Contents
How does the current ripple in a PWM work?
Most modern motor controllers and amplifiers are based on a PWM power output adapting the required motor voltage by a PWM pulse width modulation. The PWM controlled motor voltage leads to a current ripple that reflects the increasing and decreasing current inside the winding each PWM cycle.
How does PWM frequency affect DC bus voltage?
A linear servo drive would have an “infinite” PWM frequency and therefore zero ripple. High DC bus voltage means higher ripple, reduce the DC bus voltage to the motor nominal whenever possible. Low resistance motors have lower current ripple.
How is ripple counting used in brushed DC motor?
Using PIC®MCUs and Core Independent Peripherals (CIPs), the ripple counting technique based on the current drawn by the motor, can be used. These CIPs are utilized to drive the motor with minimum CPU intervention.
What is the PWM frequency of an Ingenia drive?
Low PWM frequency means higher ripple, increasing the PWM will reduce the current ripple. Typically, Ingenia servo drives have PWM frequencies of 20 kHz or 40 kHz, consult the exact value with the datasheet or HW configuration file. A linear servo drive would have an “infinite” PWM frequency and therefore zero ripple.
What causes the inrush current on a capacitor?
However, due to the characteristics of the capacitors, inrush current is caused at the input side of the power supply. If the inrush current is not suppressed, the input power might have no output due to protection circuit, and it maybe damage the input circuit or fuse.
How does a power converter reduce ripple noise?
In order to reduce the input or output ripple noise or EMI noise, current power converter usually connected in parallel with capacitors or filter at the input side, as Figure 1 show. The filter usually composed of an inductor or capacitor.
How does an inrush current suppression circuit work?
An inrush current suppression circuit is according to Figure 3.3, and the parameters are calculated in accordance with formula (6). Figure 3.4 is a test waveform using a resistor and diode suppression circuit. At the same input voltage and input capacitance, the surge current of the input capacitor is suppressed at 2.386A.