The establishment of solar PV projects at two RLNG-fired projects in Punjab has been proposed by the NPCC, SO, according to well-informed sources who spoke to media.
The establishment of solar PV projects at two RLNG-fired projects in Punjab has been proposed by the National Power Control Centre (NPCC), the System Operator (SO), according to well-informed sources who spoke to media.
The studies would cover system stability and network reinforcement. NPCC’s “operational studies for solar PV projects planned to be developed at Jhang/ Trimmu and Layyah/ Haveli Bahadur Shah” report gives a summary of the operational effects of connecting solar parks close to Jhang/ Trimmu and Layyah/ Haveli Bahadur Shah.
According to NPCC a load-flow analysis has been conducted for each location to determine the maximum power evacuation from the solar park under summer peak load conditions, a summary of 500 MW solar park at 220-kV near Jhang Trimmu is as follows:
(i) the network capacity for power evacuation from Trimmu Solar and Trimmu CCPP is 1100-MW under normal network conditions and 900-MW under N-I contingency conditions;
(ii) daily start-up and shutdown of Trimmu CCPP during the solar hours is not possible as the number of starts for the steam turbine is restricted to 56 per year;
(iii) since the minimum operating point for Trimmu CCPP in combined cycle mode is 560-MW, Trimmu Solar would be restricted to 340-MW when Trimmu CCPP is operating;
(iv) to increase the capacity of Trimmu solar without risking curtailment, the solar park should also be interconnected to the 132KV networks of FESCO and/ or MEPCO.
It is possible to discuss additional analysis of 132kV interconnections with the transmission planning divisions of the relevant Discos.
The following observations were made on the 1000 MW solar park at 500 kV near Layyah and Haveli Bahadur Shah by NPCC:
(i) while there is sufficient capacity on the 500kV transmission lines, the 200/ 220kV step-down transformers at 500kV Multan and 500kV Muzaffargarh are overloaded under N-I contingency conditions resulting in temporary curtailment;
(ii) this problem can be mitigated by either reinforcing the transformation capacity at Multan & Muzaffargarh, or by extending 500KV Layyah to 220kV or 132kV voltage levels.