Dynamic Control Method of Thermal Power Units Compensating for Wind Power Disturbance

Abstract

The randomness and volatility of wind power generation are the main reasons restricting the capacity of power grid to absorb wind power. Thermal power units are the main force of power grid frequency modulation. The speed of load adjustment rate determines their response ability to power grid load. Based on the analysis of the characteristics of wind power generation, the nonlinear multiscale decomposition of the automatic power generation control (AGC) load command is carried out. Combined with the different load regulation rates of different types of units, the rational allocation of unit combinations can effectively ensure the power grid load regulation capacity and compensate the random disturbance of wind power.

Improving Wind Power Utilization in System Dispatch Considering Output and Ramp Rate Dependent Generator Costs

“…Third, the extraction pressure regulating of heating units can send the extraction steam to the turbine to generate extra output that would otherwise be used to generate heat. In Liu et al (2014), load changing instructions of the heating unit were reconstructed and optimized by non-linear multi-scale decomposition of the AGC load instruction. In Wang (2013), ramp rates of heating units were improved to more than 5% per minute of their rated capacities by making use of their heat storage.…”

“…Ramp up or down capabilities of a thermal generator usually depend on its coal inputs, and its efficiency in converting coal to power. Recent publications (Wang et al, 2006;Yao et al, 2006;Xing, 2007;Wang et al, 2010;Yao et al, 2010;Wang, 2013;Liu et al, 2014;Wang et al, 2014b;Wang et al, 2015;Hu et al, 2015a;Hu et al, 2015b;Wang et al, 2017) have studied various fast ramping techniques for thermal units. As one of the key results, Wang et al (2014b) presented a method to improve unit ramping capabilities through controlling cooling water flow, which usually keeps constant in regular operations.…”

“…In Wang et al (2014b), the unit is operated in a "fast mode" where the condenser pressure changes with the cooling water flow, so that the steam heat storage is relived or accumulated to make the tur-bine power output ramp up or down faster than regular. Other flexible control techniques for thermal units include condenser cold source throttling (Yao et al, 2006;Yao et al, 2010;Hu, 2015b), the extraction pressure regulating for heating units (Wang, 2013;Liu et al, 2014), optimal load dispatch at the plant level (Wang et al, 2006;Xing, 2007) and so on. With the increasing integration of renewable energy sources in future grids, the above flexible control techniques will gradually change the functions of coal-fired thermal generators from the "base load supliers" to the "peak load balancers", so that the more economical, environmental friendly and renewable power can be better utilized.…”

Application of Heat Storage in Heating Network for Surplus Wind Power Consumption

“…[18] and [19] believes that the CHP unit could actively respond the short-time load disturbance from the power grid by utilizing the heat storage capacity of distributed heating system, based on that those papers present a coordinating control designing scheme which increase the feed forward compensation of CHP unit. [20][21][22] argue that the wind power consumption could be promoted by using the heat storage capacity of the pipe network, heat exchangers and heat radiators within heating system, also, the author strives for shrinking the wind power curtailment by optimizing the operation of AGC units. But all those papers only focus on one or some heating equipment, the articles that consider the whole heating system as an organic whole to analyze its heating storage capacity are relatively less.…”