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Volume 48,Issue 10,2021 Table of Contents
2021, 48(10):1-6，13.
DOI: 10.12177/emca.2021.084
Abstract:
The linear maglev synchronous motor (LMSSM) which drives the maglev platform is controlled by TS model-based fuzzy control. The structure and operation mechanism of LMSSM are studied, and the mathematical model of LMSSM is established, including voltage equation, thrust equation and motion equation. Because the mathematical model of LMSSM has the characteristics of uncertainty, the TS fuzzy control is adopted, in which the speed error e and the change rate of speed error ec are selected as the input language variables, the triangle membership function with high sensitivity is adopted when the error is large. The trapezoidal function is adopted when the error approaches zero, and the linear combination of functions is adopted as the output of the fuzzy controller. According to the characteristics of the object, four fuzzy control rules are extracted. The designed controller is simulated by MATLAB software, and the results show that the controller has less rules. The control system has fast response speed and good anti-interference performance.
The linear maglev synchronous motor (LMSSM) which drives the maglev platform is controlled by TS model-based fuzzy control. The structure and operation mechanism of LMSSM are studied, and the mathematical model of LMSSM is established, including voltage equation, thrust equation and motion equation. Because the mathematical model of LMSSM has the characteristics of uncertainty, the TS fuzzy control is adopted, in which the speed error e and the change rate of speed error ec are selected as the input language variables, the triangle membership function with high sensitivity is adopted when the error is large. The trapezoidal function is adopted when the error approaches zero, and the linear combination of functions is adopted as the output of the fuzzy controller. According to the characteristics of the object, four fuzzy control rules are extracted. The designed controller is simulated by MATLAB software, and the results show that the controller has less rules. The control system has fast response speed and good anti-interference performance.
2021, 48(10):7-13.
DOI: 10.12177/emca.2021.092
Abstract:
The schemes of three model predictive current control (MPCC) for permanent magnet synchronous motor (PMSM) is compared. The conventional MPCC strategy applies one voltage vector which can minimizes a cost function in each sampling period. The two-vector-based MPCC strategy outputs two voltage vectors in each sampling period, and calculates the working time of them respectively. The method makes the resulting voltage vector closer to the expected voltage vector. The three-vector-based MPCC strategy outputs two optimal voltage vectors and one zero vector in each sampling period. In this method, the coverage range of alternative voltage vectors is expanded and the current ripples are reduced. The dynamic performance and steady state behavior of three control schemes is compared by the simulation experiments. Simulation results show that three-vector-based or two-vector-based MPCC strategy has good steady state and dynamic performance. Compared with the conventional MPCC strategy, the proposed method can reduce the current ripples effectively.
The schemes of three model predictive current control (MPCC) for permanent magnet synchronous motor (PMSM) is compared. The conventional MPCC strategy applies one voltage vector which can minimizes a cost function in each sampling period. The two-vector-based MPCC strategy outputs two voltage vectors in each sampling period, and calculates the working time of them respectively. The method makes the resulting voltage vector closer to the expected voltage vector. The three-vector-based MPCC strategy outputs two optimal voltage vectors and one zero vector in each sampling period. In this method, the coverage range of alternative voltage vectors is expanded and the current ripples are reduced. The dynamic performance and steady state behavior of three control schemes is compared by the simulation experiments. Simulation results show that three-vector-based or two-vector-based MPCC strategy has good steady state and dynamic performance. Compared with the conventional MPCC strategy, the proposed method can reduce the current ripples effectively.
2021, 48(10):14-19.
DOI: 10.12177/emca.2021.090
Abstract:
The sensorless technology cannot directly obtain the absolute position of the permanent magnet linear synchronous motor (PMLSM) mover, and the mover position is estimated by integrating the speed. However, the speed is estimated by sensorless technology, and there is still a slight error between the actual speed. With the continuous movement of the motor, the accumulated deviation eventually causes the deviation between the estimated position and the actual position to diverge, or even make the position servo system based on sensorless control collapse. A new low-cost, high-precision position correction strategy is proposed, and the simulation verification is conducted. The simulation results show that this strategy improves the accuracy of the position estimation results and eliminates the risk of sensorless position servo system breakdown due to accumulated deviations.
The sensorless technology cannot directly obtain the absolute position of the permanent magnet linear synchronous motor (PMLSM) mover, and the mover position is estimated by integrating the speed. However, the speed is estimated by sensorless technology, and there is still a slight error between the actual speed. With the continuous movement of the motor, the accumulated deviation eventually causes the deviation between the estimated position and the actual position to diverge, or even make the position servo system based on sensorless control collapse. A new low-cost, high-precision position correction strategy is proposed, and the simulation verification is conducted. The simulation results show that this strategy improves the accuracy of the position estimation results and eliminates the risk of sensorless position servo system breakdown due to accumulated deviations.
2021, 48(10):20-28.
DOI: 10.12177/emca.2021.095
Abstract:
The high-frequency signal injection method solves many of the problems of the permanent magnet motor without speed sensing control in zero- and low-speed operation, but its slow dynamic performance is also a major shortcoming. To address the dynamic response of high-frequency injection permanent magnet synchronous motor (PMSM) with speed sensorless control, an improved phase locked loop (PLL) structure based on variable structure sliding mode control is proposed. The structure is designed based on the traditional PLL, and the dynamic performance of the PLL is improved by performing the sliding mode control on the input signal of the PLL after the high-frequency signal is mediated. Compared with the traditional PLL structure, the method enhances the dynamic response of the system, and does not require motor parameters, and enhances the robustness of the system due to the introduction of the variable structure sliding mode function. Simulation and experimental results prove that the method shortens the motor dynamic response time and reduces the dynamic response overshoot, which proves the feasibility and effectiveness of the improved algorithm.
The high-frequency signal injection method solves many of the problems of the permanent magnet motor without speed sensing control in zero- and low-speed operation, but its slow dynamic performance is also a major shortcoming. To address the dynamic response of high-frequency injection permanent magnet synchronous motor (PMSM) with speed sensorless control, an improved phase locked loop (PLL) structure based on variable structure sliding mode control is proposed. The structure is designed based on the traditional PLL, and the dynamic performance of the PLL is improved by performing the sliding mode control on the input signal of the PLL after the high-frequency signal is mediated. Compared with the traditional PLL structure, the method enhances the dynamic response of the system, and does not require motor parameters, and enhances the robustness of the system due to the introduction of the variable structure sliding mode function. Simulation and experimental results prove that the method shortens the motor dynamic response time and reduces the dynamic response overshoot, which proves the feasibility and effectiveness of the improved algorithm.
2021, 48(10):29-34.
DOI: 10.12177/emca.2021.088
Abstract:
Affected by the band-pass filter, the rotor position estimation accuracy in the pulsation injection method of the PMSM is low. For this reason, a method of sensorless control of PMSM based on variable universe fuzzy PI is proposed. The variable universe fuzzy method is used to dynamically adjust the fixed PI parameters on the speed loop. The system delay is reduced and the accuracy of rotor position estimation is improved. The simulation results show that the variable universe fuzzy PI can be used for rotor position estimation, and it reduces the average error of 0.331 degrees than that of the traditional sensorless control method.
Affected by the band-pass filter, the rotor position estimation accuracy in the pulsation injection method of the PMSM is low. For this reason, a method of sensorless control of PMSM based on variable universe fuzzy PI is proposed. The variable universe fuzzy method is used to dynamically adjust the fixed PI parameters on the speed loop. The system delay is reduced and the accuracy of rotor position estimation is improved. The simulation results show that the variable universe fuzzy PI can be used for rotor position estimation, and it reduces the average error of 0.331 degrees than that of the traditional sensorless control method.
2021, 48(10):35-40，83.
DOI: 10.12177/emca.2021.087
Abstract:
In the structure of two parallel-connected asynchronous motors controlled by a single inverter under the same bogie of metro, factors such as wheel diameter difference or different motor parameters will lead to the large torque difference between the motors and torque ripple. In order to solve this problem, a speed coupling load model of double asynchronous motors in parallel under the same bogie of metro is established. The direct torque control strategy based on space vector modulation is adopted, and the weighting coefficient of real-time calculation is introduced, so that the weight of direct torque control tends to the motor with smaller torque. The control scheme has the characteristics of smaller torque ripple, constant switching frequency of inverter, and smaller torque difference between motors. The simulation results show that compared with the average direct torque control, the weighted direct torque control method can effectively reduce the torque difference between the motors and decrease the torque ripple.
In the structure of two parallel-connected asynchronous motors controlled by a single inverter under the same bogie of metro, factors such as wheel diameter difference or different motor parameters will lead to the large torque difference between the motors and torque ripple. In order to solve this problem, a speed coupling load model of double asynchronous motors in parallel under the same bogie of metro is established. The direct torque control strategy based on space vector modulation is adopted, and the weighting coefficient of real-time calculation is introduced, so that the weight of direct torque control tends to the motor with smaller torque. The control scheme has the characteristics of smaller torque ripple, constant switching frequency of inverter, and smaller torque difference between motors. The simulation results show that compared with the average direct torque control, the weighted direct torque control method can effectively reduce the torque difference between the motors and decrease the torque ripple.
2021, 48(10):41-44.
DOI: 10.12177/emca.2021.100
Abstract:
Mostly stator flux linkage is obtained by integration of back electromotive force (back-EMF). The initial value and DC bias of the back-EMF can make the integral result deviation seriously. The amplitude and phase relationships of stator voltage, back-EMF and stator flux linkage in three-phase induction motor are analyzed, and a new method is proposed for the calculation of stator flux. This method is simple in theory, easy to be implemented and has small amount of calculation. The MATLAB simulation prove the feasibility and effectiveness of the proposed method.
Mostly stator flux linkage is obtained by integration of back electromotive force (back-EMF). The initial value and DC bias of the back-EMF can make the integral result deviation seriously. The amplitude and phase relationships of stator voltage, back-EMF and stator flux linkage in three-phase induction motor are analyzed, and a new method is proposed for the calculation of stator flux. This method is simple in theory, easy to be implemented and has small amount of calculation. The MATLAB simulation prove the feasibility and effectiveness of the proposed method.
2021, 48(10):45-50，70.
DOI: 10.12177/emca.2021.107
Abstract:
The performance of permanent magnet synchronous motor (PMSM) is excellent. However, the permanent magnet excitation cannot be regulated, which leads to a limited speed regulation range. A novel rotor structure of negative-salient permanent magnet synchronous motor (NSPMSM) is proposed by utilizing the magnetic bridge to increase d-axis inductance and the W-shaped permanent magnet to decrease q-axis inductance. The characteristics of torque and flux-weakening speed regulation of the NSPMSM are analyzed by theoretical analysis, and the negative-salient polarity is verified by the finite element method. The influences of rotor structure parameters on the electromagnetic torque and speed regulation performance of the NSPMSM are studied. The flux-weakening simulation results obtained by finite element method are consistent with the theoretical analysis results, which verifies the effectiveness of the structure in improving the flux-weakening speed regulation range.
The performance of permanent magnet synchronous motor (PMSM) is excellent. However, the permanent magnet excitation cannot be regulated, which leads to a limited speed regulation range. A novel rotor structure of negative-salient permanent magnet synchronous motor (NSPMSM) is proposed by utilizing the magnetic bridge to increase d-axis inductance and the W-shaped permanent magnet to decrease q-axis inductance. The characteristics of torque and flux-weakening speed regulation of the NSPMSM are analyzed by theoretical analysis, and the negative-salient polarity is verified by the finite element method. The influences of rotor structure parameters on the electromagnetic torque and speed regulation performance of the NSPMSM are studied. The flux-weakening simulation results obtained by finite element method are consistent with the theoretical analysis results, which verifies the effectiveness of the structure in improving the flux-weakening speed regulation range.
2021, 48(10):51-57.
DOI: 10.12177/emca.2021.103
Abstract:
With the extensive use of all-electric aircraft, how to achieve lightweight motor and improve power density to meet higher performance requirements has gradually become a hot research issue. An outer rotor surface permanent magnet synchronous motor (SPMSM) used in all-electric aircraft is taken as the research object. Based on finite element simulation, the static mechanical field of 6063t6 aluminum alloy and steel is analyzed, and the lighter 6063t6 aluminum alloy is selected. Under the premise of safety factor of 10, end cover thickness is reduced to 2 mm and shell thickness is 5 mm. Then, a hollow-out casing structure is proposed, and with the “crab clamp” stiffener, the safety factor of the proposed structure is successfully improved from 5.5 to 10, and the weight of optimized casing is reduced by 51.92%. By comparing the structure of the “crab clamp” type with linear type stiffeners, the superiority of “crab clamp” type stiffener is verified. The optimized motor structure meets both lightweight design and reliable operation requirements.
With the extensive use of all-electric aircraft, how to achieve lightweight motor and improve power density to meet higher performance requirements has gradually become a hot research issue. An outer rotor surface permanent magnet synchronous motor (SPMSM) used in all-electric aircraft is taken as the research object. Based on finite element simulation, the static mechanical field of 6063t6 aluminum alloy and steel is analyzed, and the lighter 6063t6 aluminum alloy is selected. Under the premise of safety factor of 10, end cover thickness is reduced to 2 mm and shell thickness is 5 mm. Then, a hollow-out casing structure is proposed, and with the “crab clamp” stiffener, the safety factor of the proposed structure is successfully improved from 5.5 to 10, and the weight of optimized casing is reduced by 51.92%. By comparing the structure of the “crab clamp” type with linear type stiffeners, the superiority of “crab clamp” type stiffener is verified. The optimized motor structure meets both lightweight design and reliable operation requirements.
2021, 48(10):58-64.
DOI: 10.12177/emca.2021.099
Abstract:
Aiming at the problem that the permanent magnet coupler produces a large amount of heat on the copper plate side of the conductor during operation and the device cannot work normally, a structure that can effectively improve the heat dissipation capacity of the conductor copper plate is proposed. First, based on the fluid-solid coupling mathematical model and the theoretical equations of heat transfer, the temperature distribution of the conductor copper plate of the permanent magnet coupler under different slips and different air gap lengths is calculated through finite element simulation, and the simulation results are compared with the experimental test results. The comparison verifies the accuracy of the simulation calculation method. Second, in view of the problem that the temperature of the conductor copper plate is too high and the heat cannot be dissipated, a structure with air guide heat sink added to the outside of the end cover is proposed, and the influence of heat sinks of different shapes on the heat dissipation effect is simulated and analyzed. Finally, the influences of the height, thickness and quantity of the air guide heat sinks on the temperature rise of the conductor copper plate are analyzed, and the optimal ranges of the design parameters of the air guide heat sink are obtained, providing scientific basis for the design of the air cooling heat dissipation structure of the permanent magnet coupler.
Aiming at the problem that the permanent magnet coupler produces a large amount of heat on the copper plate side of the conductor during operation and the device cannot work normally, a structure that can effectively improve the heat dissipation capacity of the conductor copper plate is proposed. First, based on the fluid-solid coupling mathematical model and the theoretical equations of heat transfer, the temperature distribution of the conductor copper plate of the permanent magnet coupler under different slips and different air gap lengths is calculated through finite element simulation, and the simulation results are compared with the experimental test results. The comparison verifies the accuracy of the simulation calculation method. Second, in view of the problem that the temperature of the conductor copper plate is too high and the heat cannot be dissipated, a structure with air guide heat sink added to the outside of the end cover is proposed, and the influence of heat sinks of different shapes on the heat dissipation effect is simulated and analyzed. Finally, the influences of the height, thickness and quantity of the air guide heat sinks on the temperature rise of the conductor copper plate are analyzed, and the optimal ranges of the design parameters of the air guide heat sink are obtained, providing scientific basis for the design of the air cooling heat dissipation structure of the permanent magnet coupler.
2021, 48(10):65-70.
DOI: 10.12177/emca.2021.105
Abstract:
The steady-state and dynamic operating performances of the motor can be directly affected by inductance. The effects of magnetic circuit saturation and cross-coupling are more serious for the vehicle drive motor, so that the accurate calculation of the inductance parameters will be more difficult. Ignoring the saturation effect when calculating the inductance will reduce the torque control accuracy. At the same time, the load current range will become very large and the change of magnetic circuit saturation will be complicated in the vehicle drive motor. By comparing the apparent inductance and incremental inductance when the load current is increased, the relationship and change law between them are analyzed, and the influence of skewed rotor on the inductance is studied. The results show that large difference exists between the calculation results when the magnetic circuit is highly saturated, for which the incremental inductance is 11%~30% of the apparent inductance. The changes in permeability with skewed rotor have a great impact on the motor’s self-inductance parameters, followed by mutual inductance.
The steady-state and dynamic operating performances of the motor can be directly affected by inductance. The effects of magnetic circuit saturation and cross-coupling are more serious for the vehicle drive motor, so that the accurate calculation of the inductance parameters will be more difficult. Ignoring the saturation effect when calculating the inductance will reduce the torque control accuracy. At the same time, the load current range will become very large and the change of magnetic circuit saturation will be complicated in the vehicle drive motor. By comparing the apparent inductance and incremental inductance when the load current is increased, the relationship and change law between them are analyzed, and the influence of skewed rotor on the inductance is studied. The results show that large difference exists between the calculation results when the magnetic circuit is highly saturated, for which the incremental inductance is 11%~30% of the apparent inductance. The changes in permeability with skewed rotor have a great impact on the motor’s self-inductance parameters, followed by mutual inductance.
2021, 48(10):71-76，83.
DOI: 10.12177/emca.2021.089
Abstract:
In current researches on reducing torque ripple of interior permanent magnet synchronous motor (IPMSM) by asymmetric method, there is no detailed study on the influence on electromagnetic vibration noise of the motor. For this reason, taking a 37 kW IPMSM as the research object, the electromagnetic field finite element model and the vibration noise coupling model of the original motor and the motor with asymmetric magnetic barrier structure are established. The effects of the asymmetric magnetic barrier structure on the vibration noise of the motor are compared and analyzed. The order and frequency characteristics of the radial electromagnetic force wave of the permanent magnet motor are analyzed theoretically, and the radial electromagnetic force wave at the air gap is decomposed by using the finite element method and two-dimensional Fourier decomposition method. The finite element model of the stator structure is established and its modal analysis is carried out. Then the vibration noise coupling model is built on the simulation platform to obtain the vibration response and electromagnetic noise of the motor stator. The results show that, although the design method of asymmetric magnetic barrier can reduce the torque ripple of the motor and does not sacrifice the output torque of the motor, it will generate other frequency multiplied electromagnetic force and increase the vibration response of the corresponding frequency points, and deteriorate the vibration noise of the motor, which should be considered comprehensively in the design.
In current researches on reducing torque ripple of interior permanent magnet synchronous motor (IPMSM) by asymmetric method, there is no detailed study on the influence on electromagnetic vibration noise of the motor. For this reason, taking a 37 kW IPMSM as the research object, the electromagnetic field finite element model and the vibration noise coupling model of the original motor and the motor with asymmetric magnetic barrier structure are established. The effects of the asymmetric magnetic barrier structure on the vibration noise of the motor are compared and analyzed. The order and frequency characteristics of the radial electromagnetic force wave of the permanent magnet motor are analyzed theoretically, and the radial electromagnetic force wave at the air gap is decomposed by using the finite element method and two-dimensional Fourier decomposition method. The finite element model of the stator structure is established and its modal analysis is carried out. Then the vibration noise coupling model is built on the simulation platform to obtain the vibration response and electromagnetic noise of the motor stator. The results show that, although the design method of asymmetric magnetic barrier can reduce the torque ripple of the motor and does not sacrifice the output torque of the motor, it will generate other frequency multiplied electromagnetic force and increase the vibration response of the corresponding frequency points, and deteriorate the vibration noise of the motor, which should be considered comprehensively in the design.
13 Real-Time Diagnosis of Traction Motor Over-Current Based on Time-SeriesFeature Pattern Recognition
2021, 48(10):77-83.
DOI: 10.12177/emca.2021.098
Abstract:
Aiming at the real-time diagnosis and accurate fault tracing of motor over-current in traction drive system, a real-time diagnosis method based on fault time-series feature pattern recognition is proposed. Firstly, the common fault sources leading to over-current of traction motor are analyzed. Then, by summarizing the change law of event time-series strongly related to working conditions, the diagnosis rule base of motor over-current fault time-series feature pattern is designed off-line. Then, the relevant sensor signals and system working condition information are collected online in real time, the relevant feature quantities and event flags are calculated, and the patterns and diagnostic rules in the off-line designed diagnosis rule base are matched in real time, so as to realize the real-time diagnosis and accurate tracing of traction motor over-current fault. Finally, the effectiveness of the proposed method is verified by field fault cases testing.
Aiming at the real-time diagnosis and accurate fault tracing of motor over-current in traction drive system, a real-time diagnosis method based on fault time-series feature pattern recognition is proposed. Firstly, the common fault sources leading to over-current of traction motor are analyzed. Then, by summarizing the change law of event time-series strongly related to working conditions, the diagnosis rule base of motor over-current fault time-series feature pattern is designed off-line. Then, the relevant sensor signals and system working condition information are collected online in real time, the relevant feature quantities and event flags are calculated, and the patterns and diagnostic rules in the off-line designed diagnosis rule base are matched in real time, so as to realize the real-time diagnosis and accurate tracing of traction motor over-current fault. Finally, the effectiveness of the proposed method is verified by field fault cases testing.
2021, 48(10):84-90，102.
DOI: 10.12177/emca.2021.096
Abstract:
In order to improve the selectivity and quick action of generator loss of field (LOF) protection, a method for LOF protection based on support vector machine (SVM) for intelligent identification of trajectory is proposed. The measured impedance trajectory of the generator contains lots of generator operation information, and the motion characteristics can reflect the generator's operating state. First, the global and local features of the measured impedance trajectory of the generator are extracted, and the extracted motion feature sequence is calculated separately for statistical parameters to form 24-dimensional features. Then through principal component analysis of the feature space to reduce the dimensionality, the corresponding training input feature space is formed, and genetic simulated annealing algorithm is used for the SVM to optimize the parameters support. Finally, sample simulation verifies that this method can accurately identify the LOF. Compared with the traditional LOF protection, the proposed method improves the selectivity and quickness of the protection.
In order to improve the selectivity and quick action of generator loss of field (LOF) protection, a method for LOF protection based on support vector machine (SVM) for intelligent identification of trajectory is proposed. The measured impedance trajectory of the generator contains lots of generator operation information, and the motion characteristics can reflect the generator's operating state. First, the global and local features of the measured impedance trajectory of the generator are extracted, and the extracted motion feature sequence is calculated separately for statistical parameters to form 24-dimensional features. Then through principal component analysis of the feature space to reduce the dimensionality, the corresponding training input feature space is formed, and genetic simulated annealing algorithm is used for the SVM to optimize the parameters support. Finally, sample simulation verifies that this method can accurately identify the LOF. Compared with the traditional LOF protection, the proposed method improves the selectivity and quickness of the protection.
2021, 48(10):91-97，102.
DOI: 10.12177/emca.2021.094
Abstract:
In the process of power switching in ultra-high voltage (UHV) substation, the electric shock current of the synchronous condenser circulating water pump will be too large, leading to the situation of multistage tripping. In order to study the switching strategy, the frequency and amplitude of the residual voltage are quantitatively analyzed over time, and relevant simulation studies are carried out. The transient state of reclosing is studied, and the change law of impulse current with time is obtained through simulation. According to the simulation, it is found that the maximum value of the shock current lags slightly behind the point with opposite phase, the minimum value lags slightly behind the point with same phase, and the lag depends on the decay rate of the loss residual voltage. On this bases, a switching method based on the difference between the loss residual voltage and the amplitude of the supply voltage is proposed. The simulation results are analyzed to provide some references for maintenance personnel, so as to reduce the impulse current in the switching process as much as possible and avoid switching failure.
In the process of power switching in ultra-high voltage (UHV) substation, the electric shock current of the synchronous condenser circulating water pump will be too large, leading to the situation of multistage tripping. In order to study the switching strategy, the frequency and amplitude of the residual voltage are quantitatively analyzed over time, and relevant simulation studies are carried out. The transient state of reclosing is studied, and the change law of impulse current with time is obtained through simulation. According to the simulation, it is found that the maximum value of the shock current lags slightly behind the point with opposite phase, the minimum value lags slightly behind the point with same phase, and the lag depends on the decay rate of the loss residual voltage. On this bases, a switching method based on the difference between the loss residual voltage and the amplitude of the supply voltage is proposed. The simulation results are analyzed to provide some references for maintenance personnel, so as to reduce the impulse current in the switching process as much as possible and avoid switching failure.
2021, 48(10):98-102.
DOI: 10.12177/emca.2021.093
Abstract:
For a film capacitor used in SiC controller, the internal temperature distribution is studied by combining finite element thermal simulation analysis and bench test. The internal structure of film capacitor is designed, the structure layout of the film capacitor in the SiC controller is introduced, and the thermal simulation model of the film capacitor is established. The temperature distribution rule of the film capacitor under the rated working condition of the SiC controller is mainly studied. The film capacitor sample is made and thermocouples are embedded in it. The actual temperature of the film capacitor under the rated working condition is verified by bench test. Through the comparative analysis of the simulation and test results, the effectiveness of using finite element thermal simulation to study the film capacitor of SiC controller is proved. The research results can provide certain reference value for the efficient heat dissipation design of the film capacitor for SiC controller.
For a film capacitor used in SiC controller, the internal temperature distribution is studied by combining finite element thermal simulation analysis and bench test. The internal structure of film capacitor is designed, the structure layout of the film capacitor in the SiC controller is introduced, and the thermal simulation model of the film capacitor is established. The temperature distribution rule of the film capacitor under the rated working condition of the SiC controller is mainly studied. The film capacitor sample is made and thermocouples are embedded in it. The actual temperature of the film capacitor under the rated working condition is verified by bench test. Through the comparative analysis of the simulation and test results, the effectiveness of using finite element thermal simulation to study the film capacitor of SiC controller is proved. The research results can provide certain reference value for the efficient heat dissipation design of the film capacitor for SiC controller.
2021, 48(10):103-109.
DOI: 10.12177/emca.2021.102
Abstract:
The instantaneous output power of the two-stage single-phase inverter contains the pulsating power whose frequency is twice as much as the output voltage frequency. For this reason, the secondary ripple current exists in the input of the front-stage DC/DC converter. The control loop optimization of the pre-stage DC/DC converter is an effective and low-cost method to solve this problem. The equivalent circuit models of single loop control and double loop control are given through loop equivalence. Based on the concept of virtual impedance, the functions of voltage outer loop and current inner loop in secondary ripple current transfer process are analyzed. On this basis, the suppression principles of the conventional control strategies are explained and summarized, the limitations of existing control strategies are pointed out, and two optimization schemes are given. Finally, a 1.5 kVA two-stage single-phase inverter prototype is built for simulation and experimental verification, which verifies the feasibility of the analysis method and the effectiveness of the control strategy optimization.
The instantaneous output power of the two-stage single-phase inverter contains the pulsating power whose frequency is twice as much as the output voltage frequency. For this reason, the secondary ripple current exists in the input of the front-stage DC/DC converter. The control loop optimization of the pre-stage DC/DC converter is an effective and low-cost method to solve this problem. The equivalent circuit models of single loop control and double loop control are given through loop equivalence. Based on the concept of virtual impedance, the functions of voltage outer loop and current inner loop in secondary ripple current transfer process are analyzed. On this basis, the suppression principles of the conventional control strategies are explained and summarized, the limitations of existing control strategies are pointed out, and two optimization schemes are given. Finally, a 1.5 kVA two-stage single-phase inverter prototype is built for simulation and experimental verification, which verifies the feasibility of the analysis method and the effectiveness of the control strategy optimization.
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Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
沪ICP备16038578号-3
Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
