1041 results about "Variable load" patented technology

A decentralized load management and control system and method are provided herein. A plurality of loads in a system are associated with a multitude of respective networked load controllers. If energy demand exceeds optimum limits in operation then the networked load controllers collaborate to determine which load(s) will be shed based on an optimization algorithm that considers, inter alia, variable load priority and business objectives. Additionally and/or alternatively, if the metered energy demand is less than optimum, the load controllers can determine which loads to reconnect again based at least upon load priority and business objectives.

Control of a variable output appliance of a small energy consumer participating in an electrical load shedding program. A baseline operating characteristic of the appliance is determined for ordinary operation (such as in an absence of any load shedding requirements). An amount by which to reduce output of the appliance is determined in accordance with the load shedding program. Operation of the appliance is controlled to achieve the output reduction in accordance with the load shedding. This approach enables providing incentive for the small energy consumer to participate in the load shedding program, the incentive being based on the amount by which output is reduced, thereby representing a reduction of actual energy consumption for that small energy consumer.

The throttle of an engine in an engine driven generator system operating subject to a wide and rapidly variable load, as in supplying current to a welder, is operated such that control signals are sent to a throttle actuator for adjusting the engine throttle position in response to load changes. The throttle actuator may be a solenoid pulling against a spring in accordance with the average current through the solenoid coil. In this embodiment, the processor causes pulse width modulated signals to be applied across the solenoid coil with throttle position changes being reflected in changes to the width of the pulses, such changes in the pulse width being delayed for at least the predetermined time since the last preceding adjustment to the throttle. Alternatively, the throttle actuator may be a stepper motor which is stepped by throttle position change signals from a processor which monitors engine speed and generator load to determine whether the throttle should be adjusted and, if so, in which direction and to what extent for optimum response.

A method and an apparatus are provided for providing a tunable substrate integrated waveguide (SIW) for which a parameter of at least some element or portion thereof may be altered or varied to alter the propagation of a signal propagating through the SIW thereby achieving a tunable SIW. In some embodiments a plurality of capacitively variably loaded transverse slots achieve the tunability for the SIW.

An electric vehicle comprises a first power source and a second power source. The first power source can be used to supply a substantially constant base power level and the second power source can be used to supply a variable power level such that a variable load demand can be filled by combining the base power level and the variable power level. The first source can be used to supply power to the second source when the second source is operating at a decreased charge or power level. The base power level can be varied based upon the remaining charge or power level contained within the second source. A number of control methods for operating the power supply of the electric vehicle are disclosed.

A current controlled delay circuit is disclosed. Two currents of constant sum are generated to control the delay of the circuit. The circuit includes a differential pair to switch one of the two currents from one leg of the circuit to another leg of the circuit. The circuit includes a cross-coupled pair to switch the other of the two currents from one leg of the circuit to another leg of the circuit. The circuit may include a fixed or variable load.

A receiver circuit includes a first differential amplification unit including a variable load section, and configured to receive first and second input signals, and to generate first and second output signals, which are amplified based on an impedance value of the variable load section and a voltage difference between the first and second input signals, a second differential amplification unit configured to receive the first and second output signals and to generate a third output signal based on a voltage difference between the first and second output signals, and a signal generating unit configured to generate an equalization signal for controlling the variable load section based on the third output signal.

The invention provides an integral optimization method and system for an automatic power generation system of a coal-fired unit. The method comprises the steps of carrying out control valve flow characteristic test and adjustment according to control valve flow characteristic parameters, carrying out combustion optimization on a wind and smoke subsystem and a combustion subsystem, carrying out a fuel disturbance test and a control valve disturbance test to generate typical test parameters, using the typical test parameters to generate a dynamic unit model, constructing a coordinating simulation system according to a coordinating controller and the dynamic unit model, using the dynamic unit model to optimize a feedforward controller and carry out simulation verification on the coordinating simulation system simultaneously, carrying out DCS configuration and parameter debugging in the simulation system, carrying out a constant-voltage slide-voltage variable-load test and a constant-load voltage-transformation test to generate technical indexes of the variable-load rate, the variable-load accuracy, variable-load response time and the main steam pressure accuracy, judging whether the technical indexes meet the preset technical indexes, and if on yes judgment, carrying out a slide-voltage variable-load test to enable the coal-fired unit to operate normally.

A calibration verification system 20 comprises a trainer 40 having a load generator, a variable load control system (hidden by the cover of the load generator) connected in electrical communication with the load generator, and an exercise trainer computer system 140 connected in communication with the variable load control system. In operation, the exercise trainer computer system 140 outputs commands to the variable load control system. These commands can, for example, instruct the variable load control system to energize the load generator at predetermined times and power levels in order to simulate changes in terrain. The calibration verification system 20 also allows the user to verify the calibration of the trainer 40 by implementing a user initiated process, which conducts a calibration verification test of the trainer and outputs the test data at the exercise trainer computer system 140.

This disclosure provides systems, methods and apparatus for increasing the efficiency of an amplifier when driven by a variable load. In one aspect a transmitter device is provided. The transmitter device includes a driver circuit characterized by an efficiency. The driver circuit is electrically connected to a transmit circuit characterized by an impedance. The transmitter device further includes a filter circuit electrically connected to the driver circuit and configured to modify the impedance to maintain the efficiency of the driver circuit at a level that is within 20% of a maximum efficiency of the driver circuit. The impedance is characterized by a complex impedance value that is within a range defined by a real first impedance value and a second real impedance value. A ratio of the first real impedance value to the second real impedance value is at least two to one.

A strategy for determining the critical supply duct pressure in variable-air-volume heating, ventilating, and air-conditioning systems that compensates for duct leakage and variable loads, enabling its use during normal system operation. The strategy consists of a static pressure sensor, an airflow sensor, a supply fan, a fan modulating device, a controller coupled to the static pressure sensor and the airflow sensor, and a data processing algorithm for analyzing results from a function test using these components. The functional test involves changing the supply duct pressure setpoint, waiting for equilibrium, recording pressure, flow, and time, then changing the supply duct pressure setpoint to the next setting in the sequence.

A variable load power amplifier that improves the performance of a power amplifier that provides both envelope tracking (ET) and average power tracking (APT). The variable load power amplifier can include a plurality of amplifiers that are each selectively connectable into one of a plurality of parallel combinations, each of the plurality of parallel combinations characterized by a corresponding load line. The variable load power amplifier can also include a plurality of control elements arranged to selectively connect one or more of the plurality of amplifiers into one of the plurality of parallel combinations, each of the plurality of control elements having a respective input terminal provided to receive a respective control signal, each of the plurality of control elements responsive to the respective control signal.

The present invention is directed to a high-powered (e.g., >500 W) ultrasonic generator for use especially for delivering high-power ultrasonic energy to a varying load including compressible fluids. The generator includes a variable frequency triangular waveform generator coupled with pulse width modulators. The output from the pulse width modulator is coupled with the gates of an Isolated Gate Bipolar Transistor (IGBT), which amplifies the signal and delivers it to a coil that is used to drive a magnetostrictive transducer. In one embodiment, high voltage of 0-600 VDC is delivered across the collector and emitter of the IGBT after the signal is delivered. The output of the IGBT is a square waveform with a voltage of ±600V. This voltage is sent to a coil wound around the ultrasonic transducer. The voltage creates a magnetic field on the transducer and the magnetorestrictive properties of the transducer cause the transducer to vibrate as a result of the magnetic field. The use of the IGBT as the amplifying device obviates the need for a Silicon Controlled Rectifier (SCR) circuit, which is typically used in low powered ultrasonic transducers, and which would get overheated and fail in such a high-powered and load-varying application.

The invention relates to a brushless doubly-fed motor excitation control system, which is characterized by comprising a PWM (Pulse-Width Modulation) rectifying unit, a first current sensor, a smoothing reactor, a contactor, an excitation controller and an inverter unit, an operation and display unit, an energy storage device, a BOOST reactor, a soft start circuit, a first voltage detection circuit and a second voltage detection circuit. The brushless doubly-fed motor excitation control system can always keep a speed-variable load-variable constant-frequency and constant-voltage power generation state when a brushless doubly-fed motor is at an electric operating state, the rotating speed of a brushless rotor rapidly changes and the load condition is within a larger range; and when the brushless doubly-fed motor is at the electric operating state, the brushless doubly-fed motor excitation control system can finish rapid adjustment of the rotating speed of the brushless rotor by excitation control and realizes multiple electric operating modes, such as synchronous operating, asynchronous operating and doubly-fed speed adjustment. When the load condition changes in a larger range, the brushless doubly-fed motor excitation control system can always keep the hard mechanical property of a synchronous motor. The invention also comprises the control method using the brushless doubly-fed motor excitation control system.

A digitally-controlled oscillator (DCO) (60), such as may be used in clock generator or clock recovery circuitry in an integrated circuit, is disclosed. The disclosed DCO (60) is a single-stage oscillator including a variable load implemented as a binary-weighted array of switched capacitors (40). Each of capacitors (40) has a plate connected to a common node (X), and a plate that receives a signal corresponding to one bit of a digital control word (DCOCW). The common capacitor node (X) is also connected to the input of a Schmitt trigger (42) that produces the output clock signal (OUTCLK) and a feedback signal that is applied to logic (38, 39) that inverts the common node of the capacitors (40). The switching time at the input of Schmitt trigger (42) depends upon the variable load presented by the array of switched capacitors (40), which is controlled by the digital control word (DCOCW). As a result, the clock signal (OUTCLK) is digitally synthesized by a single stage of the DCO (60). A digital phase-locked loop (PLL) clock generator circuit (50) including a phase detector (64), digital loop filter (62) in combination with the DCO (60), and a programmable frequency divider (66) providing a feedback path from the output of the DCO (60) to the phase detector (64), is also disclosed. The PLL clock generator (50) may be used in an integrated circuit such as a digital signal processor (30) or microprocessor, and is particularly well-suited for use in a battery-powered portable electronic system (200).

The invention relates to a life tester for an alternating-current contactor and a control method thereof. The life tester consists of a test control cabinet, a specimen cabinet, a 1/6Ue power supply cabinet and a load cabinet, wherein the test control cabinet comprises an industrial personal computer, a driving circuit and a contact state detection circuit; the specimen cabinet comprises a first accompanied specimen, a contactor specimen and a first breaker; the 1/6Ue power supply cabinet comprises a second accompanied specimen and a second breaker; and the load cabinet comprises a load circuit. The life tester is controlled by the industrial personal computer, so a life test of the alternating-current contactor can be completed automatically and accurately, and the automation level of the life test is improved; and four electrical life tests of a switch-on test, a break-off test, a dead load test and a variable load test of the alternating-current contactor can be performed, and a mechanical life test of the alternating-current contactor also can be performed. The life tester has an integral data protection function, namely test data is not lost in case of unexpected outage, the collected test data is not damaged after the power supply restores, and the test data is saved perpetually.

The invention discloses a method for jointly scheduling power generation load by using a wind power generation unit and a thermal power generation unit. A wind power plant, a circulating fluidized bed unit, a heating unit and the like which are within a same area or belong to a same power generation group are equivalent to a virtual unit, unified load instructions are issued from a power grid side, and the load instructions are decomposed on a unit side according to characteristics of various units to realize operation of the wind power plant at the maximum power generation power, wide-range variable load operation of the circulating fluidized bed unit and high-rate variable load operation of the heating unit. Mutual coordination of the wind power plant, the circulating fluidized bed unit and the heating unit is realized under the joint scheduling of a power grid, advantages of each unit are fully utilized, capacity of the power grid to receive wind power generation load is greatly improved, and the maximum-power operation of the wind power plant is realized while safety in operation of the power grid is guaranteed, so that waste of wind energy is reduced and power generation cost and environmental pollution are reduced.

A method of indicating the length of a mini cells in a mobile telephony network. Non linear coding of a short fixed length field in the header of the mini cell is described. Either an extension bit method or an extension code method is used to extend the length field so as to increase the number of length values available for coding of the mini cell sizes. The length of a mini cell is indicated in the individual mini cell or is indicated indirectly using a CID/length mapping table. Mini cell sizes are changed during a connection and methods are described for doing this. Cell header reading devices for extracting user information of individual mini cells are described. A mobile telephone network using the cell header reading devices is described.