【摘要】：目前,分布式發(fā)電(Distributed Generation, DG)大量地引入電網(wǎng)中,有效地減小環(huán)境污染、降低能量損耗、提高了電力系統(tǒng)可靠性和靈活性。為了充分發(fā)揮分布式發(fā)電技術(shù)的優(yōu)勢,協(xié)調(diào)配電網(wǎng)與分布式電源之間的矛盾,將分布式電源、負(fù)荷、儲能裝置及控制裝置組成微電網(wǎng),并合理的接入配電網(wǎng)。然而分布式電源接入將對配電網(wǎng)保護(hù)帶來較大的影響,傳統(tǒng)的故障檢測方法和繼電保護(hù)模式很難滿足電網(wǎng)安全運(yùn)行的需要,因此,研究微電網(wǎng)及其對配電網(wǎng)保護(hù)影響和相關(guān)保護(hù)算法具有重要意義。 論文綜述了含分布式電源的配電網(wǎng)保護(hù)方法。分析了經(jīng)逆變器接口分布式電源的特點(diǎn),結(jié)合逆變器在dq旋轉(zhuǎn)坐標(biāo)系下的數(shù)學(xué)模型,研究了恒功率控制(PQ控制)和恒壓恒頻控制(VF控制)的逆變器控制策略,進(jìn)而構(gòu)成PQ控制與VF控制相結(jié)合的微電網(wǎng),使其既可運(yùn)行于并網(wǎng)模式又可運(yùn)行于孤網(wǎng)模式,且在模式切換時(shí)無需改變逆變器的控制策略。 其次,基于Digsilent軟件,建立了PQ控制、VF控制分布式電源的仿真模型,并驗(yàn)證了模型的正確性。用PQ控制分布式電源模擬光伏發(fā)電,VF控制分布式電源模擬蓄電池,再加入同步發(fā)電機(jī)和負(fù)荷構(gòu)成微電網(wǎng),通過仿真驗(yàn)證了微電網(wǎng)建模的正確性。 接著,研究了同步分布式電源接入配電網(wǎng)對電流保護(hù)、距離保護(hù)和重合閘的影響；研究了經(jīng)逆變器接口分布式電源(Inverter Interfaced DG,ⅡDG)和微電網(wǎng)接入對配電網(wǎng)電流保護(hù)的影響,通過仿真驗(yàn)證了理論分析的正確性。 針對分布式電源接入對電流保護(hù)的影響,研究了自適應(yīng)電流速斷保護(hù)：對于同步發(fā)電機(jī)接入的情況采用引入補(bǔ)償系數(shù)的改進(jìn)自適應(yīng)電流速斷保護(hù)方案,對于IIDG接入的情況采用未接入IIDG時(shí)的自適應(yīng)電流速斷保護(hù)方案仍具有很好的保護(hù)性能,并進(jìn)行仿真驗(yàn)證。
[Abstract]:At present, distributed generation (Distributed Generation, DG) is introduced into the power network, which can effectively reduce environmental pollution, reduce energy loss, and improve the reliability and flexibility of power system. In order to give full play to the advantages of distributed generation technology and coordinate the contradiction between distribution network and distributed generation, the micro-grid is composed of distributed power source, load, energy storage device and control device, and the distribution network is connected reasonably. However, distributed power supply access will have a great impact on distribution network protection. The traditional fault detection method and relay protection mode are difficult to meet the needs of the safe operation of the power network. It is of great significance to study microgrid and its influence on distribution network protection and related protection algorithms. This paper summarizes the method of distribution network protection with distributed generation. The characteristics of distributed power supply via inverter interface are analyzed. Combined with the mathematical model of inverter in dq rotating coordinate system, the inverter control strategies of constant power control (PQ) and constant voltage constant frequency control (VF) are studied. The microgrid, which combines PQ control with VF control, can run in both grid-connected mode and isolated mode, and the control strategy of inverter is not changed when switching mode. Secondly, based on Digsilent software, the simulation model of PQ control VF control distributed power supply is established, and the correctness of the model is verified. PQ is used to control the distributed photovoltaic power generation and VF to control the distributed power simulation battery, and then the synchronous generator and load are added to form the microgrid. The correctness of the modeling of the microgrid is verified by simulation. Then, the influence of synchronous distributed power supply access to distribution network on current protection, distance protection and reclosing is studied, and the influence of (Inverter Interfaced DG, 鈪，

本文編號：2252073