CN117895782A - Method for reducing conducted EMI (electromagnetic interference) periodic frequency modulation considering switching loss and time domain diffusion coefficient - Google Patents
Method for reducing conducted EMI (electromagnetic interference) periodic frequency modulation considering switching loss and time domain diffusion coefficient Download PDFInfo
- Publication number
- CN117895782A CN117895782A CN202410099994.0A CN202410099994A CN117895782A CN 117895782 A CN117895782 A CN 117895782A CN 202410099994 A CN202410099994 A CN 202410099994A CN 117895782 A CN117895782 A CN 117895782A
- Authority
- CN
- China
- Prior art keywords
- switching
- switching frequency
- time domain
- function
- expected
- 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
- 238000009792 diffusion process Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 31
- 230000000737 periodic effect Effects 0.000 title claims abstract description 23
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 238000009827 uniform distribution Methods 0.000 claims description 3
- 125000004122 cyclic group Chemical group 0.000 claims 5
- 238000010586 diagram Methods 0.000 description 7
- 230000002596 correlated effect Effects 0.000 description 6
- 238000001228 spectrum Methods 0.000 description 6
- 230000001629 suppression Effects 0.000 description 6
- 230000000875 corresponding effect Effects 0.000 description 3
- 101100233916 Saccharomyces cerevisiae (strain ATCC 204508 / S288c) KAR5 gene Proteins 0.000 description 2
- 101001121408 Homo sapiens L-amino-acid oxidase Proteins 0.000 description 1
- 101000827703 Homo sapiens Polyphosphoinositide phosphatase Proteins 0.000 description 1
- 102100026388 L-amino-acid oxidase Human genes 0.000 description 1
- 102100023591 Polyphosphoinositide phosphatase Human genes 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
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
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
-
- 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
- H02M1/0048—Circuits or arrangements for reducing losses
- H02M1/0054—Transistor switching losses
- H02M1/0058—Transistor switching losses by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero
-
- 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
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Inverter Devices (AREA)
Abstract
一种考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，属于电力电子技术领域。本发明针对电机驱动控制系统中传导EMI的存在影响系统运行的问题。包括：根据SVPWM策略的电压源逆变器中每个开关器件的开关损耗功率与开关频率和电流幅值的正比关系，确定开关频率和电流幅值负相关关系；由三相电流幅值之和的变化趋势得到期望开关频率函数的变化趋势；设置二分之一变化周期对应的开关频率最大值和开关频率最小值；再结合期望开关频率函数在时域的扩散系数计算得到期望开关频率函数的表达式，进行开关器件的开关频率调制。本发明用于实现传导EMI的降低。
A periodic frequency modulation method for reducing conducted EMI by considering switching loss and time domain diffusion coefficient belongs to the field of power electronics technology. The present invention is aimed at the problem that the existence of conducted EMI in a motor drive control system affects the operation of the system. It includes: determining the negative correlation between the switching frequency and the current amplitude according to the proportional relationship between the switching loss power of each switching device in the voltage source inverter of the SVPWM strategy and the switching frequency and the current amplitude; obtaining the change trend of the expected switching frequency function from the change trend of the sum of the three-phase current amplitudes; setting the maximum switching frequency and the minimum switching frequency corresponding to half of the change cycle; and then calculating the expression of the expected switching frequency function in combination with the diffusion coefficient of the expected switching frequency function in the time domain, and performing switching frequency modulation of the switching device. The present invention is used to achieve the reduction of conducted EMI.
Description
技术领域Technical Field
本发明涉及考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，属于电力电子技术领域。The invention relates to a periodic frequency modulation method for reducing conducted EMI by considering switching loss and time domain diffusion coefficient, and belongs to the technical field of power electronics.
背景技术Background technique
近年来随着科学技术的迅猛发展，电力电子器件的性能越来越高，为了提高系统的性能且实现电能的高效利用，逆变器中功率器件的开关频率和开关速度越来越高，由此带来的一些负面影响开始受到学者们的关注，电磁干扰(Electromagnetic Interference,EMI)就是其中一个较为严重的问题。EMI包括共模电磁干扰和差模电磁干扰，会影响电子、电气设备的正常运行，阻碍电子器件向高速化方向发展。In recent years, with the rapid development of science and technology, the performance of power electronic devices has become higher and higher. In order to improve the performance of the system and achieve efficient use of electric energy, the switching frequency and switching speed of power devices in the inverter are getting higher and higher. Some negative effects brought about by this have begun to attract the attention of scholars. Electromagnetic interference (EMI) is one of the more serious problems. EMI includes common-mode electromagnetic interference and differential-mode electromagnetic interference, which will affect the normal operation of electronic and electrical equipment and hinder the development of electronic devices towards high speed.
为降低电机驱动控制系统中传导EMI的影响，有必要对驱动控制系统中EMI进行抑制和削弱；目前常用的抑制方法主要分为从源头上的抑制和从传导路径上的抑制。从源头上的抑制主要包括采用先进的调制策略降低系统的共模电压幅值和频率以此来降低共模EMI或者改变驱动控制系统的逆变器拓扑结构，但这些都增加了软件的处理难度和系统硬件成本。从传导路径上的抑制主要分为设计有源EMI滤波器等措施，但滤波性能取决于有源器件的最大工作带宽，因此抑制效果有限。In order to reduce the impact of conducted EMI in motor drive control systems, it is necessary to suppress and weaken EMI in drive control systems; currently, the commonly used suppression methods are mainly divided into suppression from the source and suppression from the conduction path. Suppression from the source mainly includes adopting advanced modulation strategies to reduce the common-mode voltage amplitude and frequency of the system to reduce common-mode EMI or changing the inverter topology of the drive control system, but these increase the difficulty of software processing and the cost of system hardware. Suppression from the conduction path is mainly divided into measures such as designing active EMI filters, but the filtering performance depends on the maximum operating bandwidth of the active device, so the suppression effect is limited.
发明内容Summary of the invention
针对电机驱动控制系统中传导EMI的存在影响系统运行的问题，本发明提供一种考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法。In view of the problem that the existence of conducted EMI in a motor drive control system affects the operation of the system, the present invention provides a periodic frequency modulation method for reducing conducted EMI by taking switching loss and time domain diffusion coefficient into consideration.
本发明的一种考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，包括，A periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient of the present invention comprises:
根据SVPWM策略的电压源逆变器中每个开关器件的开关损耗功率与开关频率和电流幅值的正比关系，得到使开关损耗功率降低的开关频率和电流幅值成负相关关系；According to the proportional relationship between the switching power loss of each switch device in the voltage source inverter of the SVPWM strategy and the switching frequency and current amplitude, it is obtained that the switching frequency and current amplitude that reduce the switching power loss are in a negative correlation;
根据传统SVPWM策略中电压源逆变器在一个开关周期内三相电流幅值之和的变化趋势，得到与三相电流幅值之和的变化趋势负相关的期望开关频率函数的变化趋势，由期望开关频率函数的变化趋势设置期望开关频率函数的二分之一变化周期对应的开关频率最大值和开关频率最小值；According to the variation trend of the sum of the three-phase current amplitudes of the voltage source inverter in a switching cycle in the traditional SVPWM strategy, the variation trend of the expected switching frequency function negatively correlated with the variation trend of the sum of the three-phase current amplitudes is obtained, and the maximum switching frequency and the minimum switching frequency corresponding to half the variation cycle of the expected switching frequency function are set according to the variation trend of the expected switching frequency function;
同时计算期望开关频率函数在时域的扩散系数，使期望开关频率函数在时域上呈现均匀分布形式；At the same time, the diffusion coefficient of the expected switching frequency function in the time domain is calculated so that the expected switching frequency function presents a uniform distribution in the time domain;
结合开关频率最大值、开关频率最小值和期望开关频率函数在时域的扩散系数，计算得到期望开关频率函数的表达式；Combining the maximum switching frequency, the minimum switching frequency and the diffusion coefficient of the expected switching frequency function in the time domain, the expression of the expected switching frequency function is calculated;
按照所述期望开关频率函数进行开关器件的开关频率调制，实现传导EMI的降低。The switching frequency of the switching device is modulated according to the desired switching frequency function to achieve reduction of conducted EMI.
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，每个开关器件的开关损耗功率与开关频率和电流幅值的关系表达式为：According to the periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient of the present invention, the relationship between the switching loss power of each switching device and the switching frequency and current amplitude is expressed as follows:
式中Ploss表示一个开关周期内每个开关器件的开关损耗功率，Udc表示电压源逆变器的直流供电电压，ton表示开关器件的导通延时时间，toff表示开关器件的关断延时时间，fs0(θ)为电压源逆变器的单相非负开关频率函数，fi0(θ)为电流幅值函数，θ为电流相位角；Where P loss represents the switching loss power of each switching device in a switching cycle, U dc represents the DC supply voltage of the voltage source inverter, t on represents the turn-on delay time of the switching device, t off represents the turn-off delay time of the switching device, f s0 (θ) is the single-phase non-negative switching frequency function of the voltage source inverter, fi0 (θ) is the current amplitude function, and θ is the current phase angle;
由公式(1)，得到使开关损耗功率降低的开关频率和电流幅值成负相关关系。From formula (1), it can be obtained that the switching frequency and current amplitude that reduce the switching power loss are negatively correlated.
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，所述期望开关频率函数的变化趋势呈现在一个开关周期内具有六个变化周期；且在每个变化周期的前二分之一个变化周期中，呈现单调递减趋势，电流相位角θ的最小值对应期望开关频率函数的最大值，电流相位角θ的最大值对应期望开关频率函数的最小值；在每个变化周期的后二分之一个变化周期中，呈现单调递增趋势。According to the periodic frequency modulation method for reducing conducted EMI taking into account switching losses and time domain diffusion coefficients of the present invention, the change trend of the expected switching frequency function presents six change cycles within one switching cycle; and in the first half of each change cycle, it presents a monotonically decreasing trend, the minimum value of the current phase angle θ corresponds to the maximum value of the expected switching frequency function, and the maximum value of the current phase angle θ corresponds to the minimum value of the expected switching frequency function; in the second half of each change cycle, it presents a monotonically increasing trend.
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，期望开关频率函数的最大值为fs(0)，期望开关频率函数的最小值为 According to the periodic frequency modulation method for reducing conducted EMI considering switching loss and time domain diffusion coefficient of the present invention, the maximum value of the expected switching frequency function is fs (0), and the minimum value of the expected switching frequency function is
fs(0)＝fcs， fs (0)＝ fcs ,
式中fs为期望开关频率函数，在第一个二分之一个变化周期中电流相位角θ的最小值为0；fcs为传统开关频率值；Where fs is the expected switching frequency function, and the minimum value of the current phase angle θ in the first half of the change cycle is 0; fcs is the traditional switching frequency value;
在第一个二分之一个变化周期中电流相位角θ的最大值为m为开关频率的扩频深度。The maximum value of the current phase angle θ in the first half of the change cycle is m is the spread spectrum depth of the switching frequency.
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，期望开关频率函数在时域的扩散系数表示为ρ[fs(θ)]：According to the periodic frequency modulation method for reducing conducted EMI considering switching loss and time domain diffusion coefficient of the present invention, the diffusion coefficient of the expected switching frequency function in the time domain is expressed as ρ[f s (θ)]:
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，根据公式(2)和(3)，计算得到期望开关频率函数的表达式fs(θ)的表达式为：According to the periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient of the present invention, according to formulas (2) and (3), the expression of the desired switching frequency function f s (θ) is calculated as follows:
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，将公式(4)中的指数函数取泰勒级数展开的前三项得到：According to the periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient of the present invention, the exponential function in formula (4) is expanded by taking the first three terms of the Taylor series to obtain:
按照公式(5)在数字信号处理器中进行开关器件的开关频率调制，实现传导EMI的降低。According to formula (5), the switching frequency of the switching device is modulated in the digital signal processor to achieve the reduction of conducted EMI.
根据本发明的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，所述电压源逆变器为三相两电平逆变器。According to the periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient of the present invention, the voltage source inverter is a three-phase two-level inverter.
本发明的有益效果：本发明基于开关损耗和时域扩散系数的考虑进行周期频率调制来降低传导EMI，从源头上抑制了传导EMI。Beneficial effects of the present invention: The present invention reduces conducted EMI by performing periodic frequency modulation based on considerations of switching loss and time domain diffusion coefficient, thereby suppressing conducted EMI from the source.
本发明通过在周期频率函数中同时考虑传统三相两电平逆变器的开关损耗问题和时域扩散系数，有效地降低了驱动控制系统传导EMI在高次谐波上的幅值，避免了在特定频点处的EMI尖峰，同时有效降低了逆变器的开关损耗，可提高整个电机驱动控制系统的效率。The present invention effectively reduces the amplitude of the EMI conducted by the drive control system on high-order harmonics by simultaneously considering the switching loss problem and the time domain diffusion coefficient of the traditional three-phase two-level inverter in the periodic frequency function, avoids EMI peaks at specific frequency points, and effectively reduces the switching loss of the inverter, thereby improving the efficiency of the entire motor drive control system.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1是三相两电平逆变器的电路拓扑图；图中Udc表示电压源逆变器的直流供电电压，Cbus为电容，S1至S6为开关管，D1至D6为二极管，A点为逆变器的A相桥臂中点，B点为逆变器的B相桥臂中点，C点为逆变器的C相桥臂中点，接地点为O点，N点为三相负载中点；L为电感，R为电阻，ea为电机A相反电势，eb为电机B相反电势，ec为电机C相反电势；FIG1 is a circuit topology diagram of a three-phase two-level inverter; in the figure, U dc represents the DC supply voltage of the voltage source inverter, C bus is a capacitor, S 1 to S 6 are switch tubes, D 1 to D 6 are diodes, point A is the midpoint of the A-phase bridge arm of the inverter, point B is the midpoint of the B-phase bridge arm of the inverter, point C is the midpoint of the C-phase bridge arm of the inverter, the grounding point is point O, and point N is the midpoint of the three-phase load; L is an inductor, R is a resistor, e a is the reverse potential of motor A, e b is the reverse potential of motor B, and e c is the reverse potential of motor C;
图2是三相电流幅值之和与期望开关频率函数的变化趋势图；图中ia为A相电流，ib为B相电流，ic为C相电流，图中最大值表示电流最大值，总和表示三相电流幅值之和，Figure 2 is a trend diagram of the sum of the three-phase current amplitudes and the desired switching frequency function; in the figure, ia is the A-phase current, ib is the B-phase current, and ic is the C-phase current. The maximum value in the figure represents the maximum current, and the sum represents the sum of the three-phase current amplitudes.
图3是期望开关频率函数依据泰勒级数展开方式拟合的示意图；FIG3 is a schematic diagram of the expected switching frequency function being fitted according to the Taylor series expansion method;
图4是SVPWM策略中采用固定开关频率的输出相电流的频谱图；FIG4 is a spectrum diagram of the output phase current using a fixed switching frequency in the SVPWM strategy;
图5是采用本发明方法的周期频率调制的输出相电流的频谱图。FIG. 5 is a spectrum diagram of the output phase current using the periodic frequency modulation method of the present invention.
具体实施方式Detailed ways
下面将结合本发明实施例中的附图，对本发明实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动的前提下所获得的所有其它实施例，都属于本发明保护的范围。The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
需要说明的是，在不冲突的情况下，本发明中的实施例及实施例中的特征可以相互组合。It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.
下面结合附图和具体实施例对本发明作进一步说明，但不作为本发明的限定。The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.
具体实施方式一、结合图1和图2所示，本发明提供了一种考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制方法，包括，Specific implementation method 1, in conjunction with FIG. 1 and FIG. 2, the present invention provides a periodic frequency modulation method for reducing conducted EMI taking into account switching loss and time domain diffusion coefficient, including:
根据SVPWM策略的电压源逆变器中每个开关器件的开关损耗功率与开关频率和电流幅值的正比关系，得到使开关损耗功率降低的开关频率和电流幅值成负相关关系；According to the proportional relationship between the switching power loss of each switch device in the voltage source inverter of the SVPWM strategy and the switching frequency and current amplitude, it is obtained that the switching frequency and current amplitude that reduce the switching power loss are in a negative correlation;
根据传统SVPWM策略中电压源逆变器在一个开关周期内三相电流幅值之和的变化趋势，得到与三相电流幅值之和的变化趋势负相关的期望开关频率函数的变化趋势，由期望开关频率函数的变化趋势设置期望开关频率函数的二分之一变化周期对应的开关频率最大值和开关频率最小值；According to the variation trend of the sum of the three-phase current amplitudes of the voltage source inverter in a switching cycle in the traditional SVPWM strategy, the variation trend of the expected switching frequency function negatively correlated with the variation trend of the sum of the three-phase current amplitudes is obtained, and the maximum switching frequency and the minimum switching frequency corresponding to half the variation cycle of the expected switching frequency function are set according to the variation trend of the expected switching frequency function;
同时计算期望开关频率函数在时域的扩散系数，使期望开关频率函数在时域上呈现均匀分布形式；At the same time, the diffusion coefficient of the expected switching frequency function in the time domain is calculated so that the expected switching frequency function presents a uniform distribution in the time domain;
结合开关频率最大值、开关频率最小值和期望开关频率函数在时域的扩散系数，计算得到期望开关频率函数的表达式；Combining the maximum switching frequency, the minimum switching frequency and the diffusion coefficient of the expected switching frequency function in the time domain, the expression of the expected switching frequency function is calculated;
按照所述期望开关频率函数进行开关器件的开关频率调制，实现传导EMI的降低。The switching frequency of the switching device is modulated according to the desired switching frequency function to achieve reduction of conducted EMI.
周期频率调制技术介绍：Introduction to periodic frequency modulation technology:
传统PWM调制策略的载波频率是固定不变的，使载波频率在一个固定的频率周围按周期函数变化即为周期频率调制技术。本实施方式中，分析传统的三相两电平逆变器拓扑形式下的空间矢量脉宽调制(Space Vector Pulse Width Modulation,SVPWM)策略的考虑开关损耗和时域扩散系数的降低传导EMI的周期频率调制，如图1所示。The carrier frequency of the traditional PWM modulation strategy is fixed, and the periodic frequency modulation technology is to make the carrier frequency change according to a periodic function around a fixed frequency. In this embodiment, the space vector pulse width modulation (SVPWM) strategy under the traditional three-phase two-level inverter topology is analyzed to consider the periodic frequency modulation of the conducted EMI in terms of switching loss and time domain diffusion coefficient reduction, as shown in Figure 1.
在使用传统的SVPWM技术的基础上，为了进一步降低传导电磁干扰的峰值，引入了考虑开关损耗和时域扩散系数的周期频率调制方法，以在特定频率点扩散电磁干扰。为了得出考虑开关损耗的频率变化函数，进行以下数学和理论分析。On the basis of using the traditional SVPWM technology, in order to further reduce the peak value of the conducted electromagnetic interference, a periodic frequency modulation method considering the switching loss and the time domain diffusion coefficient is introduced to diffuse the electromagnetic interference at a specific frequency point. In order to obtain the frequency variation function considering the switching loss, the following mathematical and theoretical analysis is carried out.
进一步，采用SVPWM策略的电压源逆变器中每个开关器件的功率损耗与开关频率和电流幅值成正比，每个开关器件的开关损耗功率与开关频率和电流幅值的关系表达式为：Furthermore, the power loss of each switching device in the voltage source inverter using the SVPWM strategy is proportional to the switching frequency and current amplitude. The relationship between the switching loss power of each switching device and the switching frequency and current amplitude is expressed as:
式中Ploss表示一个开关周期内每个开关器件的开关损耗功率，Udc表示电压源逆变器的直流供电电压，ton表示开关器件的导通延时时间，toff表示开关器件的关断延时时间，fs0(θ)为电压源逆变器的单相非负开关频率函数，fi0(θ)为电流幅值函数，θ为电流相位角；Where P loss represents the switching loss power of each switching device in a switching cycle, U dc represents the DC supply voltage of the voltage source inverter, t on represents the turn-on delay time of the switching device, t off represents the turn-off delay time of the switching device, f s0 (θ) is the single-phase non-negative switching frequency function of the voltage source inverter, fi0 (θ) is the current amplitude function, and θ is the current phase angle;
由公式(1)，得到使开关损耗功率降低的开关频率和电流幅值成负相关关系。如果开关频率和电流可以负相关，开关损耗就可以降低。From formula (1), it can be obtained that the switching frequency and current amplitude that reduce the switching loss power are negatively correlated. If the switching frequency and current can be negatively correlated, the switching loss can be reduced.
本实施方式中，所述期望开关频率函数的变化趋势呈现在一个开关周期内具有六个变化周期；且在每个变化周期的前二分之一个变化周期中，呈现单调递减趋势，电流相位角θ的最小值对应期望开关频率函数的最大值，电流相位角θ的最大值对应期望开关频率函数的最小值；在每个变化周期的后二分之一个变化周期中，呈现单调递增趋势。In this embodiment, the change trend of the expected switching frequency function presents six change cycles within one switching cycle; and in the first half of each change cycle, it presents a monotonically decreasing trend, the minimum value of the current phase angle θ corresponds to the maximum value of the expected switching frequency function, and the maximum value of the current phase angle θ corresponds to the minimum value of the expected switching frequency function; in the last half of each change cycle, it presents a monotonically increasing trend.
图2显示了三相电流的绝对值之和以及所需的开关频率函数的变化趋势。Figure 2 shows the change trend of the absolute value sum of the three-phase current and the required switching frequency function.
假设期望开关频率函数的最大值为fs(0)，期望开关频率函数的最小值为 Assume that the maximum value of the desired switching frequency function is fs (0) and the minimum value of the desired switching frequency function is
fs(0)＝fcs， fs (0)＝ fcs ,
式中fs为期望开关频率函数，在第一个二分之一个变化周期中电流相位角θ的最小值为0；fcs为传统开关频率值；Where fs is the expected switching frequency function, and the minimum value of the current phase angle θ in the first half of the change cycle is 0; fcs is the traditional switching frequency value;
在第一个二分之一个变化周期中电流相位角θ的最大值为m为开关频率的扩频深度。The maximum value of the current phase angle θ in the first half of the change cycle is m is the spread spectrum depth of the switching frequency.
为了扩大频带的均匀性，使电磁干扰尖峰更均匀地分布在频带上。结合图2中的开关频率函数曲线趋势，对开关频率函数进行详细的数学理论推导，以寻找最佳的变化函数。从理论分析可知，当开关频率越高时，采集速率越快，时域中该频率点的采集点越多。而当开关频率变化率的绝对值较小时，时域中该频率点的采集点也会越多。因此，时域中给定频率的采集点数量与开关频率的大小成正比，与开关频率变化率的绝对值成反比。In order to expand the uniformity of the frequency band and make the electromagnetic interference peaks more evenly distributed on the frequency band. Combined with the trend of the switching frequency function curve in Figure 2, the switching frequency function is derived in detail by mathematical theory to find the best change function. From the theoretical analysis, it can be seen that when the switching frequency is higher, the acquisition rate is faster, and the more acquisition points there are at this frequency point in the time domain. When the absolute value of the switching frequency change rate is small, there will be more acquisition points at this frequency point in the time domain. Therefore, the number of acquisition points for a given frequency in the time domain is proportional to the size of the switching frequency and inversely proportional to the absolute value of the switching frequency change rate.
因此得到期望开关频率函数在时域的扩散系数表示为ρ[fs(θ)]：Therefore, the diffusion coefficient of the desired switching frequency function in the time domain is expressed as ρ[f s (θ)]:
再进一步，根据公式(2)和(3)，计算得到期望开关频率函数的表达式fs(θ)的表达式为：Furthermore, according to formulas (2) and (3), the expression of the desired switching frequency function f s (θ) is calculated as:
再进一步，结合图3所示，为便于数字控制系统的实施，开关频率函数中的指数函数被泰勒级数展开的前三项所取代，将公式(4)中的指数函数取泰勒级数展开的前三项得到：Furthermore, in combination with FIG3 , in order to facilitate the implementation of the digital control system, the exponential function in the switching frequency function is replaced by the first three terms of the Taylor series expansion, and the exponential function in formula (4) is replaced by the first three terms of the Taylor series expansion to obtain:
按照公式(5)在数字信号处理器中进行开关器件的开关频率调制，实现传导EMI的降低。According to formula (5), the switching frequency of the switching device is modulated in the digital signal processor to achieve the reduction of conducted EMI.
作为示例，当选取m为0.8时，此时的泰勒级数展开误差已小于0.002，便于实际的数字控制系统实现且误差较小。As an example, when m is selected as 0.8, the Taylor series expansion error is less than 0.002, which is convenient for the actual digital control system to be implemented with a small error.
由此，根据公式(1)和公式(4)，可以计算电压源逆变器在一个基本周期内的开关损耗功率：Therefore, according to formula (1) and formula (4), the switching loss power of the voltage source inverter in one basic cycle can be calculated:
式中Ploss_VSI为电压源逆变器在一个基本周期内六个开关器件的总开关损耗功率，fi0(θ)为电流幅值函数，为三相电流幅值之和，Im为相电流的峰值，f0为相电流的频率；Where P loss_VSI is the total switching loss power of the six switching devices of the voltage source inverter in one basic cycle, fi0 (θ) is the current amplitude function, which is the sum of the three-phase current amplitudes, Im is the peak value of the phase current, and f0 is the frequency of the phase current;
k为SVPWM调制策略的调制比：k is the modulation ratio of the SVPWM modulation strategy:
式中Uref为SVPWM调制的参考电压矢量幅值；σ(k)为中间变量，用于替换公式中相应的部分，为关于k的函数；为关于m的单调递增的函数。Where U ref is the reference voltage vector amplitude of SVPWM modulation; σ(k) is an intermediate variable used to replace the corresponding part in the formula and is a function of k; is a monotonically increasing function of m.
因此，在确定逆变器参数时，开关损耗与变量m和变量k呈正相关。故而可以根据逆变器对效率的限制要求选取合适的变量m和变量k值。综上所述，本发明方法不仅能减少EMI峰值，还能有效降低逆变器的开关损耗，从而提高整个系统的效率。Therefore, when determining the inverter parameters, the switching loss is positively correlated with the variable m and the variable k. Therefore, appropriate values of the variable m and the variable k can be selected according to the efficiency restriction requirements of the inverter. In summary, the method of the present invention can not only reduce the EMI peak, but also effectively reduce the switching loss of the inverter, thereby improving the efficiency of the entire system.
本实施方式中，所述电压源逆变器为三相两电平逆变器。In this implementation, the voltage source inverter is a three-phase two-level inverter.
图4是采用固定开关频率的SVPWM调制技术的输出相电流的频谱图，图5是采用本发明提出的考虑逆变器开关损耗和时域扩散系数的输出相电流的频谱图。可以看到，采用本发明方法可以使得驱动控制系统在开关频率及其整数倍频处的谐波含量幅值大幅降低。在40kHz开关频率处谐波含量由1.9％降低到了0.33％；在80kHz二倍开关频率处谐波含量由0.45％降低到了0.07％。验证了本发明方法的可行性和有效性。Figure 4 is a spectrum diagram of the output phase current using the SVPWM modulation technology with a fixed switching frequency, and Figure 5 is a spectrum diagram of the output phase current using the method proposed by the present invention taking into account the inverter switching loss and the time domain diffusion coefficient. It can be seen that the use of the method of the present invention can greatly reduce the amplitude of the harmonic content of the drive control system at the switching frequency and its integer multiples. The harmonic content at the switching frequency of 40kHz is reduced from 1.9% to 0.33%; the harmonic content at the double switching frequency of 80kHz is reduced from 0.45% to 0.07%. The feasibility and effectiveness of the method of the present invention are verified.
虽然在本文中参照了特定的实施方式来描述本发明，但是应该理解的是，这些实施例仅仅是本发明的原理和应用的示例。因此应该理解的是，可以对示例性的实施例进行许多修改，并且可以设计出其他的布置，只要不偏离所附权利要求所限定的本发明的精神和范围。应该理解的是，可以通过不同于原始权利要求所描述的方式来结合不同的从属权利要求和本文中所述的特征。还可以理解的是，结合单独实施例所描述的特征可以使用在其它所述实施例中。Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It will also be understood that the features described in conjunction with a single embodiment may be used in other described embodiments.
Claims (8)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410099994.0A CN117895782B (en) | 2024-01-24 | 2024-01-24 | Cyclic frequency modulation method for reducing conducted EMI considering switching losses and time-domain diffusion coefficient |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410099994.0A CN117895782B (en) | 2024-01-24 | 2024-01-24 | Cyclic frequency modulation method for reducing conducted EMI considering switching losses and time-domain diffusion coefficient |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN117895782A true CN117895782A (en) | 2024-04-16 |
| CN117895782B CN117895782B (en) | 2024-12-31 |
Family
ID=90644603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410099994.0A Active CN117895782B (en) | 2024-01-24 | 2024-01-24 | Cyclic frequency modulation method for reducing conducted EMI considering switching losses and time-domain diffusion coefficient |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117895782B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6462962B1 (en) * | 2000-09-08 | 2002-10-08 | Slobodan Cuk | Lossless switching DC-to-DC converter |
| CN104243053A (en) * | 2013-06-19 | 2014-12-24 | 华为技术有限公司 | Input signal processing method and device |
| CN104820782A (en) * | 2015-05-06 | 2015-08-05 | 华北电力大学（保定） | Linear method for estimating switching loss of IGBT module |
| CN106385196A (en) * | 2016-09-27 | 2017-02-08 | 华中科技大学 | Current ripple real-time prediction model-based three-level voltage source variable switching frequency control method |
| CN107104657A (en) * | 2017-04-26 | 2017-08-29 | 西安理工大学 | A kind of wrong cycle control methods of the digitlization of digital active electromagnetic interface filter |
| WO2019165618A1 (en) * | 2018-02-27 | 2019-09-06 | 西南交通大学 | Distributed device for monitoring electromagnetic interference along high-speed rail in real time and related method |
| CN111464019A (en) * | 2020-04-09 | 2020-07-28 | 石家庄通合电子科技股份有限公司 | Method and device for optimizing LL C resonant converter load transient dynamics |
| CN111934577A (en) * | 2020-07-17 | 2020-11-13 | 华中科技大学 | Current source inverter variable switching frequency modulation method and system |
| CN112230069A (en) * | 2020-08-05 | 2021-01-15 | 北京经纬恒润科技股份有限公司 | Integrated circuit electromagnetic interference diagnostic system and method |
-
2024
- 2024-01-24 CN CN202410099994.0A patent/CN117895782B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6462962B1 (en) * | 2000-09-08 | 2002-10-08 | Slobodan Cuk | Lossless switching DC-to-DC converter |
| CN104243053A (en) * | 2013-06-19 | 2014-12-24 | 华为技术有限公司 | Input signal processing method and device |
| CN104820782A (en) * | 2015-05-06 | 2015-08-05 | 华北电力大学（保定） | Linear method for estimating switching loss of IGBT module |
| CN106385196A (en) * | 2016-09-27 | 2017-02-08 | 华中科技大学 | Current ripple real-time prediction model-based three-level voltage source variable switching frequency control method |
| CN107104657A (en) * | 2017-04-26 | 2017-08-29 | 西安理工大学 | A kind of wrong cycle control methods of the digitlization of digital active electromagnetic interface filter |
| WO2019165618A1 (en) * | 2018-02-27 | 2019-09-06 | 西南交通大学 | Distributed device for monitoring electromagnetic interference along high-speed rail in real time and related method |
| CN111464019A (en) * | 2020-04-09 | 2020-07-28 | 石家庄通合电子科技股份有限公司 | Method and device for optimizing LL C resonant converter load transient dynamics |
| CN111934577A (en) * | 2020-07-17 | 2020-11-13 | 华中科技大学 | Current source inverter variable switching frequency modulation method and system |
| CN112230069A (en) * | 2020-08-05 | 2021-01-15 | 北京经纬恒润科技股份有限公司 | Integrated circuit electromagnetic interference diagnostic system and method |
Non-Patent Citations (1)
| Title |
|---|
| 李昕;苏利捷;黄保栋;: "EV充电器中DC/DC变换器共模EMI研究与抑制", 电测与仪表, no. 06 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN117895782B (en) | 2024-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113422555B (en) | Double-phase permanent magnet synchronous motor PMSM sawtooth carrier double-random SVPWM control method | |
| CN104298107B (en) | Combined local frequency multiplication sampling algorithm for generating SPWM waves | |
| CN103401405B (en) | A kind of method adopting fixing control cycle to realize selective harmonic elimination modulation | |
| CN115987115B (en) | Modulation method for inhibiting input current distortion of current type PWM rectifier | |
| CN112072943B (en) | H-bridge inverter power supply PWM modulation method for eliminating odd-order switch harmonic waves | |
| CN119093506A (en) | Power quality improvement method and system for eliminating modulation of multiple zero-crossing drive vacancy zones | |
| Bu et al. | Multiaverage random switching frequency space vector pulsewidth modulation strategy for high-order harmonics dispersion | |
| CN102195512A (en) | Processing method during synchronous pulse width modulation carrier to noise ratio switching of inverter | |
| CN108092534B (en) | Control method and device for single-phase five-level converter | |
| Chen et al. | An improved variable switching frequency modulation strategy for three-level converters with reduced conducted EMI | |
| CN109412440B (en) | A carrier phase-shift SVPWM modulation method suitable for line-voltage cascaded triple converters | |
| Gong et al. | A novel hybrid quasi-Z-source inverter topology and its modulation strategy | |
| CN117895782A (en) | Method for reducing conducted EMI (electromagnetic interference) periodic frequency modulation considering switching loss and time domain diffusion coefficient | |
| CN103715875B (en) | Switching frequency adjusting method and device and inverters | |
| CN108418442B (en) | Integral terminal sliding mode control method for two-terminal voltage source converter HVDC transmission system | |
| CN112072909B (en) | Drive signal modulation method for inhibiting electromagnetic interference of electric vehicle power module | |
| CN110896295B (en) | A low-ripple driving method for AC motor | |
| Ma et al. | Application of periodic carrier frequency modulation for harmonic and EMI reduction in GaN-based motor drive | |
| Liu et al. | Uniform distribution spread-spectrum modulation strategy for MMC to reduce conducted EMI and switching loss | |
| CN111628665B (en) | Medium-high voltage power electronic transformer based on series digital voltage stabilizer | |
| Dai et al. | PCC Voltage Switching Harmonic Mitigation by Periodic Carrier Frequency Pulsewidth Modulation for SiC High-Frequency Active Power Filter | |
| Gao et al. | Variable switching frequency PWM for three-level NPC converter in DFIG wind turbines | |
| CN111342678A (en) | A Super Sparse Matrix Transformer with Boost Circuit | |
| CN110336476A (en) | A closed-loop zero-sequence voltage optimal injection method for cascaded H-bridge converters | |
| Alam et al. | Power Inverter Performance with Trapezoidal Triangular Carrier and Triangular Based SPWM Technique: A Comparative Analysis |
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 |