137results about "Motor control for low load efficiency" patented technology

An electric motor drive device has an inverter adjusting the voltage applied to an AC electric motor so as to drive the AC electric motor, a capacitor which is charged by a current supplied from a DC power supply supplying DC voltage between a neutral point at which a plurality of coils of the AC electric motor are connected and a positive rail or negative rail of an inverter and passing through the inverter, and a control circuit controlling the inverter so that the AC electric motor turns at a designated speed. Further, the control circuit selectively uses field weakening control and voltage boosting control for control of the inverter according to the conditions of the induced voltage generated at the AC electric motor, DC power supply, and voltage of the capacitor.

On end of a reactor (L1) is connected to a positive electrode of a battery (B1) and the other end is connected to a power line via a transistor (Q1) and to the ground via a transistor (Q2). By PWM control of the transistors (Q1, Q2), an arbitrary increased voltage is obtained in the power line. It is possible to obtain an optimal inverter input voltage (power line voltage) according to the motor drive state, thereby increasing efficiency. Thus, it is possible to optimize the inverter input voltage according to the motor drive condition.

A permanent magnet rotating electrical machine capable of conducting a variable speed operation at high output in a wide range from low speed to high speed and improving efficiency and reliability in a wide operating range. Two kinds of permanent magnets having different shapes or different magnetic characteristics are embedded in a rotor core, to form a magnetic pole. The permanent magnets arranged at the magnetic pole include a permanent magnet whose product of coercive force and thickness along a magnetizing direction is small and the permanent magnet whose product of coercive force and thickness along the magnetizing direction is large. A magnetic field created by passing a current to an armature coil for a short time is used to irreversibly magnetize the permanent magnet whose product of coercive force and thickness along magnetizing direction is small, thereby changing a total linkage flux amount, and a positive d-axis current is passed when torque is large.

The invention discloses a new intelligent motor battery control system. Based on the former connection of the storage battery, the motor and the controller of electric truck/ battery motor vehicle/electric bicycle, a management system is added for the storage battery, and the motor is internally provided with a state monitoring and communication control module; at the same time, the controller is also additionally provided with a storage battery management system and a motor communication control module. The structure, integrating the storage battery, the motor and the controller, takes advantages of the best control proposal of the control to maximum the service life of the storage battery, providing most electric energy discharging for once; meanwhile, the control proposal, which is designed according to the motor characteristics, promises the motor to optimize the operation on the high efficiency platform. Without changing to the vehicle structure of the former electric truck/ battery motor vehicle/electric bicycle, the system can conveniently and efficiently combine the storage battery, the motor and the controller, thereby improving the energy utilization efficiency of the electric truck/ battery motor vehicle/electric bicycle; moreover, with characteristic of extensive application, and as the rising demand to the electric vehicles nationwide, bringing great yearly demand, the system possesses extremely large social and economic benefits.

A system and method for controlling an AC motor drive includes a control system programmed with an energy algorithm configured to optimize operation of the motor drive. Specifically, the control system input an initial voltage-frequency command to the AC motor drive based on an initial voltage/frequency (V/Hz) curve, receives a real-time output of the AC motor drive generated according to the initial voltage-frequency command, and feedback a plurality of modified voltage-frequency commands to the AC motor drive, each of the plurality of modified voltage-frequency commands comprising a deviation from the initial V/Hz curve. The control system also determines a real-time value of the motor parameter corresponding to each of the plurality of modified voltage-frequency commands, and feeds back a modified voltage-frequency command to the AC motor drive so that the real-time value of the motor parameter is within a motor parameter tolerance range.

At a time of a heating high-load operation, a harmonic current is flown in an armature winding to induction-heat rare-earth magnets, thus reducing a residual magnetic flux density. Thereby, the number of rotations of a radial gap type motor is improved. The rare-earth magnets are provided near a cooling medium passage extending substantially in parallel with a flow line of a cooling medium, so that the cooling medium recovers heat of the heated rare-earth magnets. At a time of a cooling high-load operation, a greater number of rotations are obtained with respect to the same torque command value, by a field weakening control by means of a current-phase advance.

In a power converter, vibration and noise of a motor due to pulsation of a direct current link voltage are reduced. An inverter circuit is provided, which is configured to convert a direct current link voltage having a pulsating component to an alternating current to output the alternating current to a permanent magnet synchronous motor. A controller is provided, which is configured to control the inverter circuit by vector control and which, in a control state in which fundamental voltage vectors do not include a zero vector (voltage vector for which a motor terminal voltage is zero), performs such control that the phase of a resultant voltage vector of a d-axis voltage vector and a q-axis voltage vector of the permanent magnet synchronous motor varies depending on pulsation.

A motor controller (4) and method for maximizing the energy savings in an AC induction motor (3) at every load wherein the motor is calibrated at two or more load points to establish a control line (6), which is then programmed into a non-volatile memory (30) of the motor controller. A DSP-based closed-loop motor controller observes the motor parameters of the motor such as firing angle/duty cycles (23), voltage (37), current (9) and phase angles to arrive at a minimum voltage necessary to operate the motor at any load along the control line. The motor controller performs closed-loop control to keep the motor running at a computed target control point, such that maximum energy savings are realized by reducing voltage through pulse width modulation.

A system and method for controlling an AC motor drive includes a control system programmed with an algorithm configured to optimize operation of the motor drive. Specifically, the control system is programmed to input an initial voltage-frequency command to the drive. The initial voltage-frequency command includes a voltage reference and a frequency reference corresponding to an operating point of an initial voltage/frequency (V/Hz) curve. The control system monitors a real-time output of the drive, modifies the voltage reference based on the real-time output of the drive, and transmits a modified voltage-frequency command to the drive. The modified voltage-frequency command corresponds to an operating point of a modified V/Hz curve defined by the modified voltage reference and the initial V/Hz curve.

Embodiments of the present invention are directed to compensating for force ripple of an apparatus driven by a force produced by a linear motor. In one embodiment, a method of compensating for force ripple comprises generating force commands for a trajectory starting at a plurality of starting positions of the apparatus driven by the linear motor to produce different trajectory motions based on the same trajectory at the plurality of starting positions, the force commands each including peaks of large acceleration/deceleration and valleys of low force levels; calculating an average of the force commands during large acceleration/deceleration generated based on trajectory motions for the plurality of starting positions; calculating a variation ratio of the force command for each trajectory motion to the calculated average of the force commands; and compensating for force ripple in the apparatus based on the calculated variation ratio to control the force applied by the linear motor to the apparatus.

The invention discloses a motor energy-saving conversion controller, relating to the field of motor control. The structure of the controller is a contactor structure of a relay; buttons on a control panel are connected with an intermediate relay coil by a conversion board; the relay electric shock extends a contactor outwards and the contactor then controls the running of the motor; three contactors can realize the star-triangle conversion of the overall working process; the three contactors are respectively KM1, KM2 and KM3, and each contactor is provided with two pairs of auxiliary contacts. The three-phase contacts of KM1 and KM2 are shortly connected correspondingly to form the star connection and the phase contacts of KM1 and KM3 are connected from beginning to end to form the triangle connection. When working, a starting button PSB2 is pressed, and then a PLC controller controls automatically according to collection signals to realize the triangle-star automatic conversion connection of the motor. The motor energy-saving conversion controller has the advantages that the PLC automatic controller is adopted to realize the star-triangle automatic mutual conversion in the running process, a large amount of energy is greatly saved, the cost of the controller is low and installation and use is convenient.

This invention discloses a hoist power system supplied by DC bus including a generator set, a supply and distribution system, a frequency conversion system and a speed regulation motor, in which, the supply and distribution system includes a large power commutation device, a DC bus and an energy management unit, the DC bus is parallel with a DC energy-storage device capable of supplying the conversion system at the same time, which includes several inverters connected on the DC bus, the speed regulation motor is a lifted motor, a jumbo motor or a trolley motor, in which, the lifted motor is converted to generator mode to store the re-generated energy source to an energy storage device when a lifted subject falls, the energy management unit controls the operation speed and generation volume of the generator set to realize real time match of output power and load power.

The invention provides a drive apparatus for the combined running of an induction motor with high starting performance and a frequency converter, relating to the field of motor drive. The invention solves the problems that the traditional frequency conversion drive apparatus capacity is obviously higher than the actual load. A three-phase power supply of the apparatus is connected with three static ends of a first AC contactor KM1 and a three-phase power supply input end of a frequency conversion system, three power output ends of the frequency conversion system are connected with three follower ends of the first AC contactor KM1 by a fourth AC contactor KM4, the three follower ends of the first AC contactor KM1 are respectively connected with a three-phase winding of a three-phase motor, a main controller detects three-phase current, a control signal output end of the main controller is connected with a control signal input end of the frequency conversion system, and two control signal output ends of the main controller are respectively connected with coils of two AC contactors. The invention is widely used in various drive occasions, especially in the over loading starting operating condition by means of good energy saving effect.

A boost circuit is arranged to reduce rise and fall times of pulsed power used for pulsed control operation of electric machines. Magnetic energy present in the electric machine at the end of a pulse is extracted by the boost circuit to reduce the pulse fall time. The energy is stored by the boost circuit and then applied at the beginning of a subsequent pulse to reduce the rise time. By reducing rise and fall times compared to not using such a boost circuit, machine efficiency is improved.

The present invention relates to an energy-saving system for three-phase induction motors and is based on the principle of variable voltage control at constant speed. It is composed of a microprocessor, exampling circuit, sensing circuit, acquiring circuit, firing circuit, and AC to AC converter. The system is to automatically adjust the voltage to the induction motor with the variation in the motor load, in order to obtain high operating power factor and efficiency. The system will result in considerable energy-savings when a three-phase induction motor runs under constant light-load or variable-load with low duty ratio.

A drive for motor that can be operated up to a high load while improving efficiency of an inverter is provided. The drive for a motor includes: a voltage conversion circuit 2 that changes a value of a DC voltage and outputs the DC voltage; an inverter 3 that converts the DC voltage output from the voltage conversion circuit into an AC voltage, the conversion being performed by a switching operation of a switching element; and control means that controls the DC voltage output from the voltage conversion circuit and controls a voltage output from the inverter by the switching element so as to drive the motor 1. The control means executes DC voltage adjustment control in which the DC voltage output from the voltage conversion circuit is controlled based on a modulation factor of the DC voltage modulated by the inverter so that the modulation factor becomes closer to 1.