Control system for dynamic current limits on a rotating electrical machine
A control system for generating a modified torque command for a rotating electrical machine in a battery electric vehicle (BEV) includes a microprocessor, capable of reading executable commands stored in non-volatile memory, configured to electrically connect to an inverter, determine a rated maximum current of the rotating electrical machine, receive sensor input indicating a temperature or estimating the temperature of at least one portion of the BEV, output a modified maximum current based on the received sensor input, and generate a torque command to the rotating electrical machine based on the modified maximum current.
1 . A control system for generating a modified torque command for a rotating electrical machine in a battery electric vehicle (BEV), comprising:
a microprocessor, capable of reading executable commands stored in non-volatile memory, configured to electrically connect to an inverter, determine a rated maximum current of the rotating electrical machine, receive sensor input indicating a temperature or estimating the temperature of at least one portion of the BEV, output a modified maximum current that exceeds a rated maximum current and a duration for operating at the modified maximum current based on the received sensor input indicating the temperature or the estimated temperature, and generate a torque command to the rotating electrical machine based on the modified maximum current.
2 . The control system recited in claim 1 , wherein the microprocessor determines at least one power loss of the BEV.
3 . The control system recited in claim 1 , wherein the microprocessor determines a temperature of a stator winding, a temperature of a rotor, a temperature of a bulk capacitor, a temperature of a power semiconductor, or a temperature of a bus bar.
4 . The control system recited in claim 1 , wherein the sensor input includes coolant temperature or coolant flow rate.
5 . The control system recited in claim 1 , wherein the rated maximum current of the rotating machine is stored at the BEV in a lookup table.
6 . The control system recited in claim 1 , wherein the microprocessor determines a rated maximum current of an electric drive system.
7 . The control system of claim 1 wherein the memory stores a look-up table that includes temperature inputs and corresponding temperature/current combinations associated with the temperature inputs, wherein the microprocessor determines the modified maximum current values using the look-up table.
8 . A control system for generating a modified torque command for a rotating electrical machine in a battery electric vehicle (BEV), comprising:
a microprocessor, capable of reading executable commands stored in non-volatile memory, configured to electrically connect to an inverter, including a power loss modeling block that determines at least one power loss of the rotating electrical machine, a thermal modeling block that monitors at least one temperature at the BEV, and a maximum phase determination block that determines a rated maximum current of the rotating electrical machine and modifies the rated maximum current, based on the at least one temperature, to generate a modified maximum current exceeding a rated maximum current and a duration for operating at the modified maximum current, used to generate a torque command to the rotating electrical machine.
9 . The control system recited in claim 8 , wherein the microprocessor determines the at least one power loss of the rotating electrical machine based on phase current, power factor, modulation index, fundamental frequency, or DC link voltage.
10 . The control system recited in claim 8 , wherein the thermal modeling block determines a temperature of a stator winding, a temperature of a rotor, a temperature of a bulk capacitor, a temperature of a power semiconductor, or a temperature of a bus bar.
11 . The control system recited in claim 8 , wherein the microprocessor receives sensor input including coolant temperature or coolant flow rate.
12 . The control system recited in claim 8 , wherein the rated maximum current of the rotating machine is stored at the BEV in a lookup table.
13 . A method of generating a modified torque command for a rotating electrical machine in a battery electric vehicle (BEV), comprising the steps of:
(a) determining a rated maximum current of the rotating electrical machine;
(b) receiving sensor input indicating a temperature or estimating the temperature of at least one portion of the BEV;
(c) outputting a modified maximum current that exceeds the rated maximum current of the rotating electrical machine and a duration for operating at the modified maximum current based on the received sensor input indicating the temperature or the estimated temperature; and
(d) generating a torque command to the rotating electrical machine based on the modified maximum current.
14 . The method recited in claim 13 , further comprising the step of determining at least one power loss of the BEV.
15 . The method recited in claim 13 , further comprising the step of determining a temperature of a stator winding, a temperature of a rotor, a temperature of a bulk capacitor, a temperature of a power semiconductor, or a temperature of a bus bar.
16 . The method recited in claim 13 , wherein the sensor input includes coolant temperature or coolant flow rate.
17 . The method recited in claim 13 , wherein the rated maximum current of the rotating machine is stored at the BEV in a lookup table.
18 . The control system recited in claim 13 , further comprising the step of determining a rated maximum current of an electric drive system.