LEONICS designed, supplied and commissioned the 3.3 Megawatt and 4.2 Megawatt Stand-alone PV-Diesel Hybrid Mini-Grid Systems in Malaysia. The first two of total of fourhybrid systems in Malaysia which powered by PV array with diesel generators and use Leonics' unique DC&AC coupling configuration together for highest system performance.
Four Megawatt-scale PV-diesel hybrid power systems in Malaysia have been awarded to Leonics. The systems have total power of 3.3 MW in Perak, 3.4 MW in Sarawak, and 4.2 MW and 4.9 MW in Sabah. The first two systems, 3.3 MW and 4.2 MW hybrid systems are commissioned in November 2012 while the other two systems are planned to be commissioned in Q1 and Q2 or 2013. These hybrid systems generated electrical energy from PV array to reduce the diesel consumption and continuous supply power to remote villages. The utility company plan to supply 1 kW electrical power with 8 kWh of energy per one family. All investments are from government budget to provide electricity for improve quality of living and enhance opportunity to do more economic activities for Malaysian in remote area.
Leonics's Megawatt-scale off-grid hybrid systems determine total power by combination of PV, Bi-directional battery inverter, grid connected inverter, and diesel generators together. The 3.3 MW hybrid system can generate energy from PV for 1.28 GWh and supply electrical power to 4 villages for 400 families, school, clinic and government house over 5 km distribution network in Kemar, Gerik, Perak, Peninsular Malaysia. The 4.2 MW hybrid system can generate energy from PV for 1.82 GWh and supply electrical power to 7 villages for 700 families, school, clinic, and government house over 14 km distribution network in Tanjung Labian, Lahad Dhatu, Sabar, East Malaysia.
3.3 MW Stand-alone PV/Diesel Hybrid System at Kemar, Gerik, Perak, Malaysia
4.2 MW Stand-alone PV/Diesel Hybrid System at Tanjung Labian, Lahad Datu, Sabah, Malaysia
With Leonics' unique combination of DC&AC coupling configuration, the hybrid system combine PV at DC coupling and PV at AC coupling to generated energy from the sun to supply load. The AC coupling is designed based on day time load while DC coupling is designed to charge battery for using load at night time. Both DC and AC coupling work with both main inverters and diesel generator to generate 24 hours high reliable electricity from PV and diesel fuel to inhabitants of the remote villages.
The systems operate in fully automatic from black start with diesel generators to energize medium voltage transformer and distribution line after the system is energized and hybrid system supervisory controller found that load is low then it will switch to supply the mini grid by Bi-directional battery inverters and stop all diesel generator.
Leonics' Bi-directional battery inverter can be operated in parallel up to 4 units which make the total power of 1.2 MW. The inverter can supply active and reactive power with stable voltage and frequency to the mini grid network. For Kemar hybrid system, there are 3 units of 200 kW inverters operate in parallel while at Tanjung Labian hybrid system there are 3 units of 300 kW inverters. The grid forming power is 600 kW and 900 kW respectively. The high power bi-directional inverters are used to replace spinning reserve of diesel generator and allow the system to stop diesel generator as long as we still have store energy in battery.
During day time, grid connected inverter will feed energy from PV to the system at AC distribution line and these energy will flow to supply load directly and the excess energy can be used to charge battery. As system is designed to supply day time load by AC coupling thus most of energy at day time generated by AC coupling will be consumed by load with high conversion efficiency.
The PV at DC coupling is connected to MPPT charger controller which will charge battery and in case that load consume power more than grid connected inverter can generated then the balance will be from the DC coupling through bi-directional inverter.
At night time when the AC coupling configuration cannot supply power to load, the bi-directional inverter shall supply load by using energy stored in battery. When connected load power is higher than total power of bi-directional inverter or energy stored in battery is low, the diesel generator will be started. Once, the bi-directional inverter start the supervisory controller to operate the diesel generator at the most optimum fuel efficiency and select the proper power rating for supplying to the system.
This hybrid system also operate with System Monitoring Unit (SMU), Hybrid Inverter System Controller (ISC), and Hybrid System Control and Command Unit (HCCU) to optimize the system performance. The System Monitoring Unit (SMU) can monitor all Meteorological data, such as PV temperature, solar irradiation, solar irradiance, etc. The Hybrid system Control and Command Unit (HCCU) will control and command the Hybrid Inverter System Controller (ISC) to control all parallel-connected inverters and grid connected inverter for remote controlling and monitoring the system data and parameters via www.leonics-moc.com
Sample application of Megawatt-scale Stand-alone PV-Diesel Hybrid Mini-Grid System
• For rural electrification or remote village electrification