Hybrid Power technology is actually configured by the integrated chipset graphics card to support the technology in the drive and the operating system under the control of the time when the system load using only integrated graphics chip to reduce power consumption, and when full time work load by the integrated graphics with discrete graphics cards to further enhance the efficiency of this technique one can reduce system power consumption, especially those who can benefit from a system with discrete graphics, but can also enhance the system to some extent integrated graphics performance.
HPFC (Hybrid Power Flow Controller ) Donsión Hybrid Power Flow Controller (HPFC) - Topology The Hybrid Power Flow Controller (HPFC) uses two equally rated voltage-sourced converters to upgrade the functionality of the existing switched capacitors or static VAR compensators (SVCs). Since static converters are used together with passive devices, the power flow controller can be considered hybrid 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Hybrid Power Flow Controller (HPFC) - Topology The HPFC is installed at some point along the transmission line connecting two electrical regions characterized by their Thevenin's equivalent voltage sources VS and VR. The line is thereby divided into two segments represented by the equivalent reactances XS and XR. Indices "S" and "R" identify "sending" and "receiving" end/segment of the line. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Hybrid Power Flow Controller (HPFC) - Topology Central to the HPFC's topology is the shunt connected source of reactive power – shown as the variable capacitance, in the Figure. Next, there are two voltage–sourced converters (VSCs) connected to the associated line segments in series using coupling transformers. The converters share a common DC circuit, coupling each other's DC terminals. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Hybrid Power Flow Controller (HPFC) - Topology By controlling the magnitudes and angles of voltages supplied by the converters, the flow of active power through the line and the amounts of reactive power supplied to the corresponding line segments can be simultaneously and independently controlled. The control of the shunt device is coordinated with the control of converters to supply the bulk of the total required reactive power. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión HPFC – Equivalent circuit and operating constraints 24/08/2007 HPFC (Hybrid Power Flow Controller ) The variable capacitance, labelled BM, represents the controllable shunt connected variable susceptance. The range of values this parameter can assume depends on the installed power components; in general case it can be positive (capacitive), zero, or negative (inductive). Voltage sources VX and VY represent the high voltage equivalents of voltages generated by the VSCs. The common DC circuit of the VSCs is represented by the capacitor CDC, and this capacitor is charged or discharged based on the difference of active powers coupled by the converters. First, converters' voltage ratings impose magnitude limits on VX and VY. Donsión Additionally, magnitudes of IS and IR are limited, as these currents flow through the converters' switches. Then, line insulation requires that magnitudes of voltages V1 and V2 are limited, and voltage ratings of the shunt susceptance require limited magnitude of VM. And finally, in order to operate the converters, we require that VDC is maintained at a steady value, so in steady state PX has to be equal PY. This new FACT equipment is only a proposal by J. Bebic, "A Symmetrical Hybrid Power Flow Controller", Ph.D. Thesis, University of Toronto, 2003. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión HPFC – Transformation of condition of converters' power balance 24/08/2007 HPFC (Hybrid Power Flow Controller ) Constant power line Donsión It is advantageous to provide a geometric interpretation for the condition of converters' power balance. Power is proportional to scalar product of voltage and current. Hence, for a given vector VS, sending end power PS is proportional to the projection of IS onto VS. Therefore, as depicted in the Figure. Current vectors IS1 and IS2 transfer the same sending end power, as would any other current vector that has its tip on the same line perpendicular to VS. This line may be considered a "constant power line". 24/08/2007 HPFC (Hybrid Power Flow Controller ) a) b) Donsión c) d) A procedure for solving steady state operating points based on specified PR(=PS), QS, and QR 24/08/2007 HPFC (Hybrid Power Flow Controller ) Voltage vectors VS and VR, and equal power lines corresponding to the desired power flow PR(=PS) are shown in Figure (a). Current vectors IS and IR are chosen so that their tips lie on these equal power lines. There is hence one degree of freedom in choosing the location for each vector. This degree of freedom can be viewed as freedom to select the amount of reactive power supplied from the corresponding line end. Specifying QS selects a unique IS, and specifying QR selects a unique IR. Voltages V1 and V2 are obtained by subtracting and adding Donsión voltage drops across the respective line segments, as shown in Figure (b). Next, IM and VM are obtained as shown in Figure (c). Finally, VX and VY are found as shown in Figure (d). 24/08/2007 HPFC (Hybrid Power Flow Controller ) HPFC used to reduce the power flow on a line Donsión Let us first discuss the operating point that we just found – we repeated it in the Figure. It corresponds to the power flow lower than the "naturally occurring" power flow. Notice that V1 and V2 are positioned in such way as to reduce the angular difference between the voltages VS and VR. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Maintaining the same line operating point using step changed value of BM The diagram in Figure demonstrates a possibility to maintain the same line currents for a step changed value of BM. Now, if IS and IR are to be maintained at the same value, IM has to remain the same; hence VM must be increased. The Figure demonstrates that this can be accomplished by reconfiguring the converters' voltages. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Decoupled control of QR The Figure demonstrates the decoupled control of reactive power supplied to the receiving end of the line. Converters' voltages are now configured so as to move IR along its constant power line and reduce the value of QR. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Increased power flow Increased power flow is shown in the Figure. Notice that V1 is now "below" and V2 "above" VM – resulting in the increased combined angle. As expected, the magnitudes of IS and IR are increased. 24/08/2007 HPFC (Hybrid Power Flow Controller ) Donsión Power flow reversal Finally, we show the reversal of power flow in the Figure. Relative position of VM and IM indicates that BM is inductive in this case. 24/08/2007 HPFC (Hybrid Power Flow Controller ) The steady state operating points presented by these vector diagrams show that the Hybrid Power Flow Controller has the qualitative characteristics of a UPFC. Specifically, it can control the flow of active power through the transmission line and supply the prescribed amounts of reactive power to sending and receiving segments of the line. But, while the UPFC uses a shunt connected converter, the HPFC needs only a shunt connected capacitor – a considerable Donsión advantage considering the converter costs. 24/08/2007 HPFC (Hybrid Power Flow Controller ) The P–δ curves of the HPFC and the P–δ curves of the UPFC are compared in the Figure Curves 1 and 2 correspond to the line controlled by the HPFC to maximize and minimize the power flow, respectively; Curve 3 corresponds to the line compensated by the underlying SVC; Curve 4 corresponds to the power flow on the uncompensated line; Curves 5 Donsión and 6 correspond to the line controlled by the UPFC to maximize and minimize the power flow, respectively; and curve 7 corresponds to the power flow on the line Comparison of P–&delta curves – HPFC compensated by the underlying vs. UPFC STATCOM. 24/08/2007
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