Safe torque off (STO) circuit and method for STO circuit
AssigneeABB Beijing Drive Systems Co., Ltd.
InventorsJibin Wang, Petri Havanto, Ville Kärjä, Ville Samuel Forsström
Life of this patent
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Abstract
Embodiments of present disclosure relate to a Safe Torque Off (STO) circuit and a method for the STO circuit. The STO circuit has an input suitable for receiving an input signal, channels coupled to the input in parallel, wherein each of the channels includes a switch, a level conversion circuit, and an isolation circuit connected in series. Each isolation circuit being configured to be turned on when the respective switch is closed and to be turned off when the respective switch is opened. Each of the channels also includes an inverter module, a control unit, a first switch unit, and a second switch unit.
Claims20
A safe torque off (STO) circuit comprising:
- an input suitable for receiving an input signal;
- first and second channels coupled to the input in parallel and each comprising a switch, a level conversion circuit and an isolation circuit connected in series, each isolation circuit being configured to be turned on when the respective switch is closed and to be turned off when the respective switch is opened;
- an inverter module comprising high-side and low-side transistors and configured to generate an output signal for driving a motor;
- a control unit configured to provide a first driving signal for driving the high-side transistors of the inverter module via a first output terminal and a second driving signal for driving the low-side transistors of the inverter module via a second output terminal when both of the switches of the first and second channels are closed;
- a first switch unit arranged between the first output terminal of the control unit and the inverter module and comprising a first control terminal coupled to the isolation circuit of the first channel;
- and
- a second switch unit arranged between the second output terminal of the control unit and the inverter module and comprising a second control terminal coupled to the isolation circuit of the second channel.
A method for a safe torque off (STO) circuit, the STO circuit comprising an input suitable for receiving an input signal;
- first and second channels coupled to the input in parallel and each comprising a switch, a level conversion circuit and an isolation circuit connected in series, each isolation circuit being configured to be turned on when the respective switch is closed and to be turned off when the respective switch is opened;
- an inverter module comprising high-side and low-side transistors and configured to generate an output signal for driving a motor;
- a control unit configured to provide a first driving signal for driving the high-side transistors of the inverter module via a first output terminal and a second driving signal for driving the low-side transistors of the inverter module via a second output terminal when both of the switches of the first and second channels are closed;
- a first switch unit arranged between the first output terminal of the control unit and the inverter module and comprising a first control terminal coupled to the isolation circuit of the first channel;
- and a second switch unit arranged between the second output terminal of the control unit and the inverter module and comprising a second control terminal coupled to the isolation circuit of the second channel, the method comprising:
- in response to both of the switches of the first and second channels being closed, turning on the first and second switch units so as to transmit the first and second driving signals to the inverter module;
- and
- in response to the switches of the first and second channels being opened, turning off the first and second switch units so as to block the first and second driving signals from being transmitted to the inverter module.
Dependencies are inferred from the claim text.