An analytical approach for evaluating the risk of SSR for reciprocating engine based generation in series compensated networks

There has been limited focus on evaluation of Sub-synchronous Resonance (SSR) risk between reciprocating engine based generation and series compensated transmission networks. This paper aims to provide an analytical approach for investigating SSR issues associated with reciprocating engine based generators and series compensated transmission lines. Eigen value analysis is performed to determine the torsional modes and associated modal damping for the mechanical system. Transmission system side frequency scans in conjunction with generator electrical characteristics are used to derive the electrical damping at sub-synchronous frequencies. A comparison of electrical damping with the modal damping is used as a screening technique to identify potential conditions of SSR concerns. Detailed Electro-Magnetic Transient (EMT)-type simulations are conducted to evaluate potential SSR concerns for conditions shortlisted via the screening assessment. Sensitivity analysis around select transmission system and generator parameters is performed to comment on the impact of variations around the parameters on SSR risk.