Overview of New Technology
Overview of New Technology
| Name of Technology |
Inverter (single-phase, up to 5kw) manufacturing technology that enables independent operation without ESS |
| Certificate No. |
0811 |
| Certificate Validity |
2014.4.23~2016.4.22 |
Features of grid-connected photovoltaic system having the self-operation function
- During power failure, it is switched to the independent operation mode, which makes it as an independent power generation device
- Assessed as the best efficiency (97.5%) product in Korea at the test conducted by the KNREC’s New Regenerative Energy Center for certification for grid-connected inverter for 5kw or below
- Transferrable using the mechanical switch from grid-connected to independent operation or vice versa to prevent safety accident during transfer
New Technology (NET) - Patents
New Technology (NET) - Patents
| No |
Type |
Name |
Reg Date |
Country |
Reg No |
| 1 |
Registration |
Maximum power point tracking method for mis matched photovoltaic generation device |
2013.06.17 |
Korea |
10-1277762 |
| 2 |
Application |
THD reduction method for PCS output current of fuel cell using the notch filter and the PCS device for fuel cell |
2014.07.03 |
Korea |
10-1417962 |
| 3 |
Application |
Hybrid topology system for single-phase photovoltaic inverter |
Under review |
Korea |
10-2013-0151750 |
| 4 |
Application |
DC offset current detection device for trans-less grid-connected inverter and the method thereof |
Under review |
Korea |
10-2013-0084612 |
| 5 |
Application |
Variable DC Link Voltage Control according to Grid Voltage |
Under review |
Korea |
10-2014-0003413 |
1DB based MPPT Algorism
Mis-matching occurs when the output characteristics of solar cell modules in serial or parallel connection are out of balance (creating shadow on some parts of the cells).
- When the maximum power tracking curve and tolerance exceed 10% of the maximum power point, it is deemed the ‘incorrect maximum power point’.
- Differential algorithm to be performed at Vop*0.3 for re-tracking to reach MPPT
2THD reduction technology for PCS output current using notch filter
Efficiency changed from 96.62% before using notch filter to 96.80% with notch filter, showing an increase of 0.2%
3Single-phase photovoltaic inverter technology with the modified hybrid method of switching pattern
- With the hybrid method, EMI voltage ripple occurs. Only the 3rd and the 4th switches are intensively used causing IGBT to age unevenly leading to consequential problems
- With the modified hybrid method, the EMI voltage ripple disappears.
- With the modified hybrid method, efficiency increases by 0.19% at1.2kW
4DC offset current detection device for trans-less grid-connected inverter and the method thereof
- When the alternating current mixed with the direct current components flows into the grid, the ‘horseshoe’ phenomenon on the pole transformer etc may cause malfunction of other electrical facilities or the grid.
- Tolerance shall be compensated through integral controller for the direct current components created from output of single-phase grid-connected inverter so as to remove the direct current components.
5Variable DC Link Voltage Control according to Grid Voltage
- The system control unit of the grid-connected photovoltaic inverter calculates the real- time optimum DC link voltage based on the voltage detected at the grid voltage detection unit to make setting to the DC link reference unit.
- When boosted to the optimum DC link voltage by controlling the boost converter unit and the inverter unit, the booster converter unit is operated at a minimum level thereby improving the conversion efficiency.
