Hybrid Power System
This solar PV, wind turbine generator and Fuel Cell charge controllers referred to as SCC, WTGCC and FCCC respectively are designed to utilize solar, wind and fuel cell energy to power the critical load. These Charge Controllers along with SMPS based charger for grid and DG set. Constitute the Hybrid power system that has been configured for critical load applications in the infra-structure development areas like Telecom, Railway signaling etc.
The following features have been built into the S/WTG/FC CC for improved system performance.
- Use of blocking devices to prevent the flow of reverse current from the battery to the FC/WTG/SPV module.
- Lighting / transient protection has been incorporated to protect the control circuitry from damage due to the excessive voltage through proper rated surge suppression devices.
- Programmable charging capacity, change over settings and peak power point.
- Programmable maximum power point tracking (MPPT) logic with the built in embedded logic controller.
The SCC charges the battery efficiently from the solar SPV array. Blocking diodes employed to prevent the discharge of battery through the SPV Module during high or cloudy days.
The WTGCC charges the battery efficiently from the Wind Turbine Generator. Contactor employed to prevent the discharge of battery through the WTG during no wind period.
The FCCC charges the battery efficiently from the Fuel Cell. Blocking diode employed to prevent the discharge of battery through the FC during other charging modes.
The FC/WTG/S CC is capable of operating in the float and boost charge mode to charge the batteries as well as supply power to the critical load. The FC/WTG/S CC provides a built in monitor with a selector switch to view/monitor various voltages and currents, apart from the visual indications with LED’s to monitor the system operation.
The details of integration of the SPV Modules, Wind Turbine Generator, Fuel Cell, AC Mains, DG set, SMPS Charger, SCC, WTGCC, FCCC, Batteries, Inverter and the loads are shown in fig. 1. This configuration is called Hybrid Power Supply or Integrated Power Supply. Most of the customers either have Fuel Cell or DG set, but not both. With the Inverter AC loads are also accommodated with the necessary back-up requirement. Dual inverters with automatic bypass can be provided for the redundancy and to avoid any single point failure.
Maximum of three Battery strings can be added for the redundant operation of the system for all critical loads. Battery Health Monitoring and Remote Monitoring features are optional. Also it can be extended to add the customer specific load termination distribution boxes for AC and DC loads with necessary switch gear and protection circuitry.
Changeover Logic operates on sensing the presence of WTG voltage, SPV voltage, FCC voltage, Battery voltage, Battery current & AC supply as per the following conditions:-
|2||No||Available||—||On Mains||* @70% of battery DOD|
|3||No||No||Available||On FC/DG set||* @50% of battery DOD|
|4||No||No||No||On Battery||Till reaches Cut off (@ 44.4 for 48VDC nominal)|
|5||No||No||Restores||On FC/DG set||* after one min. delay if battery DOD is < 55%|
|6||No||Restores||—||On Mains||* after one min. delay if battery DOD is < 75%|
|7||Restores||—||—||On SPV/WTG||* after one minute delay|
* These are user programmable parameters.
The voltage and current ratings of the system can vary with the customer load requirements. Maximum DC voltage of 220V is envisaged so far but the other configurations are also available. The construction is modular to increase the reliability and to provide the scale up option to the customer