A system comprising: a subsea electrical system , wherein the subsea electrical system comprises first components (510, 530; 550) and second components electrically interconnected with the first components (510, 530; 550); and a control and monitoring circuit , comprising a controller circuit configured to provide control inputs to the first components (510, 530; 550); a simulator circuit coupled to the controller circuit and configured to maintain first models of the first components (510, 530; 550) and second models of the second components , apply the control inputs provided to the first components (510, 530; 550) to the first models ; and modify at least one of the first models and at least one of the second models responsive to system outputs from the first components (510, 530; 550); and a monitor circuit coupled to the simulator circuit , wherein the monitor circuit is configured to detect a failure of one component of the second components of the subsea electrical system responsive to the modification of the at least one first model and the at least one second model ; and wherein the first components (510, 530; 550) comprise a power converter , a switch , and a motor drive , and wherein the second components comprise a power line and/or a motor . a subsea electrical system , wherein the subsea electrical system comprises first components (510, 530; 550) and second components electrically interconnected with the first components (510, 530; 550); and a control and monitoring circuit , comprising a controller circuit configured to provide control inputs to the first components (510, 530; 550); a simulator circuit coupled to the controller circuit and configured to maintain first models of the first components (510, 530; 550) and second models of the second components , apply the control inputs provided to the first components (510, 530; 550) to the first models ; and modify at least one of the first models and at least one of the second models responsive to system outputs from the first components (510, 530; 550); and a monitor circuit coupled to the simulator circuit , wherein the monitor circuit is configured to detect a failure of one component of the second components of the subsea electrical system responsive to the modification of the at least one first model and the at least one second model ; and a controller circuit configured to provide control inputs to the first components (510, 530; 550); a simulator circuit coupled to the controller circuit and configured to maintain first models of the first components (510, 530; 550) and second models of the second components , apply the control inputs provided to the first components (510, 530; 550) to the first models ; and modify at least one of the first models and at least one of the second models responsive to system outputs from the first components (510, 530; 550); and maintain first models of the first components (510, 530; 550) and second models of the second components , apply the control inputs provided to the first components (510, 530; 550) to the first models ; and modify at least one of the first models and at least one of the second models responsive to system outputs from the first components (510, 530; 550); and a monitor circuit coupled to the simulator circuit , wherein the monitor circuit is configured to detect a failure of one component of the second components of the subsea electrical system responsive to the modification of the at least one first model and the at least one second model ; and wherein the first components (510, 530; 550) comprise a power converter , a switch , and a motor drive , and wherein the second components comprise a power line and/or a motor . <EOS>