A matrix power conversion device including a plurality of three-phase switching modules and a controller is provided. Each three-phase switching module includes a plurality of bidirectional switches connected to the input phase voltages of the three-phase input power respectively and outputs a corresponding output phase voltage of the three-phase output power. The controller determines a maximum voltage, an intermediate voltage and a minimum voltage among all the input phase voltages to acquire a waveform of a control carrier wave in a switching cycle. The controller acquires output expected values corresponding to all output phase voltages and compares them with the waveform of the control carrier wave for acquiring a turning-on time of each of the plurality of bidirectional switches. Accordingly, the controller controls the matrix power conversion device to switch the three-phase input power so as to change the three-phase output power for driving the motor.

A method of setting up an electrical motor speed control in a fluidic system including a turbomachine, an electric motor having a number p of pole pairs rotating the turbomachine, a variable speed drive controlling the speed of the electric motor, a sensor measuring a parameter H, Q of the turbomachine, and a system controller receiving the sensor's measurements and controlling the operation of the fluidic system. The method includes driving the electric motor at a predetermined electrical frequency, Fe, such that the turbomachine rotates with a controlled rotational speed N, determining the point of intersection of the system curve of the fluidic system and of the performance curve of the turbomachine to obtain the turbomachine's nominal operating point, and thus the nominal value, Hn, Qn, of the turbomachine parameter, measuring, with the sensor, the current value, H, Q of the turbomachine parameter, calculating the controlled rotational speed N by inputting, into the Affinity Laws, the determined nominal value, Hn, Qn, the measured current value, H, Q, and the known nominal rotational speed, Nn, of the turbomachine, determining the number p of pole pairs of the electric motor based on the ratio of the electrical frequency Fe and the calculated controlled rotational speed N, and adapting the setup of the variable speed drive to match the determined number p of pole pairs.

Systems and methods are for a machine having an alternating current (AC) power source with a first side and a second side, at least one winding, a voltage polarity sensor, a Hall effect sensor, four bi-directional power switches each comprising two DC power switches, and a motor controller. The motor controller is configured to, based on signals from the voltage polarity sensor and the Hall effect sensor, opens or closes or operates with pulse-width modulation the DC power switches to obtain a first direction of current flow through the at least one winding and a second direction of current flow from the first side of the AC power source to the second side of the AC power source or from the second side of the AC power source to the first side of the AC power source.

A control system for a permanent split capacitor (PSC) motor is provided herein. The control system includes a motor drive circuit configured to condition AC input voltage from an AC voltage source to an output voltage for operating the PSC motor at a variable speed. The control system also includes a switch device configured to couple the AC input voltage from the AC voltage source directly to the PSC motor for operating the PSC motor at a fixed speed.

A control system for a permanent split capacitor (PSC) motor is provided herein. The control system includes a motor drive circuit configured to condition AC input voltage from an AC voltage source to an output voltage for operating the PSC motor at a variable speed. The control system also includes a switch device configured to couple the AC input voltage from the AC voltage source directly to the PSC motor for operating the PSC motor at a fixed speed.

A multi-phase power converter comprising a plurality of phases for generating an output voltage according to a switching signal and an input voltage, each phase of the plurality of phases comprising a switching element and inductance; wherein the plurality of phases is connected to a common star point, wherein an output capacitor is connected to the common star point. The phases of the multi-phase power converter are not identical in terms of their inductance. Therefore, at least one phase may be optimized for a low current such that, in low power operation, said at least one phase is optimal for lower current levels.

A multi-phase power converter comprising a plurality of phases for generating an output voltage according to a switching signal and an input voltage, each phase of the plurality of phases comprising a switching element and inductance; wherein the plurality of phases is connected to a common star point, wherein an output capacitor is connected to the common star point. The phases of the multi-phase power converter are not identical in terms of their inductance. Therefore, at least one phase may be optimized for a low current such that, in low power operation, said at least one phase is optimal for lower current levels.

A battery state estimating apparatus as an embodiment includes a state estimator, a power estimator, and a determiner. The state estimator estimates a state of a battery. The power estimator estimates first power amount charged/discharged by the battery within a charging/discharging period, based on the state. The determiner compares the first power amount with second power amount inputted/outputted to/from the battery within the charging/discharging period and thereby determines validity of the state.

A variety of methods, controllers and electric machine systems are described for pulse control of electric machines (e.g., electric motors and generators). To improve the energy conversion efficiency of the machine, pulse control involves determining if the machine should operate in a continuous mode or pulse mode, and if the latter, defining a magnitude, duty cycle, and frequency for the pulses. One or more tables, indexing by a wide range of speeds and torque requests, is/are used to define the pulsing frequency or a pulsing frequency pattern.

A method is for a network synchronization of a permanently excited three-phase machine including a soft starter, including thyristors, and mechanical bypass contacts for bridging the thyristors in the network operation. The method includes generating a first control signal, to initiate switching the mechanical bypass contacts to become conductive, after a criterion is reached while running up the three-phase machine on the soft starter, a time at which the first control signal is generated representing actuation time of the bypass contacts; generating ignition pulses for the thyristors within a time period, running from the actuation time to a contact time of the bypass contacts, using a second control signal; and operating the three-phase machine in the network operation via the bypass contacts. Each ignition pulse for a thyristor is generated when a phase current measurement indicates that the current strength in the assigned phase has fallen below a threshold value.