Synchronization and Reactive Current Support of PMSG based Wind Farm during Severe Grid Fault

ABSTRACT:

Framework codes require wind ranch to stay on-matrix and infuse explicit responsive current when network blame happens. To fulfill the prerequisites, receptive power gadgets, for example, the static synchronous compensator (STATCOM) are normally utilized in present day wind ranches. So as to create responsive flows, the breeze vitality age framework (WECS) and the STATCOM are regularly controlled with the stage bolted circle (PLL)- situated vector control strategies. Because of the dynamic power unevenness between the age and utilization, the breeze cultivate has the danger of losing synchronization with the framework under serious blame conditions. This paper investigates the dynamic synchronization system and strength criteria of the breeze cultivate and proposes a planned current control plot for the WECS and the STATCOM amid serious lattice blame period. The synchronization strength of both the WECS and the STATCOM is stayed by the dynamic power adjusting control of the breeze cultivate. The control targets of the generator-and matrix side converters for the WECS are swapped to maintain a strategic distance from the communication between the dc-interface voltage control circle and the synchronization circle. The synchronized STATCOM produces extra receptive flows to enable the breeze to cultivate meet the necessities of the network code. Adequacy of the hypothetical examinations and the proposed control technique are checked by recreations.

  

BLOCK DIAGRAM:

Fig. 1. Configuration of the PMSG-based wind farm

  

EXPECTED SIMULATION RESULTS:

Fig. 2. System response of the PMSG-based wind farm with conventional control strategy during severe fault

Fig. 3. System response of the PMSG-based wind farm with proposed strategy during severe fault

 

CONCLUSION:

This paper examined the LOS instrument and the planning LVRT plan of the PMSG based breeze cultivate when extreme lattice voltage plunge happens. The accompanying ends can be gotten from the hypothetical investigations and reproduction check:

(1) Variable-speed wind turbines and STATCOM both have the LOS chance when the matrix voltage plunge is extreme.

(2) The proposed dynamic power adjusting control conspire which depends on the recurrence dynamic of the PLL can accomplish the synchronization strength of the WECS. Be that as it may, receptive current capacity of the WECS would be yielded to actualize such plan.

(3) The organized current control between the PMSG based WECS and the STATCOM can accomplish both the synchronization strength and the responsive current help as indicated by the framework code under extreme matrix blame. The examination results and proposed conspire are likewise accessible for the LVRT of other sustainable power source change frameworks.

(4) It ought to be brought up that this paper centers around the symmetrical blame conditions. In useful applications, unsymmetrical shortcomings happen more frequently than symmetrical ones. Some Europe lattice codes, for example, “VDE-AR-N 4120” code in Germany, are requiring the WECS to give negative succession current remuneration amid unsymmetrical blame period. In such cases, the progressed PLL, for example, the second request summed up integrator (SOGI) PLL, ought to be utilized to isolate the positive and negative succession parts from the lattice voltage. The progressed PLLs have significantly more confounded structures and models contrasted and the regular one as showed in this paper. Likewise the synchronization strength ought to be talked about in both positive and negative groupings. By further considering the coupling of the PLL and control circles amid network blames comparably with the case examined in this paper, the synchronization issue would be progressively confused. More examinations are normal in this issue and would be our future work.

Power Quality Improvement of PMSG Based DG Set Feeding Three-Phase Loads

IEEE Transactions on Industry Applications, 2015

ABSTRACT: This paper presents power quality improvement of PMSG (Permanent Magnet Synchronous Generator) based DG (Diesel Generator) set feeding three-phase loads using STATCOM (Static Compensator). A 3-leg VSC (Voltage Source Converter) with a capacitor on the DC link is used as STATCOM. The reference source currents for the system are estimated using an Adaline based control algorithm. A PWM (Pulse Width Modulation) current controller is using for generation of gating pulses of IGBTs (Insulated Gate Bipolar Transistors) of three leg VSC of the STATCOM. The STATCOM is able to provide voltage control, harmonics elimination, power factor improvement, load balancing and load compensation. The performance of the system is experimentally tested on various types of loads under steady state and dynamic conditions. A 3-phase induction motor with variable frequency drive is used as a prototype of diesel engine with the speed regulation. Therefore, the DG set is run at constant speed so that the frequency of supply remains constant irrespective of loading condition.

KEYWORDS:

  1. STATCOM
  2. VSC
  3. IGBTs
  4. PMSG
  5. PWM
  6. DG Set
  7. Power Quality

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig. 1 Configuration of PMSG based DG set feeding three phase loads.

EXPECTED SIMULATION RESULTS:

 

Fig. 2. Dynamic performance at linear loads (a) vsab, isa,isb and isc ,(b) vsab, iLa,iLb and iLc (c) Vdc, isa,iLa and iCa

CONCLUSION:

The STATCOM has improved the power quality of the PMSG based DG set in terms voltage control, harmonics elimination and load balancing. Under linear loads, there has been negligible voltage variation (From 219.1 V to 220.9 V) and in case of nonlinear load, the voltage increases to 221 V. Thus, the STATCOM has been found capable to maintain the terminal voltage of DG set within ± 0.5% (220 ±1 V) under different linear and nonlinear loads.

Under nonlinear loads, the load current of DG set is a quasi square with a THD of 24.4 %. The STATCOM has been found capable to eliminate these harmonics and thus the THD of source currents has been limited to 3.9 % and the THD of terminal voltage has been observed of the order of 1.8%. Therefore, the THDs of source voltage and currents have been maintained well within limits of IEEE-519 standard under nonlinear load.

It has also been found that the STATCOM maintains balanced source currents when the load is highly unbalanced due to removal of load from phase ‘c’. The load balancing has  also been achieved by proposed system with reduced stress on the winding of the generator.

The proposed system is a constant speed DG set so there is no provision of frequency control in the control algorithm.

However, the speed control mechanism of prototype of the diesel engine is able to maintain the frequency of the supply almost at 50 Hz with small variation of ±0.2 %.

Therefore, the proposed PMSG based DG set along with STATCOM can be used for feeding linear and nonlinear balanced and unbalanced loads. The proposed PMSG based DG set has also inherent advantages of low maintenance, high efficiency and rugged construction over a conventional wound field synchronous generator based DG set.

 REFERENCES:

[1] Xibo Yuan; Fei Wang; Boroyevich, D.; Yongdong Li; Burgos, R., “DC-link Voltage Control of a Full Power Converter for Wind Generator Operating in Weak-Grid Systems,” IEEE Transactions on Power Electronics, vol.24, no.9, pp.2178-2192, Sept. 2009.

[2] Li Shuhui, T.A. Haskew, R. P. Swatloski and W. Gathings, “Optimal and Direct-Current Vector Control of Direct-Driven PMSG Wind Turbines,” IEEE Trans. Power Electronics, vol.27, no.5, pp.2325-2337, May 2012.

[3] M. Singh and A. Chandra, “Application of Adaptive Network-Based Fuzzy Inference System for Sensorless Control of PMSG-Based Wind Turbine With Nonlinear-Load-Compensation Capabilities,” IEEE Trans. Power Electronics, vol.26, no.1, pp.165-175, Jan. 2011.

[4] A. Rajaei, M. Mohamadian and A. Yazdian Varjani, “Vienna-Rectifier-Based Direct Torque Control of PMSG for Wind Energy Application,” IEEE Trans. Industrial Elect., vol.60, no.7, pp.2919-2929, July 2013.

[5] Mihai Comanescu, A. Keyhani and Dai Min, “Design and analysis of 42-V permanent-magnet generator for automotive applications,” IEEE Trans. Energy Conversion, vol.18, no.1, pp.107-112, Mar 2003.