Abstract: An electrical drive system includes an electrical machine controlled by an electronic controller, which requires feedback of signals representing quantities associated with the operation of the electrical machine. These signals may represent, for example, flux, current and/or rotor position. The integrity of these signals is validated by setting suitable thresholds for the signals and confirming that both are present at the appropriate time.

Abstract: A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimized and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold.

Abstract: A brushless electrical machine has at least one phase winding which produces magnetic flux in the machine. A controller controls the flux in the machine with reference to a demanded flux and a stabilisation signal which, in combination, enable the controller to operate in a stable manner in the presence of disturbances in the inputs or parameters of the controller. The controller is able to operate with either a hardware rotor position detector or with a sensorless position algorithm.

Abstract: A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimized and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold.

Abstract: A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimized and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold.

Abstract: A brushless electrical machine has at least one phase winding which produces magnetic flux in the machine. A controller controls the flux in the machine with reference to a demanded flux and a stabilisation signal which, in combination, enable the controller to operate in a stable manner in the presence of disturbances in the inputs or parameters of the controller. The controller is able to operate with either a hardware rotor position detector or with a sensorless position algorithm.

Abstract: An electrical drive system includes an electrical machine controlled by an electronic controller, which requires feedback of signals representing quantities associated with the operation of the electrical machine. These signals may represent, for example, flux, current and/or rotor position. The integrity of these signals is validated by setting suitable thresholds for the signals and confirming that both are present at the appropriate time.

Abstract: A drive system has a number of electrical machines. One machine operates as a generator supplying an output to a DC link, which in turn supplies one or more machines operating as motors to drive loads. The motors are supplied through power converters. The total capacitance of the DC link is minimised and the link kept in a stable condition by preventing it falling to a hazardous level. One embodiment prevents the phase currents adding in such a manner as to reduce the DC link voltage. Another embodiment employs freewheeling in the phase currents to prevent the DC link voltage falling below a predetermined threshold.

Abstract: An electrical machine is controlled without using a physical rotor position detector. Rotor position is estimated by an algorithm which receives feedback from a parameter which represents the behavior of a phase of the machine. Before the algorithm estimates position, it checks the value of the parameter to ensure that the phase is healthy. In the event of the parameter indicating that the phase is faulty, the algorithm does not attempt to estimate position from that phase, thereby avoiding the generation of faulty position data. Operation of the machine may be continued using only the healthy phases.

Abstract: A switched reluctance drive is controlled without using a physical rotor position detector. The control method estimates the standing flux-linkage associated with the phase and uses this estimate to improve its subsequent estimate of rotor position. The method works robustly regardless of whether the current is continuous or is discontinuous.

Abstract: A switched reluctance drive, operating either as a motor or a generator, is controlled in a stable manner in the continuous current mode in the presence of supply voltage or electrical load variation. The use of a current control parameter Ix in addition to the conventional on- and off-angles ?on, ?off gives the ability to operate smoothly in the continuous current mode and to transition smoothly between operating modes. Once the phase current reaches a pre-determined level Ix, the phase winding may be placed in a freewheel state, thereby controlling the standing current in the phase winding and/or the output voltage.

Abstract: A switched reluctance drive is controlled without using a physical rotor position detector. The control method estimates the standing flux-linkage associated with the phase and uses this estimate to improve its subsequent estimate of rotor position. The method works robustly regardless of whether the current is continuous or is discontinuous.

Abstract: A switched reluctance machine is supplied from two voltage sources during a cycle of excitation. The higher voltage is a conventional bus voltage obtained, e.g., from a low-voltage storage battery and an up-converter. The lower voltage is supplied directly from the battery. The higher voltage supplies the machine during only part of an excitation cycle, the lower voltage supply supplying the energy directly to the machine during the remainder of the excitation cycle. This reduces the duty of the up-converter and increases the efficiency of the overall drive. One method of operation of the circuit allows the elimination of the up-converter.

Abstract: A polyphase switched reluctance machine is controlled by a control system using sensorless position detection. The controller is robust and reliable and operates over the entire current chopping range of the machine. Diagnostic pulses of predetermined flux-linkage are injected into a phase, whether or not it has residual current flowing.

Abstract: A polyphase switched reluctance machine is controlled by a control system using sensorless position detection. The controller is robust and reliable and operates over the entire current chopping range of the machine. Diagnostic pulses of predetermined flux-linkage are injected into a phase, whether or not it has residual current flowing.

Abstract: A rotor position transducer for an electronically commutated electric motor has a vane mounted to rotate with the rotor and a pair of sensors, according to one embodiment. One sensor has an output coincident with positions of zero torque. The other sensor produces signals slightly in advance. Overlapping portions of the signals denote regions of different levels of torque. The second sensor output can also be used in high-speed, single-pulse control of the motor. Method embodiments and other apparatus embodiments are also disclosed.