Unlock instant, AI-driven research and patent intelligence for your innovation.

Photovoltaic grid-connected power generation participation system frequency adjustment method

A technology of system frequency and adjustment method, applied in photovoltaic power generation, AC network circuits, electrical components, etc., can solve problems such as poor economy and damage to photovoltaic power generation efficiency, and achieve the effect of improving anti-interference ability and frequency support ability

Pending Publication Date: 2022-05-27
QINGHAI ELECTRIC POWER DESIGN INST
View PDF0 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since the photovoltaic unit does not contain rotating components, it cannot be controlled to mobilize the hidden "inertia" by decoupling from the power grid. It can only provide frequency adjustment capabilities by using load-shedding operation or active power backup in the form of energy storage. However, load-shedding operation makes photovoltaic operation On the suboptimal curve, the efficiency of photovoltaic power generation is damaged, and the economy is poor. Therefore, the present invention focuses on the way of photovoltaic configuration energy storage and frequency regulation

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Photovoltaic grid-connected power generation participation system frequency adjustment method
  • Photovoltaic grid-connected power generation participation system frequency adjustment method
  • Photovoltaic grid-connected power generation participation system frequency adjustment method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0058] This embodiment provides a new method for using energy storage batteries to realize photovoltaic grid-connected power generation participating in system frequency regulation, including the following steps:

[0059] S1: The DC boost converter detects the output voltage and current of the photovoltaic array, and adjusts the voltage through the corresponding MPPT algorithm to ensure the maximum output of photovoltaics.

[0060] According to the P-V curve characteristics of the photovoltaic array, when the output voltage of the photovoltaic array is adjusted, the output power of the photovoltaic system will change accordingly. The derivative of active power and DC voltage is 0, that is:

[0061]

[0062] Then it can be obtained from formula (1):

[0063]

[0064] Then transform the formula (2) to get:

[0065]

[0066] If the condition of formula (3) is not satisfied, the PI regulator in the DC boost converter will accumulate the generated difference and output a...

Embodiment 2

[0096] like figure 1 As shown, the three-machine nine-node system includes two thermal power units and one hydropower unit, both of which have an output of 150MW, and the inertia time constant is set to 5s. A photovoltaic system with a capacity of 20MW·h energy storage battery is connected to BUS5 system, its transmission power can reach 10MW.

[0097] like figure 2 Shown is the overall structure diagram of the photovoltaic power generation grid-connected system proposed by this method. The system as a whole consists of photovoltaic arrays, DC boost converters, battery energy storage systems, corresponding DC bidirectional converters, grid-connected It is composed of measurement computing components and communication parts.

[0098] The ambient temperature and light intensity of the photovoltaic system sense will change continuously. After the step-up transformer detects the change of the photovoltaic DC bus voltage, it starts the MPPT control algorithm, which is realized b...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention belongs to the field of photovoltaic power generation system control and stable operation, and particularly relates to a photovoltaic grid-connected power generation participation system frequency adjustment method. Comprising the following steps: detecting the voltage of a photovoltaic direct-current bus, and regulating and controlling the voltage to be in a maximum output state by adopting an MPPT (Maximum Power Point Tracking) algorithm; the regulated voltage is detected, the duty ratio of the Boost circuit is controlled and regulated, and the DC voltage of the boost bus is kept stable; detecting whether the SOC of the energy storage battery is maintained at a normal level, and if not, controlling energy storage charging and discharging to adjust active reserve when the power grid frequency is stable; and detecting whether the power grid frequency deviates or not, controlling the energy storage battery to charge and discharge to adjust the power grid frequency under the condition that the SOC of the energy storage battery meets the condition, and after the frequency deviation is eliminated or the SOC of the energy storage battery does not meet the condition, enabling the energy storage battery to quit operation. According to the method, the photovoltaic system can stably operate in the maximum output state, the energy storage battery can participate in frequency modulation of the power system, economic benefits are guaranteed, and the frequency supporting capacity of the power grid can be enhanced.

Description

technical field [0001] The invention belongs to the field of control and stable operation of a photovoltaic power generation system, and in particular relates to a method for adjusting the frequency of a photovoltaic grid-connected power generation participating system. Background technique [0002] Against the backdrop of the depletion of fossil energy and increasingly prominent environmental problems, clean and harmless new energy generator technology has developed rapidly all over the world, and my country's power system is gradually evolving into a system with a high proportion of clean energy and a high proportion of power electronic devices "Double high" power system. However, photovoltaic and other new energy power generation has strong volatility and randomness. The current grid-connected new energy units do not contain or hide the moment of inertia. With the gradual transformation and upgrading of the power system to new energy such as photovoltaic and wind power, I...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H02J3/24H02J3/46H02J3/32H02J13/00
CPCH02J3/241H02J3/466H02J3/32H02J13/00028H02J2300/26H02J2203/20Y02E70/30
Inventor 孙建聿孙双魁王鹏李书山吕钧章刘小兵马宏霞赵修文赖丽陈永超董朝辉马鸿翔王玲张强张存朝周冰雁张玮蒋秀婷
Owner QINGHAI ELECTRIC POWER DESIGN INST