Abstract: The invention proposed a space vector pulse width modulation (SVPWM) method for any level cascaded H-bridge inverter. The multilevel space vector diagram is re-divided, and the coordinates of the nearest three vectors (NTVs) are directly obtained by judging the position of the reference vector. The duty cycles of the NTVs is calculated through additional vector which is equivalent to the reference vector. Then, the switching states are obtained by zero-sequence component and coordinate transformation, and the desired reference vector is synthesized for the SVPWM modulation. The invention realizes multilevel modulation in Cartesian coordinates without any iterative calculation, and the calculation is independent of the level number. Furthermore, the locating of the reference vector and the calculation of the duty cycles are simplified, and the calculation complexity is reduced.

Abstract: A control system of a flexible permanent magnet brushless DC motor, comprising a DC power supply, a filter capacitor, a voltage source inverter, a permanent magnet brushless DC motor and a controller, wherein an output end of the DC power supply is connected with the filter capacitor in parallel; the voltage source inverter is provided with m bridge arms which are connected with both ends of the filter capacitor in parallel; upper and lower controllable switching devices are arranged on each bridge arm; the phase number of armature winding of the permanent magnet brushless DC motor is equal to the number of bridge arms; head ends of armature windings of each phase are correspondingly connected with intermediate contacts of the upper and lower controllable switching devices of one bridge arm, tail ends of armature windings of each phase are connected together.

Abstract: A direct-drive type annular flexible transportation system and a collaborative control method thereof are provided. The direct-drive type annular flexible transportation system includes an annular base, a primary excitation type linear motor, an power supplying module, a power driving module, a position detection module, and a wireless communication module. The primary excitation type linear motor includes a long stator and a plurality of movers. The long stator is formed by connection of stator iron cores presenting a multi-segment cogging structure and is installed on the annular base. Each of the movers includes a short primary, a power driving module, a position detection module, and a wireless communication module. The short primary is formed by an asymmetrically-structured permanent magnet array, an armature winding, and a primary iron core.

Abstract: The present disclosure provides a predictive control method of current increment for a permanent magnet synchronous motor includes: substituting a mathematical expression of a stator voltage during one control period into a continuous time domain current model to obtain a discrete current prediction model and a predicted current at the next time point; obtaining a predicted current increment from a current increment prediction model by subtracting a predictive current at a present time point from a predictive current at a next time point; establishing a cost function according to a preset reference current increment and the predicted current increment; obtaining an optimal voltage increment by minimizing the cost function; superposing the optimal voltage increment on a stator voltage of a present control period to obtain an optimal stator voltage of a next control period for controlling control the permanent magnet synchronous motor.

Abstract: The invention discloses a control method for balancing scaling errors of multiple current sensors for PMSM. An impedance network is set between a direct current power supply and a three-phase inverter connected to a PMSM to avoid positive and negative poles of the direct current power supply being short-circuited under actions of shoot-through vectors. Under actions of two shoot-through vectors in a PWM cycle, three-phase current sensors are used to respectively sample the sum of currents in each branch of three-phase output branches of the three-phase inverter and a branch of the same bridge arm of the three-phase inverter, according to the sampled currents, operating to obtain the relationship between the scaling error coefficients of the three-phase current sensors. Then, correction coefficients are calculated. The correction of the scaling errors of the current sensors is implemented using correction coefficient feedback control.

Abstract: A direct-drive type annular flexible transportation system and a collaborative control method thereof are provided. The direct-drive type annular flexible transportation system includes an annular base, a primary excitation type linear motor, an power supplying module, a power driving module, a position detection module, and a wireless communication module. The primary excitation type linear motor includes a long stator and a plurality of movers. The long stator is formed by connection of stator iron cores presenting a multi-segment cogging structure and is installed on the annular base. Each of the movers includes a short primary, a power driving module, a position detection module, and a wireless communication module. The short primary is formed by an asymmetrically-structured permanent magnet array, an armature winding, and a primary iron core.

Abstract: The present disclosure provides a predictive control method of current increment for a permanent magnet synchronous motor includes: substituting a mathematical expression of a stator voltage during one control period into a continuous time domain current model to obtain a discrete current prediction model and a predicted current at the next time point; obtaining a predicted current increment from a current increment prediction model by subtracting a predictive current at a present time point from a predictive current at a next time point; establishing a cost function according to a preset reference current increment and the predicted current increment; obtaining an optimal voltage increment by minimizing the cost function; superposing the optimal voltage increment on a stator voltage of a present control period to obtain an optimal stator voltage of a next control period for controlling control the permanent magnet synchronous motor.

Abstract: A motor fault detection system is based on coupling injection of high-frequency signal. An input end of the motor is connected with the high-frequency detection signal source circuit through the coupling circuit to inject a high-frequency detection signal into the motor winding; an input end of the high-frequency detection signal source circuit is connected with an output end of the controller to control the output of the high-frequency detection signal; an output end of the response signal processing circuit is connected with an input end of the controller to send the received voltage or current response signal to the controller; and the controller judges whether the motor has a fault and the degree of the fault by analyzing the response signal after applying an excitation.

Abstract: A control system of a flexible permanent magnet brushless DC motor, comprising a DC power supply, a filter capacitor, a voltage source inverter, a permanent magnet brushless DC motor and a controller, wherein an output end of the DC power supply is connected with the filter capacitor in parallel; the voltage source inverter is provided with m bridge arms which are connected with both ends of the filter capacitor in parallel; upper and lower controllable switching devices are arranged on each bridge arm; the phase number of armature winding of the permanent magnet brushless DC motor is equal to the number of bridge arms; head ends of armature windings of each phase are correspondingly connected with intermediate contacts of the upper and lower controllable switching devices of one bridge arm, tail ends of armature windings of each phase are connected together.

Abstract: The invention proposed a space vector pulse width modulation (SVPWM) method for any level cascaded H-bridge inverter. The multilevel space vector diagram is re-divided, and the coordinates of the nearest three vectors (NTVs) are directly obtained by judging the position of the reference vector. The duty cycles of the NTVs is calculated through additional vector which is equivalent to the reference vector. Then, the switching states are obtained by zero-sequence component and coordinate transformation, and the desired reference vector is synthesized for the SVPWM modulation. The invention realizes multilevel modulation in Cartesian coordinates without any iterative calculation, and the calculation is independent of the level number. Furthermore, the locating of the reference vector and the calculation of the duty cycles are simplified, and the calculation complexity is reduced.

Abstract: A position-sensorless control method and device for long-cable drive permanent magnet motors, including: adding a coupling circuit after boost transformers in the long-cable drive circuit of a permanent magnet motor; coupling three high frequency detection signals with different frequencies into a power supply cable and windings of the motor through three coupling transformers in the coupling circuit respectively; obtaining high frequency voltage components on primary windings of the coupling transformers by bandpass filters; obtaining the position signals according to relations among effective values of the high frequency voltage components; and finally realizing the position-sensorless control of the motor by a controller according to the obtained position signals.

Abstract: A motor fault detection system is based on coupling injection of high-frequency signal. An input end of the motor is connected with the high-frequency detection signal source circuit through the coupling circuit to inject a high-frequency detection signal into the motor winding; an input end of the high-frequency detection signal source circuit is connected with an output end of the controller to control the output of the high-frequency detection signal; an output end of the response signal processing circuit is connected with an input end of the controller to send the received voltage or current response signal to the controller; and the controller judges whether the motor has a fault and the degree of the fault by analyzing the response signal after applying an excitation.

Abstract: A position-sensorless control method and device for long-cable drive permanent magnet motors, including: adding a coupling circuit after boost transformers in the long-cable drive circuit of a permanent magnet motor; coupling three high frequency detection signals with different frequencies into a power supply cable and windings of the motor through three coupling transformers in the coupling circuit respectively; obtaining high frequency voltage components on primary windings of the coupling transformers by bandpass filters; obtaining the position signals according to relations among effective values of the high frequency voltage components; and finally realizing the position-sensorless control of the motor by a controller according to the obtained position signals.

Abstract: An active front-end rectifier filter delay compensation method based on model predictive control is disclosed. The method includes following steps: detecting a three-phase grid voltage and three-phase input current sampling value of an active front-end rectifier, and transforming both via Clarke transformation to acquire grid voltage sampling values e? and e?, and input current sampling values if? and if? under a two-phase stationary coordinate system; establishing an equivalent mathematical model of rectifier on the basis of voltage balancing equation (1) in an actual rectifier, and establishing an equivalent filter model on the basis of a transfer function corresponding to the actual filter, thus constituting a filter delay observer; and, compensating the difference value between the input current sampling values if? and if?, and equivalent current sampling values iof? and iof? into an input of the filter delay observer via a proportional controller.

Abstract: The present invention relates to a direct torque control method for inhibiting torque ripples, mainly comprising the following steps: establishing an MC voltage vector switching table visually displaying degrees of change in torque and flux, and, proposing, on the basis of the MC voltage vector switching table visually displaying the degrees of change in torque and flux, an MC-DTC mark-to-space ratio computing policy for torque quantification control. The MC-DTC mark-to-space ratio computing policy allows for inhibition of torque ripples of a PMSM speed control system and for a constant switching frequency, uses the MC voltage vector switching table visually displaying the degrees of change in torque and flux, has a simple algorithm, does not reply on motor parameters, and obviates the need for rotational coordinate transformation.

Abstract: Robust design method for a textile-manufacturing-dedicated multiphase asynchronous motor, including the steps: designing a motor with design variables for a high-efficient, energy-saving, multiphase asynchronous motor; selecting a number of controllable variables and their level values to build an inner orthogonal table; selecting a number of noise factors and their level values to build an outer orthogonal table; using a Taguchi method, determining the optimal combination of level values of the controllable variables and corresponding values ranges for a tolerance design, resulting in an optimal design scheme; producing technical drawings for each parts of the motor according to the optimal design scheme and producing a physical motor; comparing the performance of the physical motor with the predetermined performance target and repeating the above steps as many times as necessary until the performance target is met and the motor achieves the optimal balance between the quality and cost.

Abstract: The present invention relates to a direct torque control method for inhibiting torque ripples, mainly comprising the following steps: establishing an MC voltage vector switching table visually displaying degrees of change in torque and flux, and, proposing, on the basis of the MC voltage vector switching table visually displaying the degrees of change in torque and flux, an MC-DTC mark-to-space ratio computing policy for torque quantification control. The MC-DTC mark-to-space ratio computing policy allows for inhibition of torque ripples of a PMSM speed control system and for a constant switching frequency, uses the MC voltage vector switching table visually displaying the degrees of change in torque and flux, has a simple algorithm, does not reply on motor parameters, and obviates the need for rotational coordinate transformation.

Abstract: An active front-end rectifier filter delay compensation method based on model predictive control is disclosed. The method includes following steps: detecting a three-phase grid voltage and three-phase input current sampling value of an active front-end rectifier, and transforming both via Clarke transformation to acquire grid voltage sampling values e? and e?, and input current sampling values if? and if? under a two-phase stationary coordinate system; establishing an equivalent mathematical model of rectifier on the basis of voltage balancing equation (1) in an actual rectifier, and establishing an equivalent filter model on the basis of a transfer function corresponding to the actual filter, thus constituting a filter delay observer; and, compensating the difference value between the input current sampling values if? and if?, and equivalent current sampling values iof? and iof? into an input of the filter delay observer via a proportional controller.

Abstract: A robust design method for a textile-manufacturing-dedicated, high-efficient, energy-saving, multiphase asynchronous motor, includes the following steps: designating a motor; designating design method; designating design variables of the high-efficient, energy-saving, multiphase asynchronous motor; building mathematical models of each index respectively to constitute a robust design model with multiple indexes; building the controllable factor level table; selecting appropriate orthogonal table according to the number of the optimizing variables and the level number of each variable; building an inner orthogonal table for inner design; building an outer orthogonal table for outer design; computing the values of the output characteristics and signal to noise ratio of the experimental schemes determined by the inner and outer orthogonal tables; determining the optimal combination of parameters; going through tolerance design; drawing the parts of the textile-manufacturing-dedicated, high-efficient, energy-savin