323results about "Synchronous generator control" patented technology

The invention discloses an optimal virtual inertia control method based on a virtual synchronous generator in the distributed power generation control field. According to the method, a control strategy of a virtual synchronous generator is employed for a micro-grid inverter to organically combine three control degrees of freedom including a droop coefficient m, a virtual inertia J and a virtual damping D, and thus optimization of key parameters of the virtual synchronous generator is achieved. Through adoption of the method, the inertia advantage of a conventional synchronous generator is fully exhibited, and the stability and the inherent dynamic performance of an inverter are also taken into consideration. Moreover, the output power and frequency oscillation problems brought by virtual inertia are solved while the power and the capacity configuration of an energy storage apparatus are considered.

The invention discloses a method for estimating a rotor position of a three-stage brushless AC synchronous motor. A main exciter of the three-stage brushless AC synchronous motor is a three-phase field winding, and a three-phase alternating current is connected to the three-phase field winding, wherein the three-phase alternating current acts as the three-phase exciting current of the main exciter; the slip frequency of exciting magnetic potential and motor rotors is set as one-sixth of the high-frequency signal frequency that is expected to be injected; and after the alternating current induced at the rotor side passes a rotary rectifier, a DC current with high-frequency harmonic components is generated so as to provide excitation for the main generator field winding, detect output current of the main generator, and realize the determination of the initial motor rotor position and the estimation of the rotor position during the starting operation. By use of the method for estimating the position disclosed by the present invention, a more accurate position estimation value can be obtained, and the method is insensitive to the accuracy of the injected high-frequency signal frequency and phase, and has certain anti-interference ability.

The present subject matter is directed to a system and method for regulating reactive power in a wind farm connected to a power grid so as to improve reactive speed-of-response of the wind farm. The method includes receiving a voltage feedback from the power grid and a voltage reference and calculating a linear voltage error as a function of the voltage feedback and the voltage reference. A further step includes generating a first output based on the linear voltage error via a first control path having a first voltage regulator. A further step includes determining a non-linear voltage error based on the linear voltage error via a second control path having a second voltage regulator. A second output is generated via the second control path based on the non-linear voltage error. As such, a reactive power command is generated as a function of the first and second outputs.

The invention relates to a switched reluctance generator current transformer topology and a control method thereof. The topology comprises an excitation power source, a main current transformer circuit, a bus capacitor, an isolated DC/DC converter and a discharging circuit, wherein the excitation power source supplies electric excitation for the main current transformer circuit. Through the main current transformer circuit structure and the control method thereof, the excitation effect can be enhanced, the charging circuit works when a storage cell of the excitation power source needs charging and enhancing power output capability and protection, power generation initial current capability is protected and properly enhanced through controlling the discharging circuit, whole system intelligence, high efficiency and high benefits are realized, a special excitation initiating power source is omitted, and the topology and the method are suitable for application in the small and medium switched reluctance generator current transformer field.

The invention discloses a starting method of a senseless permanent magnet synchronous motor, comprising the following steps: S10), after short-circuiting a motor winding, detecting a motor induced current by driving a sampling module of a controller; S20), determining whether the motor induced current is less than a predetermined value of induced current, if so, proceeding to step S30), or if not,proceeding to step S40); S30), performing open-loop start control; S40), determining whether the motor is in a forward or reverse rotation state, if in the forward rotation state, proceeding to stepS50), if not, proceeding to step S60); S50), performing forward rotation closed-loop vector start control; and S60), performing reverse rotation closed-loop vector start control. The starting method ensures the fast and low-current high-efficiency start when the permanent magnet synchronous motor is stationary or tends to be stationary, realizes fast closed-loop vector control under strong downwind or upwind conditions, reduces energy consumption, shortens start time, and makes motor start smooth.

A signal detecting device detects, as analog voltage signals, a current flowing through an exciting coil of an electric power generator, a source voltage and a temperature of a regulator that change as a current is fed to the exciting coil by an FET. These analog voltage signals are subjected to A/D conversion by a single A/D converter circuit. The detected current is subjected to A/D conversion in a period during which the FET is ON, while the detected source voltage and the detected temperature are subjected to A/D conversion in a period during which the FET is OFF.

The invention relates to a control method for a variable excitation synchronous motor MTPA (Maximum Torque per Ampere) based on multi-line fitting, and provides a multi-line fitting method for a rectangular axis current solving module in a control structure drawing. An excitation magnetic chain is discretized in the variable scope; and then under each specific excitation magnetic chain, an electromagnetic torque is used as a single argument to carry out the quadratic polynomial fitting of a rectangular axis current solving function, and then a plurality of fitting curves under different excitation magnetic chains can be obtained. When the system runs, at the excitation magnetic chain at one moment, two closest fitting curves are selected firstly to carry out the current calculation of the rectangular axis respectively; then based on the two sets of values, the size of the excitation magnetic chain at the moment is used as a node to carry out linear interpolation, and the set value of the current value of the rectangular axis at the moment can be obtained; and finally, the control of the current ratio of the maximum torque of the variable excitation synchronous machine is completed.

The present invention provides a torque feedforward control method of a double-PWM permanent magnet electric driving system. According to the control method and control device, the load torque of a motor is converted into given torque current corresponding to the output torque of a generator, so that the output power of the generator can be rapidly changed, and therefore, the load torque response time of the motor can be shortened. According to a traditional double-PWM permanent magnet electric driving system, when the load torque of the motor changes, corresponding adjustment information is provided only after the voltage of a direct-current bus-bar changes, so that the output power of the generator is adjusted, and as a result the problem of the long load torque response time of the motor is brought about, while, with the torque feedforward control method and control device adopted, the problem can be solved. The invention also provides a torque feedforward control device of the double-PWM permanent magnet electric driving system. According to the control device, a torque observer and a torque current converter connected with the torque observer are only required to be additionally arranged between the motor and generator of the existing system, so that torque feedforward can be realized. The control device has the advantages of simple structure, convenient maintenance of the system and high response speed and convenience in use and generalization.

The invention discloses a permanent magnet starting power generation system with an open-circuit fault-tolerant capability and a control method thereof. A permanent magnet starter generator is a high-impedance permanent magnet synchronous motor, and a bidirectional bridge converter has a redundant bridge arm to continuously detect the motor winding current when the generator starts and a system outputs stable direct current voltage, so as to realize vector control and fault detection. When an open circuit fault of a switching tube is detected, a driving signal of the bridge arm where a faultyswitch tube is located is blocked, a corresponding bidirectional thyristor is turned on, and the redundant bridge arm replaces the faulty bridge arm to work; when a motor winding open fault is detected, a driving signal of bridge arm connected to the winding is blocked, the corresponding bidirectional thyristor is turned on, a neutral point of the motor winding is connected to a midpoint of the redundant bridge arm, and the stable output of a torque or direct-current side voltage of the motor can be realized through a certain current compensation algorithm. According to the permanent magnet starting power generation system with the open-circuit fault-tolerant capability and the control method thereof provided by the invention, the starting torque is stable, and the power generation controlis simple; and the permanent magnet starting power generation system can operate stably under the open circuit state of the switching tube or the open circuit state of the motor winding, the fault-tolerant capability is high, and the reliability is high.

The invention discloses a real-time monitoring method of low-power wind power converters during networking. By means of the method, the running states of multiple low-power wind power converters can be monitored in real time, failures can be conveniently found and removed in time, all control microcomputer modules can be controlled through an upper computer, the converters do not need to be detached when instructions are regulated and issued, and operation is facilitated for users. During actual networking of low-power wind turbine generators, usually various types of permanent magnet synchronous power generators exist. By means of the method, one low-power wind power converter can adapt to various types of permanent magnet synchronous power generators, and cost and networking difficulty are decreased. The method is improved on the basis of the MODBUS RTU protocol, the start and the stop of messages are quite conveniently judged, interrupt processing can be conveniently conducted through the control microcomputer modules and the upper computer which are in communication through serial ports, and the wind power converters are quite conveniently networked and connected with an industrial personal computer, a PLC and other devices due to the characteristics and wide application range of the protocol itself.

The invention discloses a control method of a gas turbine power generation device used for energy storage of a natural gas power station super capacitor and the gas turbine power generation device and relates to the technical field of distributed power generation of micro gas turbines in order to enhance the anti-impacting-load capacity of the micro gas turbine power generation device used for a natural gas power station. A PWM rectification controller obtains a PWM driving signal after a stator current and a direct-current bus voltage are calculated so that a PWM rectification switch module can be driven; a power compensation controller obtains a direct-current conversion driving signal after a super-capacitor current and a super-capacitor voltage are calculated so that a direct-current conversion driving circuit can be driven; an inverter controller obtains an inversion driving signal after a load current and an output voltage are calculated so that an inversion switch module can be driven; a central controller controls the PWM rectification controller, the power compensation controller and the inverter controller to act and is further used for controlling a micro gas turbine through the backward signals of the PWM rectification controller, the power compensation controller and the inverter controller. The control method of the gas turbine power generation device used for energy storage of the natural gas power station super capacitor and the gas turbine power generation device are applicable to the fields where impacting loads exist and the natural gas power station needs to supply power.

The invention provides a dual three-phase synchronous motor and a harmonic magnetic field oriented brushless excitation method thereof in allusion to problems of motor starting and low harmonic excitation utilization ratio, and belongs to the field of permanent magnet synchronous motors. According to the invention, a motor rotor is provided with a rotor DC excitation winding F and a rotor harmonicinduction winding H, the pitch of the rotor DC excitation winding is 1, the pitch of the rotor harmonic induction winding is 1/3, a motor stator winding is two sets of stator windings in star connection, the phase shift is 30 degrees, and neural points are connected together. The current waveform of the two sets of stator windings is controlled, the current of each three-phase stator winding is enabled to contain an alternating zero-sequence current component, the alternating zero-sequence current components of the two sets of stator windings are orthogonal in phase, harmonic magnetic field oriented control is performed according to the rotor position so as to enable the alternating harmonic magnetic field to induce the harmonic electromotive force in the rotor harmonic induction windingH, and thus a rotor main magnetic field is established through rotating, rectifying and supplying the rotor DC excitation winding F, so that brushless electrical excitation of the synchronous motor isrealized.

A control arrangement of a multiple-stator machine, comprising a frequency converter for each of the plurality of stators and a controller for each frequency converter, wherein a controller of a frequency converter is realized to generate control signals for that frequency converter on the basis of current values relating to that stator, and to generate a compensation current value for a further controller on the basis of the received current values in the event of an open-circuit fault in a frequency converter; to receive a compensation current value from a further controller; and to compute a voltage reference for a subsequent transform stage of the controller on the basis of the received current values is provided. The invention further describes a current control module of a frequency converter controller of such a multi-stator machine; a multi-stator machine; and a method of performing fault-tolerant control of a multi-stator machine.

The invention discloses a synchronous motor parameter identification method based on an atom decomposition method. The method comprises the steps as follows: 1) constructing a related atom library and continuing an atom discretization parameter; 2) rapidly extracting fundamental current, direct current and frequency multiplication current from sudden short-circuit current of a synchronous motor with an evolution matching pursuit algorithm; 3) calculating a synchronous motor parameter from each decomposed atom signal characteristic parameter. The method has the benefits as follows: in order to solve the defects of traditional algorithms, particularly the poor decomposition effect of adopted EMD (empirical mode decomposition) and Prony algorithms on noise-containing signal short-circuit current and the poor anti-noise performance, the algorithm can extract the synchronous motor parameter accurately and has better anti-noise performance.

The invention belongs to the field of wave energy power generation, and particularly relates to a wave energy power generation system maximum power tracking device and a control method. The device comprises a swing plate, a pedestal, a rotating shaft, a chain, a gear box, a permanent magnet synchronous power generator, a rectifier, a DC/DC converter, an MPPT controller, a speed sensor, a voltage sensor, a current sensor, a water level sensor, a rotating speed sensor, a first capacitor, a second capacitor, a driving module and a load. The speed sensor, the water level sensor and the rotating speed sensor which are arranged in front of the swing plate for 2m and arranged at the same horizontal plane with the center of gravity of the swing plate are installed to acquire work vectors, and large number of actual samples of work vector-optimal work voltage are acquired and a work vector-optimal work voltage prediction model is established by utilizing a support vector machine. Maximum power tracking is performed via combination of the prediction model and a small-step disturbance observation method, and power generation efficiency of a wave energy power generation system can be effectively enhanced.

A synchronous machine (100) has a frame (110), a shaft (115), a main section (120), and an exciter section (125). The main section (120) has a stator winding (130) which is mounted on the frame, and a rotor winding (135) which is mounted on the shaft. The exciter section has a transformer (140) and a rectifier (145). The transformer has a primary winding (140A) mounted on the frame and a secondary winding (140B) mounted on the shaft. The rectifier is mounted on the shaft and rectifies an output of the secondary winding to provide a rectified output to the rotor. A control unit (170) provides a high-frequency control signal to the primary winding. This signal is magnetically coupled to the secondary winding, rectified, and then applied to the rotor to control the operation of the synchronous machine.

The invention discloses a matrix converter-based PMSG proportional-integral resonance control method under an unbalanced power grid. The method can effectively realize control objectives of stator current balance and PMSG electromagnetic torque stability, has no positive and negative sequence separation link in a control loop, reduces the problems of time delay, a phase angle and a detection error of an amplitude value brought by a positive and negative sequence separation process, is simple and convenient to calculate, has good dynamic characteristics, and can realize rapid and precise control. A proportional-integral coefficient in the control method provided by the invention can directly adopt design parameters of a PI regulator under traditional balanced conditions, and has relatively strong adaptability. At the same time, the matrix converter-based PMSG proportional-integral resonance control method under the unbalanced power grid further verifies feasibility and scientificity of application of a matrix converter to a direct-driven type permanent magnet power generation technology, enables a matrix converter-based PMSG system to realize a good operation effect both in an ideal power grid and under unbalanced network voltage, and has very good research value and practical value.

The invention discloses a method and system for calculating the influence of excitation additional difference adjustment on the synchronous torque of a synchronous generator. The method includes the following steps that: the Phillips-Heffron mathematical model of a single-machine infinite bus system is expanded, a difference adjustment model under additional difference adjustment is established; the oscillation frequency of the single-machine infinite bus system under no difference adjustment is solved according to the eigenvalue of the state equation set of the single-machine infinite bus system under no difference adjustment; the oscillation frequency of the single-machine infinite bus system under additional difference adjustment is solved according to the eigenvalue of the state equation set of the single-machine infinite bus system under additional difference adjustment; the synchronous torque coefficient KS of an excitation system under no additional difference adjustment ( a condition that Xc=0) is calculated according to the oscillation frequency of the single-machine infinite bus system under no difference adjustment; the value of the synchronous torque coefficient KS of the excitation system under additional difference adjustment (a condition that Xc is not equal to 0) is calculated according to the oscillation frequency of the single-machine infinite bus system underadditional difference adjustment; and the difference value of the synchronous torque coefficient KS of the excitation system under no additional difference adjustment (the condition that Xc is equalto 0) and the synchronous torque coefficient KS of the excitation system under additional difference adjustment (the condition that Xc is not equal to 0) is obtained by means of comparison.

The present invention provides a realization method of excitation regulator stator over-current limitation. The objective of the invention is to solve the problem of power oscillation of a unit caused by the misoperation of an excitation regulator stator over-current limiter under some conditions in the operating process of a synchronous generator. The method includes the step that: in the operating process of the synchronous generator, the stator over-current limiter carries out integral calculation so as to obtain a stator heat-emission constant Cf and a stator cooling constant Cl, when the difference value of the stator heat-emission constant Cf and the stator cooling constant Cl is larger than a stator heat-emission time constant C, and the reactive component absolute value abs (Igq) of stator current is larger than reactive current starting threshold value Iqmin of the stator over-current limiter, the stator over-current limiter outputs stator over-current limiting signals. When the limiter adopting the method of the invention is compared with a traditional stator over-current limiter, the calculation data of the limiter are all reactive components, and therefore, adjustment is more accurate and more reliable.

The invention discloses a voltage regulation device of a mixed excitation direct-current generator and a voltage regulation method. The device comprises a mixed excitation generator, an alternating-current/direct-current switching circuit, a bidirectional excitation regulator and a load circuit, wherein an A-phase voltage output end, a B-phase voltage output end and a C-phase voltage output end of the mixed excitation generator are electrically connected with an input end of the alternating-current/direct-current switching circuit; direct-current output of the alternating-current/direct-current switching circuit is connected to the load circuit; an output end of a three-phase rectifier bridge and a filter capacitor Co in the alternating-current/direct-current switching circuit are electrically connected with corresponding connecting ends of the excitation regulator; an excitation winding connecting end of the mixed excitation generator is electrically connected with the corresponding connecting end of the excitation regulator. The circuit structure is simple, the production cost is lower, the device has fast dynamic response and can obtain better dynamic property, and output voltage static difference during generation is reduced.

The invention relates to the technical field of motor control, and provides a PMSM (permanent magnet synchronous motor) grid-connected operation control method and system, and a quasi-synchronization controller. The method comprises the following steps: obtaining the frequency and voltage of a power grid; detecting the output frequency, output voltage and phase of a motor controller in a process that the motor controller drives a motor to operate; adjusting the rotating speed of the motor through the motor controller according to the frequency of the power grid, wherein the output frequency is the same as the frequency of the power grid; controlling the motor to carry out grid-connected operation when the output voltage of the motor controller and the voltage of the power grid are judged to meet conditions of grid-connected operation, enabling a PMSM to operate without the controller, and enabling the efficiency of an operation system to be improved. Moreover, the method achieves the feedback of energy when the motor is in a state of power generation. The energy saving of the system is achieved through employ less equipment cost.

When a vehicle is traveling in a state in which an abnormality has occurred in a second resolver, a PWM control unit periodically calculates an estimated electrical angle value of a second motor generator and generates a control command for an inverter using the estimated electrical angle value. The estimated electrical angle value in each cycle can be calculated by correcting an electrical angle estimation error with respect to a sum of an estimated rotation angle change value between cycles and an estimated electrical angle value in a previous cycle. The PWM control unit generates the control command for the inverter such that an output of the inverter is a constant potential while an absolute value of the electrical angle estimation error is greater than a predetermined value during traveling of the vehicle.