30 results about "Negative inductance" patented technology

The invention discloses a low-voltage micro-grid inverter control system based on virtual impedance and a virtual power source. The control system comprises a droop controller, a virtual controller and a voltage/current dual-loop controller, and is characterized by establishing the droop controller capable of simulating the function of the virtual power supply through improvement of droop parameters, and carrying out tracking control on the voltage of the droop controller through fractional-order PID; by analyzing relation between virtual negative inductance and micro-source reactive power sharing, determining the value of virtual negative inductance required for accurate reactive power sharing, realizing virtual impedance in the virtual controller, and feeding back voltage drop of the virtual controller to the droop controller to participate in fractional-order PID tracking control of voltage of the virtual power source; and carrying out tracking control on inverter voltage through fractional-order PID in the voltage/current dual-loop controller, determining filtering parameters in the controller according to a transfer function of a filter, and carrying out optimization on fractional-order PID controller parameters through a difference genetic algorithm. The control system can ensure low-voltage micro-grid power decoupling and improve a reactive power sharing effect.

The invention discloses an active broadband matching method of a short-wave frequency-band electrically small antenna and a matching circuit thereof, the electrically small antenna is matched by a non-Forster reactive element and a passive broadband matching network, the non-Forster reactive element is realized by a negative impedance converter, the negative impedance converter and the passive broadband matching network are cascaded into an active broadband matching network with two ports, one port of the matching network is connected with the electrically small antenna, and said two ports are connected with an emitter/receiver. In the invention, the non-Forster reactive element and the passive broadband matching network are comprehensively considered, led loss is regulated in realization process of the non-Forster reactive element, single traditional negative capacitor can be replaced by in series connecting a negative capacitor and a negative inductor to better neutralize the impedance imaginary part, a transmission line transformer is led into the matching network, and the deviation between a testing value and a design value can be compensated by slightly adjusting the transformation ratio of the transmission line transformer.

A differential circuit topology that produces a tunable floating negative inductance, negative capacitance, negative resistance/conductance, or a combination of the three. These circuits are commonly referred to as “non-Foster circuits.” The disclosed embodiments of the circuits comprises two differential pairs of transistors that are cross-coupled, a load immittance, multiple current sources, two Common-Mode FeedBack (CMFB) networks, at least one tunable (variable) resistance, and two terminals across which the desired immittance is present. The disclosed embodiments of the circuits may be configured as either a Negative Impedance Inverter (NII) or a Negative Impedance Converter (NIC) and as either Open-Circuit-Stable (OCS) and Short-Circuit-Stable (SCS).

The invention provides an inverter virtual impedance vector diagram analysis method. The size and nature of output impedance at the fundamental frequency of an inverter are analyzed under different types of virtual impedances added. By introducing virtual impedance, the size and nature of the original output impedance of an inverter can be changed, and an inverter output impedance can be acquired as needed. A virtual impedance module is added on the basis of the original voltage and current double-closed-loop feedback control system. The adopted current feedback is inductive current feedback. Thus, the change in output impedance at the fundamental frequency of an inverter under five conditions, namely, adding virtual positive inductance, adding virtual negative inductance, adding virtual positive resistance, adding virtual negative resistance, and adding virtual complex impedance composed of virtual positive resistance and virtual negative inductance, can be analyzed and verified based on a vector diagram and a corresponding Bode diagram.

The invention provides a low-voltage micro-grid distributed control method and system based on adaptive virtual impedance. The method comprises the following steps: generating adaptive virtual resistance by using a product of a ratio of active power output by a local inverter and voltage magnitude and a virtual impedance coefficient; determining virtual negative inductance according to an inductive reactance part of equivalent output impedance of the local inverter, so that the equivalent output impedance of the local inverter has a resistance property; obtaining the adaptive virtual impedanceaccording to the complex accumulation of the adaptive virtual resistance and the virtual negative inductance; according to a dq-axis current component of the adaptive virtual impedance and local inverter outlet three-phase current, generating dq-axis virtual voltage; and using the dq-axis virtual voltage to compensate a voltage reference value obtained by resistance droop control to obtain finalreference voltage.

This antenna array includes at least one primary antenna, at least one secondary antenna and at least one load coupled to a secondary antenna. The load includes two separate components, a first component being a resistor and a second component being selected from an inductor or a capacitor. The antenna array can include one or more of the following characteristic features, taken into consideration individually or in accordance with any technically possible combinations: the first component has negative resistance; the second component has negative inductance or a negative capacitance; at least one load has an adjustable impedance. The antenna array may be used in a system, such as a vehicle, a terminal, a mobile telephone, a wireless network access point, a base station, or a radio frequency excitation probe.

The invention provides an inverter control method without a power grid voltage sensor. The inverter control method comprises two parts, namely analog negative resistance control and stabilization control based on analog negative inductance. The analog negative resistance control is used for transmitting the power of an inverter to a power grid and ensuring that the output current of the inverter is kept sine. The stabilization control based on analog negative inductance is used for making up for unstable poles caused by the analog negative resistance control so as to realize safe and stable operation of the inverter. In addition, according to the method, only the output current of the inverter is sampled, so the reliability of a system is improved, and sensor cost is reduced. Meanwhile, the method is easy to control, has small calculation amount and is suitable for practical application.

The invention relates to the field of electronics, more particularly to the wire bonds incorporated into an integrated circuit package such as a quad flat pack. a ball grid array or hybrid style module. The present invention takes the normally undesirable wire bond inductance and uses it in an operational circuit where positive inductance is required. The circuit in which the wire bond inductance is used is located primarily in the integrated circuit die housed in the integrated circuit package, but may also include off-die components. In one example, a wire bond is used as the required series inductance in a discrete circuit impedance inverter which consists of two shunt-to-ground negative inductances and one series positive inductance. One of the negative inductances is located on-die, while the other is located off-die.

A low pass filter includes a first inductor, a second inductor magnetic-field-coupled to the first inductor, a third inductor, and a first capacitor. The first inductor is electrically connected between a first port and an intermediate node, being a node to which the second inductor is electrically connected, between the first inductor and the second port. The second inductor is electrically connected between the intermediate node and a ground terminal. The third inductor is electrically connected between the intermediate node and the second port, and a first parallel resonant circuit is defined by the third inductor and the first capacitor. The first inductor and the second inductor are coupled to each other in such a relationship that a negative inductance is generated between the intermediate node and the third inductor due to magnetic field coupling between the first inductor and the second inductor.

The invention discloses a control method for improving the stability of a grid-connected inverter under a low short circuit ratio, and the method comprises the steps: sampling a PCC point voltage, a grid-connected current, and a DC bus voltage; the grid-connected inverter obtains the voltage phase of the PCC point through the PLL; obtaining a grid-connected current reference value according to the PCC point voltage phase and current amplitude information obtained by PLL locking, and adding the grid-connected current reference value to the actively injected inter-harmonic current reference to obtain the total reference of the grid-connected current; harmonic response components in PCC point voltage and grid-connected current are extracted through a discrete Fourier transform algorithm, so that power grid line impedance is evaluated, and then a line inductance value is obtained. Feeding back the product of the virtual negative inductance and the grid-connected current to a current loop controller according to the evaluated line inductance value and the line negative inductance with the virtual inductance value larger than the current loop controller, obtaining a final modulation signal, comparing the modulation signal with a carrier signal, and generating a PWM signal to drive an inverter switching tube.

A switched mode negative inductance circuit includes an input node responsive to a voltage signal. The circuit also includes first and second voltage sources, first and second controlled switches having first poles coupled to the first and second voltage sources, respectively and an inductor having a first electrode coupled to second poles of the first and second controlled switches and a second electrode coupled to the input node. The input node is coupled to a control electrode of the first controlled switch, and to a control electrode of the second controlled switch through a voltage inverting circuit. The disclosure also illustrates balanced negative inductance circuits and implementation approaches using NMOS transistors.

The invention relates to a negative capacitance device, a negative inductance device, and a circuit including the same. According to one embodiment, a negative capacitance device is provided having afirst terminal and a second terminal. The negative capacitance device includes: a first operational amplifier having a first non-inverting input terminal connected to the first terminal of the negative capacitance device, a first inverting input terminal connected to the second terminal of the negative capacitance device, and a first output terminal; a first capacitor connected between the first non-inverting input terminal and the first output terminal of the first operational amplifier; a first resistor connected between the first inverting input terminal and the first output terminal of thefirst operational amplifier; and a second resistor connected between the first inverting input terminal of the first operational amplifier and the second terminal of the negative capacitance device.

The invention discloses a rectifier and a control method and system thereof, and the method comprises the steps: determining an error between a DC voltage outputted by the rectifier and a DC reference voltage, and determining an expected resistance value needed to be simulated by a rectifier port based on the error; determining harmonic compensation voltage for compensating harmonic according to the power grid current of the input end of the rectifier and the simulated harmonic impedance; according to the equivalent inductance estimation value of the rectifier, determining negative inductance needing to be simulated at the port of the rectifier, and determining an inductance voltage drop compensation value used for compensating the inductance voltage drop of the rectifier through the negative inductance; according to the expected resistance value, the harmonic compensation voltage and the inductance voltage drop compensation value, determining a currently required voltage reference value of a rectifier port so as to modulate PWM pulses and perform driving control of the rectifier. By applying the scheme of the invention, the current harmonic of the rectifier is effectively reduced without a power grid voltage sensor, and a high power factor is realized.

The invention relates to a soft start device for a DC-DC converter. The soft start device comprises a first power transistor and a second power transistor which are connected in parallel with an inductor of the DC-DC converter; a negative inductor current detection unit which detects a negative inductor current on the basis of a voltage difference between both ends of the first power transistor; asoft start circuit unit that generates a soft start signal on the basis of the enable signal of the DC-DC converter; a negative inductor current control signal generation unit that generates a negative inductor current control signal, which controls the negative current level flowing through the inductor on the basis of the output signal of the negative inductor current detection unit and the output signal of the soft start circuit unit; and a pulse width modulation controller that alternately turns on/off the two power transistors according to a signal applied from the voltage comparator andturns off the first power transistor during application of the negative inductor current control signal. By controlling the peak level of the negative inductor current in the soft start section, deterioration of the inductor and excessive response of the output voltage can be prevented.