Design of output lcl filter and control of singlephase. The leakage currents of the motors, flow through common ground, will interfere with other equipment because of the high density of electrical and electronic systems in the. Finally, a simulation is performed with the software matlab. An analytical design approach for passively damping. Active damping of resonance oscillations in lclfilters. The best options are found for a ratio of three and four. The results of simulations of the inverter system connected to. Highorder passive filters hopf have the best harmonic mitigation performance, but they are the most difficult to tune, design, and operate. Lclfilter have been comprehensively discussed in literature 2, 10 and 11. The results are simulated by matlabsimulink software. Lc filters design tool calculate lc filters circuit values with lowpass, highpass, bandpass, or bandstop response.
Rf filter design requires that you be very good with a simulator, network analyzer, and layout tools. However, as it is shown, some damping techniques influence the harmonics suppression. To meet the space constraint requirement, specific design attention is focused on a customized amorphous cored inductor, with a comprehensive study of the relationships of inductor winding with respect to emi noise. Inverters connected to the grid, filter is required as an interface between the inverter and the electric grid.
Analysis and design of a passively damping lcl filter in. Active damping of resonance oscillations in lclfilters based on virtual flux and virtual resistor gullvik william. Lcl filter design and performance analysis for grid interconnected systems a. The lcl filter improves the harmonic mitigation in a broader band but more challenging to design and operate than the lc filter. Reduction emi of bldc motor drive based on software analysis. In this case, lcl filter is better in the sense that it can provide the similar attenuation effect with smaller. Depending on the cutoff frequency and inputoutput impedances desired for either a lowpass or a highpass filter, one or the other of the possible configurations will lend. Select chebyshev, elliptic, butterworth or bessel filter type, with filter order up to 20, and arbitrary input and output impedances. Why do engineers prefer lcl filters over other kinds of. Whereas the transfer function leading to the capacitor current, i c, is given by equation 9. They are based on articles published in the specialized literature combined with the experience of the authors in order to. Single phase circuit of an lcl filter with passive damping ii. This paper also proposes the lcl filter design to eliminate the harmonics.
An lcl filter in a t configuration is a lowpass filter. Lcl filter design with emi noise consideration for grid. Basically, you can choose the inner inductor as 715 % of the rated base impedance for high power application, the rest is explained in the matlab script. Reading instructions the bibliography is on page 71. Calculate and design audio classd lc filters in minutes using the classd lc filter designer. The conduction and switching losses that are caused by the filter are calculated and are optimized considering the level of reduction of harmonics. Optimized design of an lcl filter for grid connected.
A lcl filter is often used to interconnect an inverter to the utility grid in order to filter the harmonics produced by the inverter. Suppression of the lcl filter resonance is guaranteed by a proper damping technique design. Lclfilters are a standard solution for gridtie inverters, and many papers on the topic are published. In the bldc motordrive system, the leakage current from a motor to a ground network and existence of highfrequency components of the dc link current are the most important factors that cause conducting interference. To design an lcl passive filter several rules should be considered as listed in below. Keywordslcl filter, doubly fed induction generator dfig.
Lcl filter design and performance analysis for grid. Secondly, the design of the output lcl filter is proposed in this paper. This software will help do the easy part, which is, coming up with a good starting point for your simulator and optimizer. Threephase lclfilter for gridconnected inverter using. In a second time we present the design of a control line of the lcl filter on the referential theory giving rise to a simpler way the calculation of different characteristics or combinations such as peak resonance, impedance as well as certain elements that consume reactive and active energy from the rc branch of our lcl filter.
A more common selection is between the lcl filter and the regular l or lc filter. The lclfilter design process is complex and takes an iterative approach due to the coherence. Figures are numbered continuously in their respective chapters. Design and control of voltage source converters with lclfilters. The lcl filter design procedure presented here is similar to that presented in references 1 and 2. An experimentation example of lclfilter design has been reported based on the simulation and, and with the obtained values, the filter has been realized and. Abstractthe use of power converters is very important in maximizing the power transfer from renewable energy sources. There are 4 basic ways to build an lc band pass filter. Optimized design of an lcl filter for grid connected photovoltaic system 622 4. Optimal lcl filter design for gridinterfaced distributed power generation system a thesis to be submitted in partial fulfillment of the requirements for the award of the degree of master. The voltage drop of the filter inductor is smaller than 5% 10% of the network voltage under the rated circumstances 11. We design and produce custommade lc lcl filters, compatible with your transformers and other power magnetic components. Lc filter is passive components which pass or reject specific frequency band. The design is simple and no changes needed in the control software.
N2 voltage source converters use filters to connect to the grid in order to limit the harmonic content injected to the grid. The considered design methodology takes into account the lcl filter topologies, which can be based either on wye or delta connected capacitors. Lclfilters are preferred over conventional lfilters for gridconnected voltage source inverters vsi due to their superior harmonic attenuation, smaller filter size and weight. Even though there is an extensive amount of literature available describing lcl filters, there has been a gap in providing a systematic design methodology. Lcl filter design and current control of grid interfaced. Lcl filter design for grid connected threephase inverter. Lcl filter for photovoltaic gridconnected inverter. Topological structure of threephase pv gridconnected inverters wit h lcl filter.
So far, there is lack of a statespace mathematical modeling approach that considers practical cases of delta and wyeconnected. Design of lclfilters for gridconnected voltage source. Example of lcl filter output current with rms value 1. Optimized design of an lcl filter for grid connected photovoltaic system and analysis of the impact of neighbors consumption on the system jes journal of electrical systems systems this paper presents an optimized design method for an lcl filter for a grid connected photovoltaic system. Design of the lcl filter the greater part of the configuration mathematical statements. Then there is an example of lcl filter design at a 30 kw threelevel inverter of which the output peak point current is 60 a. In table 8, a comparison for different values for the lcl filter is made, based on the ratio of the filter design, which yields an effect on the reliability, mtbf, and thd. Moreover, the passively damped filter may downgrade to a secondorder system, which will definitely compromise its attenuation. The b84143g405 series improves the thdi to less than 5% and covers a current range from 16 a to 400 a at a rated voltage of 520 v and a maximum motor cable length of 150 m. The structure of lcl filters is as shown in the schematics below.
Lcl filter for regen drives and active infeed converters. Simulation results under matlabsimulink software tool demonstrate the. The calculated lcl parameters have been used in the simulink model to check the performance of the lcl filter and thd content of the voltages and currents. Lcl filter is becoming an attractive choice over conventional l filters for gridconnected voltage source inverters vsi due to smaller inductor size and better attenuation of the ripple components in the grid current. Another aim is to control power factor at grid, to feed power into the grid and to decrease phase current distortion of vsi. Constraints of current ripples the maximum current ripple on the inverter side is generally chosen to be between 10% and 20% of the rated current, whereas the maximum grid ripple must be less than or equal. Designing of lcl filter and stability analysis of a three. In this study, lcl filter design was performed by simulating and theoretical analysis detail of a gridconnected system in matlab simulink environment.
Finally, verify the selected lc components with multiple speaker. The procedures shown in the chapter are well proven and simple to implement. Keywordslcl filter, doubly fed induction generator dfig, matrix converter mc, indirect spacevector modulation isvm. But im having trouble designing something like this. Stability of gridconnected inverter with lcl filter. The components of the filter on each phase are considered to be identical, so the circuit below is suitable for the other two phases. Transfer function of the lcl filter in order to obtain the transfer function of the lcl filter, the single phase electrical diagram in fig. In the simulink model, the voltage at the load bus is regulated with the help of pi controller.
The classd lc filter designer is the perfect quick and easy tool to get started on your next classd audio design. Nagar, chennai 17, behind big bazaartamilnadu,india mobile. The most effective filter for suppressing of the current harmonics occurring from the switching frequency injected into. An lcl filter is often used to interconnect an inverter to the utility grid in order to filter the harmonics produced by the inverter. Lcl filters reduce the lineside harmonics generated by regenerative frequency converters. Lcl filter for regen drives and active infeed converters schaffner is aiming at active front end afe drives and active infeed converters aic with a range of threephase lcl mains filters. Designing of lcl filter for unipolar inverter file. Called fn 6840, they come in a variety of specifications and are ready to be installed and connected in a single unit as all the necessary components. Murata delivers high performance ltcc packaged product by multilayer ceramics integration technorogy. However, lcl filter design is complex and needs to consider many constraints, such as current ripple through inductors, total impedance of the filter, switching harmonic attenuation, resonance. Lcl filter design and performance analysis for gridinterconnected systems international journal of advanced technology and innovative research volume. D s 3 s 5 s 4 s 6 s 2 ua l a1 c s l 1 l c 1 s 1 k 1 l a2 b 2 l c2 ub uc u d c i dc pv a i i c fig.
In some cases reactor l4, is already placed in front of the converter. This chapter covers the basic control principles for the lclfilter design and its damping. Design and control of voltage source converters with lcl. A clc filter in a t configuration is a highpass filter. Using elsie software to design filters michael betts. Nonetheless, the damping resistor increases the encumbrances and the losses could claim for forced cooling 6. I read that for gridtied inverters it is common to use a lcl filter like above, to turn the pwm output from the hbridge into a sine. The advantages and drawbacks of each topology are discussed in order to achieve an optimal design. Simple and systematic lcl filter design for threephase.
This components are used for extracting the specific frequency band, or rejecting for noise reduction. Lcl filter design for gridconnected inverters by analytical estimation of pwm ripple voltage abstract. Select from 4 different filter types based on classd output, switching topology and performance. Lcl filter design inlcuding the current control tuning. Finally, verify the selected lc components with multiple speaker loads using the frequency response graph and qfactor calculations. In such case l2 may be unnecessary m 3 lcl filter mains impedance converter l1 l2 l3 c l4 fig. Therefore, the efficiency decrease becomes a key point. Systematic design of the leadlag network method for. If youd calculate the voltage at the right end without the resistor, l2 doesnt do anything and its just an lc filter. Input corner frequency and quality q factor to fine tune the audio frequency response. Power quality improvement by designing the lcl filters for. Design and control of an lcl filter based three phase active rectifier,marco liserre. In this model, the lcl filter parameters are designed using a matlab script.
1007 755 1247 1622 388 1605 1036 1460 244 228 730 604 681 125 553 1276 930 1079 1344 524 485 63 320 610 1115 1222 10 1249 249 1061 845 91 753 1007 1265 63 936 626 1336 62 637 182 188