High Country Tek HGC-2, Closed Loop Controller - Manual (Page 5)

5
Electronic Controller Solutions for the Global Fluid Power Industry
Controller Set-up: PID Tuning
B
C
System Repeatability & Stability:
Run Open loop using CC ( Constant Current ) mode
1) Set fixed current value for CC mode test using GUI and entering mA level at
2) Connect meter as shown in – measuring DC valve current in mA.
3) Connect fixed load to generator – non voltage/frequency dependent ( i.e. heater element )
4) Connect meter as shown in to measure generator AC voltage output
5) Set engine throttle to fixed, steady position ( i.e. high idle )
6) Close ‘Normal Enable’ and ‘CC mode enable’ switches together
7) Now Open the enable CC mode switch – leave Normal Enable switch closed
8) Allow readings to settle and measure/note current to valve coil
9) Allow readings to settle and measure/note generator output voltage
10) Open the HGC-2 ’Normal Enable’ switch
11) Meter reading output current to valve in 8) should go to near zero
12) Meter reading generator voltage will reduce or collapse to near zero
13) Repeat steps 6-10, x5 times, noting valve DC current and generator AC voltage readings
14) Look for DC valve current to be within +/- 10 mA each time if not bleed system
15) Look for generator AC voltage to be within +/- 10% each time
NOTES:

If readings are repeatable and stable when running, proceed to tuning the PID for closed
loop speed control.

If readings are NOT repeatable or system hunts, do the following:
Item Problem Action
Air Causes oscillations in valve/pump
control and repeatability issues Bleed valve, pumps, hoses & system at
highest point.
Hoses Acts like accumulator and causes
spongy operation / hunting / of system Reduce hose length, higher number of
wires in hose, replace with solid piping
Oil Viscosity changes due to age and heat Cool the oil if needed to maintain
constant temperature.
Leaks Loose fittings, worn ‘O’ rings, porosity Replace parts as needed, tighten
fittings and bolts e.t.c.
Reasons for instability:
A