to simplify and make the control more efficient, the SVM combines with HCC.
FIG. 7 illustrates a method for constant switching frequency control for voltage source converter, in accordance with an embodiment of the present disclosure. As illustrated, at step 702 the present method 700 detecting, by a processor, a current error in a load current based on a comparison between the load current and a reference current. The load current is received from a load associated with the voltage source converter. At step 704, a current error derivative is computed by the processor from the current error. At step 706 a region of operation of the voltage source converter is detected by the processor. At step 708, the current error derivative is located in the region of operation of the voltage source converter by the processor to minimize the current error for achieving constant switching frequency of the voltage converter.
The present disclosure provides a method for proving constant switching frequency. In constant switching frequency, range of output voltage control is large and hence duty cycle can be varied from 0 to 1 (practically from 0.05 to 0.95). Further, in constant switching frequency, the voltage source converter can generate constant and specific harmonics (only magnitude of harmonics may change). This allow to design a simple filter for this harmonics but in variable switching frequency, harmonics spectrum changes with switching frequency which makes design a complex with high order filter
Moreover, in interpreting the specification, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms "comprises" and "comprising" should be interpreted as referring to elements, components, or steps in a non exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ... .and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.
While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
1/6
Figure Figure 1
2/6
Figure 3
3/6
4/6
5/6
6/6
AU2021105482A 2021-08-13 2021-08-13 A system and method for constant switching frequency control for converter Ceased AU2021105482A4 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2021105482A AU2021105482A4 (en) 2021-08-13 2021-08-13 A system and method for constant switching frequency control for converter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
AU2021105482A AU2021105482A4 (en) 2021-08-13 2021-08-13 A system and method for constant switching frequency control for converter

Publications (1)

Publication Number Publication Date
AU2021105482A4 true AU2021105482A4 (en) 2022-01-27

Family

ID=79690036

Family Applications (1)

Application Number Title Priority Date Filing Date
AU2021105482A Ceased AU2021105482A4 (en) 2021-08-13 2021-08-13 A system and method for constant switching frequency control for converter

Country Status (1)

Country Link
AU (1) AU2021105482A4 (en)

Similar Documents

Publication Publication Date Title
KR102612334B1 (en) Multilevel hysteresis voltage controller for voltage modulator and its control method
Nguyen et al. Disturbance-rejection-based model predictive control: Flexible-mode design with a modulator for three-phase inverters
Chen et al. Adaptive sliding-mode voltage control for inverter operating in islanded mode in microgrid
US9590530B2 (en) Controlling a modular converter in two stages
EP3501091B1 (en) Modulation of ac/ac mmc
CN102195554B (en) Control apparatus for electric rotating machine
CN109429541B (en) Inverter control method and device and inverter
US11245334B2 (en) Energy accumulator emulator and method for emulation of an energy accumulator
Monfared et al. High performance direct instantaneous power control of PWM rectifiers
CN107667460B (en) Method, apparatus, control unit and medium for a multilevel power converter
US10110139B1 (en) Matrix converter and method for determining constants of alternating-current motor
US20170207718A1 (en) Power converting device
AU2021105482A4 (en) A system and method for constant switching frequency control for converter
Noguchi et al. Direct power control of PWM converter without power source voltage sensors
GB2545445A (en) Voltage balancing of voltage source converters
Mohamed et al. Three-phase inverter with output LC filter using predictive control for UPS applications
Dasgupta et al. Design and Control of Matrix Converters
Venkateswaran et al. Capacitor voltage based predictive voltage control and fault diagnosis for four-port converter
KR20200079135A (en) Apparatus and method for driving control of power conversion system based on model predictive control
CN113994579A (en) Method for operating a power electronic converter and power electronic converter
Rawa et al. Space‐vector current control of cascaded half‐bridge three‐phase three‐wire voltage source inverter
JP6372642B2 (en) Reactive power control device, reactive power control method, and program
EP3200336B1 (en) Power conversion device
EP4250527A1 (en) Electric power conversion apparatus and estimation apparatus
Fereidouni et al. Adaptive Space-Vector Hysteresis-Based Control with Constant Switching-Frequency for Three-Level Shunt Active Power Filters

Legal Events

Date Code Title Description
FGI Letters patent sealed or granted (innovation patent)
MK22 Patent ceased section 143a(d), or expired - non payment of renewal fee or expiry