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The estimated speed is obtained only from the measurementof the main and auxiliary windings stator currents and that of areferenceq-axis current generated by the control algorithm. Aspeed estimation method is proposed to overcome the problemsof system complexity and cost. Simulation and experimental re-sults are presented to demonstrate the main characteristics of theproposed drive system. The sensorless speed control algorithmis employed in this work and is implemented at rated, low, andzero speed operation
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Voltagedips are oneof the most occurring powerquality problems. Off course, for anindustry anoutage isworse, than avoltagedip,butvoltage dips occur moreoften and cause severeproblems andeconomical losses.Utilities often focuson disturbancesfrom end-userequipment as the main powerquality problems. This iscorrectfor many disturbances, flicker, harmonics, etc., butvoltagedips mainly have their origin in the highervoltagelevels. Faults due tolightning, is one of the most commoncauses to voltagedips on overhead lines. If the economicallosses due to voltage dips are significant, mitigationactions can be profitable for the customer and even in
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Ensuring reliability of the physical power system is nolonger the only responsibility for the RTO/ISOs. Alot of theRTOs/ISOs are also responsible for operating wholesaleelectricity markets. To facilitate market transparency and toensure reliability of the physical power system, anoptimization-based framework is used to provide aneffectivecontext for defining comprehensive rules for scheduling,pricing, and dispatching. Taking advantage of themathematical rigor contained in formal optimizationmethodology, the rules are likely to be more consistent, andthus more defensible against challenges that invariably arise inany market. Congestion management via the mechanismoflocational marginal pricing (LMP) becomes an integral part ofdesign of many wholesale electricity markets throughout theworld and security-constrained economic dispatch (SCED)becomes a critical application to ensure the transmissionconstraints are respected while generation resources are beingdispatched economically. The other important aspectofmarket-based dispatch is the size of the dispatch system. Atypical system like PJM or Midwest ISO is usually more than
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The proposed interface circuit is shown inFig. 1. The main bidi-rectional buck and boost converter is composed of two bidirec-tional switches S1and S2and filter inductorL. The auxiliarycircuit is composed of a bidirectional switch Sa1, a unidirectionalswitch Sa2, two small resonant inductorsLrandLS, and a small res-onant capacitorCr. The auxiliary circuit provides the soft switchingcondition for S1and S2while its semiconductor devices are alsosoft switched. In order to simplify the theoretical analysis, it isassumed that all semiconductor devices are ideal. Also, inductorLis large enough to assume its current is constant in a switchingcycle. The converter operation is analyzed in both buck modeand boost mode
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An interesting variant of the shadowing problem is one in which the so-called shadower does not want to track or intercept the shadowee. Instead, the shadower wishes to move from its present location F (which is treated as a fixed point) to a target location (+) as illustrated in figure 4, and to do so without allowing its motion to be detected by the shadowee. The shadower can see the target, but does not know how far away it is; can this be accomplished, and if so, how? Motion camouflage dictates that the shadower be constrained to move such that it always lies on the camouflage constraint line (which, in this case, is the line connecting the instantaneous position of the shadowee to the location of the stationary object F that the shadower emulates). As before, the camouflage constraint can be achieved by using either of the algorithms described above. However, there is the additional requirement that the shadower must reach the target. To do this, the shadower must adjust its radial speed such that it has moved the correct distance away from F at the instant when the camouflage
A DPSP of 1 means that the load will never be satisfied and
the DPSP of 0 means that the load will be always satisfied.
From the above-described situations, a program is developed
in MATLAB to size the components for each configuration,
for a particular DPSP specified by the user. The
flow chart of HPWES model is illustrated in Fig. 3. In this
program, PPV,min, PPV,max and PW,min, PW,max represent
the lower and higher limits of the variation interval of
the PV and wind generator rated power, respectively. DPpv
and DPW represent the variation step of the PV and wind
power, Dt the simulation step and DSD is the step of storage
days. In this study the maximum number of storage days,
NSD = 3.
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