The protection of generators over the past fifty years has evolved from discrete or single function electromechanical relays to static (electronic) single function protection relays and finally to multifunctional digital protection systems. Beckwith Electric began manufacturing protection during the static protection era. Through cooperative efforts with the Gas Research Institute, the multifunctional digital relay was developed.
The Pride Relays used for interconnection of distributed generation contained of the protection functions used to protect generator and launched Beckwith into the generator protection business. Company founder, Robert W. Beckwith immediately saw the future of protective relay to be low cost highly reliable multifunction digital relays
Fast forward to today…
The industry’s application of multifunction generator protection relays, combined with recent developments in providing more sophisticated and innovative protection functions required for utility-sized generators, has lead Beckwith to the forefront of modern generator protection systems. These new protective features include field ground fault detection (64F) using an injection approach, brush liftoff detection (64B) to detect high-resistance brush contact with the rotor shaft and out-of-step protection (78).
Commissioning multifunction digital relays and motor bus transfer controls offers some unique challenges to the user. Multifunction relays have protective functions that interact with each other, making testing more complicated. They can also be programmed to do control logic, which must be verified. In addition, digital relays can have multiple setting groups that may be switched to address varying system conditions. This flexibility increases the commissioning complexity. Beckwith relays have significant input monitoring capability and integral graphic commissioning tools that greatly assist the user in determining whether these relays are set properly and are properly connected to their CT and VT inputs. This reduces commissioning time and helps to verify that the relay is functioning properly.
Important Digital Relay Features
Multifunction digital relays have features that were not available on electromechanical or static relays. These include:
- Oscillography and event recording – The capability of storing analog data and sequence of events allows the user to quickly analyze tripping events.
- Multiple Setting Groups – This allows a user to select different settings for different operating conditions.
- Multiple Output & Input Contacts – This allows the user increased flexibility in designing trip/alarm output circuitry. Programmable inputs allow the user to block or alter settings based on circuit breaker open/close status or other external conditions.
- Metering –Depending on the display capability and accuracy, the protection package may displace or supplement traditional metering. The metering capability also allows easier testing of the relay and its associated wiring.
- Monitoring – Monitoring of external inputs/outputs, such as trip circuits, enhances security. Current and voltage transformer circuits can be monitored and abnormal condition detected.
- Communications – Local and remote communication capabilities allow easy input of settings and changes, as well as access to event data. With the proper interface/protocol conversion, the relay can be integrated with other intelligent devices into a distributed control system.
- Self-Monitoring and Diagnostics – Self-monitoring software in relays allows detection of a failure of a major piece of hardware or a software module. The relay outputs can be disabled and an alarm generated, signaling the failure.
- Programmable Logic – With all the information brought to the relay, programmable logic permits a combination of protection and control functions within the relay. This can eliminate significant wiring external to the relay, but increases the complexity of testing the relay to verify internal relay control logic.
With thousands of Generator Protection, Motor Bus Transfer, Synchronizing and Transformer Protection Relays engineered, installed and properly working in the field, Beckwith Electric has the best expertise in the industry to supply Power Plant Owners with engineered protection products and systems.
Beckwith’s in-depth knowledge of power systems and the application of protection systems allow the Customer Technical Support team to rapidly and efficiently assist a client with the selection and use of the proper element, product or engineered system to provide the right solution now and in the future. Beckwith protection systems are specifically designed to meet the latest industry standards.
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