Power Flow Control Solutions for a Modern Grid Using SMART Power Flow Controllers. Kalyan K. Sen
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Название: Power Flow Control Solutions for a Modern Grid Using SMART Power Flow Controllers
Автор: Kalyan K. Sen
Издательство: John Wiley & Sons Limited
Жанр: Физика
isbn: 9781119824381
isbn:
1.6.1 Example of an SPFC
In a particular application, the functional requirement of an SPFC may be written as follows:
The SPFC shall provide voltage regulation, phase angle regulation, positive and negative resistance regulation, capacitive and inductive reactance regulation, four‐quadrant impedance regulation, and independent regulation of active and reactive power flows in a line by connecting in series with the line a compensating voltage that has the following characteristics:
Figure 1-36 Interconnected transmission system, integrated with a SMART Power Flow Controller (SPFC).
1 variable in magnitude within its design limit
2 variable in phase angle with respect to the line voltage or the prevailing line current
3 response time in the range of operation in less than 30 seconds
4 availability of 99.9999% of the time.
1.6.2 Justification
The natural power flow in an AC transmission line depends on (i) line voltage magnitude, (ii) its phase angle, and (iii) line impedance. The power flow in a line may be controlled by regulating any of these three parameters to optimize the voltage profile and the power flow in the line while maintaining the voltage stability and minimum power loss in the line.
1.6.3 Additional Information
The desired features of an SPFC are as follows:
High reliability with the lowest number of components used
Impedance control feature using a Shunt–Series configuration
Lowest installation cost
Lowest operating cost with minimum maintenance and losses
Practically relocatable when the system needs change
Free from component obsolescence for at least three decades, and
Interoperability so that components from various suppliers can be used, resulting in a global manufacturing standard, ease of maintenance, and ultimately lower cost to consumers.
To meet the above‐mentioned functional requirements, thyristor‐based SVC and transformer/LTCs‐based ST may be a suitable solution as shown in Figure 1-37. Since the proposed solution is based on functional requirements and the lowest cost, it is considered to be an SPFC.
Figure 1-37 Voltage regulation with an SVC and independent power flow regulation with an ST.
1.7 Discussion
Various compensators for utility applications are summarized in Table 1-3. The features, advantages, and benefits of various solutions are listed in Table 1-4. The objective of using any of these solutions is to increase utility asset utilization.
It is recognized that the superior response capability of a power electronics inverter‐based solution may be beneficial in applications where a voltage flicker, caused by an electric arc furnace load, needs to be reduced and dynamic voltage stability is required for critical loads. The final selection of a solution, however, depends on knowing the functional requirements and analyzing the cost and benefit of each available solution to determine the cost‐effective solution that provides the most features at the least total cost. In the case of a simple voltage regulation at a utility bus, a SC may be an adequate solution, whereas for an arc furnace type of constantly variable load, the power electronics VSC‐based STATCOM may be the best solution.
With the introduction of the first commercial STATCOM at TVA in 1995, it was anticipated that the power electronics VSC‐based voltage regulation technique would be the new wave of the future. Instead, rotating machinery‐based SynCons are being installed to provide some inertia to the power grid, since the grid is now becoming heavily loaded with IBRs that convert renewable wind and solar energy into usable AC electricity. Note that the IBRs do not have any mechanical inertia that is available in rotating machinery‐based conventional power grid. In the meantime, many of the nine inverters from the first‐generation FACTS Controllers were decommissioned prematurely due to component obsolescence and without much payback.
Table 1-3 Various compensators for utility applications.
| Compensators | Commercial names |
|---|---|
| Non‐power electronics‐based technology | Transformer and LTCs‐based Voltage‐Regulating Transformer (VRT) and Phase Angle Regulator (PAR), reactors/capacitors, Synchronous Condenser (SynCon), motor/generator, and Sen Transformer (ST) |
| Power electronics thyristor‐based technology | Static Var Compensator (SVC) and Thyristor‐Controlled Series Capacitor (TCSC) |
| Power electronics VSC‐based technology | STATic synchronous COMpensator (STATCOM), Static Synchronous Series Compensator (SSSC), and Unified Power Flow Controller (UPFC) |
Table 1-4 Features, advantages, and benefits of various solutions.
| Solutions | Feature(s) | Advantage | Benefit |
|---|---|---|---|
| Shunt Reactor/Shunt Capacitor, VRT, SynCon, TCR, TSC, SVC, STATCOM | Voltage regulation | Meets operating voltage requirement of the load | Higher asset utilization |
| PAR | Phase angle regulation | Power flow magnitude and direction control | |
| Series Reactor/Series Capacitor, TCSC, SSSC | Reactance regulation | ||
| ST, UPFC | Voltage regulation, phase angle regulation, and impedance regulation |
The power industry’s pressing need for the most economical ways to transfer bulk power along a СКАЧАТЬ