Synchronous Generators and Associated Control Equipment Datasheets Required for Power System Transient Stability Studies SABP-P-006
The purpose of this Practice is to streamline the process of receiving and compiling equipment data provided by manufacturers. Template datasheets for synchronous generator dynamic data and associated machine control equipment data are provided in this document ready to be filled by the manufacturers. These dynamic data are required for performing power system stability and other system studies.
This Best Practice provides template datasheets to be filled by equipment manufacturers of generating units, as well as the associated equipment necessary to operate and control electrical power generation. This compilation is a collection of publicly available data and conforms to the PSS/E format. This collection by no means represents all the available equipment in the market today. The advent of new technologies and the advancement of microprocessor- based controllers will continually lead to the introduction of newer equipment, and therefore, the intent is to periodically update this compilation. Furthermore, many equipment are no longer manufactured, hence some were omitted from the provided list. The goal of this practice is to provide a handy standardized forms and to facilitate and speed up the process of conducting power system stability studies.
References
Industry Codes and Standards American National Standards Institute
ANSI C50.10 Rotating Electrical Machinery – Synchronous Machines
ANSI C50.12 Requirements for Salient-Pole Synchronous Generators
ANSI C50.13 Rotating Electrical Machinery – Cylindrical-Rotor Synchronous Generators
ANSI C50.14 Requirements for Combustion Gas-Turbine- Driven-Cylindrical-Rotor Synchronous Generators
American Petroleum Institute
API STD 546 Brushless Synchronous Machines – 500 kVA and Larger
Institute of Electrical and Electronics Engineers, Inc.
IEEE 115 Test Procedures for Synchronous Machines
IEEE 421A Guide for Identification, Testing and Evaluation of the Dynamic Performance of Excitation Control Systems
IEEE 421.1 IEEE Standard Definitions for Excitation Systems for Synchronous Machines
International Electrotechnical Commission
IEC 60034 Series Rotating Electrical Machines
National Electrical Manufacturer’s Association
NEMA MG 1 Motors and Generators
When soliciting bids for generation plants, or once a particular manufacturer is selected, the provided datasheets serve as a template to be given to those manufacturers to fill and return to Saudi Aramco. The datasheets cover the following types of equipment:
Synchronous Generator and Step-up Transformer Data
Regardless of the manufacturer of a generating unit or HV power transformers, the type of parameters of these equipment is pretty much the same. Therefore, no specific frame type or model is identified in this document. Rather a single datasheet is provided for the synchronous generator and for the GSU transformer. Those are the only data required for system studies.
Excitation System and Power System Stabilizer Data
Identify appropriate IEEE model block diagram of excitation system and power system stabilizer (PSS) for computer representation in power system stability simulations and the corresponding excitation system and PSS constants for use in the model.
Governor System Data
Identify appropriate IEEE model block diagram of governor system for computer representation in power system stability simulations and the corresponding governor system constants for use in the model.
Definitions
What is Automatic Generation Control (AGC):
The automatic regulation of the power output of electric generating facilities within a prescribed range in response to a change in system frequency, or tie-line loading, to maintain system frequency or scheduling interchange with other areas within predetermined limits.
What is AVR System Automatic Voltage Regulator of generation units.
What is Base Load Plant: Capacity used to serve an essentially constant level of customer demand. Base load generating units typically operate whenever they are available, and they generally have a capacity factor that is above 60%. Base load is the minimum amount of electric power delivered or required over a given period at a constant rate.
What is Black Start Capability The ability of a generating unit or station to go from a shutdown condition, following a system blackout, to an operating condition and start delivering power without assistance from the power system.
What is Capacity Factor: The ratio of the total energy generated by a generating unit for a specified period to the maximum possible energy it could have generated if operated at the maximum capacity rating for the same specified period, expressed as a percent.
What is Cogeneration: The sequential production of electricity and heat, steam, or useful work from the same fuel source.
What is Combined-Cycle: An electric generating technology in which electricity and process steam is produced from otherwise lost waste heat exiting from one or more combustion turbines. The exiting heat is routed to a conventional boiler or to a heat recovery steam generator for use by a steam turbine in the production of electricity. This process increases the efficiency of the electric generating unit.
What is Current: A flow of electric charge in an electrical conductor. The strength or rate of movement of the electricity is measured in amperes.
What is Exciter: A direct current generator that provides current for the field of an alternating current generator. It can provide DC current by use of a commutator or solid state diodes.
What is Excitation System Control:
Part of the AVR systems which adjusts the field current excitation in the rotor of the generator in order to keep terminal voltage constant.
Frequency: The number of cycles occurring in a given interval of time (usually one second) in an electric current. Frequency is commonly expressed in Hertz (Hz); one Hz equals one cycle per second.
What is Generator: The physical electrical equipment that produces electric power.
What is Generator Controls: This includes speed governing and voltage regulation systems. The main purpose of these control systems is to act on dynamical changes in the system, such as load changes, in order to minimize voltage and frequency deviations. Thus their operation is essential in ensuring quality of supply and the secure operation of power plants.
What is Generator Step-Up (GSU) Transformer:
Use Delta/Grounded-Wye connections for step-up transformers. The High-Side is solidly-grounded Wye (with no impedance). With this arrangement, 3rd harmonic and zero-sequence quantities do not pass through the transformer from one side to the other. Grounded side has enough zero sequence current to operate ground relays for a wide range of earth faults.
What is Governor:A control system apparatus which adjusts the flow to the turbine driving the generator in order to keep rotor speed constant.
Hertz (Hz): The term denoting cycles per second or frequency.
IEEE (The Institute of Electrical and Electronics Engineers):
Among other things, the IEEE develops technical standards applicable to the electric industry including relays, transformers, and metering.
What is Lagging Power Factor: Occurs when reactive power flows in the same direction as real power. Stated with respect to the generator, lagging power factor occurs when the generator is producing Vars.
What is Leading Power Factor: Occurs when reactive power flows in the opposite direction to real power. Stated with respect to the generator, leading power factor occurs when the generator is absorbing Vars.
What is Peaking Plant: A peaking plant is usually a simple cycle gas turbine generator, which generally operates for few hours per year during peak demand. Capacity factor of peaking generating units is normally less than 20%.
What is Power Factor: The ratio of real (MW) power to apparent power (MVA). Power factor is the cosine of the phase angle difference between the current and voltage of a given phase.
What is Power Plant: A facility at which are located prime movers, electric generators, and auxiliary equipment for converting mechanical, chemical, and/or nuclear energy into electric energy. A plant may contain more than one type of prime mover.
Power System Stabilizer (PSS):
A device that adds power system damping and excitation limiter functionality to synchronous generators. As part of the AVR system, the PSS adds damping to oscillations, typically through a phase lead-lag compensation circuit, in order to maintain power system stability.
What is Prime mover: The engine, turbine, water wheel or similar machine that drives an electric generator.
What is Reactive Power: The portion of electricity that establishes and sustains the electric and magnetic fields of alternating-current equipment. Reactive power must be supplied to most types of magnetic equipment, such as motors and transformers. It also must supply the reactive losses on transmission facilities. Reactive power is provided by generators, synchronous condensers, or electrostatic equipment such as capacitors, and directly influences electric system voltage. It is usually expressed in kilovars (kVAR) or megavars (MVAR).
What is Real Power: The rate of producing, transferring or using electrical energy, usually expressed in kilowatts (kW) or megawatts (MW). Watts AC = volts x amperes x power factor (single- phase circuits).
What is Self-excited: A term to describe an electric machine in which the field current is secured from its own armature current. In the case of induction generators, it refers to the condition in which the induction generator is separated from its normal excitation source and is unintentionally excited by the power-factor correction capacitors in the vicinity.
Separately Excited: Use of an exciter for sending current through the field windings of an electric machine in place of taking the field current from its own armature current.
Star-Connected Circuit (“Y” Connected Circuit):
A term applied to the manner in which a motor’s windings or a transformer’s windings are connected, i.e., star- connected armature having one end of each of the coils connected to a common junction. A star-connected transformer is one in which the primaries and secondaries are connected in a star grouping.
Simple Cycle: Generation of electricity by operation of a gas turbine without the resulting heat as useful thermal energy. Contrast with Combined Cycle.
What is Step-Down Transformer:
A transformer in which the secondary winding has fewer turns than the primary, so that the secondary delivers a lower voltage than is supplied to the primary.
What is Step-Up Transformer: A transformer in which the secondary winding has more turns than the primary, so that the secondary delivers a higher voltage than is applied to the primary.
Stability: The ability of an electric system to maintain a state of equilibrium during normal and abnormal system conditions and following disturbances. The stability of a power system is its ability to develop restoring forces equal to or greater than the disturbing forces so as to maintain a state of equilibrium.
Synchronism: Expresses the condition across an open circuit wherein the voltage sine wave on one side matches the voltage sine wave on the other side in frequency and without phase angle difference.
What is Transformer: An electric device, without continuously moving parts, in which electromagnetic induction transforms electric energy from one or more other circuits at the same frequency, usually with changes in value of voltage and current.
What is Turbine: A machine for generating rotary mechanical power from the energy of a stream of fluid (such as water, steam, or hot gas). Turbines convert the kinetic energy of fluids to mechanical energy through the principles of impulse and reaction, or a mixture of the two.
Voltage: A measure of the energy required to move a charge from one point to another. A difference in the amount of an electric charge between two points creates a difference in potential energy, measured in volts, which causes electrons to flow from an area with more electrons to an area with fewer, producing an electric current.
Volt-Ampere: A unit of apparent power in an alternating-current circuit.
Equal to the product of volts and amperes without reference to the phase difference, if any. At unity power factor, a volt-ampere equals a watt. Whenever there is any phase difference between voltage and current, the true power in watts is less than the apparent power in volt- amperes.
What is Voltage Ratio of Transformer:
The ratio of the effective primary voltage to the effective secondary voltage of a transformer.
Synchronous Generator and GSU Transformer Data
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- Generator Data
| MVA | kV | pf | Frequency | Connection (Y/delta) | Speed |
Xd, Xq, X’d, X’q, X”d, X”q, Xl, H, and D are in pu, machine MVA base.
Curves
The manufacturer should also provide the following Curves:
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- Saturation Curve
- V (Vee) Curve
- Reactive Capability Curve
- Capacity Temperature Correction Curves.
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Generator Step-Up Transformer Data
| Parameter | Value |
| HV rated voltage (kV) | |
| LV rated voltage (kV) | |
| MVA rating (OA/FA/FA) | |
| Connection (HV-LV) | |
| Taps HV (%) | |
| Positive sequence impedance (on self-cooled MVA rating) | |
| X/R ratio | |
| Zero sequence impedance (on self-cooled MVA rating) | |
| X/R ratio |
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