- Email: [email protected]
Study on the Simulation for Closed-Loop Control Based on Synchronous Rotating Coordinate for MC
Available online at www.sciencedirect.com
Energy Procedia 17 (2012) 1281 – 1287
Study on the Simulation for Closed-Loop Control Based on Synchronous Rotating Coordinate for MC Wen-Jun Huaia,Jin-Feng Zhanga,She-Yi Renb a
Department of Electronic Information Engineering,Suzhou Vocational University ,Suzhou, China {hwj, zjinfeng}@jssvc.edu.cn b Zao Zhuang Power Supply Company,Shan Dong, China, [email protected]
Abstract A new kind of modulation strategy was put forward for on matrix converter (MC), which output voltage in open-loop control can not be adjusted automatically when a disturbance encountered. This paper presents an improved method which adopts the closed-loop control of the output voltage. First of all, the output voltage can be changed into space vector by coordinate transformation. Then, that compared with the target voltage vector to obtain deviation in order to feedback control. Finally, this paper carried out simulation on device modeling, control strategy and voltage closedloop control method using Matlab. Two kinds of interference , typically, are simulated and analyzed in two control ways, and the result shows that the closed-loop control is better than open-loop control, which has a good control effect for input disturbance.
© 2012 and/or peer-review under responsibility of Hainan University. © 2011 Published Publishedby byElsevier ElsevierLtd. Ltd.Selection Selection and/or peer-review under responsibility of [name organizer] Keywords: MC, voltage closed-loop control, equivalent transformation, space vector modulation (SVM), simulation
1.Introduction MC as a new AC - AC power inverter, the circuit topology is proposed, but characterized only by the people attention and study until 1979, when MC theory and control strategy by the scholar M. Venturini and A. Alesina proposed in Italian. MC can realize all parameters of alternating current (phase number, phase, amplitude and frequency) of commutation. Eenergy transfer through two-way switch has the following advantages as a general-purpose inverter. It can provide sinusoidal input current and output voltage. Power can flow in both directions, and can use renewable energy, better than the Pulse-Width Modulation (PWM) frequency converter. The parameter of the output voltage, such as phase and frequency, can be adjusted. The frequency can be higher than the input frequency. The phase of input current can be advanced, delayed or equal to the input voltage’s, and no intermediate DC link, small size, light weight and so on [1] [2]. A variety of methods have been proposed on the control strategy of MC by domestic and foreign scholars, such as the Venturini method and the space vector method [3] [4], but these methods all in voltage control, targeted to control the output voltage. Generally, MC in (SVM) is open-loop control, when
1876-6102 © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Hainan University. doi:10.1016/j.egypro.2012.02.239
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Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
it comes to disturbances, the output voltage wave is not be adjusted automatically, whether the load side or the grid side. According to this problem, we propose a method in voltage closed-loop control, base on the actual output voltage compared with a desired output voltage, in order to calculate a deviation of space voltage vector, and add the error to the next calculation process, which is the switching state duty cycle in sampling period as the reference of negative feedback conditionally, realizes the voltage closed-loop control in system [5]. In this paper, the performance of MC in SVM is simulated in Matlab software though the experiment of voltage closed-loop control, which shows its effectiveness. 2.The algorithm of voltage closed-loop control Use space vector and coordinate transformation, making three-phase variables transformed between three-phase stationary coordinate system and two-phase coordinate system. So the three-phase model can be converted to two-phase coordinate system, the mathematical model is simplified and the system order is reduced. In practice, ABC coordinate system usually converted to DE stationary reference frame and dq rotating coordinate system. 2.1.Equivalent Relation in Three Coordinates Systems These coordinate systems are ABC coordinate, DE stationary coordinate and dq rotating coordinate. In a vector space, D axis will be fixed with the direction of A axis, the E axial leads the D axis by 90°. The components in the stationary coordinate system can be obtained with the AC component is still keep a frequency Z , it from the standard three-phase sinusoidal signal. If q-axis ahead of the d-axis 90°, the coordinate system will synchronous rotation with complex vector composition at an angular velocity Z t . The DC component can be obtained in dq coordinate system though static and rotation transformation from power supply. Its value relate with amplitude X m and initial angle T 0 . After the three-phase variable rotation transforms, the following will be included. (1) Positive sequence component is DC component. (2) Third-harmonic component is zero. Accordingly, the amplitude of composite vector is zero in a vector space. (3) The positive sequence component will reduce one order, and the negative sequence component will raise one order. It can be seen, the component after transformed can reflect the harmonic distribution intuitively and visually. The third harmonic symmetrically can not constitute a loop in a three-phase. So it can be ignored. The static-rotation transformation may be considered as an equivalent alteration, which is basic of control in synchronously rotating frame of reference with three-phase system [6]. 2.2.Relationship between DE and dq Coordinate The SVM of two coordinate systems is same based on the principle, a transform relation between DE coordinate and dq coordinate may be defined as following.
ª xd º «x » ¬ q¼
ª cos T « sin T ¬
ª xD º «x » ¬ E¼
ªcos T « sin T ¬
ª xD º T2 S / 2 d « » ¬xE ¼
(1)
ª xd º sin T º ª xd º « x » T2 d / 2 S « x » » cos T ¼ ¬ q ¼ ¬ q¼
(2)
sin T º ª xD º « » cos T »¼ ¬ x E ¼
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Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
The calculation of SVM is finally decided by some vectors from amplitude and angle. ABC coordinate can be transformed into dq coordinate via the coordinate transformationˈand got amplitude and angle respectively which make it suitable for computation in SVM. 3.Voltage closed-loop control strategy By the basic principle of SVM on MC, switch control matrices was synthesized from links of shaft and generator, which can obtain the desired output voltage and current by turn on and turn off the main switch. In this method, everything went according to expected about the calculation of duty ratio. When the input voltage happen to aberration or mutation on MC, the output will change inevitably and stray from the right path, but system take no consideration for deviation due to its working in open-loop status. Hence, the need for control system to adds a feedback mechanism. In this modulation system, MC is transformed into an equivalent topology resulting from the combination of a rectifier and an inverter, the part of rectifier subject to input current which is influenced by a number of factors. Its injection point for use current vector as feedback to control system in closedloop, which can not been performed based on double space vector modulation [7]. But the part of virtual rectifier is an important element on power factor correction for MC, which also controls the power factor angles and reactive power. In this paper, the open-loop control still adopted for universality and operability in the control algorithm [8], and changed the expectations of power factor to 1. Virtual inverter is still using voltage closed-loop control. Set the actual output voltage are UAB, U BC and U CA , using these principle of coordinate transformation transformed into a space vector is: Uo
(3)
o o 2 (U AB U BC e j120 U CAe j120 ) U om M 3
Suppose expected output voltage are UAB, U BC and U CA , the result obtained is: *
Uo
(4)
* * * * o o 2 * (U AB U BC e j120 U CA e j120 ) U om M 3
*
U The following relationship assumed to exist the amplitude and phase between U o and *
'U o
'M
Uo U o *
M M
o
. (5) (6)
After get the error of vector amplitude by formula 5, and the error of vector angel from formula 6. These deviations can be reducing by adjustment voltage vector ratio dD ˈ d E and d v 0 in virtual inverter. Therefore, it can inhibit the error from actual voltage and desired voltage. According to the SVM analyses, need to rotate voltage space vector in its voltage sector of the relative angle and voltage modulation than. The relative position angle T sv and anomalous ratio mv on voltage sectors is needed to calculate the duty cycle of voltage vector in inverter. Consequently, the error 'M can be reduced through control the sector angles T sv , It is the same with voltage modulation ratio framework can be seen below in figure 1.
mv and vector amplitude 'U 0 . The whole
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Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
Figure 1. Module structure of voltage closed-loop control
During closed-loop control in virtual inverter, the deviation of output voltage vector is calculated. And then, adjust the voltage vector ratio in virtual inverter [9]. As a matter of fact, the control principle is feedback-plus - feed-forward. feed-forward is given by the desired output voltage, feedback is decided by error, and the value of voltage vector can be assured in common from two parameters. 4.Simulation analysis of close-loop Control The MC’s control is very complexity. It can be equivalent as two parts of virtual inverter and virtual rectifier in SVM. But voltage closed-loop control is just effective to inverted circuit. So firstly, the effectiveness of the virtual inverter are verified by the simulation with Matlab, which refer to input current modulation and regulate on power factor. 4.1.Simulation of Virtual Rectifier To verify this strategy, a simulation model of virtual rectifier applied in power system is established with power system block set of Matlab. The algorithm is researched, which use S function realization the specific function. The voltage Root Mean Square (RMS) value is 380 V, and input power factor can be adjusted to 1. The voltage of virtual circuit shows in the upper half of figure 2, and the mean value shows in the lower part after filtering. Upn
600 500 400 300 200 100 0 500 400 300 200 100 0
0.002 0.004 0.006 0.008
0.01 0.012 0.014 0.016 0.018
0.02
Figure 2. The voltage of virtual rectifier when nput power factor is one
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 Upn
500
0
-500 15 10 5
0
0.002 0.004 0.006 0.008
0.01 0.012 0.014 0.016 0.018
0.02
Figure 3. The voltage of virtual rectifier when input power factor is zero
In figure 2, when the vector angle in 30 degrees, the input power factor can be adjusted to one in theory. It has been shown that voltage value and voltage transfer ration is the highest on virtual rectifier. In figure 3, when the vector angle in 120 degrees, the input power factor can be adjusted to zero in theory. It has been shown that the waveform with positive-sequence and negative-sequence just go together, which voltage amplitude not exceeds 15 V, relative to input voltage, approximate to zero. Although power factor of SVM on MC can be adjusted in theory, but the range is limited actually. 4.2.Simulation of Voltage Close-Loop Control The voltage close-loop feedback unit is designed to solve the validity of algorithms in Matlab software based on SVM, as shows in figure 4. 1 Ua
a1
2 Ub
b1
3 Uc
c1
2*pl*50
w
1 d1
1/269.4 den(s) Gain
1 q1
1/269.4 den(s)
w
0
Gain1
Subsystem
Convert
2 Eq
Convert
1 Ed
Uq
0.5 Ud
Figure 4. The design of voltage closed-loop feedback unit
x Input Disturbance for Step Signal Hypothesis, an interference of step signal generated which amplitude in 50 V at 0.02 sec. The simulation results as shows in figure 5. There will be a transition pulse happened at the same time, but then something as been adjusted by closed-loop controlled circuit. Finally, the distortion will not happen in output voltage. x Input Disturbance for Third Harmonic An interference of third harmonic which amplitude in 30 V, the simulation results as shows in figure 6. Effectiveness can be proved with there is no any distortion.
1285
1286
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 UA
400 200 0 -200 -400
IA
200 100 0 -100 -200
0.01
0.02
0.03
0.04
0.05
0.06
Figure 5. The wave of voltage and current by the step disturb signal UA
400 200 0 -200 -400
IA
200 100 0 -100 -200
0.01
0.02
0.03
0.04
0.05
0.06
Figure 6. The wave of voltage and current by the third harmonic signal
5.Conclusion In this paper, a method to improve the interference problem from power grid on MC was put forward. According to the interference problem from power grid on MC, proposed a new kind of control strategy as the control of voltage closed-loop, constitutes mathematic model of the system and carries out computer simulation about virtual inverted circuit in Matlab. This thesis discusses adjustable range to adjust power factor, then experiments with a SVM implementation have shown that the SVM policy is workable. By analysis of two kinds of inference in Matlab, it shows that the results of voltage closed-loop control are presented to validate for the input interference suppression. 6.Acknowledgment This paper was supported by the Youth Foundation of Suzhou vocational university (No.2010SZDQ03). References [1]
Blaabjerg F㧘Casadei D㧘Klumpner C㧚Comparison of two current modulation strategies for matrix converters under
unbalanced input voltage conditions [J]. IEEE Trans. on Industrial Electronics. 2002, vol. 49(2), pp. 289-296㧚 [2]
Lars H㧘Larsen K㧘Blaabjerg F㧚Evaluation of modulation schemes for three-phase to three-phase matrix converters
[J]㧚IEEE Trans. on Industry Electronics. 2004, vol. 51(1), pp. 158-171㧚 [3]
Chen xi-you, Cong shu-jiu, Chen xue-yun. The analysis of the relationship between the voltage sectors and the
performances of matrix converter based on two voltage synthesis [J]. Proceedings of the CSEE. 2001, vol. 21(9), pp. 63-67㧚
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 [4]
Wang yong, Lü zheng-yu, Chen wei, Wang you-sheng. Dead-time compensation based on thr improved space vector
modulation strategy for matrix converter [J]. Proceedings of the CSEE, 2005, vol. 25(11), pp. 42-45㧚 [5]
Wang yi, Chen xi-you, Xu dian-guo. The research of closed-loop control method for matrix converter based on space
vector modulation [J]. 2003, vol. (6), pp. 164-169. [6]
Deng Wen-lang, Yang Xin-rong, Zhu Jian-lin. Study of Closed Loop Control Based on Synchronous Rotating
Coordinate for TSMC [J]. 2007, vol. 32(2), pp. 20-24. [7]
Su mei, Sun yao, Qin heng-si, Zhang tai-shan. An multi-objective optimized design of input filter of matrix converter [J].
Proceedings of the CSEE. 2007, vol. 27(1), pp. 70-75㧚 [8]
WHQ Zhao-fang, DX Jian-sheng. Design of Closed-Loop Control Method for Matrix Converter with Space Vector
Modulation[J]. Journal of Beijing Institute of Technology. 2005, vol. 25(7), pp. 599-607. [9]
Zhang Vhao, Ge Kong-juan, Mu [in-hua. System Implement of Voltage-Current Dual Closed-loop Control Model of AC-
AC Matrix Converter [J]. IEEE ICEMS, 2005, vol. 2, pp. 1134-1137.
1287
Energy Procedia 17 (2012) 1281 – 1287
Study on the Simulation for Closed-Loop Control Based on Synchronous Rotating Coordinate for MC Wen-Jun Huaia,Jin-Feng Zhanga,She-Yi Renb a
Department of Electronic Information Engineering,Suzhou Vocational University ,Suzhou, China {hwj, zjinfeng}@jssvc.edu.cn b Zao Zhuang Power Supply Company,Shan Dong, China, [email protected]
Abstract A new kind of modulation strategy was put forward for on matrix converter (MC), which output voltage in open-loop control can not be adjusted automatically when a disturbance encountered. This paper presents an improved method which adopts the closed-loop control of the output voltage. First of all, the output voltage can be changed into space vector by coordinate transformation. Then, that compared with the target voltage vector to obtain deviation in order to feedback control. Finally, this paper carried out simulation on device modeling, control strategy and voltage closedloop control method using Matlab. Two kinds of interference , typically, are simulated and analyzed in two control ways, and the result shows that the closed-loop control is better than open-loop control, which has a good control effect for input disturbance.
© 2012 and/or peer-review under responsibility of Hainan University. © 2011 Published Publishedby byElsevier ElsevierLtd. Ltd.Selection Selection and/or peer-review under responsibility of [name organizer] Keywords: MC, voltage closed-loop control, equivalent transformation, space vector modulation (SVM), simulation
1.Introduction MC as a new AC - AC power inverter, the circuit topology is proposed, but characterized only by the people attention and study until 1979, when MC theory and control strategy by the scholar M. Venturini and A. Alesina proposed in Italian. MC can realize all parameters of alternating current (phase number, phase, amplitude and frequency) of commutation. Eenergy transfer through two-way switch has the following advantages as a general-purpose inverter. It can provide sinusoidal input current and output voltage. Power can flow in both directions, and can use renewable energy, better than the Pulse-Width Modulation (PWM) frequency converter. The parameter of the output voltage, such as phase and frequency, can be adjusted. The frequency can be higher than the input frequency. The phase of input current can be advanced, delayed or equal to the input voltage’s, and no intermediate DC link, small size, light weight and so on [1] [2]. A variety of methods have been proposed on the control strategy of MC by domestic and foreign scholars, such as the Venturini method and the space vector method [3] [4], but these methods all in voltage control, targeted to control the output voltage. Generally, MC in (SVM) is open-loop control, when
1876-6102 © 2012 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of Hainan University. doi:10.1016/j.egypro.2012.02.239
1282
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
it comes to disturbances, the output voltage wave is not be adjusted automatically, whether the load side or the grid side. According to this problem, we propose a method in voltage closed-loop control, base on the actual output voltage compared with a desired output voltage, in order to calculate a deviation of space voltage vector, and add the error to the next calculation process, which is the switching state duty cycle in sampling period as the reference of negative feedback conditionally, realizes the voltage closed-loop control in system [5]. In this paper, the performance of MC in SVM is simulated in Matlab software though the experiment of voltage closed-loop control, which shows its effectiveness. 2.The algorithm of voltage closed-loop control Use space vector and coordinate transformation, making three-phase variables transformed between three-phase stationary coordinate system and two-phase coordinate system. So the three-phase model can be converted to two-phase coordinate system, the mathematical model is simplified and the system order is reduced. In practice, ABC coordinate system usually converted to DE stationary reference frame and dq rotating coordinate system. 2.1.Equivalent Relation in Three Coordinates Systems These coordinate systems are ABC coordinate, DE stationary coordinate and dq rotating coordinate. In a vector space, D axis will be fixed with the direction of A axis, the E axial leads the D axis by 90°. The components in the stationary coordinate system can be obtained with the AC component is still keep a frequency Z , it from the standard three-phase sinusoidal signal. If q-axis ahead of the d-axis 90°, the coordinate system will synchronous rotation with complex vector composition at an angular velocity Z t . The DC component can be obtained in dq coordinate system though static and rotation transformation from power supply. Its value relate with amplitude X m and initial angle T 0 . After the three-phase variable rotation transforms, the following will be included. (1) Positive sequence component is DC component. (2) Third-harmonic component is zero. Accordingly, the amplitude of composite vector is zero in a vector space. (3) The positive sequence component will reduce one order, and the negative sequence component will raise one order. It can be seen, the component after transformed can reflect the harmonic distribution intuitively and visually. The third harmonic symmetrically can not constitute a loop in a three-phase. So it can be ignored. The static-rotation transformation may be considered as an equivalent alteration, which is basic of control in synchronously rotating frame of reference with three-phase system [6]. 2.2.Relationship between DE and dq Coordinate The SVM of two coordinate systems is same based on the principle, a transform relation between DE coordinate and dq coordinate may be defined as following.
ª xd º «x » ¬ q¼
ª cos T « sin T ¬
ª xD º «x » ¬ E¼
ªcos T « sin T ¬
ª xD º T2 S / 2 d « » ¬xE ¼
(1)
ª xd º sin T º ª xd º « x » T2 d / 2 S « x » » cos T ¼ ¬ q ¼ ¬ q¼
(2)
sin T º ª xD º « » cos T »¼ ¬ x E ¼
1283
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
The calculation of SVM is finally decided by some vectors from amplitude and angle. ABC coordinate can be transformed into dq coordinate via the coordinate transformationˈand got amplitude and angle respectively which make it suitable for computation in SVM. 3.Voltage closed-loop control strategy By the basic principle of SVM on MC, switch control matrices was synthesized from links of shaft and generator, which can obtain the desired output voltage and current by turn on and turn off the main switch. In this method, everything went according to expected about the calculation of duty ratio. When the input voltage happen to aberration or mutation on MC, the output will change inevitably and stray from the right path, but system take no consideration for deviation due to its working in open-loop status. Hence, the need for control system to adds a feedback mechanism. In this modulation system, MC is transformed into an equivalent topology resulting from the combination of a rectifier and an inverter, the part of rectifier subject to input current which is influenced by a number of factors. Its injection point for use current vector as feedback to control system in closedloop, which can not been performed based on double space vector modulation [7]. But the part of virtual rectifier is an important element on power factor correction for MC, which also controls the power factor angles and reactive power. In this paper, the open-loop control still adopted for universality and operability in the control algorithm [8], and changed the expectations of power factor to 1. Virtual inverter is still using voltage closed-loop control. Set the actual output voltage are UAB, U BC and U CA , using these principle of coordinate transformation transformed into a space vector is: Uo
(3)
o o 2 (U AB U BC e j120 U CAe j120 ) U om M 3
Suppose expected output voltage are UAB, U BC and U CA , the result obtained is: *
Uo
(4)
* * * * o o 2 * (U AB U BC e j120 U CA e j120 ) U om M 3
*
U The following relationship assumed to exist the amplitude and phase between U o and *
'U o
'M
Uo U o *
M M
o
. (5) (6)
After get the error of vector amplitude by formula 5, and the error of vector angel from formula 6. These deviations can be reducing by adjustment voltage vector ratio dD ˈ d E and d v 0 in virtual inverter. Therefore, it can inhibit the error from actual voltage and desired voltage. According to the SVM analyses, need to rotate voltage space vector in its voltage sector of the relative angle and voltage modulation than. The relative position angle T sv and anomalous ratio mv on voltage sectors is needed to calculate the duty cycle of voltage vector in inverter. Consequently, the error 'M can be reduced through control the sector angles T sv , It is the same with voltage modulation ratio framework can be seen below in figure 1.
mv and vector amplitude 'U 0 . The whole
1284
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287
Figure 1. Module structure of voltage closed-loop control
During closed-loop control in virtual inverter, the deviation of output voltage vector is calculated. And then, adjust the voltage vector ratio in virtual inverter [9]. As a matter of fact, the control principle is feedback-plus - feed-forward. feed-forward is given by the desired output voltage, feedback is decided by error, and the value of voltage vector can be assured in common from two parameters. 4.Simulation analysis of close-loop Control The MC’s control is very complexity. It can be equivalent as two parts of virtual inverter and virtual rectifier in SVM. But voltage closed-loop control is just effective to inverted circuit. So firstly, the effectiveness of the virtual inverter are verified by the simulation with Matlab, which refer to input current modulation and regulate on power factor. 4.1.Simulation of Virtual Rectifier To verify this strategy, a simulation model of virtual rectifier applied in power system is established with power system block set of Matlab. The algorithm is researched, which use S function realization the specific function. The voltage Root Mean Square (RMS) value is 380 V, and input power factor can be adjusted to 1. The voltage of virtual circuit shows in the upper half of figure 2, and the mean value shows in the lower part after filtering. Upn
600 500 400 300 200 100 0 500 400 300 200 100 0
0.002 0.004 0.006 0.008
0.01 0.012 0.014 0.016 0.018
0.02
Figure 2. The voltage of virtual rectifier when nput power factor is one
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 Upn
500
0
-500 15 10 5
0
0.002 0.004 0.006 0.008
0.01 0.012 0.014 0.016 0.018
0.02
Figure 3. The voltage of virtual rectifier when input power factor is zero
In figure 2, when the vector angle in 30 degrees, the input power factor can be adjusted to one in theory. It has been shown that voltage value and voltage transfer ration is the highest on virtual rectifier. In figure 3, when the vector angle in 120 degrees, the input power factor can be adjusted to zero in theory. It has been shown that the waveform with positive-sequence and negative-sequence just go together, which voltage amplitude not exceeds 15 V, relative to input voltage, approximate to zero. Although power factor of SVM on MC can be adjusted in theory, but the range is limited actually. 4.2.Simulation of Voltage Close-Loop Control The voltage close-loop feedback unit is designed to solve the validity of algorithms in Matlab software based on SVM, as shows in figure 4. 1 Ua
a1
2 Ub
b1
3 Uc
c1
2*pl*50
w
1 d1
1/269.4 den(s) Gain
1 q1
1/269.4 den(s)
w
0
Gain1
Subsystem
Convert
2 Eq
Convert
1 Ed
Uq
0.5 Ud
Figure 4. The design of voltage closed-loop feedback unit
x Input Disturbance for Step Signal Hypothesis, an interference of step signal generated which amplitude in 50 V at 0.02 sec. The simulation results as shows in figure 5. There will be a transition pulse happened at the same time, but then something as been adjusted by closed-loop controlled circuit. Finally, the distortion will not happen in output voltage. x Input Disturbance for Third Harmonic An interference of third harmonic which amplitude in 30 V, the simulation results as shows in figure 6. Effectiveness can be proved with there is no any distortion.
1285
1286
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 UA
400 200 0 -200 -400
IA
200 100 0 -100 -200
0.01
0.02
0.03
0.04
0.05
0.06
Figure 5. The wave of voltage and current by the step disturb signal UA
400 200 0 -200 -400
IA
200 100 0 -100 -200
0.01
0.02
0.03
0.04
0.05
0.06
Figure 6. The wave of voltage and current by the third harmonic signal
5.Conclusion In this paper, a method to improve the interference problem from power grid on MC was put forward. According to the interference problem from power grid on MC, proposed a new kind of control strategy as the control of voltage closed-loop, constitutes mathematic model of the system and carries out computer simulation about virtual inverted circuit in Matlab. This thesis discusses adjustable range to adjust power factor, then experiments with a SVM implementation have shown that the SVM policy is workable. By analysis of two kinds of inference in Matlab, it shows that the results of voltage closed-loop control are presented to validate for the input interference suppression. 6.Acknowledgment This paper was supported by the Youth Foundation of Suzhou vocational university (No.2010SZDQ03). References [1]
Blaabjerg F㧘Casadei D㧘Klumpner C㧚Comparison of two current modulation strategies for matrix converters under
unbalanced input voltage conditions [J]. IEEE Trans. on Industrial Electronics. 2002, vol. 49(2), pp. 289-296㧚 [2]
Lars H㧘Larsen K㧘Blaabjerg F㧚Evaluation of modulation schemes for three-phase to three-phase matrix converters
[J]㧚IEEE Trans. on Industry Electronics. 2004, vol. 51(1), pp. 158-171㧚 [3]
Chen xi-you, Cong shu-jiu, Chen xue-yun. The analysis of the relationship between the voltage sectors and the
performances of matrix converter based on two voltage synthesis [J]. Proceedings of the CSEE. 2001, vol. 21(9), pp. 63-67㧚
Wen-Jun Huai et al. / Energy Procedia 17 (2012) 1281 – 1287 [4]
Wang yong, Lü zheng-yu, Chen wei, Wang you-sheng. Dead-time compensation based on thr improved space vector
modulation strategy for matrix converter [J]. Proceedings of the CSEE, 2005, vol. 25(11), pp. 42-45㧚 [5]
Wang yi, Chen xi-you, Xu dian-guo. The research of closed-loop control method for matrix converter based on space
vector modulation [J]. 2003, vol. (6), pp. 164-169. [6]
Deng Wen-lang, Yang Xin-rong, Zhu Jian-lin. Study of Closed Loop Control Based on Synchronous Rotating
Coordinate for TSMC [J]. 2007, vol. 32(2), pp. 20-24. [7]
Su mei, Sun yao, Qin heng-si, Zhang tai-shan. An multi-objective optimized design of input filter of matrix converter [J].
Proceedings of the CSEE. 2007, vol. 27(1), pp. 70-75㧚 [8]
WHQ Zhao-fang, DX Jian-sheng. Design of Closed-Loop Control Method for Matrix Converter with Space Vector
Modulation[J]. Journal of Beijing Institute of Technology. 2005, vol. 25(7), pp. 599-607. [9]
Zhang Vhao, Ge Kong-juan, Mu [in-hua. System Implement of Voltage-Current Dual Closed-loop Control Model of AC-
AC Matrix Converter [J]. IEEE ICEMS, 2005, vol. 2, pp. 1134-1137.
1287