Generator control architecture

1 . An electric machine control system comprising:

a control unit, wherein the control unit includes inputs for:

a point of regulation (POR) voltage feedback,

an electric machine current feedback,

a permanent magnet generator (PMG) feedback, and

an input speed feedback; and

a protection unit, wherein the protection unit includes inputs for:

the POR voltage feedback,

the electric machine current feedback,

the PMG feedback, and

the input speed feedback;

wherein at least one trip connection connects between the control unit and the protection unit; and

wherein the control unit is configured to prevent the protection unit, when failed or acting erroneously, from inducing abnormal power quality in an electric machine.

2 . The system as recited in claim 1 , wherein at least one of:

the control unit includes at least one of a digital signal processor (DSP) or a field programmable gate array (FPGA); or

the protection unit includes at least one of a microprocessor or a field programmable gate array (FPGA).

3 . The system as recited in claim 1 , wherein the at least one trip connection is configured to provide separate voltage reduction and frequency reduction trip commands.

4 . The system as recited in claim 1 , further comprising an exciter drive configured to drive electric machine excitation, wherein the exciter drive is operatively connected to receive exciter drive control commands from the control unit and to receive a generator control relay (GCR) enable signal from the protection unit for enabling and disabling the exciter drive.

5 . The system as recited in claim 4 , wherein the control unit includes an input connected to receive the GCR enable signal from the protection unit.

6 . The system as recited in claim 1 , further comprising a servo drive, wherein the servo drive is operatively connected to receive servo drive control commands from the control unit and to receive a servo control relay enable signal from the protection unit for enabling and disabling the servo drive.

7 . The system as recited in claim 6 , wherein the control unit includes an input connected to receive the servo control relay enable signal from the protection unit.

8 . The system as recited in claim 1 , further comprising an inverter drive, wherein the inverter drive is operatively connected to receive inverter drive control commands from the control unit and to receive an inverter control relay enable signal from the protection unit for enabling and disabling the inverter drive.

9 . The system as recited in claim 8 , wherein the control unit includes an input connected to receive the inverter control relay enable signal from the protection unit.

10 . The system as recited in claim 1 , further comprising a contactor driver configured to drive an electric machine contactor, wherein the contactor driver is operatively connected to receive a contactor command signal from the protection unit and to receive a contactor enable signal from the control unit for enabling and disabling the contactor driver.

11 . The system as recited in claim 1 , wherein the at least one trip connection includes:

a first trip connection for providing trip output from the protection unit as input to the control unit for communicating a protection trip to the control unit; and

a second trip connection for providing trip output from the control unit as input to the protection unit for communicating a need for a trip from the control unit to the protection unit.

12 . The system as recited in claim 1 , wherein the control unit further includes inputs for:

a generator control switch (GCS) feedback,

a generator line contactor (GLC) auxiliary feedback, and

a weight on wheels feedback,

wherein the protection unit further includes inputs for:

the GCS feedback,

the GLC auxiliary feedback, and

the weight on wheels feedback.

13 . The system as recited in claim 12 , wherein the control unit includes internal enable logic for enabling and disabling an internal enable of the control unit based on the POR voltage feedback, the electric machine current feedback, the PMG feedback, the input speed feedback, the GCS feedback, the GLC auxiliary feedback, and the weight on wheels feedback, wherein there is no enable connection from the protection unit to the control unit.

14 . The system as recited in claim 1 , further comprising a built in test (BIT) command connection from the protection unit to the control unit for initiating a BIT procedure.

15 . A method of generator control comprising:

receiving an input speed feedback, a generator line contactor (GLC) auxiliary feedback, a generator control switch (GCS) feedback, and a weight on wheels feedback in a control unit; and

determining within the control unit whether to enable voltage regulation and/or frequency regulation independent from a protection unit operatively connected to the control unit;

wherein the control unit prevents the protection unit, when failed or acting erroneously, from inducing abnormal power quality in an electric machine.

16 . The method as recited in claim 15 , further comprising receiving separate voltage reduction and frequency reduction trip commands from the protection unit to the control unit, and disabling voltage and/or frequency command output from the control unit to an exciter drive or servo drive based on the trip commands.

17 . The method as recited in claim 15 , wherein the control unit includes a GLC enable logic that either outputs an enable signal as input to a contactor driver or controls a contactor coil return.

18 . The method as recited in claim 15 , further comprising initiating, by the protection unit, built in test (BIT) tests, wherein the control unit includes logic to prevent the BIT tests from inducing erroneous control from the protection unit.

19 . The method as recited in claim 15 , further comprising monitoring, by the control unit, the protection unit for outputs from the protection unit.

20 . The method as recited in claim 15 , further comprising, upon determining an error of a protective function, using the control unit to disable voltage regulation.