We will explain these components one by one 81 Microgrid in GridConnected Mode

We will explain these components one by one 81

This preview shows page 81 - 86 out of 106 pages.

We will explain these components one by one. 81 Microgrid in Grid­Connected Mode Inverter control diagram for regulating power exchanges with the utility grid
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Power Controller (Reference Current Calculator): We assume: The instantaneous power components are passed through low­pass filters to eliminate high frequency harmonics and obtain the real and reactive powers P and Q corresponding to the fundamental component. ω c represents the cut­off frequency of low­pass filters. So Then, Equivalently, 82 Microgrid in Grid­Connected Mode o oq od o oq od v v jv i i ji ± ± o od od oq oq o od oq oq od p v i v i q v i v i ± ³ ² ² c o c od od oq oq c o c od oq oq od s P v i v i s Q v i v i Z Z Z Z ± ± ± ³ d d d d o c o c od od oq oq o c o c od oq oq od P P v i v i t Q Q v i v i t Z Z Z Z ³ ± ± ³ ± ³ , c c c c P p Q q s s Z Z Z Z ± ± ² ²
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Power Controller (Reference Current Calculator): The corresponding small signal equations are Or where If the power controller (for matching with ) is a “proportion plus integral (PI)” controller, the power controller transfer function is 83 Microgrid in Grid­Connected Mode 0 0 0 0 0 0 0 0 o c o c od od c od od c oq oq c oq oq o c o c od oq c oq od oq od od oq P P v i i v v i i v Q Q v i i v v i i v Z Z Z Z Z Z Z Z x x ' ³ ' ± ' ± ' ± ' ± ' ' ³ ' ± ' ± ' ³ ' ³ ' o PQ o PQi odq PQvo odq PQ A PQ B i B v x ' ' ± ' ± ' 0 0 0 0 0 0 0 0 0 , , 0 c c od c oq c od c oq PQ PQio PQvo c oq c od c oq od v v i i A B B v v i i Z Z Z Z Z Z Z Z ª º ª º ³ ª º « » « » « » ³ ³ ³ « » « » ¬ ¼ ¬ ¼ ¬ ¼ ( ) ( ) ip p pp iq q pq K G s K s K G s K s ± ± o PQ ref o PQ
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Power Controller (Reference Current Calculator): So, in time domain, the output of this controller is obtained If we denote, Then In addition, assign , and we have . So, where 84 Microgrid in Grid­Connected Mode d ref ref P pP o o iP o o K P P K P P t H ³ ± ³ ³ d ref ref Q pQ o o iQ o o K Q Q K Q Q t H ³ ± ³ ³ ref PQ I d d , d d q ref ref d o o o o P P Q Q t t I I ³ ³ , ref ref P pP o o iP d Q pQ o o iQ q K P P K K Q Q K H I H I ³ ± ³ ± ref ld P ref Q lq i i H H ª º ª º « » « » « » ¬ ¼ ¬ ¼ ref ref ld pP o o iP d ref ref lq pQ o o iQ q i K P P K i K Q Q K I I ª º ª º ³ ± « » « » ³ ± « » « » ¬ ¼ ¬ ¼ 1 2 ref ref ldq V dq V o V o i C D PQ D PQ I ª º ª º ' ' ± ' ± ' ª º ¬ ¼ ¬ ¼ ¬ ¼ 1 2 0 0 0 , , 0 0 0 iP pP pP V V V iQ pQ pQ K K K C D D K K K ³ ª º ª º ª º « » « » « » ³ ¬ ¼ ¬ ¼ ¬ ¼
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Current Controller: This would be the same as islanding mode section: where Along with where 85 Microgrid in Grid­Connected Mode 1 2 ldq ref ref idq C dq C ldq C odq odq i v C D i D v i J ' ª º « » ª º ª º ' ' ± ' ± ' ª º ¬ ¼ ¬ ¼ ¬ ¼ « » « » ' ¬ ¼ 1 2 0 0 , 0 0 0 0 0 0 0 0 0 0 pc ic C C pc ic pc n f C n f pc K K C D K K K L D L K Z Z ª º ª º « » « » ¬ ¼ ¬ ¼ ³ ³ ª º « » ³ ¬ ¼ Current controller diagram 1 2 0 ldq ref dq dq C ldq C odq odq i B i B v i J J ' ª º ª º « » ª º ' ' ± ' ± ' ª º ¬ ¼ ¬ ¼ « » « » ¬ ¼ « » ' ¬ ¼ .
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  • Spring '14
  • MohammadShahidehpour
  • Trigraph, Electric power, Electricity distribution

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