Does china have Russian equivalent of S-400 and S-500 anti-air systems?
They only acquired S300PMU and S400 for evaluation, no S500. Not really a good time to ask Russia for one right now, maybe they could after the war. Or since cooperation deepened, China can just directly examine data from Russian sources.
S500 corresponds best with late variant hq-9 in China's own arsenal. China continously update them without changing the official designation, but people unofficially call the late variants B or C. Unlike the S400 family, hq-9s are track by missile, it's accused from some speculative sources that they descend from Patriot acquired from Israel, but this is with near 100% certainty not true, they only happen to share the basic tracking principles.