Research On LED Lighting Loads Participating In Power System Primary Frequency Response And Reserve Optimal Allocation

The increasingly serious energy and environmental problems prompt the rapid development of renewable energy generations.The proportion of renewable energy generations is increasing continuously.The volatility,randomness,intermittency,and low inertia features of the renewable energy generations will bring a great challenge to the power balancing control of the power systems.In order to ensure the security and reliability of the power systems,sufficient reserve should be reserved for renewable energy generations.If the reserve is only provided by the online generator units,it will significantly affect the economic operation of the power systems.With the development of smart grid technology,it will prompt the development of the advanced measurement and sensing technology.The refinement of electric and non-electric parameters are become a reality.Meanwhile,with the development of global innovation in electric power market,the flexible and interactive electricity market and compensation incentive mechanism for flexible controllable loads is gradually established and improved,respectively.The flexible controllable loads have the condition in participating in the operation of the power systems.Furthermore,the users have gradually understood the social benefits brought by the demand response,and allow the aggregators to control their electric equipments.The controllable loads participacting in the operation of power systems have been widely studied.With the widly application of semiconductor technology,LED luminaires are known as the fourth-generation lighting source due to the high luminous efficiency,long lifespan,non-pollution,and high controllability.Unlike the lighting control technology to the traditional lighting source,the LED luminaires have excellent controllability in achieving the accurate and rapid dimming control by Pulse Width Modulation(PWM)technology.As a kind of controllable loads,LED lighting loads can regulate the power consumption with reasonable control method to regulate the working statues of LED luminaires.The LED lighting loads have the potential in participating in the operation the power systems.In view of aforementioned backgrounds,this dissertation takes LED lighting loads as the research object.According to the control performance of LED,this dissertation proposes control and responding strategies for the illumination control,designs the strategy in actively participating in primary frequency response of the power system and the model for the optimal allocation of power system spinning reserve.The main contributions and innovations of this dissertation are described as follows:(1)A LED lighting load model based on lighting power density is proposed,and utilization coefficient method is used to obtain the average illumination.The average illumination calculation model is used to calculate the illumination level on the working table and to achieve the illumination control of LED lighting loads.The Monte Carlo simulation method is used to aggregate the LED lighting loads in participating in primary frequency response,while the loads which are distributed in the power system with the random working statuses.In addition,a polynomial model is established to evaluate the relationships among the controllable capacity,the adjustment of average illumination and daylight.The obtained controllable capacity evaluation model is the basis to the following research of LED lighting loads.(2)A dimming control strategy of LED lighting loads is designed based on the developed model and control factors of LED lighting loads.Based on the flexible control of LED lighting loads,a dimming control model is designed considering users' lighting comfort.The objective function of the model is to satisfy the users'lighting comfort with the minimum lighting power consumption.The main objective function method is used to address the optimization issue of the two targets,the users' lighting comfort is regarded as a constraint condition.Afterwards,a fuzzy comfort evaluation model is developed considering daylight and artificial lighting sources.In the evaluation model,there are three evaluation factors,which are the total illumination,daylight and artificial lighting.The total illumination level is composed by daylight and artificial lighting,it directly affect the users' lighting comfort.The daylight has a higher weight to users'lighting comfort compared with artificial lighting.Simulation results in the DIALux verify the proposed dimming control model in energy savings and the illumination distribution.At last,the platform of illumination control for LED lighting loads is developed based on DALI(Digital Addressable Lighting Interface,DALI)protocol.(3)Based on the fast characteristics of LED lighting loads,a response control mechanism is designed for LED lighting loads to participate in power system??primary frequency response.The LED lighting loads are incorporated in active power/frequency balance control system.Firstly,a frequency responding model considering LED lighting loads is developed.Three frequency responding modes of LED lighting loads are designed considering different users' lighting comfort,which are lighting preference mode,no control mode and frequency response mode.Secondly,a droop control strategy of LED lighting loads to respond power system primary frequency is designed.The droop control strategy is developed to avoid the step change in power during the switching of three control modes.When the frequency deviation occurs,LED lighting loads can change the illumination linearly to change the power demand according to the frequency deviation and the duration of frequency deviation.Under the response mechanism,a decentralized control mode is developed to give full play the fast responding speed of LED lighting loads.Finally,simulation results in the single-machine model indicate that:the LED lighting loads with proposed responding strategy in providing frequency support under different frequency events.Meanwhile,during the process of LED lighting loads in responding frequency deviations,the illumination flicker of LED lighting loads will occur if the system frequency fluctuated in a high frequency.An improved IEC flicker decomposition model is adopted to evaluate the flicker severity index which is caused by illumination control of LED lighting loads.(4)Under the framework of dynamic economic dispatch,the research of LED lighting loads in participating in power system reserve optimal allocation is studied.Firstly,the compensation mechanism and the optimized scheduling framework of LED lighting loads are designed.In the designed compensation mechanism,the user's response behavior is related to the compensation price of LED lighting loads considering the consumer psychology.The designed optimized scheduling framework has three layers,which are power system dispatch layer,load aggregation layer and load terminal layer.Secondly,a model for cooperative allocation of supply-demand side reserve is proposed considering LED lighting loads based on deterministic model.The objective function of proposed model is to minimize the total operating cost during the dispatch interval.The power network constraints,the controllable capacity and the compensation cost of LED lighting loads are considered in the proposed model.Finally,by using the proposed model and compensation mechanism in the IEEE 30 bus system,the scheduling results and allocating reserve of the generation units,and the reserve capacity of LED lighting loads at each bus are obtained.