A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids
The cascaded droop-voltage-current controller plays a key role in the effective operation of microgrids, where the controller performance is critically impacted by the desigheme, a constant value n of the droop controller. Moreover, in critical loading (e.g.: connection/disconnection of large induc...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-12-01
|
| Series: | Symmetry |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-8994/15/1/1 |
| _version_ | 1797946605154861056 |
|---|---|
| author | Mandarapu Srikanth Yellapragada Venkata Pavan Kumar |
| author_facet | Mandarapu Srikanth Yellapragada Venkata Pavan Kumar |
| author_sort | Mandarapu Srikanth |
| collection | DOAJ |
| description | The cascaded droop-voltage-current controller plays a key role in the effective operation of microgrids, where the controller performance is critically impacted by the desigheme, a constant value n of the droop controller. Moreover, in critical loading (e.g.: connection/disconnection of large inductive load), the pre-set value of the droop coefficient brings asymmetry in transient performance leading to instability. Hence, to improve symmetry by reducing the trade-off between transient response and stability margin, this paper proposes a state machine-based droop control method (SMDCM) aided with droop coefficients’ tuning through in-feasible range detection. Here, to realize the issues and the role of the droop controller’s dynamics on the microgrid’s stability, a small-signal stability analysis is conducted, thereby, an in-feasible range of droop values is identified. Accordingly, safe values for droop coefficients are implemented using the state machine concept. This proposed SMDCM is compared with the conventional constant droop control method (CDCM) and fuzzy logic-based droop control method (FLDCM) in terms of frequency/power/voltage characteristics subjected to different power factor (PF) loading conditions. From the results, it is seen that CDCM failed in many metrics under moderate and poor PF loadings. FLDCM is satisfactory under moderate PF loading, but, showed 54 Hz/48 Hz as maximum/minimum frequency values during poor PF loading. These violate the standard limit of ±2%, but SMDCM satisfactorily showed 50.02 Hz and 49.8 Hz, respectively. Besides, FLDCM levied an extra burden of 860 W on the system while it is 550 W with SMDCM. System recovery has taken 0.04 s with SMDCM, which completely failed with FLDCM. Similarly, voltage THD with FLDCM is 58.9% while with SMDCM is 3.08%. Peak voltage due to capacitive load switching is 340V with FLDCM and 150 V with SMDCM. These findings confirm that the proposed SMDCM considerably improved the transient performance of microgrids. |
| first_indexed | 2024-04-10T21:13:41Z |
| format | Article |
| id | doaj.art-f09a1540d0f84247ba56ac22109745de |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-04-10T21:13:41Z |
| publishDate | 2022-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-f09a1540d0f84247ba56ac22109745de2023-01-20T15:41:44ZengMDPI AGSymmetry2073-89942022-12-01151110.3390/sym15010001A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of MicrogridsMandarapu Srikanth0Yellapragada Venkata Pavan Kumar1School of Electronics Engineering, VIT-AP University, Amaravati 522237, Andhra Pradesh, IndiaSchool of Electronics Engineering, VIT-AP University, Amaravati 522237, Andhra Pradesh, India The cascaded droop-voltage-current controller plays a key role in the effective operation of microgrids, where the controller performance is critically impacted by the desigheme, a constant value n of the droop controller. Moreover, in critical loading (e.g.: connection/disconnection of large inductive load), the pre-set value of the droop coefficient brings asymmetry in transient performance leading to instability. Hence, to improve symmetry by reducing the trade-off between transient response and stability margin, this paper proposes a state machine-based droop control method (SMDCM) aided with droop coefficients’ tuning through in-feasible range detection. Here, to realize the issues and the role of the droop controller’s dynamics on the microgrid’s stability, a small-signal stability analysis is conducted, thereby, an in-feasible range of droop values is identified. Accordingly, safe values for droop coefficients are implemented using the state machine concept. This proposed SMDCM is compared with the conventional constant droop control method (CDCM) and fuzzy logic-based droop control method (FLDCM) in terms of frequency/power/voltage characteristics subjected to different power factor (PF) loading conditions. From the results, it is seen that CDCM failed in many metrics under moderate and poor PF loadings. FLDCM is satisfactory under moderate PF loading, but, showed 54 Hz/48 Hz as maximum/minimum frequency values during poor PF loading. These violate the standard limit of ±2%, but SMDCM satisfactorily showed 50.02 Hz and 49.8 Hz, respectively. Besides, FLDCM levied an extra burden of 860 W on the system while it is 550 W with SMDCM. System recovery has taken 0.04 s with SMDCM, which completely failed with FLDCM. Similarly, voltage THD with FLDCM is 58.9% while with SMDCM is 3.08%. Peak voltage due to capacitive load switching is 340V with FLDCM and 150 V with SMDCM. These findings confirm that the proposed SMDCM considerably improved the transient performance of microgrids. https://www.mdpi.com/2073-8994/15/1/1droop coefficients tuningdroop controlIn-feasible range detectionmicrogridsstate machinestransient performance |
| spellingShingle | Mandarapu Srikanth Yellapragada Venkata Pavan Kumar A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids Symmetry droop coefficients tuning droop control In-feasible range detection microgrids state machines transient performance |
| title | A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids |
| title_full | A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids |
| title_fullStr | A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids |
| title_full_unstemmed | A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids |
| title_short | A State Machine-Based Droop Control Method Aided with Droop Coefficients Tuning through In-Feasible Range Detection for Improved Transient Performance of Microgrids |
| title_sort | state machine based droop control method aided with droop coefficients tuning through in feasible range detection for improved transient performance of microgrids |
| topic | droop coefficients tuning droop control In-feasible range detection microgrids state machines transient performance |
| url | https://www.mdpi.com/2073-8994/15/1/1 |
| work_keys_str_mv | AT mandarapusrikanth astatemachinebaseddroopcontrolmethodaidedwithdroopcoefficientstuningthroughinfeasiblerangedetectionforimprovedtransientperformanceofmicrogrids AT yellapragadavenkatapavankumar astatemachinebaseddroopcontrolmethodaidedwithdroopcoefficientstuningthroughinfeasiblerangedetectionforimprovedtransientperformanceofmicrogrids AT mandarapusrikanth statemachinebaseddroopcontrolmethodaidedwithdroopcoefficientstuningthroughinfeasiblerangedetectionforimprovedtransientperformanceofmicrogrids AT yellapragadavenkatapavankumar statemachinebaseddroopcontrolmethodaidedwithdroopcoefficientstuningthroughinfeasiblerangedetectionforimprovedtransientperformanceofmicrogrids |