Adjustment of Hydro-Governor Characteristics Using Separate Drive for the Speed-Sensing Element

1965 ◽  
Vol 87 (1) ◽  
pp. 13-17 ◽  
Author(s):  
L. M. Hovey
Keyword(s):  
Direct Current ◽  
Low Frequency ◽  
Alternating Current ◽  
Variable Speed ◽  
Sensing Element ◽  
Variable Speed Drive ◽  
Precise Control ◽  
Speed Change ◽  
Method Of Adjustment

This paper describes the application of a variable-speed drive for the speed-sensing element of a conventional hydro-governor which makes it possible to measure accurately the deflection of the speeder rod for a given speed change from normal. When this characteristic is determined in the field, changes can be made to the control springs if necessary, to make all machines consistent. The device may also be applied to measure directly both the permanent and temporary speed droops of the governor and allow these quantities to be readjusted to the desired values. The advantage of this method of adjustment is that it permits all the work to be carried out with the main machine shutdown. The variable-speed drive consists of a small motor-generator set which supplies direct-current power to a rotary converter, which in turn delivers low-frequency alternating-current power to the speed-sensing motor on the governor. The rotary converter and the motor-generator set are controlled by a system which gives precise control over the speed which is measured by an accurate tachometer.

scholarly journals Variable-Speed Engines on Wind Farm Support Vessels

2020 ◽  
Vol 8 (3) ◽  
pp. 229 ◽  
Author(s):  
Kristian Eikeland Holmefjord ◽  
Lars Husdal ◽  
Martijn de Jongh ◽  
Sverre Torben
Keyword(s):  
Direct Current ◽  
Diesel Engines ◽  
Wind Farm ◽  
East Coast ◽  
Frequency Converter ◽  
Real Life ◽  
Alternating Current ◽  
Variable Speed ◽  
Fixed Frequency ◽  
Fuel Savings

We examine the fuel savings of Edda Passat, a newly constructed wind farm support vessel that utilizes a common direct current (DC) grid. This enables its diesel engines to operate at variable speeds by using frequency converter technology. A detailed investigation of these benefits has been performed based on real-life measurements from three months of operations in the Race Bank wind farm off the east coast of England. The calculated fuel savings of Edda Passat achieved via its variable-speed engines are 21% lower compared to using a conventional alternating current (AC) grid with a fixed frequency. This paper will explain the technology, measurements, and results in detail.

scholarly journals Design of a three phase four quadrant variable speed drive for permanent magnet brushless DC motors

2016 ◽  
Author(s):  
◽  
Jonas-Yelee Dakora
Keyword(s):  
Permanent Magnet ◽  
Direct Current ◽  
Dc Motor ◽  
Bldc Motor ◽  
Variable Speed ◽  
Suitable Alternative ◽  
Variable Speed Drive ◽  
Three Phase ◽  
Electric Bicycle ◽  
Four Quadrant

The aim of this research project is to design a three phase four quadrant variable speed drive (VSD) for a permanent magnet brushless direct current motor (PMBLDC) that can be applied to an electric bicycle (e-bike). The design is confined to PMBLDC motors with a maximum power rating of 1.5kW. The speed controller operates in current mode at a maximum voltage and current rating of 50V and 30A, respectively. The VSD has the ability to smoothly control the current delivered to the DC motor and therefore controls its torque. The motor’s current is limited in all four quadrants of operation, and its speed is limited in the forward and reverse directions. The performance of the proposed DC motor VSD system is tested on an electric- bicycle. The PMBLDC motor has three hall sensors embedded into the stator to determine rotor position. A phase switcher module interprets the position signals and produces a switching pattern. This effectively transforms the BLDC motor into a direct current (DC) brushed motor. The unipolar switching scheme used ensures that current flows out of the battery only for motoring operation and into the battery during regenerative braking. The current and torque are directly proportional in a BLDC motor. Torque control is achieved in the BLDC motor using a single channel current controller. The phase switcher current is monitored and used to control the duty cycle of the synchronous converter switches. The proposed e-bike speed control system provides efficient control in all four quadrants of operation and it is a suitable alternative for a low cost transportation mode.

DESIGN, SIMULATION AND IMPLEMENTATION MONITORING SYSTEM FOR SYSTEM CONTROL C4 FEEDING PUMP FOR FEED VAPORIZATION IN THE BUTADIENE PLANT

2020 ◽  
Vol 1 (1) ◽  
pp. 31-35
Author(s):  
Fahmi Yunistyawan ◽  
Yunistyawan J Berchmans ◽  
Gembong Baskoro
Keyword(s):  
Motor Control ◽  
Control System ◽  
Field Operator ◽  
System Control ◽  
Variable Speed ◽  
Variable Speed Drive ◽  
Software And Hardware ◽  
Discharge Pressure ◽  
Selection Of

This study implements the auto start control system on an electric motor 3 phase C4Feeding pump when the discharge pressure is low-low (4.3 kg /cm²). The C4 feeding pumpmotor was initially manually operated from the local control station, this was very ineffectiveand inefficient because it still relied on the field operator to operate the pump motor and whenthe plant was in normal operating it is very risk if the field operator late to operate motor then itwill impact to quality of the product, and if the delay time to operate motor is too long then planthave to shut down, therefore improvement is needed in the C4 feeding pump motor controlsystem. In this paper, various types of 3-phase motor control are explained which allow it to beapplied to the C4 feeding pump motor that are on-off, inverter, and variable speed drive andefficient selection of the three systems control of the motor. Software and hardware used in thisthesis work are DCS CENTUM VP Yokogawa.

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