E-190 pilot reported electrical system failures resulting in numerous system malfunctions while on approach to land. Crew landed after performing checklist procedures.

Narrative

On approximately 20 mile final approach to ZZZ XR; multiple failures occurred in the electrical system and the EICAS displayed several associated message. Crew discontinued ILS approach; [request priority handling] with ATC and requested vectors to troubleshoot the malfunctions and run appropriate QRH procedures. Notable items were >DC BUS 2 OFF; >AVNX MAU 2A FAIL; >AVNX MAU 3B FAIL. These 3 items caused approximately 30 system failures all correctly listed in the QRH and noted by flight crew. Some highlights were loss of display unit 5; FMS 1; nose-wheel steering; some spoilers; RALT; HYD ELEC PUMPS 1 & 3B; Auto-throttles; #2 Reverser; and several other functions. Please see the full list on pgs. X-A of QRH. Additionally COM 2 & 3 failed (single radio now); which impacted flight crew ability to communicate with ATC; ZZZ1 OPS; DISPATCH; & TECH OPS. We unsuccessfully attempted to use COM 3 voice to communicate with ZZZ1; and then it would not cycle back to data mode. Ultimately we made the decision to request off-frequency" with ATC for 4 minutes on a vector so we could inform ZZZ Ops & tech ops of our [priority handling] situation.At this point; the 19 additional related EICAS messages were also evaluated and crew agreed they were likely caused by the 3 previously noted >Items. We chose to take the most restrictive instructions from multiple QRH procedures and perform a non-normal approach IAW DC BUS 2 OFF p. X-A. The fuel state was nearing 5000 lbs and we were still clean configuration at 6000' above a 4500' broken layer. CA wanted to ensure gear and flap extension below the cloud layer with contingency fuel for further unexpected failures or a go-around. It became a decision point to commence the approach based on the information we had at that time including verification of ILS signal and VMC weather below the broken layer.Upon completion of multiple QRH procedures; CA called the inflight crew to provide situation brief and assign precautionary code. The normal cabin call button did not function properly so CA utilized [priority handling] call button to communicate with inflight. CA explained the situational need to use [priority handling] CALL since it likely generated a startle factor to them. Plus we had already [requested priority handling] with ATC so the [priority handling] call was appropriate anyway. CA also made PA announcement to customers explaining the reason for the inflight delay to troubleshoot the EICAS messages and to inform them that the aircraft would need to be towed to the gate upon landing since one of the failed systems was nose wheel steering.Crew conducted ILS XR approach using non-normal landing data required by QRH. After landing; CA taxied clear of runway using differential braking & thrust as prescribed in QRH. Once clear; crew coordinated with ZZZ OPS for a tow-in the rest of the way to gate. CA made PA to update the customers on the status of tow-in to gate. Normal deplaning conducted when parked at gate.Logbook entry of corrective maintenance action to replace TRU 2."