POWER CONVERSION APPARATUS AND POWER CONVERSION CONTROL MEANS

• Main Authors: ISHIGAKI TAKUYA, KANOUDA TAMAHIKO, MABUCHI YUICHI, SENDA TADAHIKO, NORIMATSU YASUAKI, SHIMADA TAKAE
• Format: Patent
• Language: English; Japanese
• Published: 22.12.2016
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PROBLEM TO BE SOLVED: To suppress switching loss of power devices used in a power circuit, such as a DC-DC converter and an inverter for compatibility with wide-range voltage fluctuations in photovoltaic power generation and request of high frequency for SST application when PCS for photovoltaic power is targeted although a transformer for system interconnection requests size and weight reductions and the SST application can realize the size and weight reductions, and to achieve size and weight reductions of a large current path in a pre-stage of boosting for a system voltage because the boosting is required.SOLUTION: An LLC resonance converter configuration is applied and by including an inverter in its output, the inverter is configured to have multiple connection. In addition to a MPPT voltage of photovoltaic power, the LLC resonance converter can achieve suppression of driving loss and compatibility with a voltage range by performing constant frequency control for a large output, boost control for a low output and step-down control for an upper-limit voltage, respectively.SELECTED DRAWING: Figure 1 【課題】系統連係用のトランスの小型・軽量化が求められている。トランスにＳＳＴを適用することで小型・軽量化を実現できるが、太陽光向けＰＣＳを対象とした場合、太陽光発電の広範囲な電圧変動への対応とＳＳＴ適用よる高周波化に対してＤＣ／ＤＣコンバータやインバータといった電力回路に使用されるパワーデバイスのスイッチング損失低減が必要である。また、系統電圧への昇圧が必要であり、昇圧前段における大電流経路の小型・軽量化も必要とされる。【解決手段】ＬＬＣ共振コンバータ構成を適用し、その出力にインバータを備え、インバータを多重接続構成とする。太陽光のＭＰＰＴ電圧に合わせて、ＬＬＣ共振コンバータを大出力では定周波制御、低出力では昇圧制御、上限電圧では降圧制御することで、駆動損失の低減と電圧範囲への対応を実現する。【選択図】図１