Direct Power Control of Pulse Width Modulated Rectifiers without DC Voltage Oscillations under Unbalanced Grid Conditions


Direct power control with space vector modulation (DPC-SVM) highlights straightforward structure, quick unique execution and small tuning work. Be that as it may, regular DPC-SVM can not accomplish exact power control under lopsided matrix conditions. An altered DPC-SVM is subsequently proposed for exact power control under both perfect and lopsided framework conditions. In spite of the fact that control precision is enhanced when contrasted and ordinary DPCSVM, regardless it endures profoundly mutilated framework current and DC voltage motions with an uneven system. In this manner, a power pay strategy is along these lines inferred going for the accompanying targets: taking out DC voltage motions, accomplishing sinusoidal matrix current and acquiring solidarity control factor. With that in mind, normal matrix side responsive power and motions in converter-side dynamic power are controlled as zero by essentially adding a pay to unique power reference. Moreover, the proposed technique does not require extraction of positive succession or negative arrangement part of framework voltage. Contrasted and traditional DPC-SVM in perfect network, just extra remuneration of intensity reference is required. Thus, control execution can be essentially enhanced without generous increment of unpredictability. The prevalence of the proposed technique over the earlier DPC-SVM is approved by both reenactment and trial results acquired on a two-level PWM voltage source rectifier.



Fig. 1. Control diagram of the proposed DPC-SVM.



Fig. 2. Simulation results of Uabc, Pin, Pref , Qin, Qref and Iabc for (a) the MDPC-SVM and (b) CDPC-SVM.

Fig. 3. Simulation results of Uabc, Pin, Pref , Pout, Udc and Iabc for (a) MDPC-SVM-PC and (b) MDPC-SVM

Fig. 4. Simulation results of MDPC-SVM-PC when 50% voltage dip in phase A is suddenly applied.

Fig. 5. Simulation results of MDPC-SVM-PC when both R and L in the controller are (a) 50% and (b) 150% of their actual value.

Fig. 6. Simulated results of MDPC-SVM-PC under one phase grounding fault.



In existing writing, most investigations on DPC-SVM were done under adjusted matrix voltage conditions. Under lopsided lattice voltage conditions, the consistent state execution of DPC-SVM are genuinely weakened by showing profoundly contorted current and motions in the DC-interface voltage. To adapt to these issues, this paper proposes a novel DPC-SVM strategy, which can work successfully under both adjusted and unequal lattice conditions. A fitting force remuneration is inferred, which just requires the matrix/converter voltages and their deferred qualities. By adding this power pay to the first power references without altering the inner control structure, consistent DC-connect voltage and sinusoidal network flows are accomplished at the same time without influencing the normal estimation of gridside dynamic power and receptive power. The proposed DPC-SVM is contrasted with customary DPC-SVM and its viability is affirmed by the displayed reproduction and trial results.

Because of extra figuring of intensity pay, intricacy of the proposed DPC-SVM is higher than customary power control plans. Be that as it may, twice network voltage recurrence motions can be totally disposed of in principle by the proposed strategy under unequal matrix conditions, which is valuable to the lifetime and support of capacitors. Despite the fact that utilizing a bigger capacitor can likewise decrease DC voltage swells, it might expand equipment cost and volume of the framework. In this sense, the proposed technique is progressively appropriate for the application where an excellent DC voltage is required under lopsided framework conditions.

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