Products :: Variable Speed Drives
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Subcoe is able to package, install and commission variable speed drive systems for use with Electrical Submersible Pump (ESP) systems using standard product offerings from many established manufacturers such as Siemens, Yaskawa, Toshiba, and Allen Bradley. These packages are available in low voltage, 380-690 volts as well as in medium voltage, 2300-4160 volt configurations. Standard packaging includes air cooled NEMA 1 and 3, air conditioned NEMA 3/4, and water cooled NEMA 3/4. Packages are fully customized to meet customer specific solutions to operate onshore or offshore, in desert environments, tropical environments and under artic conditions. Packaged units are available with stand alone NEMA 3/4 enclosures, to fully functional control room packages housed in custom electrical house type modules on skid bases. Low voltage VSD’s are voltage source DC link converters with IGBT inverters. This package is now the standard of the industry with the phasing out of VVI type six step drives. Medium voltage VSD’s are available in either voltage source or current source type drives. Subcoe fully understands line and load side harmonic problems. Line side solutions range from trap and linear type harmonic filters to multi-pulse converter sections utilizing 12, 18, and 24 pulse configurations. Trap, or notch type filters typically referred to as 5th, 7th, 11th and 13th harmonic filters are used when source impedance conditions are known and will not change over time. Linear type harmonic filters remove harmonics above the 4.3 harmonic and are used when source impedances are unknown and when the VSD’s are to be loaded near full load. If site conditions are varying along with the load conditions, Subcoe can provide for multi-pulse converter sections or fully active front end technology to reduce the harmonic content that feed back to the power source allowing each installation to meet IEEE 519 1992 guidelines. To provide power for 12 and 18 pulse VSD’s Subcoe is able to provide custom built dual polygon transformers that are reconfigurable to work in a bypass condition for direct on line switchboard applications. Source transformers can also be provided with tertiary windings in order to provide site power for additional loads such as well site lighting or chemical injection pumps. Pulse Width Modulated (PWM) VSD’s produce harmonics centered on their carrier frequencies and multiples thereof. The use of PWM VSD’s in ESP applications gives way to resonant conditions that allows the carrier frequency or one of its multiples to amplify the voltage seen at the motor at magnitudes that will quickly damage the motor or the cable supplying it. Subcoe is able to provide load side filtering for ESP applications that will eliminate load side harmonics being applied to the motor or the cable, in turn supplying a true sinusoidal voltage waveform to the ESP. Run life is significantly improved in these applications. Subcoe VSD packages use state of the art transient voltage surge suppressor devices (TVSS). All TVSS devices are not created equal. Most employ multiple metal oxide varistors soldered together to form a single protective block. The problem with this type of device is it is subject to the skill of the assembler to provide paths of equal impedance to each device soldered into the array. This is very difficult to do. Moreover, each individual MOV is not identical to all the others in the array. What this means is that one can fail prematurely which then produces a cascading, catastrophic failure of all the other devices in the array. This produces significant damage to the TVSS and in turn it must be replaced. Subcoe utilizes single MOV devices assembled in a non-destructive package. This allows the device to be mounted inside the VSD enclosure without the use of additional protective devices such as fuses or circuit breakers. Subcoe VSD enclosures are custom built panels with durable powder coat finishes. Coatings are available in a full range of client color choices. Neoprene gaskets finish off door openings to prevent dust and moisture ingress. Special door clasps secure doors tightly to their gasketted openings. Enclosures can be fitted with harmonic filters, bypass contactor systems, chart recorders, PLC control systems, redundant air conditioning systems, incoming and outgoing cable junction boxes, auxiliary power panels and virtually any other device the client wishes to have installed. All enclosures are mounted on steel channel bases to allow movement by fork lift as well as a solid tie down point to concrete pads or steel skid bases. By using a dedicated electrical engineer for each project we are able to fully understand our clients’ needs. Working closely with clients as the project progresses ensures each customer a final product that meets or exceeds their expectations. Subcoe is also able to offer Power System Analysis utilizing ETAP power analysis software. Power system analysis is a valuable tool to determine equipment suitability with existing and future electrical systems.
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