Sensorless Control of Permanent Magnet Synchronous Motor in Full Speed Range*

ABSTRACT:

 Aiming at resolving the limitation of the speed regulation range of sensorless control technology, a new composite sensorless control strategy is proposed to realize a control method for a permanent magnet synchronous motor (PMSM) in full speed range. In the medium- and high-speed range, the improved new sliding mode observer method is used to estimate the motor speed and rotor position information. In the zero and low speed range, in order to avoid the defects of the sliding mode method, the rotating high-frequency voltage signal injection method is used. When switching between low, medium, and high speed, the fuzzy control algorithm is adopted to achieve smooth transitions. The simulation experiment results show that the hybrid mode combining the sliding mode observer and rotating high-frequency voltage injection methods, can effectively reduce the jitter in the algorithm switching process, and realize the smooth control of a PMSM in full speed range.

KEYWORDS:

1.      PMSM

2.      Full speed range

3.      Rotating high-frequency voltage signal injection method

4.      Sliding mode observer method

5.      Fuzzy Control

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

                                       

Fig. 1 Schematic diagram of improved sliding mode observer

 EXPECTED SIMULATION RESULTS:

Fig. 2 The full range sensorless control waveform under the traditional weighting algorithm

 

 Fig. 3 Full range sensorless control waveform based on fuzzy control

Fig. 4 Comparison of the speed waveforms of the two control algorithms in the switching interval

 Fig. 5 Comparison of the rotor position waveforms of the two control algorithms in the switching interval

 

CONCLUSION:

 In this paper, the overall scheme design and control strategy of the PMSM sensorless control system, are studied, and the control method of motor running in the full-speed range, is analyzed in detail. The simulation results and experiments show that the high-frequency signal injection method in the low-speed range, and the sliding mode observer method in the medium and high speed range, can accurately estimate the rotor position and speed, and the tracking speed is fast. In the estimation process, the robustness improves. At the same time, using fuzzy control in the low-speed to medium and high-speed range, can make the PMSM switch smoothly, which has a certain application value.

REFERENCES:

[1] H Lin, H Guo, H Qian. Design of high-performance permanent magnet synchronous motor for electric aircraft propulsion. Proc. 21st Int. Conf. Electrfic. Mach. Syst. (ICEMS), 2018: 174-179.

[2] S Kim, J I Ha, S K Sul. PWM switching frequency signal Injection sensorless method in IPMSM. IEEE Transactions on Industry Application, 2012, 48(5): 1576-1587.

[3] Y P Zhou, G Yang, J H Yang. Speed control strategy of permanent magnet synchronous motor based on adaptive backstepping. Chinese Journal of Electrical Engineering, 2020, 15(3): 38-43.

[4] Y P Zhou , G Yang , J H Yang. PMSM speed control using adaptive sliding mode control based on an extended state observer. High Technology Letters, 2018(4): 422-433.

[5] S Q Peng , Y Y Song . Sensorless vector control of PMSM based on adaptive fuzzy sliding mode observer. Control and Decision, 2018, 33(4): 644-648.

Investigating The Ability Of Shunt Hybrid Power Filter Based On SRF Method Under Non-Ideal Supply Voltage

 ABSTRACT:

This study presents the capacity of a self-tuning filter based on the synchronous reference frame method with a fuzzy logic controller for the improvement of the efficiency of harmonic suppression of a shunt hybrid active power filter in an unbalanced distorted and undistorted voltage supply conditions. The simulation results indicated that the filter with a fuzzy logic controller had a good filtering performance in steady and transient states, irrespective of whether the voltage supply is distorted or unbalanced.

SOFTWARE: MATLAB/SIMULINK

CONTROL DIAGRAM:

Figure 1. SRF control strategy with STF based on SHAPF.

EXPECTED SIMULATION RESULTS:

Figure 2. SHAF response under ideal voltage situation (a) Source voltage (Vs), (b) Load current (IL),

(c) load current with filter, (d) Filter compensation current ( If) , and (e) DC link voltage of system

(Vdc).

Figure 3. THD of current (Is)under ideal voltage supply.

Figure 4. SHAF response under non ideal voltage situation (a) Source voltage (Vs), (b) Load current (Il), (c) load current with filter, (d)Filter compensation current ( If), and (e) DC link voltage of system (Vdc).

 CONCLUSION:

 This paper investigated the effectiveness of a synchronous reference frame (SRF) with a self-tuning filter (STF) control strategy in controlling the performance of a three-phase SHAPF system under conditions of non-ideal and balanced supply voltage. The fuzzy logic controller was utilized for the adjustment of the DC voltage. The performance of the SHAPF system was investigated under a dynamic and steady state and under different load operating conditions. The simulation results showed the SAPF to have successfully reduced current harmonics to about 1.7 and 2.7 % for both cases of source voltages.

REFERENCES:

 [1] Eltawil, M.A. and Zhao, Z., 2010. Grid-connected photovoltaic power systems: Technical and potential problems—A review. Renewable and Sustainable Energy Reviews, 14(1), pp.112- 129.

[2] Bhat, A.H. and Agarwal, P., 2008. Three-phase power quality improvement ac/dc converters. Electric Power Systems Research, 78(2), pp.276-289.

[3] Wagner, V.E., Balda, J.C., Griffith, D.C., Mceachern, A., Barnes, T.M., Hartmann, D.P., Phileggi, D.J., Emannuel, A.E., Horton, W.F., Reid, W.E. and Ferraro, R.J., 1993. Effects of harmonics on equipment. IEEE Transactions on Power Delivery, 8(2), pp.672-680.

[4] Mohamed, M.A., 2015. Design of shunt active power filter to mitigate the harmonics caused by nonlinear loads (Doctoral dissertation, Universiti Tun Hussein Onn Malaysia).

[5] Soomro, D.M. and Almelian, M.M., 2015. Optimal design of a single tuned passive filter to

mitigate harmonics in power frequency.

Fuzzy Logic Controller-based Synchronverter in Grid-connected Solar Power System with Adaptive Damping Factor*

ABSTRACT:

 In recent years, renewable energy sources, specifically solar power systems, have developed rapidly owing to their technological maturity and cost effectiveness. However, its grid integration deteriorates frequency stability because of insufficient rotating masses and inertial response. Hence, a synchronverter, which is an inverter that mimics the operation of a synchronous generator, is crucial to interface solar power in a power grid. It stabilizes the power grid by emulating a virtual inertia. However, a conventional proportional-integral(PI)-based synchronverter is not equipped with an adaptive damping factor (Dp) or a digitalized smart controller to manage fast-responding solar inputs. Hence, a novel fuzzy logic controller (FLC) framework is proposed such that the synchronverter can operate in a grid-connected solar power system. In this study, Dp is controlled in real time using an FLC to achieve balance between speed and stability for frequency error correction based on frequency difference. Results of four case studies performed in Matlab/Simulink show that the proposed FLC-based synchronverter can stabilize the grid frequency by reducing the frequency deviation by at least 0.2 Hz (0.4%), as compared with the conventional PI-based synchronverter.

KEYWORDS:

1.      Fuzzy logic controller (FLC)

2.      Synchronverter

3.      Renewable energy system (RES)

4.      Grid stability

5.      Solar power system

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Power section of synchronverter

EXPECTED SIMULATION RESULTS:

                                       

Fig. 2 Active power for varying resistive loads (RL)

Fig. 3 Outputs of synchronverter for first case study

Fig. 4 Testing environment for second case study

 

Fig. 5 Outputs of synchronverter for second case study

 

Fig. 6 Testing environment for third case study

 

Fig. 7 Outputs of synchronverter for third case study

 

Fig. 8 Testing environment for fourth case study

 

 

Fig. 9 Outputs of synchronverter for fourth case study

CONCLUSION:

 Herein, a novel FLC-based framework was proposed to control a synchronverter in a grid- connected solar power system under dynamic weather conditions. Four case studies were simulated in Matlab/Simulink, and the results validated the ability of the proposed controller in stabilizing fg by reducing the frequency deviation by at least 0.2 Hz (0.4%), as compared with the conventional PI-basedsynchronverter. The performance of the FLC-based synchronverter was optimal even under sudden load changes or varying irradiances and temperatures. P was injected or absorbed whenever the frequency decreased or increased, respectively. The Dp controlled by the FLC was able to balance between transient speed and stability, whereby a larger Dp afforded a more prominent dampening effect, and vice versa.

 REFERENCES:

[1] H Zsiborács, N H Baranyai, A Vincze, et al. Intermittent renewable energy sources: The role of energy storage in the European Power System of 2040. MDPI Electronics, 2019, 8(7): 729.

[2] M Z Saleheen, A A Salema, S M M Islam, et al. A target-oriented performance assessment and model development of a grid-connected solar PV (GCPV) system for a commercial building in Malaysia. Renewable Energy, 2021, 171: 371-382.

[3] Y Wang, V Silva, A Winckels. Impact of high penetration of wind and PV generation on frequency dynamics in the continental Europe interconnected system. IET Renewable Power Generation, 2014, 10(1): 10-16.

[4] F Li, C Li, K Sun, et al. Capacity configuration of hybrid CSP/PV plant for economical application of solar energy. Chinese Journal of Electrical Engineering, 2020, 6(2): 19-29.

[5] G Perveen, M Rizwan, N Goel. Comparison of intelligent modelling techniques for forecasting solar energy and its application in solar PV based energy system. IET Energy Systems Integration, 2019, 1(1): 34-51.

Evaluation of High Step-up Power Conversion Systems for Large-capacity Photovoltaic Generation Integrated into Medium Voltage DC Grids*

 ABSTRACT:

 With the increase of dc based renewable energy generation and dc loads, the mediumvoltage dc (MVDC) distribution network is becoming a promising option for more efficient system integration. In particular, large-capacity photovoltaic (PV)-based power generation is growing rapidly, and a corresponding power conversion system is critical to integrate these large PV systems into MVDC power grid. Different from traditional ac grid-connected converters, the converter system for dc grid interfaced PV system requires large-capacity dc conversion over a wide range of ultra-high voltage step-up ratios. This is an important issue, yet received limited research so far. In this paper, a thorough study of dc-dc conversion system for a medium-voltage dc grid-connected PV system is conducted. The required structural features for such a conversion system are first discussed. Based on these features, the conversion system is classified into four categories by series-parallel connection scheme of power modules. Then two existing conversion system configurations as well as a proposed solution are compared in terms of input/output performance, conversion efficiency, modulation method, control complexity, power density, reliability, and hardware cost. In-depth analysis is carried out to select the most suitable conversion systems in various application scenarios.

KEYWORDS:

1.      Photovoltaic generation

2.      Dc-dc conversion

3.      Medium voltage dc grid

4.      Large-capacity

5.      Ultra-high voltage transfer ratio

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Topology of PDSR system solution

EXPECTED SIMULATION RESULTS:

Fig. 2 Cycle waves in steady state of the solution of PDSR

Fig. 3 Power step response of the solution of PDSR

Fig. 4 Cycle waves in steady state of the solution of PDDS

Fig. 5 Power step response of the solution of PDDS

Fig. 6 Cycle waves in steady state of the solution of PPDS

Fig. 7 Power step response of the solution of PPDS

 CONCLUSION:

 In this paper, the emerging conversion systems for large-scale PV plants integrated into MVDC grid are studied. The required structural features for such a conversion system are discussed. The conversion system can be classified into four categories by series-parallel connection scheme of power modules: PDSR, PPSR, PDDS and PPDS. Features of each connection-scheme are qualitatively analyzed. A solution of PDDS is also proposed in this paper. Through comparison of the proposed solution with the existing solutions of PDSR and PPDS are conducted through module topology analysis, simulation verification, and estimates of efficiency and cost. The system-connection schemes PDDS and PPDS are most promising. Usually, the PDDS scheme leads to high PWM frequency, good response, high power density and high efficiency, but it has a high cost for active switches and has common reliability. On the other hand, the PPDS scheme leads to low PWM frequency, slow response, low power density, and common efficiency. But it has a low cost of active switches and is highly reliable

 REFERENCES:

[1] A Q Huang, M L Crow, G T Heydt, et al. The future renewable electric energy delivery and management (FREEDM) system: The energy internet. Proceedings of the IEEE, 2011, 99(1): 133-148.

[2] E Rodriguez-Diaz, J C Vasquez, J M Guerrero. Intelligent dc homes in future sustainable energy systems: When efficiency and intelligence work together. IEEE Consumer Electronics Magazine, 2016, 5(1): 74-80.

[3] M Starke, L M Tolbert, B Ozpineci. AC vs. DC distribution: A Loss comparison. 2008 IEEE/PES Transmission and Distribution Conference and Exposition, 2008, Chicago, IL, USA.

[4] M Ding, Z Xu, W Wang, et al. A review on China’s large-scale PV integration: Progress, challenges and recommendations. Renewable and Sustainable Energy Reviews, 2016, 53(9): 639-652.

[5] F Li, C Li, K Sun, et al. Capacity configuration of hybrid CSP/PV plant for economical application of solar energy. Chinese Journal of Electrical Engineering, 2020, 6(2): 19-29.

Energy Management and Control Strategy of Photovoltaic/Battery Hybrid Distributed Power Generation Systems With an Integrated Three-Port Power Converter

ABSTRACT:

 Photovoltaic (PV)/battery hybrid power units have attracted vast research interests in recent years. For the conventional distributed power generation systems with PV/battery hybrid power units, two independent power converters, including a unidirectional dc–dc converter and a bidirectional converter, are normally required. This paper proposes an energy management and control strategy for the PV/battery hybrid distributed power generation systems with only one integrated three-port power converter. As the integrated bidirectional converter shares power switches with the full-bridge dc–dc converter, the power density and the reliability of the system is enhanced. The corresponding energy management and control strategy are proposed to realize the power balance among three ports in different operating scenarios, which comprehensively takes both the maximumpower point tracking (MPPT) benefit and the battery charging/discharging management into consideration. The simulations are conducted using the Matlab/Simulinksoftware to verify the operation performance of the proposed PV/battery hybrid distributed power generation system with the corresponding control algorithms, where the MPPT control loop, the battery charging/discharging management loop are enabled accordingly in different operating scenarios.

KEYWORDS:

1.      Energy management

2.      Maximum power point tracking

3.      Bidirectional power converter

4.      Photovoltaic/battery hybrid power unit

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

 Figure 1. The Proposed Pv/Battery Hybrid Distributed Power Generation System.

 EXPECTED SIMULATION RESULTS:

Figure 2. Pv Characteristic Curves With Irradiance = 1 Kw/M2 (Red) And Irradiance = 0.5 Kw/M2 (Blue) (Temperature = 25◦C).

 Figure 3. Steady State Simulation Results Of Operation Scenario 2. (A) Dc Bus Voltage Vbus; (B) Pv Voltage Vpv; (C) Pv Current Ipv; (D) Pv Referenc Voltage Vref; (E) Battery Charging Current Ib.

 

Figure 4. Steady State Simulation Results Of Operation Scenario 4. (A) Dc Bus Voltage Vbus; (B) Pv Voltage Vpv; (C) Pv Current Ipv; (D) Pv Reference Voltage Vref; (E) Battery Charging Current Ib.

Figure 5. Steady State Simulation Results Of Operation Scenario 5. (A) Dc Bus Voltage Vbus; (B) Pv Voltage Vpv; (C) Pv Current Ipv; (D) Battery Charging Current Ib.

Figure 6. Simulation Results With Irradiance Dropping From 1000 W/M2 To 500 W/M2 At T = 2 S. (A) Dc Bus Voltage Vbus; (B) Pv Voltage Vpv; (C) Pv Current Ipv; (D) Pv Reference Voltage Vref; (E) Battery Charging Current Ib.

 

Figure 7. Simulation Results With Load Power Rising From 8 Kw To 10 Kw At T = 2 S. (A) Dc Bus Voltage Vbus; (B) Pv Voltage Vpv; (C) Pv Current Ipv; (D) Pv Reference Voltage Vref; (E) Battery Charging Current Ib.

 

CONCLUSION:

 An integrated three-port power converter as the interface for the PV/battery hybrid distributed power generation system is proposed. Compared with the conventional system topology containing an independent DC-DC unidirectional conversion stage and a bidirectional conversion stage, the proposed sys- tem has advantages in terms of higher power density and reliability. The phase shift angle of the full bridge and the switch duty cycle are adopted as two control variables to obtain the required DC bus voltage and realize the power balance among three ports. Different operating scenarios of the system under various power conditions are discussed in detail and a comprehensive energy management and control strategy is proposed accordingly. The priority controller can enable one of the control loops in different scenarios to optimize the whole system performance, taking both the MPPT benefit and the battery charging/discharging manage- ment requirements into consideration. The simulation results verify the performance of the proposed PV/battery hybrid distributed power generation system and the feasibility of the control algorithm.

REFERENCES:

[1] F. Blaabjerg, Z. Chen, and S. B. Kjaer, ‘‘Power electronics as efficient interface in dispersed power generation systems,’’ IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1184–1194, Sep. 2004.

[2] J. M. Carrasco, L. G. Franquelo, J. T. Bialasiewicz, E. Galvan, R. Potillo, M. M. Prats, J. I. Leon, and N. Moreno-Alfonso, ‘‘Power-electronic sys- tems for the grid integration of renewable energy sources: A survey,’’ IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1002–1016, Jun. 2006.

[3] BP Statistical Review of World Energy, British Petroleum, London, U.K., Jun. 2018.

[4] J. P. Barton and D. G. Infield, ‘‘Energy storage and its use with inter- mittent renewable energy,’’ IEEE Trans. Energy Convers., vol. 19, no. 2, pp. 441–448, Jun. 2004.

[5] M. S. Whittingham, ‘‘History, evolution, and future status of energy storage,’’ Proc. IEEE, vol. 100, pp. 1518–1534, May 2012.