what makes difference between absolute and incremental encoder is a need for initialization (phase search) for incremental one at power-up. More details can be found, for example, at www.drbrushless.com
If I got it correctly soft switching was mentioned in the context of clean sinusoidal output voltage. I think soft switching itself rather reduces semiconductor switch losses and has nothing to do with voltage harmonic contents.
Soft switching does allow for higher switching frequency (cleaner...
A remark about encoder vs resolver comparison in the context of brushless motor sinusoidal commutation.
Relatively expensive absolute encoder is an absolute position sensor just as resolver.
Absolute position is not available from relatively cheap incremental encoder. Therefore, Hall sensors...
There is a common spread terminology misunderstanding for permanent magnet (PM) motors. Many people use DC brushless for trapezoidal (or 6-step) current control and AC brushless for sinusoidal control. For trapez control, PM bushless motor winding may be distributed so as to assure that...
You can rouhgly view it like this. At steady state, mechanical torque developed by prime mover is equalized by generator electromagnetic torque created by active current component. As sudden 3-phase short circuit fault happens, active current dramatically reduces and so electromagnetic torque...
Another arguments for brushless motor / drive selection may be:
- torque ripple at low speed;
- torque-speed area (torque available at high speed);
- motor thermal behavior / efficiency / loss including that induced by PWM inverter operation;
- advanced drive features like phase advance for...
You can get an idea from "Advanced Unipolar PWM Technique" article at www.drbrushless.com .
If you decide to go brushless with your Electronic Speed Control (ESC), there is also some stuff.
PWM inverter operation may create the following problems - motor winding increased insulation stress and overeating due to motor additional PWM loss.
If I understand correctly, stress voltage build-up may happen because of possible cable length. This seems not to be your application case...
Both are essentially position sensors. Halls are coarse sensors with 60 el.deg resolution. May be used for DC (six step, or trapez) Brushless non-demanding speed control applications.
Resolvers - rotating electrical mini macnines - provided Resolver-to-Digital Converter deliver position in...
To be exposed to sinusoidal brushless with incremental encoder power-on issues read Smart Initialization article overview at
http://www.drbrushless.com/cgi-bin/articles.phtml
The basic idea is very simple. For constant speed, original equations are linear with sine / cosine type variable coefficients. Direct Park transformation transforms the original system into linear time-invariant (constant parameter) equations that can be relatively easily solved. The physical...
In connection with phase initialization at power-up of sinusoidal brushless motor with incremental encoder without position Hall sensors see "Smart Initialization" article overview at
http://www.drbrushless.com/cgi-bin/articles.phtml
Small correction - ETEL is rather Swiss than French company, their products - motors + control electronics - are high performance high cost for space, critical mission and so. Happened to visit them in 1994 in Moteur (near Neuchatel) ...
I suppose that we are talking about H-bridge or 3-phase bridge topology.
High (low) side free-wheeling, or anti-parallel, diode contributes to turn-on switching loss of its low (high) side transistor counterpart via reverse recovery phenomenon - at turn-on transistor sees current pulse from the...
