Systems and methods for monitoring current in an electric motor
First Claim
1. An electrical system for use in a vehicle comprising:
- a direct current (DC) interface;
an electric motor having a plurality of phases;
an inverter module coupled between the DC interface and the electric motor, the inverter module comprising a plurality of phase legs, wherein each phase leg corresponds to a respective phase of the electric motor;
a first current sensor configured to measure a DC current flowing between the DC interface and the inverter module;
a second current sensor interposed between a first phase leg of the inverter module and a first phase of the electric motor, the second current sensor configured to measure a first phase current flowing through the first phase of the electric motor; and
a control module coupled to the first current sensor and the second current sensor, wherein the control module is configured to;
determine an expected value for the first phase current based at least in part on the DC current measured by the first current sensor; and
take remedial action when a difference between the expected value for the first phase current and the measured first phase current is greater than a threshold value.
4 Assignments
0 Petitions
Accused Products
Abstract
Systems and methods are provided for monitoring current in an electric motor. An electrical system comprises a direct current (DC) interface, an electric motor, and an inverter module between the DC interface and the electric motor. A first current sensor is configured to measure a DC current flowing between the DC interface and the inverter module. A second current sensor is configured to measure a first phase current flowing through the first phase of the electric motor. A control module is coupled to the current sensors, and the control module is configured to determine an expected value for the first phase current based at least in part on the DC current measured by the first current sensor and take remedial action based on a difference between the expected value and the measured first phase current.
-
Citations
19 Claims
-
1. An electrical system for use in a vehicle comprising:
-
a direct current (DC) interface; an electric motor having a plurality of phases; an inverter module coupled between the DC interface and the electric motor, the inverter module comprising a plurality of phase legs, wherein each phase leg corresponds to a respective phase of the electric motor; a first current sensor configured to measure a DC current flowing between the DC interface and the inverter module; a second current sensor interposed between a first phase leg of the inverter module and a first phase of the electric motor, the second current sensor configured to measure a first phase current flowing through the first phase of the electric motor; and a control module coupled to the first current sensor and the second current sensor, wherein the control module is configured to; determine an expected value for the first phase current based at least in part on the DC current measured by the first current sensor; and take remedial action when a difference between the expected value for the first phase current and the measured first phase current is greater than a threshold value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method for operating an electrical system including an inverter coupled between a direct current (DC) interface and an electric motor, the method comprising:
-
measuring DC current flowing between the DC interface and the inverter; measuring a first phase current flowing between the inverter and a first phase of the electric motor; determining an expected first phase current based on the measured DC current; and taking remedial action when a difference between the measured first phase current and the expected first phase current is greater than a threshold value. - View Dependent Claims (12, 13, 14, 15, 16)
-
-
17. An electrical system comprising:
-
a direct current (DC) interface; an electric motor having a plurality of phases; an inverter module coupled between the DC interface and the electric motor, the inverter module comprising a plurality of phase legs wherein each phase leg corresponds to a phase of the electric motor; a first current sensor interposed between the DC interface and the inverter module, the first current sensor being configured to measure a DC current flowing between the DC interface to the inverter module; a second current sensor interposed between a first phase leg of the inverter module and a first phase of the electric motor, the second current sensor being configured to measure a first phase current flowing through the first phase of the electric motor; a third current sensor interposed between a second phase leg of the inverter module and a second phase of the electric motor, the third current sensor being configured to measure a second phase current flowing through the second phase of the electric motor; and a control module coupled to the first current sensor, the second current sensor and the inverter module to; generate command signals to operate the plurality of phase legs of the inverter module for a switching interval based on the first phase current and the second phase current, the command signals for the switching interval resulting in a voltage vector corresponding to a first phase of the electric motor being implemented by the inverter module during the switching interval; determine an expected first phase current based on the DC current measured by the first current sensor during the switching interval and the command signals for the switching interval by mapping the DC current measured by the first current sensor during the voltage vector to the first phase; and take remedial action when a difference between a measured first phase current from the second current sensor and the expected first phase current is greater than a threshold value.
-
-
18. A method for operating an electrical system including an inverter coupled between a direct current (DC) interface and an electric motor, the method comprising:
-
measuring DC current flowing between the DC interface and the inverter; measuring a first phase current flowing between the inverter and a first phase of the electric motor; determining an expected first phase current based on the measured DC current; determining a zero vector current based on the measured DC current; and taking remedial action when a difference between the measured first phase current and the expected first phase current is greater than a threshold value or when the zero vector current is greater than a second threshold value.
-
-
19. An electrical system for use in a vehicle comprising:
-
a direct current (DC) interface; an electric motor having a plurality of phases; an inverter module coupled between the DC interface and the electric motor, the inverter module comprising a plurality of phase legs, wherein each phase leg corresponds to a respective phase of the electric motor; a first current sensor configured to measure a DC current flowing between the DC interface and the inverter module; a second current sensor interposed between a first phase leg of the inverter module and a first phase of the electric motor, the second current sensor configured to measure a first phase current flowing through the first phase of the electric motor; and a control module coupled to the first current sensor and the second current sensor, wherein the control module is configured to; determine a zero vector current based at least in part on the DC current measured by the first current sensor; and take remedial action when the zero vector current is greater than the threshold value.
-
Specification