DC21 Brake Upgrade for Endurance E-series Turbines
DC21 has developed a new braking system for the Endurance E-series wind turbine.
This upgrade has a number of advantages that will reduce the strains placed on the turbine compared to the original braking system.
After nearly 2 years of development, the system is now available for the E-3120 wind turbine.
DC21’s system employs a hydraulic caliper and a ventilated disc to provide a progressive actuation of the braking event.
The original E-series Turbine brakes
The original brakes on the E-series turbines use a pair of spring applied / air off calipers. These Branham PFS calipers originate from the locomotive industry and can best be described as binary and mechanically unsympathetic.
Branham recommends these calipers for intermittent, holding, and emergency use.
As the pads wear the travel to make contact with the disc increases, and as a result, the friction decreases.
This means that the brakes have to be reshimmed regularly and have to be setup to stop the turbine in all conditions. The result is a sharp high torque brake event every time.
The brakes cannot be applied gradually, but are applied in full, as dictated by the force applied by the spring.
Endurance Wind Power tried various strategies to adjust the flow of air out of the calipers, but the results are far from desirable or consistent.
The rapid and often violent brake events that result from the way the standard brakes operate, place the following components under stress:
- Gearbox – maximum capacity is 1250Nm, brakes routinely apply 1000-1100Nm
- Low speed shaft, connection to gearbox and connection to rotor – these are both friction connections which can spin in violent stops
- Bedplate
- Rotor and blades, resulting in fatigue to the hub and blade holders
- Tower
DC21 Endurance Turbine braking solution
DC21’s system employs a hydraulic caliper and a ventilated disc to provide a progressive actuation of the braking event.
The pressure applied to the brake caliper is varied depending on the wind speed. In addition, the brake pressure is reduced as the rotor slows down. This significantly reduces the stresses placed on various turbine components.
Watch this video to see the latest braking system in action and for a direct comparison between the original braking system and the new improved hydraulic wind turbine brakes developed by DC21.
The original brakes are retained for parking the turbine safely and as an ultimate safety measure in the event of a hydraulic brake failure.
| Original EWP brakes | DC21 Brakes | |
|---|---|---|
| Brake event characteristics | 900-1100Nm for all brake events and for the full brake event 2-3 s brake event duration |
800Nm at full output reducing to 400Nm. 350Nm at under 5m/s reducing to 200Nm. 10-15s brake event duration |
| Servicing | Regular brake re-shims to ensure the turbine stops when needed. Replacement brake pads £250 |
No re-shimming required Replacement brake pads every 5,000 hours Replacement brake pads £100 |
Availability – E-series Endurance turbine brakes
The system is now available to purchase for the E-3120 wind turbine.
For the E-4660 turbine, the same control strategy can be applied, but revised caliper and disc hardware is needed. DC21 will support this if there is sufficient interest from E-4660 owners.
E-3120 Products, Upgrades & Repairs
E-3120 Low speed shaft (LSS)
DC21 can offer a new LSS that has been designed and manufactured in the UK. The design has several key features.
E-3120 Bedplate
DC21 can provide an alternative to replacing the bedplate by delivering a reinforced bedplate at a fraction of the cost of a new bedplate.
E-3120 Hub refurbishment
DC21 can provide complete refurbishment of the E-3120 hub, our hub removal tooling means there is very little risk of having to purchase a new hub.
Spring tubes
DC21 are pleased to offer the Serenity Wind spring tube upgrade with all E-3120 and E-4660 models. These spring tubes come with a 5 year insurance backed limited warranty.
E-3120 oil filtration
DC21 can offer a complete oil filtration retrofit for those E-3120s that did not benefit from oil filtration from new. Our kits come with the all important oil level switch system to protect the gearbox in the event of loss of oil.
E-3120 Reaction Arm
DC21 have worked with Nordlock to develop the Reaction Arm Expander pin for the E-3120.
E-3120 Gearbox Repair
Fast, efficient and cost effective E-3120 gearbox overhaul and repair from DC21. We hold complete gear sets in stock to enable a rapid repair
E-3120 Brake Upgrade
New wind turbine braking system for the Endurance E-series that will reduce the strains placed on the turbine compared to the original braking system.