A temperature monitoring device for protecting the winding of an electronically commutated electric motor from being heated over a specified limit temperature T.sub.G regardless of the rotational speed includes a phase current detection device for detecting the phase current I.sub.Winding for the motor windings, an overcurrent switch-off device for switching off the electric motor if a maximum permissible phase current I.sub.Shutdown is exceeded, and an overcurrent monitoring device, which is connected to the overcurrent switch-off device, in order to transmit to it a switch-off signal if the detected phase current I.sub.Winding exceeds the maximum permissible phase current I.sub.Shutdown ascertained by a detection and computing device, wherein an algorithm in which the measured ambient temperature T.sub.U is incorporated is used when ascertaining the maximum permissible phase current I.sub.Shutdown.

Examples described herein provide a computer-implemented method for thermal lockout for a motor of a gate crossing mechanism. The method includes monitoring a motor current across a sense resistor of the motor. The method further includes determining a present thermal capacity unit (TCU) at a time interval based on the motor current across the sense resistor. The method further includes determining whether the motor is at a thermal limit by comparing the present TCU to an expected TCU. The method further includes responsive to determining that the motor is at the thermal limit, causing initiating a hard fault.

A method for managing overcurrent protection in a self-controlled permanent-magnet synchronous motor of a motor vehicle is disclosed. The method makes it possible to adjust the activation threshold for overcurrent protection in the synchronous motor. In particular, the activation threshold is variable and depends, inter alia, on parameters representative of the temperature of the components of the synchronous motor.

A compact electric motor (1) includes a housing (2), a stator (3), a rotor (4) with a rotor winding (5) or permanent magnets located thereon. A thermal protection device protects the electric motor against overheating. A sensor unit (6) is provided as a thermal protection device. The sensor unit (6) includes a temperature sensor (7) for detecting temperature-based measurement values, a radio module (8) with an antenna (8a) for sending sensor signals of temperature-based measurement values or data or information derived therefrom by radio to an external receiving unit (9). The sensor unit (6) has a memory (13) and a microcontroller (10). The sensor unit (6) is a self-supplying assembly.

The invention relates mainly to a starter for a heat engine of a motor vehicle comprising: at least one electromagnetic contactor comprising a positive output terminal, at least one electric motor, the electric motor comprising: at least one brush cage (43), at least one positive brush (35) mounted in the brush cage (43), an electrical path (91) between the positive brush (35) and the positive output terminal (32), and at least one thermal protection (96) situated in the electrical path (91), in which the thermal protection is suitable for disconnecting the two elements (93, 95) when the thermal protection has a temperature above a temperature threshold to electrically disconnect the positive output terminal relative to the positive brush (35).

An electric motor includes a stator and a rotor. The stator has a plurality of low speed windings and a plurality of separate high speed windings. A first type of thermal overload protector is coupled with at least one of the low speed windings and a second type of thermal overload protector is coupled with at least one of the high speed windings.

Disclosed is a motor protection device (1). The motor protection device (1) includes an interrupter unit (11, Q1, Q2) for electrically connecting a power supply (Vcc) and an electric motor (M) in an operation mode and electrically disconnecting the power supply (Vcc) and the electric motor in an alternative overload mode. The motor protection device further includes an overload detection unit (12). The overload detection unit (12) is configured to monitor a motor current and to control the interrupter unit (11, Q1, Q2) to switch from the operation mode into the overload mode if the motor current indicates an overload condition of the electric motor (M) in the operation mode. The motor protection device (1) further includes a recovery detection unit (13). The recovery detection unit (13) is configured to monitor a motor temperature and to control the interrupter unit (11, Q1, Q2) to switch from the overload mode back into the operation mode if the motor temperature indicates a recovery from the overload condition.

An electric motor system having substantially independent hardware-based and software-based pathways for detecting and initiating responses to fault conditions, such as over-current conditions, in an electric motor which is powered by a power inverter which is controlled by a power module and a microprocessor. Each pathway involves comparing a voltage, which is representative of an electric current flowing to the motor, to a predetermined maximum voltage, and if the former exceeds the latter using hardware or software to initiate shutting off the motor, such as by shutting off the power inverter. When one pathway detects a fault condition it may notify the other pathway, and the notified pathway may also initiate shutting off the motor.

A motor drive device includes an inverter circuit to drive a motor, an inverter control device to control the inverter circuit, a gate-driving power supply to supply power to be used for driving the inverter circuit, a circuit pattern configured to connect the inverter circuit and the gate-driving power supply, a control power supply connected to the circuit pattern to supply power to be used for driving the inverter control device, and a thermal switch connected to the circuit pattern to interrupt power supply from the gate-driving power supply to the inverter circuit when a temperature of a winding of the motor exceeds a predetermined temperature.

It is disclosed a motor thermal protection device and operation method thereof. The motor thermal protection device utilizes a power supply of a motor for power supplying and comprises: a capacitor timing circuit, configured to time after the motor is powered off; a power-off time determining unit, configured to perform a reading operation of reading an output voltage of the capacitor timing circuit after the motor is powered on, and determine a power-off time from when the motor is powered off to when the motor is powered on according to the output voltage; and a heat accumulation calculating unit, configured to calculate a remaining heat accumulation when the motor is powered on according to the power-off time and a heat accumulation when the motor is powered off.