Abstract: A method of providing overload and short-circuit protection for a Switched Mode Power Supply (SMPS). The method may rely upon sensing a temperature change rate for a component of the SMPS and implementing a protection scheme when the temperature change rate exceeds a desired temperature change rate. The implementation scheme may include permanently or temporarily shutting-off the component.

Abstract: A current detection device for detecting an electric current flowing through an inverter, an overcurrent level generation device for generating an abnormality judgment reference value, an overcurrent detection device for generating an interruption signal to the inverter on the basis of an output of the current detection device and the abnormality judgment reference value, and an adjusting apparatus for correcting the abnormality judgment reference value of the overcurrent level generation device on the basis of the output at a time when a constant electric current is applied to the current detection device are provided. The overcurrent level generating device is provided with one or a plurality of resistance value adjusting sections, and generates the abnormality judgment reference value in correspondence to a resistance value of the resistance value adjusting section.

Abstract: A current producing circuit includes a first current source that applies a first current, the first current being changed at a first rate with respect to a temperature, a second current source that applies a second current, the second current being changed at a second rate with respect to the temperature, the second rate being different from the first rate, a third current source that applies a third current, the third current being changed at a third rate with respect to the temperature, a first differential output unit that supplies a first differential current based on a difference between the first current and the second current, and a computing unit that adds or subtracts the first differential current to or from the third current.

Abstract: An inverter system having a semiconductor device, and a railway vehicle using this inverter, provide a more accurate determination of whether an abnormal heat generation from the inverter is associated with an error of the inverter system or is due to other causes, by use of a plurality of temperature detecting elements at a plurality of sites associated with the semiconductor device. An error detection section applies inputs from the temperature detecting elements, captures a trend of the differential value based on the plurality of temperature inputs using period sampling wherein an error associated with the semiconductor device, and not from some other condition such as outside environment temperature, is determined based on differences from, or a change in, the initial trend.

Abstract: A brushless direct current motor, includes a rotor which comprises a permanent magnet, a stator which comprises coils associated with a plurality of phases which form an electrical field for generating a torque by interaction with a magnetic field which is generated by the permanent magnet, and a load prevention part which is disposed inside the stator to electrically connect and disconnect the coils of the plurality of phases according to a temperature variation.

Abstract: At least one embodiment of the invention relates to a protective circuit for protection of an appliance, in particular of an electric motor, against thermal overloading. In at least one embodiment, the protective circuit includes a first and a second terminal for connecting a temperature detection element; a detection unit for detecting whether a resistance value of the temperature detector element which is connected between the first and the second terminals, is in a first or a second resistance range; a short-circuit detector for identifying whether there is a short circuit between the first and the second terminals; signaling outputs for emitting signal messages to an evaluation unit when the detected resistance value is in the second resistance range and/or when a short circuit has been identified by the short-circuit detector; and a third terminal, which is connected to the second terminal via a predetermined resistance.

Abstract: The following invention is an electromechanical system (1) that is to be connected to an electricity supply (7), comprising: an electric machine (2) that can operate as an independent generator with a rotating shaft, and a switching system (9) allowing i) in the first configuration, the electric machine to operate as a motor in the case where the connected device (4) is normally driven or as a generator in the case where the coupled device is normally driving, and ii) in the second configuration, the electric machine to operate as an independent generator, the electrical energy generated by the electric machine (2; 22) being dissipated in the machine and in a dissipative load (13).

Abstract: An electrical switching apparatus is for another apparatus including a number of insulators, a number of temperature sensors operatively associated with the number of insulators, and a number of conductors operatively associated with the number of insulators. The electrical switching apparatus includes a number of separable contacts, an operating mechanism structured to open and close the separable contacts, a number of sensors structured to sense a number of currents flowing through the separable contacts and through the conductors, a processor structured to input the sensed currents from the sensors, and an output. The processor calculates at least one of: (a) a thermal age of the other apparatus from a number of sensed temperatures from the temperature sensors, and (b) the thermal age of the other apparatus from the sensed currents. The output includes the thermal age of the other apparatus.

Abstract: A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed.

Abstract: The invention relates to a circuit arrangement for detecting the overtemperature of a semiconductor body. The arrangement comprises at least one field effect transistor, having a parasitic diode, which is integrated in the semiconductor body, wherein the parasitic diode connects a load terminal of the field effect transistor to a bulk terminal of the semiconductor body, and comprising an evaluating unit electrically connected to the parasitic diode via the bulk terminal at the semiconductor body, which is constructed for feeding a current into the parasitic diode and evaluating a temperature-dependent voltage drop across the parasitic diode, the direction of the current fed into the diode being such that it is operated in the forward direction.

Abstract: The present invention is directed to a sensor for detecting arcing faults, the sensor combining a photodetector, a pressure detector, and an accelerometer along with integrated circuitry. The circuitry controls each detector, operates the self-test circuitry, conditions the signals from the detectors, and communicates with the external network. The circuitry receives commands from the network and transmits the output decision from the sensor.

Abstract: Provision is made for a switch-state monitoring device that not only monitors the state of a switch but also prevents a motor burnout. A switch-state monitoring device for a switch that opens and closes a main circuit by use of a motor is provided with an operating time measuring unit for detecting an operating time for the motor when the switch is opened or closed; a first determination unit for comparing an operating time for the motor detected by the operating time measuring unit with an continuous-operating-capable setting time for the motor and determining whether or not the operating time for the motor has exceeded the continuous-operating-capable setting time; a protection device for halting energization of the motor in the case where, based on an output of the first determination unit, it is determined that the operating time for the motor has exceeded the continuous-operating-capable setting time.

Abstract: To precisely detect the temperature of a power assist motor without using a temperature sensor and enhance an overheating protection function. A calorific value calculating unit calculates a calorific value based upon the difference between a calorific value by current supplied to a motor and the quantity of heat radiation. The output of the calorific value calculating unit is accumulated and an accumulated value is input to an accumulated value buffer. A cumulative value TS acquired by adding initial temperature T0 to a cumulative value Td is input to a ratio map of a target current value, ratio is read, and a target base current value is limited according to the ratio. The cumulative value TS used in the map is not an actual motor current value and is calculated based upon unlimited current acquired in an unlimited current calculating unit.

Abstract: An object of the present invention is to improve safety of a motor by instantaneously detecting the abnormality of a PWM signal. To achieve the object, provided is a motor control microcomputer for outputting PWM signals to a motor drive circuit driving a motor, which includes an abnormal signal detection circuit and a PWM signal stop circuit. The abnormal signal detection circuit receives inputs of positive-phase and negative-phase signals of the PWM signals, detects that both of the positive-phase and negative-phase signals are at the H level, and then outputs detection signals. The PWM signal stop circuit receives the detection signals from the abnormal signal detection circuit, and stops the outputs of the PWM signals.

Abstract: When a fan drive current has become excessive, a fan drive device intercepts that current, waits for just a fixed time period T1, and thereafter flows that current for a second time. The fan power supply current flowed to the fan drive device is detected by a shunt resistor R. The value of the fan power supply current detected by the shunt resistor R is inputted to a controller, and the cause of any abnormality of the fan is decided upon by this controller, based upon the magnitude of the above described fan power supply current and the time period over which it has continued.

Abstract: At least one embodiment of the invention relates to a protective circuit for protection of an appliance, in particular of an electric motor, against thermal overloading. In at least one embodiment, the protective circuit includes a first and a second terminal for connecting a temperature detection element; a detection unit for detecting whether a resistance value of the temperature detector element which is connected between the first and the second terminals, is in a first or a second resistance range; a short-circuit detector for identifying whether there is a short circuit between the first and the second terminals; signaling outputs for emitting signal messages to an evaluation unit when the detected resistance value is in the second resistance range and/or when a short circuit has been identified by the short-circuit detector; and a third terminal, which is connected to the second terminal via a predetermined resistance.

Abstract: In a protective circuit for a converter having a plurality of phases, for each phase current of the phases, a signal proportional to the respective phase current is applied to a transformer circuit that, below and in the area of a limiting frequency, functions as a low-pass filter with the limiting frequency, and above the limiting frequency, functions as a divider. The outputs of the transformer circuit are applied to a maximum generator for forming the absolute value maximum. This maximum is fed to a comparator in which the maximum is compared to a reference value.

Abstract: A protection device protecting a load circuit by shutting off a power thereof depending on an estimated present temperature of a wire provided in the load circuit to connect a load. The protection device has a first temperature estimation device estimating a rising temperature of a conductor including the wire based on both a current in the conductor and thermal properties of the conductor, a second temperature estimation device estimating a falling temperature of the conductor based on the thermal properties, a third temperature estimation device estimating an arc-induced rising temperature of the conductor when arcing occurs in the conductor, and a fourth temperature estimation device estimating the present temperature of the conductor deduced from the above estimated temperatures. If the estimated temperature exceeds a predetermined allowable temperature, the protection device shut off the power of the load circuit.

Abstract: Thermal variable-operation regulator that regulates the operation of an operating device by progressively limiting the operation of the operating device (24) as a limitation temperature (Tset) increases. The limitation temperature (Tset), based on which the operation of the operating device (24) is limited, is set to a smoothed temperature (Ttmp), obtained by performing a predetermined smoothing process on the detected temperature (Tiny), by a limitation temperature setting means when a change amount (AT) of the detected temperature (Tiny) is equal to or less than a predetermined change amount (Tref). However, when the change amount (AT) of the detected temperature (Tiny) is greater than the predetermined change amount (Tref), the limitation temperature (Tset) is set without using the detected temperature (Tiny).

Abstract: A motor protector receiving bracket (10) is shown for use with a multiphase motor protector having at least two terminal pins (4 and 5). The bracket has a back wall formed with first (12e) and second (12h) slots for receiving respective pin terminals of the protector cradled in the bracket and are formed with features to prevent any movement of the protector relative to the bracket. The bracket is in turn adapted to be attached to a spring clip (14) welded to a motor casing.

Abstract: An electric power steering device that can estimate an ambient temperature and apply current limiting without using ambient temperature detecting means is provided. The electric power steering device includes a motor that supplements the driver's steering force, a controller that determines and controls the quantity of current passed to the motor, and vehicle speed detecting means. The electric power steering device includes ambient temperature estimating means provided with a vehicle speed signal input from the vehicle speed detecting means and limits the quantity of current passed to the motor according to an output from the ambient temperature estimating means.

Abstract: A thermal overload protection for an electrical device, particularly an electric motor (M), measures a load current supplied to the electrical device (M), and calculates the thermal load on the electrical device on the basis of the measured load current, and shuts off (S2) a current supply (L1, L2, L3) when the thermal load reaches a given threshold level. The protection comprises a processor system employing X-bit, preferably X=32, fixed-point arithmetic, wherein the thermal load is calculated by a mathematic equation programmed into the microprocessor system structured such that a result or a provisional result never exceeds the X-bit value.

Abstract: The present invention is directed to a sensor for detecting arcing faults, the sensor combining a photodetector, a pressure detector, and an accelerometer along with integrated circuitry. The circuitry controls each detector, operates the self-test circuitry, conditions the signals from the detectors, and communicates with the external network. The circuitry receives commands from the network and transmits the output decision from the sensor.

Abstract: An actuator for a clutch or gear mechanism in a motor vehicle comprises an electric motor and an incremental encoder. The encoder comprises a position measurement signal output at which a position measurement signal can be output which has a number of different signal states, each of which is assigned to a relative position between a primary part and a secondary part of the electric motor. For the commutation of the electric motor, the position measurement signal output is connected to a position measurement signal input of a control device for a motor winding of the electric motor. The control device comprises a device for checking the plausibility of the position measurement signal and is designed in such a manner that on the occurrence of an implausible signal state the power supply to the electric motor is disconnected and/or the power of the electric motor is limited.

Abstract: A speed control and stall protection system 10 for an electric DC brush motor includes a DC brush motor M. At least one relay K3 is connected between the motor and a power supply. A speed sensing circuit 20 is constructed and arranged to generate a signal indicative of a speed of the motor. A motor control and protection circuit 116 is constructed and arranged to receive 1) the signal from the speed sensing circuit and 2) a control signal input for operating the at least one relay to control operation of the motor. When a stall condition is determined based on the signal from the speed sensing circuit, the motor control and protection circuit is constructed and arranged to control the at least one relay to disconnect power to the motor.

Abstract: An integrated DC circuit for a ceiling fan combined with a lamp is composed of a control circuit connected with a motor and a lamp, and a rectifying-filtering circuit connected with the control circuit. The rectifying-filtering circuit can alter an exterior AC power into a DC power for the motor and the lamp to use. As the motor and the lamp use the same DC power, electric leakage can be minimized to upgrade security and only a simplified structure with less material is needed, posing a reduction of cost.

Abstract: System to control, protect and monitor the status of forced cooling motors for power transformers and similar, is preferably applied to power transformers and auto-transformers, and this system turns conventional (1) cooling motors into “intelligent” motors, operating in a totally autonomous manner, whose electronic module (2) is installed on the actual motor cover, more specifically on the connection box (3) and is interconnected by a communication network to a digital system (4) without the need to use any external control, protection and monitoring elements or exaggerated panels for functioning thereof.

Abstract: A solid state reversing DC motor starter that is testable on-line and satisfies the requirements for nuclear safety grade equipment. The motor starter employs a bridge of solid state switches which connect the polarity of the motor winding to conform to the desired direction of travel. The reversing switch bridge is in series with the main switch that is coupled in parallel with a reduced current by-pass flow path.

Abstract: A technique is provided for controlling operation of motors of different sized or ratings. Components used to apply and interrupt current to the motors may be shared in control devices for the different motors. The components may include contactors or circuit interrupters, and instantaneous trip devices. The components may be sized for the higher rated motors, and be oversized for the lower rated motors. Control circuitry permits the devices to be controlled in accordance with the characteristics of the particular motor to which the devices are applied, providing accurate circuit interruption while reducing the number of different components and component packages in a product family for the various motors.

Abstract: Systems and methods are disclosed to construct subsurface images from diffuse seismic energy. Various disclosed system embodiments include multiple seismic sensors that each convert received seismic energy into one or more seismic signals. One or more processor combine the seismic signals to determine a subsurface map. As part of determining the map, the processor(s) systematically focus the array of seismic sensors on each bin in the subsurface volume of interest. In this manner each bin becomes a focal point of the array. For each bin, the processor(s) analyze the seismic wave travel time to each seismic sensor and apply a corresponding time shift to align the seismic signals with a uniform travel time. The time-shifted seismic signals are then combined to determine an intensity value for seismic energy radiating from the focal point. A subsurface map can then be derived from the intensity value as a function of position.

Abstract: In order to be acceptable for safety critical applications, it is necessary for an electrical machine to allow continued operation despite an electrical short circuit in one of the operational phases of that electrical machine. It will be appreciated that an electrical short circuit creates excessive electrical current through the short circuit with significant heating and other detrimental effects. However, the electrical machine can operate with one operational phase disabled. In such circumstances, the present invention incorporates means for determining an electrical short circuit has occurred and then injects an electrical current approximately equal to or greater than the rated electrical current. In such circumstances, the operational phase or coil 4, 24, 34 is effectively protected despite the electrical short circuit and hence the electrical machine can continue to operate.

Abstract: A current detection unit starts sampling of a motor current at the timing when the motor current has exceeded a threshold value, and holds a maximum motor current value for each prescribed operation cycle. An abnormality determination unit determines whether the maximum motor current value is greater than the threshold value, and counts the number of times that the maximum motor current value continuously exceeds the threshold value. When the count value has reached at least 3, the abnormality determination unit generates and outputs a detection signal indicating abnormality in the motor current to a relay drive unit and a notification unit. The relay drive unit in receipt of the detection signal generates a signal to turn off the system relays. The notification unit generates and outputs a signal AL to display means outside the power supply apparatus.

Abstract: The present invention provides an apparatus and a method for accurately detecting abnormal conditions of a motor. A ?Tc/Tj detector detects a difference (?Tc) between an environment temperature and a temperature of a field-effect transistor (FET) which turns on and off electric power supplied to a DC motor. A diagnosis control unit detects abnormal conditions such as a motor lock and a short circuit of the DC motor based upon the obtained difference. When the motor lock has been detected, the diagnosis control unit controls a pulse width modulation (PWM) control unit and a PWM oscillator (PWMOSC) and makes a frequency and duty cycle of a PWM signal lower. When the short circuit has been detected, the diagnosis control unit controls a gate driver and turns off the FET.

Abstract: In a method for operating a power tool with an energy accumulator, in particular a rechargeable energy accumulator, which supplies power to an electric drive motor, a clock frequency is generated by an electronic unit, with which a gate of a MOSFET—which supplies operating voltage to the drive motor—is switched on with each cycle, and a switching-off of the MOSFET is carried out within one cycle using different signals, as a function of operating parameters.

Abstract: The present invention is directed to a power meter or overload relay including a housing and a plurality of sensors configured to monitor operation of a motor. A processor disposed within the housing and configured to receive operational feedback from the plurality of sensor and proactively determine an operational wellness of the motor from the operational feedback.

Abstract: A protection system for an electrical device may include at least one temperature sensitive element located in a region adjacent to a component of the electrical device and configured to provide an output related to an actual temperature in the region. The system may also include a controller configured to determine the actual temperature in the region based on the output of the at least one temperature sensitive element and to determine a predicted temperature of the component based on the actual temperature in the region and on a predetermined heat dissipation characteristic of the electrical device.

Abstract: An electrically and thermally protected electrical machine is disclosed. The electrical and thermal protection is provided by one or more control components placed in a conduit box of the electrical machine to disrupt power transmission to the electrical machine upon an excessive current or temperature occurrence. Other control components may also be added to the system to provide further current or thermal protection. These additional control components may or may not be located within the conduit box. A method for providing thermal and current protection, and an aftermarket kit for adding such protection, to an electrical machine are also disclosed.

Abstract: A temperature condition of a motor is estimated more accurately based on a drive amount of the motor. An apparatus for determining overheating of a motor, includes: an information obtaining section that obtains information about a drive amount of a motor and information about a stop time etc. between drive operations of the motor; a calculating section that executes a calculation of calculating an integrated value by successively adding up the drive amount of the motor based on the information about the drive amount obtained by the information obtaining section, and a calculation of subtracting, from the integrated value, a subtraction value corresponding to the stop time etc. that is obtained based on the information about the stop time etc. obtained by the information obtaining section; and a determining section that determines that the motor is in an overheated state when the subtracted integrated value obtained by the calculating section reaches a predetermined value.

Abstract: The invention relates to a circuit (1) for protecting against overload of an electric motor (2), more particularly an electrically powered air blower for a vehicle, with the purpose of providing sufficient and appropriate protection even when several electric motors are connected in series. Said circuit is provided with at least one switching element (6) for controlling two series connected electric motors (2) independent of revolutions, in which a switch element (14) configured as a make contact element (12) is connected in parallel to the electric motor (2), said switch element causing short circuiting of the corresponding electric motor (2) in case of overheating.

Abstract: A method includes determining base-line operating parameters for a compressor, generating a high-side signal indicative of high-side compressor operating conditions, generating a low-side signal indicative of low-side compressor operating conditions, and comparing the high-side and low-side signals to the base-line operating parameters to determine a system operating condition.

Abstract: The invention relates to a regulating device (1) for a motor, comprising a housing (2) which can be associated with said motor and in which a control unit (5) and an actuator (6) are arranged. Due to heat-related reasons, said device can only be used in an encapsulated manner, for example close to a motor. In order to solve this problem, the actuator (6) comprises an electromagnetic switching element (8a,8b) and the control signal (7) for the same is designed as a timing signal which is measured—taking into consideration at least one heat source inside or optionally outside the housing (2)—in such a way that the operating temperature of the electromagnetic switching element (8a,8b) is below an upper authorised limiting value.

Abstract: A reference voltage generator uses a conventional forward junction voltage generating device and a conventional thermal generator to generate a thermal voltage. The forward junction voltage and the thermal voltages have respective thermal sensitivities that act oppositely to each other so that, when the forward junction voltage is combined with the thermal voltage to produce a reference voltage, the reference voltage is substantially insensitive to temperature. The forward junction voltage and the thermal voltage are combined to produce the reference voltage in a manner that avoids generating any voltage having a magnitude that is greater than the magnitude of the sum of the forward voltage and the thermal voltage.

Abstract: There is provided a method and a power quality indicator coupled to an electrical circuit. The indicator comprises the summing device configured to received a sensed wave form from the electrical circuit, including at least one voltage wave form. A summing device is configured to provide a summed output voltage. A low pass filter (LPF) is electrically coupled to the summing device and configured to receive a summed output voltage from the summing device. The LPF is configured to provide a LPF voltage. A microprocessor is configured to receive the sum upward voltage the LPF voltage, compute an RMS voltage value for each of the summed output voltage, determine the difference of such RMS voltage values and generate a signal representative of the difference of the RMS voltage values, wherein the signal is proportional to the harmonic content in the electrical circuit.

Abstract: A motor control system for a brushless and sensorless DC motor for driving a compressor, pump or other application, includes a protection and fault detection circuit for detecting a locked rotor and a rotor which has stopped because of lost rotor phase lock. The motor control system also includes an off-the-shelf motor control integrated circuit having an input for disabling power outputs to the motor phase coils. The protection and fault detection circuit uses a back EMF sampling circuit coupled to the motor phase coils and momentarily disables power to the motor phase coils, via the motor control integrated circuit input, to determine if the motor rotor is rotating. The system also monitors supply voltage, supply current, temperature, and motor speed limits to detect faults and protect system components.

Abstract: It is so arranged in a robot as to monitor the over-current state of each motor and that of two more than two motors when put together by seeing the total current value of the motors being monitored in parallel with absorption of both the static load torque and the dynamic load torque of each actuator/motor. Additionally, it is so arranged as to check if each of the predetermined unit members including the arm sections and the leg sections of the robot is in an over-current state or not and also if the entire robot is in an over-current state or not, while each of the motors are not in an over-current state.

Abstract: A synchronous-motor controller including an inverter for converting direct current to alternating current in order to supply a synchronous motor with a current responsive to a torque instruction value, a temperature sensor for measuring a temperature of the inverter and a control unit. The control unit detects a locking of the synchronous motor although current is supplied to the synchronous motor and calculates, based on the torque instruction value, a heating value of a switching element of the inverter at the time when the switching element is supplied with the current after the synchronous motor is in a locked condition, wherein a temperature of the switching element is estimated by adding the calculated heating value to an initial value of the temperature of the inverter measured by the temperature sensor when the locking of the synchronous motor is detected.

Abstract: A technique is provided for controlling and protecting loads such as electric motors. In the technique, current sensing circuitry detects electrical current applied to the load. Device thermal modeling circuitry, such as circuitry for modeling heating of a motor, determines heating based upon the sensed current, and generates a first trip signal in a first range based upon the current. Conductor thermal modeling circuitry estimates heating of conductors that supply current to the load, and generates a second trip signal in a second range based upon the conductor heating. The system provides an extended range of operation for a wide range of loads by effectively modeling conventional thermal overload and instantaneous trip devices.

Abstract: A power window driving apparatus includes a motor which drives a window by supplying a supply voltage of a power supply, a control circuit which controls the motor so as to stop or reverse a rotation of the motor when a motor current flowing to the motor is increased, a shunt resistance which detects the motor current as a voltage value, and is provided between the motor and a ground and a diode which is provided between a positive side of the power supply and the control circuit for protecting the control circuit.

Abstract: A protective device includes a signal input intended for connection to a sensor, a signal output intended for connection to an evaluation unit, and an isolation element for galvanically separating the signal input from the signal output. The provision of the protective device prevents a transmission of overvoltages from the sensor to the evaluating unit.

Abstract: An electric motor control unit mounted in an automotive vehicle having a motor that is variable in its rotational speed. A temperature sensing element is arranged to contact a busbar so that relays permit switching operation in response to detection of abnormal heat generation. This controls an electrical power supply to the motor to decrease the rotational speed of the motor without complete stopping of the motor. The rotational speed of the motor returns to a normal speed from the decreased speed by switching operation of the relays with diminishing of the abnormal heat generation.