47 results about "Pulse width modulation inverter" patented technology

A system to collect energy from generation systems such as, for example, wind farms or solar farms with distributed energy-generation equipment. The energy is collected and transmitted to a feed-in site. At the feed-in site, static inverters alone or in combination with pulse width modulation inverters may be used to feed the energy to a power grid. In some other cases, back-to-back static inverters create a high-voltage direct current to feed a transmission line.

An aerosol delivery device is provided that includes a substrate configured to carry an aerosol precursor composition, and a resonant transformer including a transmitter coupling device and a resonant receiver coupling device that is positioned in proximity to the substrate. The aerosol delivery device also includes a pulse width modulation (PWM) inverter configured to drive the resonant transformer. The PWM inverter includes a bridge circuit coupled to the transmitter coupling device, and a PWM controller embodied as an integrated circuit and configured to output a PWM signal to the bridge circuit configured to drive the transmitter coupling device to generate an oscillating magnetic field and induce an alternating voltage in the resonant receiver coupling device when exposed to the oscillating magnetic field. The alternating voltage causes the resonant receiver coupling device to generate heat and thereby vaporize components of the aerosol precursor composition.

A control architecture for an electrical inverter includes a command limiter that is realized as a circular voltage limiter. The command limiter includes a Cartesian-to-polar converter coupled to a command source such as a synchronous frame current regulator. The Cartesian-to-polar converter provides magnitude and phase components for d-q command voltages. The command limiter further includes a magnitude limiter that limits the magnitude component to the maximum fundamental voltage component of the inverter, and a polar-to-Cartesian converter that converts the limited magnitude component and the phase component into modified d-q command voltages.

An apparatus and method for controlling an inverter, an exemplary apparatus comprising an adjustable frequency controller receiving a reference frequency value and generating a command frequency value as a function thereof, an adjustable voltage controller receiving a reference voltage value and generating a command voltage value as a function thereof and independent of the command frequency and a modulator receiving the command frequency value and the command voltage value and generating pulse width modulated (PWM) inverter control signals as a function thereof.

An object of the present invention is to provide a turbine generation system in which a starting inverter circuit for starting a turbine generator is additionally employed so that the system comprises a high-power generation inverter and the starting inverter with low-power, thereby utilizing the inverter for multiple purposes. To this end, the present invention comprises an inverter control circuit for deactivating a pulse-width modulation inverter for generation connected to a turbine generator, and first switching means for connecting an internal power supply to the turbine generator, wherein the inverter control circuit controls the starting inverter to supply the turbine generator with power to drive it up to a purge speed and accelerate it to a predetermined starting speed.

The present invention relates to a circuit arrangement which comprises at least one 3-level pulse width modulation inverter with a snubber circuit. The snubber circuit is formed by at least one coil (L), two capacitors (Cu, Co) and a series connection comprising four diodes (Dh1-Dh4) poled in the same direction, whereof the two outer diodes (Dh1, Dh4) are in each case directly connected to the input terminals (1, 3) for the positive and the negative pole of the input voltage. The electrical connection between the two inner diodes (Dh2, Dh3) is connected on the one hand via the coil (L) to the input terminal (2) for the centre tap of the input voltage and on the other hand to the middle bridge branch of the pulse width modulation inverter. In one embodiment, the two capacitors (Cu, Co) are in each case connected with one terminal to the electrical connection between one of the inner diodes (Dh2, Dh3) and one of the outer diodes (Dh1, Dh4) and with the other terminal directly to the output terminal (4).

With the proposed circuit, switching losses are completely avoided as a matter of principle with a simple and low-cost design.

An inverter operable to supply high power factor electrical power to an AC load including an AC power grid includes a DC bus and a DC to AC converter section of the full bridge type. The inverter further includes a voltage sensor configured to produce an instantaneous output voltage signal representing instantaneous output voltage of the inverter, a rectification circuit configured to produce a rectified output voltage signal, a power signal generator, an output current sensor configured for sensing an output current of the inverter, a rectification circuit configured to produce the rectified output current signal, a sign circuit for producing a signal representing the sign of the output voltage and a control apparatus. The control apparatus includes a scaled rectified voltage signal generator, a pulse width modulation (PWM) signal generator configured to produce a pulse width modulation signal in response to the scaled rectified voltage signal and the rectified output current signal and a switching leg controller circuit configured to control the full bridge switches.

The invention relates to a low frequency fluctuation controller for an input current of a low frequency dynamic power supply mainly comprising a boost chopping circuit between an input rectifier connected to a low frequency dynamic power supply and an output pulse width modulation inverter and a voltage, current double control loop for constantly controlling the input current of the boost chopping circuit. The low frequency fluctuation of the input current in the boost chopping circuit is real-timely controlled by the power double control loop, thereby fully eliminating the great fluctuation of the input current at the side of the low frequency dynamic power supply, avoiding the current shock to the power network from the low frequency dynamic power supply and reducing the requirement to the power network capacity from the low frequency dynamic power supply. The characteristic of the invention is that the current shock to the power network from the low frequency dynamic power supply is better solved under the conditions without increasing the power supply size and weight, furthermore the control effect that the fluctuation of the input current is less than 5% is achieved.

This invention discloses a SPWM inversion supply automatic master-slave parallel control method applying transient reactive power theory and parallel inversion supply output power performance, that is to control the output active power by converting frequency of its output voltage to control the output reactive power by converting its amplitude so as to uncouple the output active power P and reactive power Q to control the invented power source frequency/phase and amplitude. Although the system exists interlink signal line, the signal transferred by it is DC which can conveniently suppress interference of long distance transmission, so, the automatic master-slave control way is available in the distributed generation and UPS systems.

A coupling unit for a battery module, includes a first input, a second input, a first output and a second output. The coupling unit is configured to connect the first input to the first output and the second input to the second output, on a first control signal, and, on a second control signal, to separate the first input from the first output and the second input from the second output, and to connect the first output to the second output.

The invention relates to a method for solving a specific harmonic cancellation pulse width modulation inverter switching angle. The method comprises the steps of firstly utilizing a trigonometric function duplication formula and a variable substitution for converting a harmonic cancellation equation set into a polynomial equation set, and solving a groebner base of the polynomial equation set; then, sequentially substituting variables into equations for solving the groebner base according to the number of the variables from small to large, and removing real solutions which do not conform to constraint conditions until all the equations are solved; finally, solving an anti-cosine to obtain the switching angle, evaluating the harmonic cancellation effect of the switching angle, and obtaining the globally optimal solution of the switching angel. The method is compared with a current frequently-used numerical algorithm, an initial value is not required to be given, all the real solutions of the harmonic cancellation equation set can be calculated, finally, the globally optimal solution is obtained, and the method has important value for practicality of a specific harmonic cancellation inverter.

The invention discloses a resonant DC link three-level soft switching inverter circuit which has advantages of simple structure and convenient control. The resonant DC link three-level soft switching inverter circuit comprises the components of: a DC power supply, an auxiliary resonance circuit, a diode clamp type three-phase three-level pulse width modulating inverter and a three-phase resistance inductive load. The auxiliary resonant circuit comprises the components of: four electrolytic capacitors with voltage dividing function, six auxiliary switches, six diodes, two resonant capacitors and two resonant inductors. When switching of a three-level inverter main switch is required, the end voltage of a resonant capacitor Cr1 is reduced to zero through resonance between the resonant capacitor Cr1 and a resonant inductor Lr1, or the end voltage of a resonant capacitor Cr2 is reduced to zero through resonance between the resonant capacitor Cr2 and the resonant inductor Lr2, thereby realizing zero voltage switching of the main switch. The resonant DC link three-level soft switching inverter circuit realizes a target of expanding a resonant DC link soft switching topology structure into a diode clamp type three-phase three-level inverter, and furthermore has the functions of: reducing number of auxiliary switching devices, reducing hardware cost and facilitating control.

An electric control system for a pulse width modulated inverter connected in parallel to an electricity distribution network for correcting or minimizing a voltage total harmonic distortion of the distribution network includes a sampler of the voltage of the electricity distribution network for obtaining samplings of the distribution network. The sampler preferably is an analog-to-digital converter. The system also includes a phase locked loop circuit that supplies a phase value of a period under examination, and a storage system for coupling the various samplings with the phase value obtained by the phase locked loop circuit.

The invention relates to an intelligent type opening multifunctional power electronic experimental device which comprises a power source, a module assembly, a display screen and a switch. A touch screen is adopted in the display screen which is provided with a plurality of functional buttons, different circuits can be selected according to requirements, and the different module functions can be achieved. The module assembly is provided with a plurality of functional modules including a direct current chopping circuit module, a phase-controlled rectification circuit module and a sine pulse width modulation inverter circuit module, each functional module corresponds to a corresponding printed circuit board, and each printed circuit board comprises an electronic element and a signal terminal. Circuits are conveniently expanded and connected, and different measuring meters and loads are connected into the circuits from the exterior. The power source is a three-phase four-line alternating current power source, is connected into the circuits through an isolation transformer and a voltage regulator, and is converted into different-stage alternating current and direct current power sources needed by various modules through an auxiliary power source inside the device. The intelligent type opening multifunctional power electronic experimental device is reasonable in design, convenient to operate, simple in structure, strong in intuition sense and capable of helping students or researchers to master the basic experimental method and strengthen basic skill training.

On the basis of: a first calculated value ic which is a product of a calculated value of a time of three-phase output voltages in a state where a positive bus, a negative bus, and a neutral line are connected respectively to three-phase phase output terminals, and a predicted neutral current value in the state; and second and third calculated values icx and icy which are products of a calculated value of a time of the three-phase output voltages that can take state 1 where two of the three-phase phase output terminals are connected to the positive bus or the neutral line, and a remaining one terminal is connected to the neutral line or the negative bus, and state 2 opposite to the state, and predicted neutral current values in states 1 and 2, a time ratio of state 1 and 2 during a PWM period is determined so as to make a current flowing through the neutral line close to zero, or a potential of the neutral line of the three-phase output voltages close to a voltage which is exactly the middle between voltages of the positive and negative busses.

The invention discloses a self-adaptative inverse decoupling control method based on non-linear filters for a bearing-free asynchronous motor. The self-adaptative inverse decoupling control method based on the non-linear filters for the bearing-free asynchronous motor relates to a suspension control subsystem and a torque control subsystem. The self-adaptative inverse decoupling control method based on the non-linear filters for the bearing-free asynchronous motor comprises the steps that a Park inverse converter, a spatial vector pulse width modulation inverter, an angle calculation model, the bearing-free asynchronous motor and a load model of the bearing-free asynchronous motor integrally form a torque winding controlled object through the torque control subsystem; an object model and an object inverse model of the torque winding controlled object are established; the weight of each non-linear filter is determined in an off-line mode; the object reverse model is copied to serve as a feedforward controller to be arranged in front of the torque winding controlled object in series, so that a self-adaptive inverse controller is formed; the difference between the output of the torque winding controlled object and the output of the object model is obtained, and the object reverse model is driven by the difference; the weight of the self-adaptive inverse controller is adjusted in an on-line mode in real time according to the output of the torque winding controlled object and the difference of a given angular speed and a rotor magnetic chain. According to the decoupling method, the control precision is high, the speed is high, the following performance is good, and the interference resistance is high.

The invention relates to a resonant pole-type soft switching inverter circuit based on auxiliary commutation of a transformer. The main circuit comprises a DC power supply, a three-phase pulse width modulation inverter and a three-phase resistance-inductance load, wherein three groups of the same auxiliary resonant circuits are arranged between the DC power supply and the three-phase pulse width modulation inverter; the three groups of the auxiliary resonant circuits are corresponding to the A phase, the B phase and the C phase of a three-phase transformer; each resonant circuit group comprises one single-phase transformer, two auxiliary switches with antiparallel diodes, one resonant inductor and four auxiliary diodes. A large-capacity grading capacitor serially connected in a DC link is avoided, and the neutral point potential change problem of the inverter is solved; inductance and current thresholds related to control of auxiliary switches do not need to be set, and no extra detection and timing circuit is needed; and the transformer is used for auxiliary commutation, each phase of auxiliary circuit is only provided with two auxiliary switches, and the auxiliary switching device and the main switching device of the inverter can realize soft switching.

The invention relates to a resonant-pole soft switching inversion circuit for driving of a brushless direct current motor. The inversion circuit is characterized by comprising a direct current power supply, a three-phase pulse width modulation inverter and the brushless direct current motor, wherein an auxiliary resonance circuit is arranged between the direct current power supply and the three-phase pulse width modulation inverter, and comprises a single-phase transformer, three auxiliary switches and two diodes. According to the inversion circuit, a large capacitor used for forming neutral point voltage is not arranged between direct current buses, and no neutral point potential change exists, so that main switches on bridge arms of the inverter can adopt a relatively simple single-side modulation method; an auxiliary circuit of the three-phase inverter is simple in structure, and only comprises three auxiliary switch devices, two auxiliary diodes and a high-frequency transformer; and zero voltage switching of main switch devices of the inverter and zero current switching of the auxiliary switch devices are realized by utilizing resonance between an equivalent inductor of the high-frequency transformer in the auxiliary circuit and a buffer capacitor parallel to the main switches of the lower bridge arm.

This invention provides parabolic method current tracking pulse width modulation controller, which contains parabolic wave generator with reset, analogy phase inverter, comparator, reset signal generator and analog selector, wherein the output signal shape of parabolic wave generator determined by the ratio of time and switch cycle subtracting the square value of said ratio, the analog phase inverter making phase inverting to the output signal of parabolic wave generator, then transmitting the inverted signal with no inverted signal to analog selector to be selected one from two signal, transmitting to input of comparator whose first way output controlling action signal of main circuit switch, second way controlling analog selector and third way used as input of reset signal generator. Said invented controller is easily integrated, capable of making the output current of pulse width modulation inverter continuous tracking instruction current value and keeping switch frequency basically constant.

For demagnetizing larger parts and charges, from about 1 kg mass, the wattless power of the demagnetization coil is so high that it is compensated with a capacitor. The capacitor for this is connected in series with the coil, and a pulse-width-modulated inverter of the usual construction type is applied for the supply. The demagnetization may be effected by impulse or by running through a magnetic field of a constant strength. The inverter in the first case produces a current impulse of a certain frequency, shape and duration. In the second case, it produces a certain constant current at a certain frequency. In order with a given exit voltage of the inverter to achieve the highest possible current in the coil, the produced frequency must correspond to the resonant frequency of the oscillation circuit. In order to ascertain the resonant frequency of the charged coil, this may be measured by way of a separate measurement coil with a small measurement current. Afterwards, the frequency in the oscillation circuit is set to this value for the demagnetisation procedure.

The invention relates to a trigger power supply capable of following a temperature characteristic of a thyristor. The trigger power supply comprises a rectifying filter, a PWM (Pulse-Width Modulation) inverter, an output rectifying filter, an output voltage stabilizer, a temperature-change voltage sampler, a temperature-change resistance network and a feedback circuit. The trigger power supply is capable of automatically adjusting the size of a trigger current by following the temperature characteristic of the thyristor within a working temperature scope of the thyristor, so as to cause the trigger current to be close to an optimum value, so that the heat productivity of related elements at high temperature is reduced, the triggering reliability is ensured and the triggering power at high temperature is efficiently reduced.