Abstract: A propulsion control device includes: a first wire connectable to a power line supplied with direct-current power or a ground line connected to a reference potential; a second wire connectable to the power line or the ground line; and a brake chopper circuit in which a first switching element to which a first diode is connected in parallel and a second switching element to which a second diode is connected in parallel are connected in series, and in the brake chopper circuit, one end of the first switching element is connected to the first wire, another end of the first switching element is connected to one end of the second switching element at a connection point, another end of the second switching element is connected to the second wire, and the connection point is connected to the first wire or the second wire via a brake resistor.

Abstract: An electric power supply management method is configured to electrically power electrical equipment of a crane, via a conversion circuit, from a primary power supply source capable of providing a primary power and from a rechargeable secondary power supply source capable of providing a secondary power. The electric power supply management method includes monitoring of a requested general power which corresponds to a power demanded by all the electrical equipment, and a monitoring of a charge level of the rechargeable secondary power supply source.

Abstract: The present application provides a method for pre-charging a cascade converter and a cascade converter. The cascade converter includes a main transformer, multiple power units, a control unit and a precharge unit. Power units connected with the precharge unit are a first power unit group, and other power units are a second power unit group. The control unit controls first switch set in the precharge unit to be turned on, and low-voltage AC power supply in the precharge unit performs pre-charging for a bus capacitor through an inverter circuit in the first power unit group. When a voltage of the bus capacitor reaches a first voltage threshold, the control unit controls a rectifier circuit in the first power unit group to work to magnetize the main transformer, thereby performing pre-charging for bus capacitors in the second power unit group.

Abstract: An estimating method includes the following steps. Firstly, if the electrical machine control system is in the generator mode, a bus voltage of the bus capacitor is monitored continuously. Then, if the switch is turned to an on state, a first current value of a current flowing through the bus capacitor during an off state of the switch is calculated. Then, the switch is turned to the on state. Then, if the switch is turned to the off state, a second current value of a current flowing through the bus capacitor during the on state of the switch is calculated, and a resistance value of the braking resistor is estimated according to the first current value and the second current value.

Abstract: A method for driving a multiphase motor by a drive circuit, wherein the drive circuit comprises a plurality of transistors, and for each phase of the motor are provided a first path and a second path, wherein at least one transistor is assigned to the first path and to the second path of each of the different phases, and wherein a normal mode, a first drive mode, and a third drive mode are provided, wherein for the first drive mode, all the transistors in the second paths are short-circuited, and for the third drive mode, all the transistors are opened. The method includes detecting an undervoltage or an overvoltage in the drive circuit, operating the drive circuit in the first drive mode if a first undervoltage has been detected, and operating the drive circuit in the second drive mode if a second undervoltage has been detected.

Abstract: Provided are embodiments for a braking system, where the system includes a controller, a motor coupled to an H-bridge network, a DC link coupled to the motor, and an electrical braking system electrically coupled to the motor. The electrical braking system includes a sense circuit configured to sense a condition of the DC link, a brake resistor coupled to the DC link, a drive circuit coupled to the sense circuit, and a transformer for regeneration. Also, provided are embodiments of a method for operating an efficient regenerative resonance electrical braking system.

Abstract: In a controller of a machine tool having a converter that converts an AC power supply to DC and a plurality of inverters that drive a feed axis and a spindle, a power outage preparation mode is judged when an AC power supply voltage becomes lower than a predetermined value, and power outage is judged when the power outage preparation mode continues for a time period exceeding a predetermined time period or when a DC voltage which is output from the converter becomes lower than VAL1. During the power outage preparation mode, a threshold VAL2 of a low voltage alarm provided at each inverter is changed to a value lower than VAL1. In addition, when the power outage is judged, a stopping operation or a retracting operation of the feed axis is executed.

Abstract: A method of controlling a power system that includes an electrical machine, e.g., wind turbine generator, a power converter, a DC circuit and a dynamic braking system (DBS) having a braking circuit having a braking resistor and being connected in series to the DC circuit, is provided. The method includes operating the DBS and controlling operation of the electrical machine based on a prevailing temperature of the braking circuit, stopping the electrical machine and controlling the electrical machine to be restarted at its rated output power once the prevailing temperature of the braking resistor reaches or falls below a lower temperature threshold. The electrical machine may be restarted at a lower output power and after restarting, its output power can be increased based on a power starting profile as the braking resistor cools.

Abstract: An apparatus (100) may include a working assembly (220) configured to perform a work function responsive to operation of the working assembly, an electric motor (230) that powers the working assembly, a power source (210) configured to selectively power the electric motor, a control circuitry (240) for controlling operation of the electric motor, and a brake function (270) configured to selectively apply braking to the electric motor responsive to a brake initiation event. The brake function may be configured to apply the braking by short-circuiting motor phase windings of the electric motor without requiring an external power supply during application of the braking.

Abstract: Aspects of the disclosed embodiments generally relate to a current monitoring and alarm system for a railroad crossing gate. The system is capable of determining that the gate is functioning properly or not. In addition, the system can issue an alarm or provide some other indicator when the gate is not functioning properly or is being subjected to excessive loading.

Abstract: Disclosed herein is an apparatus for controlling an inverter. The apparatus controls a braking resistor connected in parallel with a DC link capacitor to switch to an ON or OFF state based on at least one of the temperature and the DC link voltage of the braking resistor.

Abstract: The electric motor consists of a rotor fitted with permanent magnets and comprises a stator the armature of which is made up of two parts: a stack of laminations forming round teeth and a solid tube-shaped field frame made of a material of the stainless steel kind enveloping the said stack of laminations. This armature constitutes a non-disengageable braking system that produces a damping effect in the face of possible movements of its rotor which are brought about and/or imposed by the members with which it collaborates. This motor can be used for driving a roto-linear actuator device with satellite rollers which is used as an actuator for maneuvering the control surfaces of an aircraft, for example an aileron.

Abstract: A method and apparatus are disclosed for lowering a load on a direct current hoist motor during an electrical power interruption, the method including but not limited to determining in a crane processor that the electrical power interruption has occurred; and providing a brake assist current to shunt field on the direct current hoist motor to produce a counter torque in the hoist motor.

Abstract: An integrated power converter includes first and second auxiliary switch modules, and one or more braking switch modules. The first auxiliary switch module is mounted at a first location of a laminated bus bar, and connects a first auxiliary lead with a first power layer and a second power layer of the bus bar. The second auxiliary switch module is mounted at a second location of the bus bar, and connects a second auxiliary lead with the first and second power layers. The braking switch modules are mounted at additional locations of the bus bar, adjacent to the first and second locations. Each braking switch module connects a braking lead with one of the power layers of the bus bar, and with a dual diode module or with the other power layer of the bus bar.

Abstract: A control system for a thrust reverser with a movable cowl includes an electromechanical actuator to actuate the movable cowl, an electric drive unit (M) driving the actuator, and a power control unit capable of controlling the electric drive unit (M). The power control unit moves the movable cowl to a closed position and/or to a deployed position. In particular, the control system includes an electronic circuit for electric braking capable of braking the electric drive unit (M), in case of overspeed of the drive unit when the movable cowl is moved to the closed position and/or to the deployed position.

Abstract: The disclosure describes, in one aspect, a system for a machine having an electric drive configuration. The system includes an electric motor associated with at least one wheel and adapted to provide retarding torque to the wheel, and a controller configured to determine a power measurement of a retarding grid and control the retarding torque to the at least one wheel during retarding as a function of the power measurement.

Abstract: An electric motor controller includes controller electronics configured to control an electric motor. The electric motor controller also includes a thermoelectric cooler in thermal communication with the controller electronics. The thermoelectric cooler is configured to receive a braking current associated with braking of the electric motor and provide cooling to the controller electronics.

Abstract: A system includes a grid coupled to an electrical bus; an electrical power modulation device coupled to the electrical bus that can output modified electrical power received from the electrical bus: a blower motor coupled to the electrical power modulation device that can receive the modified electrical power output and can provide a stream of air to affect a temperature of the grid, and a controller. A speed of the blower motor may be based at least in part on an amount of the modified electrical power. The controller can receive an operating parameter, and is responsive to that parameter by causing the electrical power modulation device to vary the amount of the modified electrical power. A blower motor speed may be controlled based at least in part on the operating parameter.

Abstract: A traction motor system calculates motor flux by generating a real time effective resistance of a resistance grid calculated from motor torque and measured voltage on a DC link. Calculating effective resistance avoids solely relying on DC link voltage, which can be influenced by conditions such as wheel slip and drop out of one or more resistance grids. The effective resistance calculation is based on nominal motor values using known power levels and conditions. From these nominal values and the effective resistance, various scaling factors based on actual motor power can be generated and used to adjust a nominal flux reference to more accurately reflect actual motor flux. The scaling factors include power and torque scaling factors and a resistance scaling factor that is active during conditions such as wheel slip.

Abstract: An electric vehicle drive system includes an electric-vehicle power conversion device, and an earth ground switch that is a triple-pole single-throw switch having a switching contact unit. The electric-vehicle power conversion device includes a smoothing circuit unit that includes a filter capacitor that receives and stores therein power supplied from an overhead wire, an inverter that converts a DC voltage of the smoothing circuit unit into an AC voltage to drive an electric motor, and a brake chopper circuit that consumes excess power, which cannot be returned toward the overhead wire. A brake resistance in the brake chopper circuit is connected to the switching contact unit. When the switching contact unit is closed, the brake resistance is electrically connected between the positive electrode and the negative electrode of the filter capacitor.

Abstract: Apparatus and methods are presented for mitigating overvoltages and limiting reverse motor speeds for motor drive power loss events, in which a first power dissipation circuit is enabled at the motor drive output to limit reverse rotation of a driven motor load when motor drive power is lost, and a second power dissipation circuit in a DC bus circuit is used to mitigate over voltages following restoration of motor drive power.

Abstract: Precharging and dynamic braking circuits are presented for multilevel inverter power stages of a power converter with a shared resistor connected to charge a DC bus capacitor with current from the rectifier circuit in a first operating mode and connected in parallel with the capacitor to dissipate power in a dynamic braking mode.

Abstract: One embodiment of a drive system may include a motor shaft coupled to a gear set in connection between an input shaft and an output shaft. The system may also have a direct current motor selectively holding the motor shaft in a fixed position for engaging the input and output shafts to one another in response to a sudden power loss from a main power supply. The system may further include an auxiliary power supply enabling the direct current motor to provide a resistive torque.

Abstract: This disclosure is directed to a traction motor drive system. The traction motor drive system may include a field winding subsystem comprising a field winding associated with a traction motor. The traction motor drive system may also include an armature subsystem arranged in parallel with the field winding subsystem. The armature subsystem may include an armature having first and second armature terminals and a grid resistor selectively electrically coupled in series with the armature. The armature subsystem may also include an armature chopper arranged in parallel with the grid resistor and electrically coupled in series with the armature. The armature chopper may be configured, when the grid resistor is electrically coupled to the armature, to conditionally conduct current to the armature.

Abstract: A heating element unit according to an embodiment includes a heating element, a heat transfer base in which the heating element is provided, and a casing in which the heat transfer base is arranged. The heat transfer base includes a mounting wall on which the heating element is mounted in a close contact state, and side walls that perpendicularly extend in a same direction from both ends in a short direction of the mounting wall and are mounted on an inner surface of the casing in a contact state.

Abstract: An integrated power converter includes first and second auxiliary switch modules, and one or more braking switch modules. The first auxiliary switch module is mounted at a first location of a laminated bus bar, and connects a first auxiliary lead with a first power layer and a second power layer of the bus bar. The second auxiliary switch module is mounted at a second location of the bus bar, and connects a second auxiliary lead with the first and second power layers. The braking switch modules are mounted at additional locations of the bus bar, adjacent to the first and second locations. Each braking switch module connects a braking lead with one of the power layers of the bus bar, and with a dual diode module or with the other power layer of the bus bar.

Abstract: An electric motor system having a power supply, an electric motor connected to the power supply, an object driven by the motor having a range of motion and a substantially neutral position within the range of motion, a power sensor configured to sense power from the power supply, a position sensor configured to sense position of the object in at least a portion of the range of motion, an energy storage, a controller connected to the power supply and the energy storage, wherein the controller is configured to brake the motor as a function of the position sensor, the neutral position and the power sensor.

Abstract: The invention relates to an industrial robot having a robotic arm. The robotic arm has several axes (A1-A6) and at least one electric drive, which comprises an electric motor (7-12) and power electronics (16) actuating the electric motor (7-12) and is equipped to move the relevant axis (A1-A6). The industrial robot (1) is equipped to short-circuit the electric motor (7-12) in the event of emergency braking simultaneously by means of two independent electric current paths.

Abstract: A vehicle includes an engine, an EHC (electrical heated catalyst), a first MG (motor generator) generating a counter electromotive force at the time of vehicle collision, a battery, a PCU (power control unit) having a converter and an inverter performing power conversion between the battery and the first MG, and an ECU. The PCU is connected to the battery through an SMR (system main relay). The EHC is connected between the converter and the inverter through EHC relay. The ECU determines whether or not vehicle collision has occurred. When the vehicle collision has occurred, the ECU opens the SMR to electrically separate the battery and the PCU and closes the EHC relay to electrically connect the EHC and the first MG, so that the counter electromotive force generated in the first MG at the time of vehicle collision is consumed at the EHC.

Abstract: A traction motor system calculates motor flux by generating a real time effective resistance of a resistance grid calculated from motor torque and measured voltage on a DC link. Calculating effective resistance avoids solely relying on DC link voltage, which can be influenced by conditions such as wheel slip and drop out of one or more resistance grids. The effective resistance calculation is based on nominal motor values using known power levels and conditions. From these nominal values and the effective resistance, various scaling factors based on actual motor power can be generated and used to adjust a nominal flux reference to more accurately reflect actual motor flux. The scaling factors include power and torque scaling factors and a resistance scaling factor that is active during conditions such as wheel slip.

Abstract: An electric motor controller includes controller electronics configured to control an electric motor. The electric motor controller also includes a thermoelectric cooler in thermal communication with the controller electronics. The thermoelectric cooler is configured to receive a braking current associated with braking of the electric motor and provide cooling to the controller electronics.

Abstract: A power supply circuit for an electric motor, the circuit comprising a plurality of inverter bridge arms, each having means for connection to a respective winding of the motor, each inverter bridge arm comprising in series a first insulated gate bipolar transistor and a junction field effect transistor that are connected to a controller, the circuit including a second insulated gate bipolar transistor connected in series with each field effect transistor and connected to the controller, and a damping resistor connected in parallel with the second bipolar transistor. An aircraft flight control member including a movable airfoil associated with at least one drive motor connected to such a power supply circuit.

Abstract: The performance of a power transducer is improved while efficiently using a power semiconductor also by managing the permissible duty factor of the power semiconductor in the regenerative braking circuit provided in the power transducer. The user is allowed to set, through an operation panel provided on the power transducer, the resistance value of the regenerative braking resistor for thermally consuming the rotational energy generated during motor deceleration. The power transducer performs the steps of: calculating the current which flows in the regenerative braking circuit from the resistance value setting; obtaining the generation loss of the power semiconductor in the regenerative braking circuit with the calculated current value; and determining the permissible duty factor of the power semiconductor from the obtained generation loss.

Abstract: A system and method are provided for controlling a locomotive such that the braking effort is maintained at its optimal maximum level throughout the extended range. The method comprises detecting a first reduction in speed of the locomotive; energizing at least one solid state device connected across one or more grid resistors for a first predetermined amount of time to divert current away from the one or more grid resistors for the first predetermined amount of time; and de-energizing the solid state device after the first predetermined amount of time. The solid state device may be an Isolated Gate Bipolar Transistor (IGBT) and a plurality of solid state devices are energized, each solid state device being connected across a corresponding resistor grid.

Abstract: A drive with an electric machine which can be operated as a motor for generating a positive drive force and as a generator for generating a negative drive force (braking force), a rechargeable battery, which supplies power to the electric machine in the motor operating mode and can be recharged by the electric machine in generator operating mode, and devices including a load resistor for limiting the charging of the rechargeable battery. The limiting devices also have devices for generating a flow which dissipates heat upstream of the load resistor.

Abstract: A direct drive drawworks (100) has a permanent magnet motor (40) with a first set of windings (250) and a second set of windings (252), a shaft (41) extending from the permanent magnet motor (40) such that the permanent magnet motor directly rotates the shaft (41), a drum (43) connected to the shaft (41) away from the permanent magnet motor (40) such that the rotation of the shaft (41) causes a corresponding rotation of the drum (43), and a switch cooperative with the first set of windings and the second set of windings so as to cause the sets of windings to be selectively connected in parallel or in series.

Abstract: An electric brake system for an electromechanical machine connected to output terminals of an inverter, input terminals of which are supplied by a DC voltage source. The system includes an electrical circuit connected between the input terminals of the inverter and including, connected in series: a mechanism dissipating electrical energy returned by the electromechanical machine to the input terminals of the inverter during a braking phase of the electromechanical machine, including an inductor wound around a magnetic circuit; and a switching mechanism to close the electrical circuit during a braking phase of the electromechanical machine and to open the electrical circuit in absence of a braking phase of the electromechanical machine.

Abstract: The disclosure describes, in one aspect, a system for a machine having an electric drive configuration. The system includes an electric motor associated with at least one wheel and adapted to provide retarding torque to the wheel, and a controller configured to determine a power measurement of a retarding grid and control the retarding torque to the at least one wheel during retarding as a function of the power measurement.

Abstract: This disclosure is directed to a traction motor drive system. The traction motor drive system may include a field winding subsystem comprising a field winding associated with a traction motor. The traction motor drive system may also include an armature subsystem arranged in parallel with the field winding subsystem. The armature subsystem may include an armature having first and second armature terminals and a grid resistor selectively electrically coupled in series with the armature. The armature subsystem may also include an armature chopper arranged in parallel with the grid resistor and electrically coupled in series with the armature. The armature chopper may be configured, when the grid resistor is electrically coupled to the armature, to conditionally conduct current to the armature.

Abstract: A resistor unit adapted to be used in a resistor grid assembly. The resistor unit includes a supporting element and a resistor element. The supporting element has an aperture formed therein. The resistor element has a body portion and a tip portion at an end, which is adapted to be received in the aperture to mount the resistor element to the supporting element. Further, a tab extends from the end of the resistor element forming a part of the resistor element. The tab is configured to provide a heat shield between the supporting element and the resistor element.

Abstract: An electric brake device is provided for electronically controlled synchronous motors which are supplied with voltage by way of a converter. The synchronous motor contains a winding center point and that the winding center point is connected by way of an electric resistor and a switch to a ground point of the converter and that the phases of the converter that are connected to the ground point contain in each case a free-wheeling diode.

Abstract: An electric drive system comprises a generator, a traction motor, a brake resistor, a bus, and a control unit. The generator, the traction motor, and the brake resistor are coupled electrically to the bus. The control unit is configured to determine a pulse-width-modulation duty cycle for the brake resistor (“brake duty”) and control operation of the brake resistor according to the brake duty, wherein the brake duty can be a value intermediate of constant OFF and constant ON. A method of operating the electric drive system is also disclosed.

Abstract: Embodiments provide a ball throwing machine including a motor coupled to a rotary wheel and configured to rotate the rotary wheel at a rotational speed to throw a ball forward toward an athlete. A speed control module may be coupled to the motor and configured to rotate the rotary wheel, via the motor, at a first rotational speed during a fastball setting and a second rotational speed during a changeup setting. The speed control module may determine the second rotational speed based on the first rotational speed so that a ball thrown by the ball throwing machine will arrive in a target zone when the ball throwing machine is in the fastball setting and the changeup setting. In some embodiments, the speed control module may utilize resistive braking to transition the rotary wheel from the first rotational speed to the second rotational speed.

Abstract: Braking current generated by an electrical motor on mining equipment during a retard interval is switched through one or more grid resistors that are liquid cooled. Under low ambient temperatures, a heating current can be switched through the grid resistors when the electrical motor is not operating in a retard interval. An integrated cooling system can be used to cool grid resistors and power modules. Heat dissipated by the grid resistors and the power modules can be circulated through auxiliary heating loops to heat portions of the mining equipment under low ambient temperatures. Multiple liquid-cooled power modules, liquid-cooled grid resistors, auxiliary heating loops, control modules, radiators, and pumps can be coupled by a liquid distribution system with various combinations of parallel and serial branches. Temperature, pressure, and flow rate in each branch can be independently controlled. Operation of the integrated cooling system can be controlled by a computational system.

Abstract: Current source converter (CSC) based motor drives and control techniques are presented in which DC link current is regulated to a level set by the output inverter during dynamic braking operation by pulse width modulation of a braking resistance connection signal to maintain control of motor torque and speed while mitigating or preventing line side regenerative currents.

Abstract: A drive system for an electric drive machine having an engine, a generator, a motor, final drive wheels and auxiliary devices is provided. The drive system may include an inverter circuit and an auxiliary driver. The inverter circuit may be coupled to each of the generator and the motor. The auxiliary driver may be coupled to each of the generator and the auxiliary devices. The inverter circuit and the auxiliary driver may be configured to automatically communicate power from the engine and any power from the auxiliary devices to the motor in a propel mode, and automatically communicate power from the motor to the engine, and optionally to a hybrid system if applicable, in a dynamic braking mode so as to minimize fuel consumption during the dynamic braking mode.

Abstract: A retarding system for an electric drive machine (100) includes a direct current (DC) link (312), at which a DC voltage is developed, disposed between a rectifier (206) and an inverter (208). A first contactor switch (216) electrically communicates with a first rail of the DC link (312), and a second contactor switch (216) electrically communicates with a second rail of the DC link (312). A first resistor grid (214) is connected in series between the first contactor switch (216) and the second contactor switch (216). The first resistor grid (214) dissipates electrical energy in the form of heat by conducting a current between the first rail and the second rail of the DC link (312) when the first contactor switch (216) and the second contactor switch (216) are closed.

Abstract: A system and method are provided for controlling a locomotive such that the braking effort is maintained at its optimal maximum level throughout the extended range. The method comprises detecting a first reduction in speed of the locomotive; energizing at least one solid state device connected across one or more grid resistors for a first predetermined amount of time to divert current away from the one or more grid resistors for the first predetermined amount of time; and de-energizing the solid state device after the first predetermined amount of time. The solid state device may be an Isolated Gate Bipolar Transistor (IGBT) and a plurality of solid state devices are energized, each solid state device being connected across a corresponding resistor grid.

Abstract: If it is determined that excess power is generated based on overcharge information of a power storage device, a controller starts an operation of consuming the excess power by an excessive power consuming circuit. The controller counts elapsed time from the time point when the power consuming operation started, and if the counted elapsed time exceeds a minimum on-time set in advance, switches the excessive power consuming circuit from active to inactive state. The minimum on-time is set based on a pattern that is expected to cause generation of excessive regenerative power from an AC electric motor because of abrupt change in running status of an electric powered vehicle mounting a motor drive system.

Abstract: A braking system for an aircraft provided with undercarriage, wherein an axial-flux reversible electric machine is set between the wheel and the frame of the undercarriage; current-dissipating resistors are provided, which can be connected to the windings of the axial-flux reversible electric machine during rotation of said wheel for dissipating by the Joule effect the induced currents generated by the axial-flux electric machine, which behaves as current generator, and producing a braking effect that slows down the movement of the wheel, thus exerting a braking action.