Control system connected to an arresting gear system having an outer control loop and a plurality of inner current control loops

A control system connected to an advanced arresting gear system, the control system comprising:

• (a) an outer control loop receiving:
• (i) a port side shaft position, θp, and (ii) a starboard side shaft position θs and, based on received position information, generating a first torque control command τmp and a second torque control command τms;
• (b) a first inner control loop associated with a port-side motor current controller receiving a first pair of dq-axis current commands iqp* and idp*, the first pair of dq-axis current commands computed based on the first torque control command τmp, the first inner control loop outputting a first voltage command νabcp for controlling a port side motor that controls a port side of an arrestment cable;
• (c) a second inner control loop associated with a starboard-side motor current controller receiving a second pair of dq-axis current commands iqs* and ids*, the second pair of dq-axis current commands computed based on the second torque control command τms, the second inner control loop outputting a second voltage command νabcs for controlling a starboard side motor that controls the starboard side of the arrestment cable, and
• wherein each of the port-side motor current controller and the starboard-side motor controller comprises:
• a positive sequence controller, the positive sequence controller comprising a PI filter with a dq input and a summer connected to an output of the PI filter;
• at least one negative sequence controller, the negative sequence controller connected to the dq input and the summer comprising a rotation transformer connected to an integrator block in series with an inverse rotational transformation block;
• one or more delay state feedback to counter control loop delays, said delay state feedback providing high bandwidth, low current overshoot, small current rise time and good current stability margins;
• and one or more cross coupled gains between a d-axis and a q-axis, the cross coupled gains a linear, including proportional to, or a nonlinear function of one or more of the following:
• a speed of the port side motor, a speed of the starboard side motor, a frequency of the port side motor, and a frequency of the starboard side motor,
• wherein the one or more delay state feedback to counter loop delays is not enabled when the loop delays are below a predetermined threshold or when high bandwidth performance is not needed, and
• wherein undesirable interactions between the positive sequence controller and negative sequence controller is minimized by sharing error signals.

A method as implemented in a control system connected to an advanced arresting gear system, the method comprising:

• (a) receiving in an outer control loop:
• (i) a port side shaft position, θp, and (ii) a starboard side shaft position θs;
• (b) generating a first torque control command τmp and a second torque control command τms based on received position information;
• (c) receiving, in a first inner control loop associated with a port-side motor current controller, a first pair of dq-axis current commands iqp* and idp*, the first pair of dq-axis current commands computed based on the first torque control command τmp, the first inner control loop outputting a first voltage command νabcp for controlling a port side motor that controls a port side of an arrestment cable;
• (d) receiving, in a second inner control loop associated with a starboard-side motor current controller, a second pair of dq-axis current commands iqs* and ids*, the second pair of dq-axis current commands computed based on the second torque control command τms, the second inner control loop outputting a second voltage command νabcs for controlling a starboard side motor that controls the starboard side of the arrestment cable,
• wherein each of the port-side motor current controller and the starboard-side motor controller comprises:
• a positive sequence controller, the positive sequence controller comprising a PI filter with a dq input and a summer connected to an output of the PI filter;
• at least one negative sequence controller, the negative sequence controller connected to the dq input and the summer comprising a rotation transformer connected to an integrator block in series with an inverse rotational transformation block, one or more delay state feedback to counter control loop delays, said delay state feedback providing high bandwidth, low current overshoot, small current rise time and good current stability margins,
• where undesirable interactions between the positive sequence controller and negative sequence controller is minimized by sharing error signals,
• wherein each of the port-side motor current controller and the starboard-side motor current controller utilizes a plurality of internally generated feed forward voltages to either:
• (1) apply a priori knowledge about one or more voltage profiles used by the port-side motor current controller and/or the starboard-side motor current controller, or (2) inject one or more voltage profiles for use by the port-side motor current controller and/or the starboard-side motor current controller to help cancel one or more disturbances or help improve a response time associated with the port-side motor current controller and/or the starboard-side motor current controller, and
• wherein the one or more delay state feedback to counter loop delays is not enabled when the loop delays are below a predetermined threshold or when high bandwidth performance is not needed.