You say you have these settings:
PD001 1 (Use digital inputs for on off)
PD002 1 (Source of operating frequency)
PD003 300 (Main Frequency)
PD004 300 (Base Frequency)
PD005 300 (Max Frequency - Max RPM of the motor)
PD006 2.5 (Intermediate Frequency - Should have no relevance)
PD008 220 (Max motor voltage from motor nameplate)
PD011 200 (Minimum Frequency - Set the lower frequency based on desire minimum RPM)
PD014 10 (Acceleration Time)
PD015 10 (Deceleration Time)
PD070 0 (Analog Input - 0 = 0-10VDC input)
PD072 300 (Lowest Analog Frequency)
PD073 (Highest Analog Frequency)
PD142 8.6 (Motor Nameplate current)
PD143 4 (# of motor poles)
PD144 3000 (Motor Nameplate RPM
PD176 1 (Inverter Frequency Standard)
Since the PD011 is set to 200 then the lowest speed should be 12000 RPM
Since PD005 is set to 300 then the max speed should be 18000 rpm (Per the motor name plate at 300hz)
If you want to go less than 12000rpm, then I would think you need to reduce parameter PD011
If you want to go more than 18000rpm, then I would think you need to increase parameter PD995
You may have to change PD072 and PD073
Also, I would think your value of 3000 in PD144 is incorrect. The motor nameplate RPM for your motor is 18000
Do you have a J1 jumper and if so what is jumpered
OR do you have a jumper labeled VI?
If there is custom firmware in that HY Drive, then it would explain why you can't change some of the settings.
If you have a bench DC power supply that can provide 0-10VDC, you can connect it to the ACM (COM) and VI (0-10VDC)
and put a jumper from DCM to FWD, you should be able to run the VFD with your bench power supply, or you could use a 1.5 dry cell battery and a 9VDC dry cell battery to do something similar.
Huan Yang support email address is:
service@hy-electrical.com
They are pretty responsive.
You do need to find out if you have a genuine HY drive or a knock off.
I'm just trying to provide some ideas.
Shame but not surprising the manufacturer (Who is it? China?) wants to charge you for help.
You could always buy another VFD is that is not genuine HY or has some custom firmware perhaps...
Marty