Electric Inverters / Drives

Our MD at HWL Technical Solutions found his love for control and automation when he worked for Control Techniques which is now Emerson . CT assisted him though Staffordshire University with his Engineering studies. And one thing that is set within our company and is stress to all our engineers is that we have to work with the customer to ensure we give the best Technical Solution hence our name. So many times we have had a call for help where OEM has be call to a site and the Engineer turns up with the latest Laptop and says they need to rip full system and buy new. This is generally not the case. But in some applications new is the only way forward. We have strong links with most manufactures and we pride ourselves on not over engineering a system.

Particular applications include high accuracy cut to length systems for the steel industry, slitting, bar coding and auto packaging systems for the food industry, coating and printing systems for use in the manufacture of adhesive tape.

HWL Technical Solutions has actively assisted industry to produce existing products more efficiently and to design drive and control systems for the manufacture of new products. With our team of experienced service and commissioning engineers HWL can provide product support on a worldwide basis to all types of electronic control systems, whether originally supplied by ourselves or others.

Immediate telephone support is available along with 24 hour service cover. In addition maintenance contracts can be arranged to provide regular and effective maintenance

electric inverter

HWL Technical Solutions can supply AC inverters or variable speed drives at very competitive prices. Our engineers have many years' experience of AC & DC variable speed drive applications, and we can offer free advice on the best drive for your application, from simple motor control to complex multi-drive web processes, we can provide a cost effective solution. We can supply inverter drives as stand-alone units, or we can build bespoke control panels, as well as offering an installation & commissioning service. As independent engineers we are not tied to anyone company so if your site has a preference to any manufacture you can be assured that we can give a competitive price.

DC Variable Speed Drives

DC controllers or DC drive systems, although are not as widespread as AC inverters do have an important role to play in modern manufacturing processes. They are ideally suited to particular processes, and with a huge number of existing DC motor installations, the option to upgrade your DC drive to a modern digital model could prove far less expensive than replacing both the motor & controller for an AC model.

DC DRIVE CHARACTERISTICS utilize a converter to transform AC current into DCcurrent which is then fed to the DC motor which is designed for adjustable speed operation. Speed changes are made by increasing or decreasing the amount of DC voltage fed to the motor from the drive. Usually offer the lowest cost for medium and high HP applications.

DC Drives are often the best choice when Environmental conditions surrounding the DC motor are reasonably clean, dry, and allow the use of DPG, DPG-FV, TENV, or TEFC motor enclosures.

Dc Drives application are a good choice where it requires:-

  • A wide range of changing loads such as centre driven winders.
  • Motor speeds can reach 2500 RPM.
  • Starting torques are greater than 150% or unpredictable.
  • Application HP requirements are medium to large.

Supplies included

Control Techniques, Parker SSD DC Drives , Santerno, Sprint Electric Ltd and ABB

How Does a Variable Frequency Drive Convert AC to DC?

Explanation of AC vs. DC

Electricity can be thought of as the movement of electrons. As such, it can usually be described as being either AC (alternating current) or DC (direct current). With direct current, the electrons only move in one direction (forward) so the electrical current is always going in the same direction. Alternating current involves directions moving in two directions--backwards and forwards--which causes the electrical current to change directions. Alternating current also involves a constantly changing electrical current that can be described as a wave. This means that the direction of the current and amplitude change.

Variable Frequency Drives

Variable frequency drives are systems that are able to control the speed at which an AC electrical motor rotates. They're able to do this by changing the frequency of the electrical current that's supplied to the motor (the frequency is a measure of how quickly the alternating current completes one full cycle of its wave motion). In order to do this, the variable frequency drive must first convert the incoming AC power to DC, which it does using a rectifier bridge. A rectifier bridge is made up of at least four subunits called diodes, which keep the current always moving in one direction (forward). When the current tries to go in reverse, the diodes reroute it so that it's still moving forward, into the variable frequency drive.

Other Aspects of Variable Frequency Drives

Because the motors that are attached to variable frequency drive run on AC power, the drive must be able to convert the already converted DC power back to AC power. It uses a special kind of circuit, called an inverter switching circuit, to switch the electrical current back to a modified alternating wave form. This kind of circuit is usually able to be controlled externally by changing the settings on the control panel, which will then change the frequency at which the inverter switching circuit generates the waves. This allows for control over the speed of the attached electrical motor.