- (1.) THIS petition has been filed by the petitioner, Southern Regional Load Despatch Centre with the following prayers, namely: (a) Ensure Adequacy and healthiness of protection system in compliance with regulation 3 (e) of the CEA (Grid Standards) in terms of IEGC regulation 5.2(e); (b) Form their own expert group in protection audit for periodic protection audit of the entire substation of 220 kV and above on continuous basis and discuss such protection audit reports in the Protection Co -ordination sub -committee of SR; (c) Ensure different type (Principle of operation) and make of relays for Main -I and Main -II protection as well as different input for different protection schemes in a time bound manner on priority; (d) Ensure proper and periodical preventive maintenance of transmission lines including Row clearance, bush/jungle cutting etc., particularly in forest area adopting best O & M Practices; (e) Ensure dual source of supply for all the auxiliaries in substation; (f) Ensure availability of bus sectionalizer scheme in all the 200kV/230kV substation that may lead to Grid disturbance of category GD -I and above; (g) Ensure strict compliance of IEGC provision under clause 5.2 (r) in furnishing the detailed tripping report along with DR & EL printouts within 24 hrs of the occurrence of the event; and (h) Pass such further Order as this Hon'ble Commission may deem just and proper in the circumstances of the case. The petitioner has submitted that from January, 2013, at least 16 times Grid disturbance of Category GD -I were occurred in Southern Region (SR) due to delayed operation or failure to operate of concerned protection relays/scheme, i.e. improper functioning of Protection Schemes.
(2.) AS per the recommendations of Enquiry Committee report, a third party protection audit in SR was carried out and all constituents were agreed in principle for implementation of the recommendations. However, the status review reveals that many recommended items are yet to be implemented. In addition, there were Grid Disturbance (GD -I) instances due to not complying with the best O and M practices by the concerned utilities. The petitioner has filed this petition seeking directions to respondents to ensure timely implementation of recommendations of Protection Audit.
(3.) THE petitioner has enumerated details of events causing Grid disturbances as under The petitioner has submitted that the following measures have been taken by SRPC and SRLDC: (a) Third party protection audit has been carried out at Sharavati Hydro station on 19.11.2012 and recommendations were submitted. Following critical observations were made by the audit team: 2. ONLY 1 CVT for all feeder protection Same CT core is used for both Main -I and Main -II 3. CARRIER protection not available for many feeders 4. VERY old breakers (1964 make) in poor condition that served its life Dc earth leakage condition etc. (b) On 6.3.2013, SRPC had constituted a task force committee to visit 220 kV Sharavati Hydro station to analyze the tripping on 8/28.1.2013 and to suggest remedial measures to prevent reoccurrence of the event. The committee reviewed the progress of protection audit recommendation and identified various other things to attend by Karnataka Power Corporation Limited/Karnataka Power Transmission Corporation Limited as under: 1. Dual battery source with dual rectifier 2. Replacement of old electro -mechanical relays with numerical relays 3. Replacement of Westinghouse make OCB bus sectionalizer breaker 4. Different energisation source for breaker trip coil and etc. (c) Both reports have highlighted several inadequacies in respect of protection system at Sharavati Hydro station. Number of lapses have been observed in the reports and some even lead to non -conformity of CEA Grid Standards. (d) As per Regulations 5.2 (r) of Central Electricity Regulatory Commission (Indian Electricity Grid Code) Regulations, 2010 (Grid Code), all the regional entities are required to furnish tripping report in specific format along with Disturbance Recorder (DR) and Event Logger (EL) printouts within 24 hours of the event. However, there is significant delay in receiving detailed tripping report along with DR and EL print outs from SRLDc and SRPC. Till the completion of analysis and implementation of recommendations of SRLDc/SRPC, the system operator is exposed with the risk of operating the system without knowing the danger associated with those elements that caused the Grid disturbance. The delay in reporting also adds delay in implementation of required corrective/preventive measures. (e) There were instances of Grid disturbance due to non -clearance of bushing/jungle clearance or non -trimming of tree branches within the Row to transmission lines periodically. The instance of 13.6.2013 is a typical case of such nature. It is evident that there was no periodic patrolling of lines by KPTCL in certain portions that lead to unwarranted tripping of critical transmission elements. (f) In all control area of SR Regional Entities, following instances were reported which are affecting the security, economy and efficiency of the entire power system in Southern Region and needs to addressed quickly: (i) Inadequacies/failures in the protective system at sub -stations. (ii) Lack of proper patrolling and jungle clearance (iii) Improper time setting/relay coordination/delay in fault clearance (iv) Malfunctioning of protection system, etc.;