In the micro-grid network, it is especially difficult to support the critical load without uninterrupted power supply. The proposed micro-wind energy conversion system with battery energy storage is used to exchange the controllable real and reactive power in the grid and to maintain the power quality norms as per International Electro-Technical Commission IEC- 61400-21 at the point of common coupling. The generated micro wind power can be extracted under varying wind speed and can be stored in the batteries at low power demand hours. In this scheme, inverter control is executed with hysteresis current control mode to achieve the faster dynamic switchover for the support of critical load. The combination of battery storage with micro-wind energy generation system (μWEGS), which will synthesize the output waveform by injecting or absorbing reactive power and enable the real power flow required by the load. The system reduces the burden on the conventional source and utilizes μWEGS and battery storage power under critical load constraints. The system provides rapid response to support the critical loads. The scheme can also be operated as a stand-alone system in case of grid failure like a uninterrupted power supply. The system is simulated in MATLAB/SIMULINK and results are presented.
- Battery energy storage
- Micro-wind energy generating system
- Power quality
Fig. 1. Scheme of micro-wind generator with battery storage for critical load application.
EXPECTED SIMULATION RESULTS:
Fig. 2. (a) Source current. (b) Inverter injected current. (c) Load current.
Fig. 3. (a) Source current. (b) Load current. (c) Inverter-injected current.
Fig. 4. (a) DC link voltage. (b) Rectified current of wind generator.
(c) Current supplied by battery. (d) Charging-discharging of dc link capacitor.
Fig. 5. Source current and source voltage at PCC.
Fig. 6. (a) Source current. (b) FFT of source current.
Fig. 7. (a) Source current. (b) FFT of source current.
Fig. 8. Active and reactive power (a) at source, (b) load, and (c) inverter.
In this project, modeling of bi-directional DC-DC converter is developed for wind energy generation and simulated in MATLAB/SIMULINK. The performance of the bi-directional converter using triangle PWM technique has been analyzed from the prospective of input/output characteristics and harmonic content of output voltage and current. The multi-stage current charging method is used to charge the batteries. At various wind speeds, the system can use the battery for energy storage to keep the load voltage and load current stable. Control strategy and system design can be easily implemented and able to improve the efficiency of wind turbine systems.
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