Abstract: Described is a method of aligning a rotor of a polyphase synchronous motor having a permanent magnet rotor to a predetermined, selected, or specified rotor angle. The method comprises sensing or measuring the stator winding voltages/currents during synchronous operation of the motor. Based on the sensed or measured stator winding voltages/currents, a synchronously rotating reference frame vector voltage (Vq) in the q-axis is determined as a product of stator winding resistance (Rs) and stator winding current (iq) in the q-axis. Corresponding polyphase drive voltages for the synchronous motor for the predetermined, selected, or specified rotor angle (?) are determined from the synchronously rotating reference frame vector voltage (Vq). The polyphase drive voltages are applied to align the rotor on stopping at said predetermined, selected, or specified rotor angle (?). The polyphase drive voltages are applied by suitable PWM drive signals.

Abstract: Described is a method of determining an initial rotor position on start-up of a synchronous motor. The method comprises applying at each of a plurality of pre-set motor angles a pair of voltage vector pulses, the pair of voltage vector pulses comprising a first and second pulses, each having the same amplitude but opposite polarities, the second pulse being applied immediately or near immediately after the first pulse. The method includes determining the stator current responses to said pairs of applied voltage vector pulses at said plurality of pre-set motor angles. Then, the initial rotor position can be determined from either of a stator angle corresponding to a pair of vector voltage pulses resulting in (a) a largest sum of stator currents or (b) where the sum of stator currents changes from a negative to a positive motor angle.

Abstract: Described is a method of determining an initial speed of a synchronous motor having a permanent magnet rotor. The method comprises controlling said motor to cause the rotor to rotate or observing that the rotor is rotating. The method includes sensing stator winding currents and transforming the sensed stator winding currents into a two-dimensional (2D) coordinate system using an alpha-beta (?-?) transformation. The rotor angle ? is determined from an arc tangent (Atan) of the ratio of the current in the ?-axis to the current in the ?-axis. The initial motor speed ? is determined from the determined rotor angle ?.

Abstract: A closed-loop method of starting a permanent magnet synchronous motor comprises driving the rotor by energizing stator windings using motor control signals based on an initial standstill rotor angle. Periodically estimating values of rotor flux linkage magnitude and/or angle based on back-electromotive force (emf) induced in the stator windings by the rotating rotor. The estimated values of rotor flux linkage magnitude are used to estimate respective new rotor angles which are used to generate updated motor control signals to drive the rotor. Control of the motor is switched-over to a closed-loop synchronous operation motor control algorithm in response to any one or any combination of the following conditions: at a predetermined period of time from initiation of the closed-loop start-up method; or upon determination that the rotor has reached a minimum operating speed; or upon determination that the estimated value of rotor flux linkage magnitude reaches or exceeds a threshold value.

Abstract: An energy-conserving fluid pump is an apparatus used to transport low viscosity fluids like water and fuel without experiencing cavitation, recirculation, nor motor locking while also conserving energy. The apparatus includes a fluid diffuser, a fluid densifier, a convergent housing, and a strut assembly. The fluid diffuser improves the efficiency of the apparatus by expanding the fluid inflow and maintaining a fluid pressure buildup. The fluid densifier shears the incoming fluid flow from the fluid diffuser and increases the fluid outflow pressure. The convergent housing encloses the fluid diffuser and the fluid densifier while facilitating the outflow of the pressurized fluid without the loss of fluid pressure nor cavitation. In addition, the convergent housing facilitates the transfer of torque to the fluid diffuser for the operation of the apparatus. The strut assembly keeps the fluid densifier stationary while enabling the rotation of the convergent housing and/or the fluid diffuser.

Abstract: A multi-phase permanent magnet rotor motor comprises a plurality of phase coil windings with each phase coil winding having two free ends and the plurality of phase coil windings being without a common node. A controller is provided comprising a plurality of full-bridge inverters. Each full-bridge inverter has two output ends electrically connected to the two free ends of a corresponding phase coil winding. The controller is configured to operate the plurality of full-bridge inverters to output pulse modulated control signals to their respective phase coil windings. The outputted pulse modulated control signals can comprise a combination of sine wave signals and full-bridge space vector modulation signals.

Abstract: A system for managing power on distributed devices may include a first device having a master logic and a second device having a slave logic. The master logic may enable the first device to communicate with multiple devices having the slave logic on one or more channels. The slave logic may enable the second device having the slave logic to communicate with the first device and to communicate with a third device having the slave logic. The slave logic may enable the multiple devices having the slave logic to manage operations of the distributed devices.

Abstract: In general, one aspect disclosed features an active choke circuit, including a first three-winding choke; a second three-winding choke; and an amplifier; wherein a first winding of the first three-winding choke is electrically coupled in series with a first winding of the second three-winding choke; wherein a second winding of the first three-winding choke is electrically coupled in series with a second winding of the second three-winding choke; wherein a third winding of the first three-winding choke is electrically coupled to an input of the amplifier; and wherein a third winding of the second three-winding choke is electrically coupled to an output of the amplifier.

Abstract: Described is a method of controlling operation of a synchronous motor. The method comprises, during constant power/speed motor operation, determining a value of a stator voltage (vs2) for an orthogonal rotating reference frame of the motor. Comparing the value of the determined stator voltage (vs2) to a threshold voltage (vs2_max1), said threshold voltage (vs2_max1) having a value between that of a maximum stator voltage (vs2_max0) for a basic speed mode of operation of the motor and that of a maximum stator voltage (vs2_max2) of the motor closed loop controller. If the determined value of the stator voltage (vs2) is greater than or equal to the value of the threshold voltage (vs2_max1), then controlling operation of the motor in a flux weakening mode of operation until a value of a current component (id??id) in a d-axis reaches a maximum negative value (?idmax), or until the value of the stator voltage (vs2) is less than the value of the threshold voltage (vs2_max1).

Abstract: Voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator circuit comprises: a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch; an inductor coupled between the switching node and an output node; a capacitor coupled between the output node and ground; a driver configured to operate the first and second switches according to a pulse-width-modulated (PWM) signal; a PWM circuit configured to generate the PWM signal based on at least an error signal; and a phase detector configured to generate the error signal based on a phase difference between the PWM signal and a clock reference signal.

Abstract: A system for serial communication may include a first device and a plurality of devices on a series connection. The first device may have a master circuit and the plurality devices may have a slave circuit. The master circuit may enable the first device to communicate with the plurality devices having the slave circuit on the series connection. The master circuit may enable the first device to send a command frame on the series connection. The command frame may include an execution mode command and a plurality of commands. The second devices may execute the commands within the command frame at or after the end of the command frame based on the execution mode command indicating a synchronous mode of command execution; and may execute the commands within the command frame at the ends of individual ones of the commands based on the execution mode command indicating a non-synchronous mode of command execution.

Abstract: A tail gas exhausting pressure stabilization control system is provided. The system can control the pressure and the flow rate of a gas and a driving gas inputted therein, such that when the gas and the driving gas are mixed and outputted to a tail gas exhausting outlet, the pressure thereof can be controlled under a predetermined pressure. Besides, when the back pressure is generated because of the exhausted gases from the outlet, an energy-saving module can adjust the pressure of the driving gas outputted to an eductor in accordance with the detecting result of the back pressure in order to resist the back pressure. Thus, the exhausted gases from the outlet can be still under the predetermined pressure between the gas and a gas distribution component so as to stabilize the pressure and flow rate of the exhausted gases from the outlet and save the driving gas.

Abstract: A system for managing power on distributed devices may include a first device having a master logic and a second device having a slave logic. The master logic may enable the first device to communicate with multiple devices having the slave logic on one or more channels. The slave logic may enable the second device having the slave logic to communicate with the first device and to communicate with a third device having the slave logic. The slave logic may enable the multiple devices having the slave logic to manage operations of the distributed devices.

Abstract: A system for serial communication may include a first device and a plurality of devices on a series connection. The first device may have a master circuit and the plurality devices may have a slave circuit. The master circuit may enable the first device to communicate with the plurality devices having the slave circuit on the series connection. The master circuit may enable the first device to send a command frame on the series connection. The command frame may include an execution mode command and a plurality of commands. The second devices may execute the commands within the command frame at or after the end of the command frame based on the execution mode command indicating a synchronous mode of command execution; and may execute the commands within the command frame at the ends of individual ones of the commands based on the execution mode command indicating a non-synchronous mode of command execution.

Abstract: Voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator circuit comprises: a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch; an inductor coupled between the switching node and an output node; a capacitor coupled between the output node and ground; a driver configured to operate the first and second switches according to a pulse-width-modulated (PWM) signal; a PWM circuit configured to generate the PWM signal based on at least an error signal; and a phase detector configured to generate the error signal based on a phase difference between the PWM signal and a clock reference signal.

Abstract: A system that provides intelligent constant on-time control may include a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch, the switching node configured to be connected to an inductor and a power output; feedback paths coupled to (1) a synthesized node and (2) the power output, the feedback paths enabling feedback of signals from (1) the synthesized node, and (2) the power output; and a controller coupled to the feedback paths. The controller may be configured to control a voltage at the power output based on a combination of the signals carried by the feedback paths.

Abstract: A two-phase boost converter is provided. The converter includes a first boost converter coupled between an input node and a common node; and a second boost converter coupled between the input node and an output node, wherein the second boost converter comprises: a first transistor coupled between ground and an internal node, an inductor coupled between the input node and the internal node, a capacitor coupled between the internal node and the common node, and a second transistor coupled between the common node and the output node.

Abstract: An apparatus for carrying out endothermic reactions including a plurality of catalytic vessels, immersed in a combustion chamber having a contiguous overlaid convection chamber enclosing a top portion of the catalytic vessels wherein heat is recovered at a lower temperature level from the flue gases from the combustion chamber. The catalytic vessels may contain internal and coaxial heat recovery tubes creating an annular space filled in with a catalytic device. Both the external heat recovery through the catalyst tube outer surface and the internal heat recovery through the inner tube surface can be maximized by an enhanced catalytic device acting also as a heat transfer promoter in the process gas region. The apparatus provides enhanced and flexible heat recovery that permits to meet the request of minimum or none export steam production in one single apparatus, avoiding the need of a pre-reforming section and/or of a convective reformer downstream.

Abstract: Adaptive on-time switching voltage regulator circuits and methods therefor provided. In some embodiments, a voltage regulator comprises: a switching circuit configured to generate a switching signal at a switching node according to a pulse-width modulated (PWM) signal; a phase-lock loop (PLL) configured to lock the PWM signal to a clock reference signal, the PLL comprising: a PWM signal generator configured to generate the PWM signal according to an error signal, and a phase detector configured to generate the error signal based on the PWM signal and the clock reference signal.

Abstract: A system that provides intelligent constant on-time control may include a first switch coupled to a power input; a second switch coupled to the first switch; a switching node between the first switch and the second switch, the switching node configured to be connected to an inductor and a power output; feedback paths coupled to (1) a synthesized node and (2) the power output, the feedback paths enabling feedback of signals from (1) the synthesized node, and (2) the power output; and a controller coupled to the feedback paths. The controller may be configured to control a voltage at the power output based on a combination of the signals carried by the feedback paths.