New BIOS 1.13.1 did not solve the problem. But I found the problem.

https://linuxreviews.org/Linux_Kernel_5.5_Will_Not_Fix_The_Frequent_Intel_GPU_Hangs_In_Recent_Kernels

If I disable GPU power management then suspend works

i915.enable_dc=0

Dell 7530 has poor battery life and disabling GPU power management is a very bad solution for laptop.

This method doesn't work, I got freeze again.

But I found the same or similar problems

https://www.reddit.com/r/Dell/comments/ebyo05/sleep_issues_on_dell_precision_7530/

https://community.spiceworks.com/topic/2236519-no-video-after-hibernate-dell-precision-7530

https://www.reddit.com/r/Ubuntu/comments/anurkw/dell_precision_5530_suspend_problem_and_other/

https://www.reddit.com/r/Dell/comments/a8taiy/precision_5530_ubuntu_1810_instabilities/

Ubuntu 16.04 with Precision 7530 has many customized drivers and settings, where i can download customized Ubuntu 18.04 for 7530?

https://bartongeorge.io/2018/12/17/ubuntu-18-04-lts-now-available-on-dell-precision-mobile-workstations/

Hi, @AndreasKV 

Try the command as below to get Ubuntu OEM kernel

sudo apt-get update
sudo apt install linux-oem

Reference: https://wiki.kubuntu.org/Kernel/OEMKernel