Abstract:
An electrical controller for electric motors is provided. A control system for an electric motor comprises a supply for supplying excitation current to different windings of the motor at any given time. Furthermore, the amplitude of the excitation current is independently variable of the timing and duration of the application of the excitation current to the windings. This allows increased control of the motor and facilitates the operation of the motor at high mechanical and/or electrical speeds.
Abstract:
A control device (200) for a motor drive system (100) including an AC motor (MG1) having a magnet in a rotor, a converter (120), and an inverter (130) generates a step-up command value for the converter (120) based on a torque command value for the AC motor (MG1). The control device (200) determines whether or not to carry out field-weakening control for increasing a current in a direction weakening force of a magnet that is supplied from the inverter (130) to the AC motor (MG1), based on the step-up command value and a state of drive of the AC motor (MG1). When field-weakening control should be carried out and when an absolute value of the torque command value is smaller than a threshold value, the control device (200) further increases the generated step-up command value. By doing so, an amount of a field-weakening current can be decreased and therefore efficiency of the motor drive system (100) can be improved.
Abstract:
A three-phase regenerative drive (20) is operated based upon power from a single-phase AC source ( 12) and power from a DC source (14). The single-phase AC input power and the DC input power are converted to DC voltage on a DC bus (24) by a three-phase converter (22). DC power is provided from the DC bus (24) to a three-phase inverter having outputs connected to a motor (34). A controller (44) controls operation of the three-phase converter (22) based upon contribution factors of the AC and DC sources ( 12, 14) during motoring and regeneration. The controller (44) also controls an AC component of current from the DC source to reduce ripple current on the DC bus (24).
Abstract:
There is provided a controller for a steering device that makes it possible to prevent sudden ceasing of steering assisting power by effectively utilizing an auxiliary power source. An electric power steering device that generates steering assist force by a motor includes a battery for supplying electric power to the motor, an auxiliary power source that supplies the motor with electric power, and a control circuit for controlling a power supply to the motor. In the event of a breakdown of the battery, the control circuit adjusts a power supply to the motor from the auxiliary power source according to an amount of energy remaining in the auxiliary power source so as to reduce steering assist force.
Abstract:
A motor controller (8) for an axial-gap motor permits a reduced size of the entire system of including a drive circuit and a power source of the motor, reduced cost, and higher reliability to be achieved by controlling the energization mode of the motor. The motor controller (8) has a torque command determiner which inputs a first DC voltage to a first inverter (32a) at least either when a rotor (11) is at a halt or when the number of revolutions of the rotor (11) is a predetermined number of revolutions or less, supplies a field axis current for changing the magnetic flux of a field of the rotor (11) to a first stator (12a) from the first inverter (32a) such that the amount of energization is temporally changed, converts an induced voltage developed in a second stator (12b) by the supplied field axis current into a second DC voltage by a second inverter (32b), and outputs the second DC voltage, thereby charging a second battery.
Abstract:
The control apparatus has a battery (B1) whose positive terminal is connected to a reactor (L1). The other end of the reactor is connected to a power line and ground through the transistors (Q1,Q2) respectively. The power line voltage is increased according to the motor drive state, by pulse width modulation (PWM) control of the transistors.
Abstract:
A control device (30) calculates an upper limit value of a duty ratio (DR_Ulim) according to a voltage (Vm) from a voltage sensor (13) and a threshold voltage (OVb) when an overvoltage is determined to have been applied to a battery (B), and determines a duty ratio (DR) for providing switching control to NPN transistors (Q1, Q2) in a range lower than the calculated upper limit value of the duty ratio (DR_Ulim). The control device (30) uses the determined duty ratio (DR) to provide switching control to the NPN transistors (Q1, Q2). Then, an up-converter (12) converts a direct current voltage (Vb) from the battery (B) into the output voltage (Vm) such that an overvoltage is not applied to the battery (B).
Abstract:
A system and method for driving an electric vehicle is provided. The system has, for example, a power source generating a voltage, a voltage converter, a control system, and one or more motors for driving or propelling the vehicle. The voltage converter is configured to accept an input voltage and generate an output voltage, which is different from the input voltage. The power source provides the input voltage to the voltage converter. A switch is further provided to switch the delivery of power to the control system between a power source voltage and an increased voltage derived from the voltage converter.