This paper proposes an optimal bidding method of price-maker retailers in the electricity market with demand price quota curves (DPQC)-based probability distribution function (PDF) estimation of the market price. Different from traditional game-theory methods or agent-based methods, the proposed DPQC-based PDF estimation method unnecessity to have full knowledge of the strategies of each rival or the market operation. In detail, the DPQC method is applied to consider the impacts of the market clearing price from the price-maker retailers themselves, and the PDF model is utilized to consider the market price uncertainty. The technical key point of the proposed method is to amend the PDF along with the PQCs dynamically. Moreover, the DPQC-based PDF estimation with one-segment and multi-segment bidding rules are presented, respectively. The optimization model of the bidding problem is formulated then, and we use the genetic algorithm to solve it. The case study shows that the proposed method can help the price-maker retailers better to consider the price impacts from their bidding behaviors, and enable them to make a higher profit in the electricity market. INDEX TERMS Demand price quota curve (DPQC), optimal bidding, price-maker, power market.

The quasi-Z-source H-bridge grid-connected inverter (QHGCI) is well known with its advantages of the void of shoot-through problem and the high DC-voltage utilization. But the existence of the common-mode leakage current in the power frequency cycle, lower power density and higher thermal stress makes it hardly applicable to the grid-penetrating application. Thus with a purpose to conquer the problem relating to the QHGCI, an innovative transformerless Z-Source photovoltaic grid-connected inverter with coupled inductor coil (TZPGCI-CIC) is proposed. The circuitry topology and an unipolar SPWM strategy are firstly introduced in short. And thereafter the common-mode voltage in the whole working process is derived and evaluated through the detailed operating mode analysis, in which a constant value of it has been theoretically revealed. Lastly, a prototype platform of TZPGCI-CIC is setup and its good performance on leakage current suppression, lower thermal stress are validated with the experimental results.

No abstract