Voltage regulator

About: Voltage regulator is a research topic. Over the lifetime, 33536 publications have been published within this topic receiving 350859 citations.

A New Measurement Technique for Tracking Voltage Phasors, Local System Frequency, and Rate of Change of Frequency

Abstract: With the advent of Substation Computer Systems dedicated to protection, control and data logging functions in a Substation, it becomes possible to develop new applications which can utilize the processing power available within the substation. The microcomputer based Symmetrical Component Distance Relay (SCDR) described in the references cited at the end of this paper possesses certain characteristics which facilitate real-time monitoring of positive sequence voltage phasor at the local power system bus. With a regression analysis the frequency and rate-of-change of frequency at the bus can also be determined from the positive sequence voltage phase angle. This paper describes the theoretical basis of these computations and describes results of experiments performed in the AEP power system simulation laboratory. Plans for future field tests on the AEP system are also outlined.

Motorized cutting and fastening instrument having control circuit for optimizing battery usage

Abstract: A surgical cutting and fastening instrument. The instrument comprises an end effector and a shaft connected to the end effector. The shaft comprises a drive train for powering the end effector. The instrument also comprises a handle connected to the shaft. The handle comprises an electric, DC motor connected to the drive train for powering the drive train and a DC power source comprising one or more batteries. The handle also comprises a power regulator having an input connected to the DC power source and an output connected to an input of the motor. The power regulator comprises a power converter and a control circuit for controlling the power converter. The control circuit controls the voltage set point for the power converter so that voltage delivered from the power source is less than the voltage at which the power source delivers maximum power.

A new mathematical model and control of a three-phase AC-DC voltage source converter

Abstract: A new mathematical model of the power circuit of a three-phase voltage source converter (VSC) was developed in the stationary and synchronous reference frames. The mathematical model was then used to analyze and synthesize the voltage and current control loops for the VSC. Analytical expressions were derived for calculating the gains and time constants of the current and voltage regulators. The mathematical model was used to control a 140-kW regenerative VSC. The synchronous reference-frame model was used to define feedforward signals in the current regulators to eliminate the cross coupling between the d and q phases. It allowed the reduction of the current control loops to first-order plants and improved their tracking capability. The bandwidths of the current and voltage-control loops were found to be approximately 20 and 60 times (respectively) smaller than the sampling frequency. All control algorithms were implemented in a digital signal processor. All results of the analysis were experimentally verified.

A three-phase power flow method for real-time distribution system analysis

Abstract: This paper presents a three-phase power flow solution method for real-time analysis of primary distribution systems. This method is a direct extension of the compensation-based power flow method for weakly meshed distribution systems from single phase to three-phase, with the emphasis on modeling of dispersed generation (PV nodes), unbalanced and distributed loads, and voltage regulators and shunt capacitors with automatic local tap controls. The method proposed here is capable of addressing these modeling challenges while still maintaining a high execution speed required for real-time application in distribution automation systems. The paper also includes test results from the application of a computer program developed based on the proposed method to large primary electric distribution systems. >

System level analysis of fast, per-core DVFS using on-chip switching regulators

Abstract: Portable, embedded systems place ever-increasing demands on high-performance, low-power microprocessor design. Dynamic voltage and frequency scaling (DVFS) is a well-known technique to reduce energy in digital systems, but the effectiveness of DVFS is hampered by slow voltage transitions that occur on the order of tens of microseconds. In addition, the recent trend towards chip-multiprocessors (CMP) executing multi-threaded workloads with heterogeneous behavior motivates the need for per-core DVFS control mechanisms. Voltage regulators that are integrated onto the same chip as the microprocessor core provide the benefit of both nanosecond-scale voltage switching and per-core voltage control. We show that these characteristics provide significant energy-saving opportunities compared to traditional off-chip regulators. However, the implementation of on-chip regulators presents many challenges including regulator efficiency and output voltage transient characteristics, which are significantly impacted by the system-level application of the regulator. In this paper, we describe and model these costs, and perform a comprehensive analysis of a CMP system with on-chip integrated regulators. We conclude that on-chip regulators can significantly improve DVFS effectiveness and lead to overall system energy savings in a CMP, but architects must carefully account for overheads and costs when designing next-generation DVFS systems and algorithms.