8 results about "Dead band" patented technology

The utility model relates to the technical field of H-bridge drive circuits, and discloses a high-reliability H-bridge dead-zone generation circuit, which comprises two AND gates for preventing two MOS (Metal Oxide Semiconductor) transistors on the same side of the circuit from being switched on at the same time; the exclusive-OR gate can distinguish input signal directions and output response control signals; the Schmitt trigger is used for converting the curve waveform into a PWM (Pulse Width Modulation) square wave signal and inhibiting noise and interference in an input signal; the RC time delay circuit is connected with the Schmitt trigger and is used for realizing signal delay; the two AND gates comprise a first AND gate and a second AND gate; the first AND gate and the second AND gate are electrically connected with the exclusive-OR gate, and the exclusive-OR gate and the first AND gate are electrically connected with the Schmitt trigger; according to the utility model, the formation of dead zone time is realized through RC time delay and Schmidt characteristics, the condition of circuit damage caused by simultaneous conduction of the H-bridge drive circuit in the working process is avoided, the hardware cost is lower, and the reliability is higher than the reliability realized by software.

The invention belongs to the technical field of power system control, and the method comprises the following steps: improving a manual failure area unit of primary frequency modulation, when a frequency deviation delta F'exceeds a frequency dead zone Ef, increasing a superposition amount for the calculated frequency deviation delta F, and when primary frequency modulation action is carried out, adding a delay filtering link; optimization is carried out on the superposition amount and the delay link for adaptive adjustment, and prediction and multi-stage frequency modulation are carried out during a primary frequency modulation action; and when the primary frequency is reset, a return difference link is added. According to the method, the algorithm of the manual failure area is improved, a step-type frequency superposition amount is added to the calculated frequency difference, and the adjustment amount of frequency modulation is increased, so that the problem of insufficient integration of frequency modulation is overcome; when the frequency deviation is weak, a step type is added to form a larger output signal, the signal output form is a sudden change form, and the dead zone of each link is overcome; time delay and return difference are increased, and frequent jitter which is useless for primary frequency modulation and is caused by frequency crossing of a frequency dead zone edge of a power grid system is prevented.

To reduce the influence of a dead zone.SOLUTION: The power conversion device 10 includes a primary full-bridge circuit 30 including a plurality of primary switching elements Q1 to Q4, a secondary full-bridge circuit 40 including a plurality of secondary switching elements Q5 to Q8, and a controller 50. The control unit 50 performs phase shift control. The controller 50 derives the first phase shift amount Φ 1 from the current deviation Δ Iout between the target current Itgt and the output current Iout. When the first phase shift amount Φ 1 is included in the range of the dead zone D derived based on the input voltage Vin to the power conversion device 10 and the output voltage Vout of the power conversion device 10, the control part 50 sets the second phase shift amount Φ 2 outside the range of the dead zone as the phase shift amount Φ.SELECTED DRAWING: Figure 1

This invention relates to the field of automatic control technology for thermal power units, specifically to a method for eliminating backlash in actuators within a DCS (Distributed Control System). This invention eliminates backlash by designing a corresponding algorithm within the DCS system. Compared to traditional mechanical repair techniques, this method is implemented directly in the DCS system via an algorithm, requiring no cost and being quick. It can eliminate the total backlash even for complex actuators. Currently, most DCS systems can be configured online to eliminate backlash at any time. This method can be widely applied in thermal power units and other fields, significantly reducing delays caused by backlash in actuators and improving the quality of automatic control.

The present application belongs to the technical field of analog circuit power management, and particularly relates to a kind of adjustable dead zone or overlap time generation circuit.The circuit of the present application includes adjustable current generation circuit, delay circuit and comparator.The adjustable current generation circuit provides adjustable charging and discharging current for the delay circuit to determine the delay time, and the comparator shapes the signal passing through the delay circuit into a square wave signal.Under fixed dead zone or overlap time, the efficiency of switching power supply is relatively low or the power tube has the risk of punch-through under certain application conditions.By adjusting the size of the dead zone or overlap time with an external resistor, the efficiency of the switching power supply under all application conditions can be maximized.In addition, the present application realizes structure reuse and current self-compensation technology, thereby improving circuit utilization and implementation accuracy.

The application discloses a SiC inverter modulation method based on secondary frequency modulation and double modulation waves, initializes system parameters, sets a reference switching frequency, a spread spectrum modulation frequency, a dead time and a nonlinear threshold of secondary frequency modulation, executes a secondary frequency modulation algorithm, performs phase accumulation based on a real-time switching frequency to generate a variable-frequency triangular carrier signal, executes basic SVPWM calculation, executes dynamic double modulation wave generation logic, and generates complementary drive pulses. The application effectively reduces the residence probability of the switching frequency at the extreme value, reduces the peaks at both ends of the frequency spectrum, makes the noise energy more evenly distributed in the entire frequency band, and thus obtains a better EMI suppression effect. Through the double modulation wave technology, the offset amplitude of the modulation wave is adjusted online according to the real-time frequency, and the accurate compensation of the dead zone error caused by the frequency change is realized. No matter how the switching frequency changes, the physical dead time of the system output is always locked at the set value.

A source / sink LDO is provided with a pre-amplifier that pre-amplifies an error voltage equaling a difference between an output voltage and a reference voltage. The resulting pre-amplification reduces the dead band for the source / sink LDO by the gain of the pre-amplifier.

The invention provides a method and device for determining an optimal primary frequency modulation dead zone of multi-type frequency modulation resources, and the method comprises the steps: obtaining a primary frequency modulation simulation model which corresponds to a target regional power grid and comprises the multi-type frequency modulation resources, and the multi-type frequency modulation resources comprise at least one of thermal power, hydroelectric power, wind power, photovoltaic power and energy storage; based on the frequency modulation effect and frequency modulation cost of the multi-type frequency modulation resources, constructing a primary frequency modulation dead zone optimization model of the multi-type frequency modulation resources, the primary frequency modulation dead zone optimization model comprising a primary frequency modulation dead zone optimization objective function and constraint conditions; and performing simulation based on the dead zone combination of the multi-type frequency modulation resources and the primary frequency modulation simulation model to obtain a simulation result, and solving the primary frequency modulation dead zone optimization model based on the simulation result to obtain an optimal primary frequency modulation dead zone of the multi-type frequency modulation resources. According to the invention, overall optimization of the frequency modulation cost and the frequency modulation effect of primary frequency modulation of the regional power system can be realized.