Variable Speed Drives

Benefits, Features, Applications

Variable Speed Drives (VSD)

the ESP world leader

We are the leading VSD Manufacturer in the ESP industry. We offer the most up to date technology and topology, benefiting our Oil Company and Pump Company customers. All DOS products are designed and tested for rugged, desert and jungle on-shore applications, plus off-shore applications.

  1. Standard and custom ESP designs, for a more cost effective approach
  2. Elaborate more sophisticated designs to cover special applications
  3. Harmonic mitigation with power factor correction to lower operating cost
  4. DOS Matrix, Low Harmonic, High production, for Induction and PMM Motors

Product Reviews

DOS focuses on long term relationship with our clients to improve performance of your existing and new systems. DOS is a Canadian OEM manufacturer with an abundance of experience, both at head office and in the field. We deliver standard and custom engineered, high quality products to our customers. All DOS products are of rugged design for the intended environment; desert, jungle or arctic and off-shore applications.

About DOS Matrix AFE-VSD

DOS Matrix AFE-VSD provides 100% harmonic mitigation (cancellation) and is the best solution on the VSD market. Completely dynamic. The only ?stand alone? complete harmonic elimination (mitigation) solution available. Works 100% with unbalance and under-loaded. DOS Matrix AFE-VSD displays real time harmonics, data logs and alerts you in the event harmonics exceed user set values. DOS Matrix AFE-VSD also provides Power Factor correction (PFC) to lower power consumption and lower operating cost allowing it to pay for itself faster. It is Non-overloadable. Fastest solution available. Immune to resonance. Adapts to changing conditions, automatically.

Eliminates power quality problems. Extends the life span of the equipment it is connected to. Guaranteed to meet IEEE-519.

If the MATRIX AFE-VSD VIDEO is PASSWORD locked, please email us at and ask for your MATRIX AFE password.

See our Matrix AFE-VSD in action

About DOS Manufacturing

Our number one priority is testing. Every product designed, implemented, manufactured by DOS is thoroughly quality assurance tested by means of procedures developed over years of producing and receiving feedback from the customer in their field. We ask the customer, what do you like about this DOS product, and they let us know. Then we ask what they don't like about our product or what further features or changes they would like to see in the next production for them. DOS has recorded the field test results and they valuable answers from our customers to manicure the best systems in the world. We listen to our customers and when they see the next generation of the product, they see we carefully designed it for them.

All DOS manufactured produces meet the customer specifications. We usually exceed the specifications with proven features and quality control designs which we have carefully engineered with valuable assets learned from the 43 countries and hundreds of oil fields that DOS has worked.

See our Harmonics Power Study |27 min|

Some of our Projects

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Short bio about DOS Manufactured Products

DOS Manufacturing starting with the 6-pulse VSD with PWM Sine wave filtered output back in 1996. Then we added the passive input filter to this VSD input and manufactured these for many years with good results but with limitations.

As newer VSD technology surfaced and as per oil company specifications, we developed the 12-pulse and 24-pulse VSD and also found limitations with additional drawbacks from the passive filter approach, such that we now require an additional expense phase shifting transformer and further finding restrictions on eliminating (mitigating) harmonics due to the unbalance and less then 100% VSD loading seen at most ESP oilfield.

Since 2013, we incorporated the Active Front End AFE-VSD with a customized harmonics elimination and power factor compensation input and with 3kHz output customized Sine wave filter. The AFE has the lowest input harmonic distortion, no matter how loaded and unbalanced, highest power factor, lowest losses, lowest operating cost, lowest per barrel cost and purest sine-wave input to the power source and output to the ESP motor.