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This paper presents a synchronous machine model designed to simulate internal ground faults along the stator windings. The purpose of this model is to help to set the 100 % stator ground fault protection based on the measurement of the third harmonic in the grounding resistor. The setting of the above protection is not easy, as the third harmonic in the generator depends on the operation point and...
Experience with connecting farm biogas generation to rural distribution feeders in Ontario has revealed several challenges with electrical protection. The biogas projects are small (<;500kW), synchronous, farm-based, and looking for an affordable protection solution involving the use of only low-voltage equipments. The utility feeders are generally at the 8.3kV and 12.5kV voltage levels, can involve...
This paper investigates the settings of the generator out of step protection relays (ANSI device 78) for all six gas and steam turbine generators used in a grid connected CHP power plant. Detailed model of the CHP power system is developed in PSCAD/EMTDC tool which includes a representation of the synchronous generator, turbine governor, Automatic Voltage Regulator (AVR), Power System Stabilizer (PSS),...
Selection of the DG interconnection protective relay is based on several criteria such as power system characteristics, the dynamic response of the generator, the system grounding, the DG transformer connection, etc., as well as the protection policy of the utility and coordination requirements. The interconnection protection IED design can be summarized as follows: Disconnection of DG plants when...
Generators are critical components of the power system. In addition to being some of the most expensive pieces of equipment on the system, they are also extremely critical to power system stability. A false trip can lead to extensive testing in search of a nonexistent fault, while a delayed trip can result in unnecessary additional damage to equipment. Both misoperations result in excessive equipment...
A black start is the process of restoring a power station to operation without relying on external power sources. Normally, the electric power used within the plant is provided from the station generators. The high-voltage grid provides station service power through the transmission lines if all the main generators are shut down. This off-site power source is not available during a wide-area outage...
This paper presents the experience of the authors in the Design, Engineering, Testing and Implementation of electrical systems for large Gas Processing Plants. The following areas are covered in this paper: 1. Design Criteria for electrical systems 2. Constraints in design & engineering of electrical systems for large plants 3. Development of Protection Control & Power Management system philosophies...
Coordination between generator overcurrent voltages controlled relays (51 V) and transmission line directional overcurrent relays (67) represent a tedious task in power system protection. It depends heavily on network behavior and system parameters. Mis-coordination is sometimes happened between the two relays. In this paper an intelligent modular protection system is proposed for relays parameter...
Experience with connecting farm biogas generation to rural distribution feeders has revealed that a particular costly barrier can be protection against unplanned islanding. When the size of the generation is small compared to the load on the feeder, the cost of anti-islanding protection is very small. However, once a certain size threshold is reached, alternative protection methods are required, and...
Generation stations are considered extremely vital part of power system. Overcurrent voltage controlled relays are extensively used as backup protection of generators. Coordination between generator overcurrent voltage controlled relays and transmission line directional overcurrent relays represents a tedious task in power system protection as it depends heavily on network topology and system parameters...
The PacifiCorp Jim Bridger Power Plant has 2.2 GW of installed capacity and is connected to the main grid by three 345 kV series-compensated lines. These lines are, on average, over 200 miles long. In order to operate at full capacity and maintain stability during a system contingency, Jim Bridger requires a generation-shedding remedial action scheme (RAS). PacifiCorp is modernizing and upgrading...
This paper presents a new integrated protection relay and its associated scheme for distributed generation systems. In the scheme, an integrated relay is responsible for the protection of both line sections associated with the substation bus. Based on conventional directional overcurrent protection technique, the basic principle of the new relay is to determine whether a fault is on the protected...
Loss-of-mains (LOM) protection is a safety requirement for distributed generators intending to prevent unintentional islanded operation of a section of the distribution network. With increased numbers of small and medium scale generators connected to the system the correct operation of the LOM protection becomes critical. This paper proposes a new countrywide solution for the detection of islanded...
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