How can the output power of a motor be controlled using an inverter?

[PhysicsTest]

TL;DR Summary

Understand the logic of output power of motor using inverter

I am trying to decode and understand the output of the inverter

I have doubt on the PIN, suppose the load is increasing on the motor then it can be done in two ways, suppose the initial Pout requirement is 1KW, it can be done either by controlling the voltage or current. Now how do I control the voltage separately and current separately? I mean i want to put the constant voltage and increase current or keep current constant and increase voltage, Is it possible?

 

[berkeman]

The output of the inverter will generally be a constant AC voltage, to the extent that the inverter's output impedance is low compared to the load that it is connected to. The current varies in the load according to the impedance that the load presents to that constant inverter output AC voltage.

 

[Averagesupernova]

TL;DR Summary: Understand the logic of output power of motor using inverter

I mean i want to put the constant voltage and increase current or keep current constant and increase voltage, Is it possible?

You cannot choose a voltage, apply it to a load and then change the current without changing the voltage or the characteristics of the load. They are interdependent.

 

[Borek]

RYB cables make me think about brushless motors used in RC models. As far as I am aware they work on a constant voltage (well, not exactly constant, supplied by the battery, so it goes down during flight/ride), and the power is regulated by the pulse length - current is switched on and off.

 

[DaveE]

current is switched on and off.

Voltage is switched on and off. The inductance of the motor will force the current to continue to flow. On average, if you switch fast, you can think of this as current control with the average voltage equal to whatever the corresponding DC value would be at that current, but with voltage switched on and off as you said. Like a Buck SMPS. Then at low frequencies that current will be programmed to be sinusoidal, or at least AC with higher harmonics.

 

[Borek]

Voltage is switched on and off.

Yes, careless wording on my side, sorry about that. In Polish "prąd" means both current (amperage) and "the presence of the electricity".

Mainly what I was aiming at was that the observed power output is an average over time of quick impulses, in which only voltage is directly controlled and the current is whatever the resistance/impedance allow.

 

[sophiecentaur]

TL;DR Summary: Understand the logic of output power of motor using inverter

Now how do I control the voltage separately and current separately? I mean i want to put the constant voltage and increase current or keep current constant and increase voltage, Is it possible?

Do you remember the old favourite I = V/R ?

Your motor is basically a Resistor (ignore the reactances for simplicity) Unless you can somehow change the Resistance of the motor then V and I are tied together. What are you trying to achieve here? Give a reference to your plan.

The output of an inverter can be produced in several ways but, whether you start with a square wave or a rough approximation with samples of different values, you filter the output and get a near sinusoidal waveform.

RYB cables make me think about brushless motors used in RC models.

Brushless motors are basically multiphase AC motors and the supply is produced as with a (basically) normal inverter. Speed is controlled by using a variable frequency. As the load increases. the inverter circuit provides more current to keep the supply volts the same - a mechanical overload and the supply will run out of current and the motor can stall.