Abstract: A zonal bolt-grouting support device and method for cataclastic rock mass large deformation of a high-stress tunnel, the method includes: drill holes in surrounding rock of a tunnel against a tunnel face after rock mass excavation, install high-strength prestressed anchor members, apply a preload to anchor bolts when expansion anchoring agent is fully expanded and has a certain strength, and zonally grout the surrounding rock after stress adjustment. The high-strength prestressed anchor member comprises an anchor bolt, an expansion anchor agent, a decoupling material, a grouting device, a reverse anti-skid device, etc. The grouting device consists of a shallow grouting steel pipe, a deep grouting steel pipe and a grouting stop valve, and the grouting steel pipe is arranged side by side with the anchor bolt in a drill hole. The technical proposal of the invention effectively inhibits the large deformation of a cataclastic rock mass.

Abstract: A combined direct current circuit breaker includes a transfer branch, an energy absorption branch, at least two primary branches and at least two secondary branches; the transfer branch is connected in parallel with the energy absorption branch; the primary branches are in one-to-one correspondence with the second branches; the primary branches are connected with direct current outgoing lines of a direct current busbar in a high-voltage direct current power transmission system; the secondary branches are connected in series with the transfer branches and then connected in parallel with two ends of the primary branches corresponding to the secondary branches.

Abstract: A combined direct current circuit breaker includes a transfer branch, an energy absorption branch, at least two primary branches and at least two secondary branches; the transfer branch is connected in parallel with the energy absorption branch; the primary branches are in one-to-one correspondence with the second branches; the primary branches are connected with direct current outgoing lines of a direct current busbar in a high-voltage direct current power transmission system; the secondary branches are connected in series with the transfer branches and then connected in parallel with two ends of the primary branches corresponding to the secondary branches.