1 R. Saiju under the supervision of S. Heier, University of Kassel Isolated Grid with Micro-Hydro Power Plant, PV System and Diesel Genset as Back up System

Agenda  Aims  New HPS Possibility  Models  Control Structure  Conclusion

Aims of the Research Work  Exploring possibilities to develop new HPS without batteries For that following models has been developed  PV Plant  Diesel generator Plant  Micro-Hydro Power Plant  HPS – PV+Micro-Hydro  Implementation of Hybrid Power System (HPS) model to develop, test and verify new control strategies  Development of new hardware prototype using micro-controller, test and verify

New HPS without battery  Formation of mini-grid AC-Coupled  Expandable: Possible to connect other sources like WTG, Loads  Modular: with same control structure  State variables formation by micro-hydro

Suitability The new concept is suitable for the developing, mauntainous countries Focus country: Nepal Remote area: No road access, No grid connection, small rivers available, and sufficient radiation through out the year, specially in dry winter season For example: 1000 W/m2 nearly 300 days/ year

Some Remote Areas

Present Micro-Hydro  Example: Khani Khola Micro-Hydro Village Electrification Project  Maximum discharge in Jan: 390 lps  Average Discharge: lps  Designed discharge: 113 lps  Installed Capacity: 18 kW  No. of electrified Houses: 219  Frequency controller: Electronic Load Controller (No water flow regulation)  It means the rural electrification is only focused where water flow is more than requirement.

Advantages from new philosophy o Possible to electrify villages where water discharge is not much high o Utilisation of maximum solar energy which is available nearly 300 days/year o Possible to avoid expansive and complicated battery system o Guarantee of electricity with help of diesel genset

Models Micro Hydro Power Plant PV Power Plant Diesel Genset HPS-PV+Micro-Hydro

Micro-Hydro Power Plant  Voltage control through AVR  Frequency control through water regulation

Results

PV Power Plant Control System1:  Grid load comparison with available solar Irradiation,  Voltage guard (If grid voltage is less then lower Level, PV system is disconnected.)  Capacity: 10 kW

Inside PV System

Results For constant load and increasing irradiation

Diesel Genset Due to low cost, robust construction 3 phase induction generator is used in diesel genset. A capacitor is used to excite the generator at no load condition. Mathematical representation

Isolated Operation NLC -> LC ->

Results.. Showing behaviour of system Fig. 1: Ramp Load Increment For given constant capacitor voltage collapse. Fig. 2: Voltage establishment by increasing capacitor. Fig. 1 Fig. 2

Isolated Grid, PV-Micro-Hydro System  In this model, diesel genset is to be integrated.  Synchronous generator runs at no load, if diesel genset has to deliver power in absence of sufficient water flow.

Results

Control Structure for Microcontroller System

Conclusion Such HPS explores the possibility to electrify remote areas using locally available renewable energy sources System is economical and compact due to absence of batteries Simulation models show good results and it is possible to develop hardware system based upon this model