Service manual

2-16

AY-ZP35PR

IPM overcurrent

detection circuit

IC1

R49

Overcurrent

Shunt resistance

CiN

5. 120° Energizing control (digital position detection control)

This control system detects the digital position detection signal and adjusts the rate of acceleration/deceleration accordingly.

-

tion signal is generated as a reference voltage equaling 1/2 of 280 VDC. However, since there is no induced voltage waveform when

the PWM waveform is OFF, the microcomputer performs internal processing so that detection is enabled only when it is ON. Based on

-

racy is high.

The microcomputer performs internal processing to cancel spike voltage during the regenerative process.

Furthermore, even if the induced voltage is low, position detection is still possible, thus allowing sensor-less operation at low rotation

speed in the initial stage of operation.

This reduces the starting current and improves the IPM reliability.

Comparator output waveform

(Position signal waveform)

Terminal voltage waveform

Reference voltage

(1/2 of DC voltage)

Spike voltage

(cancelled)