CN103414232B - A kind of low cost, extra long life ladder disign gradual change type accumulating system - Google Patents

Abstract

A low-cost, ultra-long-life step-by-step buffer storage system. Several buffer storage areas and initial main storage areas are set inside the storage system. These buffer storage areas are activated one by one in a step-by-step activation mode. When the cycle life of the buffer storage area ends or fails to work normally, activate the next buffer storage area, and so on, until all the buffer storage areas are activated and put into use; the activated buffer storage area is used for high-frequency The secondary charge and discharge, the inactive buffer storage area and the initial main storage area constitute the main storage area, the input terminals of the activated buffer storage area and the main storage area are connected to the primary energy generation system in parallel, and the activated buffer storage area The output of the storage area is connected to the load, and the output of the main storage area is selectively connected to the load and the input of the activated buffer storage area. The invention will greatly improve the service life of the electric storage system, and compared with the electric storage system composed of similar storage batteries, the service life is increased by 2-4 times.

Description

A low-cost, ultra-long-life step-buffer gradient power storage system

technical field

The invention relates to a low-cost, ultra-long-life power storage system, especially a power storage system that uses solar energy, wind power, etc. as primary energy input, and needs to meet the needs of high-frequency charging and discharging, low price, and long life.

Background technique

The power storage system composed of various batteries has a wide range of applications, and more and more occasions require the existence of power storage systems, such as solar photovoltaic applications, wind power generation, various vehicles, aerospace and so on.

Different application fields have different performance requirements for power storage systems. For example, artificial satellites require high energy density and long life; in the field of solar lamps, high-frequency charging and discharging, long life, and low cost are required; in the field of wind power generation, solutions are required. High-frequency charging, long life, and low cost; vehicles, such as electric vehicles, require fast charging, long life, and low cost.

Undoubtedly, long life and low cost are the common requirements of almost all power storage system application fields. At present, the power storage system composed of various types of batteries (lithium batteries, lead-acid batteries, nickel-cadmium batteries, and nickel-hydrogen batteries) is composed of battery cells (or cells) connected in series and in parallel. The life and cost of the power storage system are almost entirely determined by the life and cost of the battery cells. The cycle life and cost of various battery cells are different. For example, the number of lead-acid cycles is the lowest, followed by nickel-cadmium, then nickel-metal hydride, and finally lithium batteries; the price gradually increases. Therefore, the existing methods of improving the life of the electric storage system and reducing the cost focus on improving the life of the single battery and reducing the cost.

All in all, the current design method of the power storage system causes the cycle life of the power storage system to directly depend on the life of the battery cells and cannot break through this limit, especially when faced with high-frequency charging and discharging requirements, the life is very short.

Therefore, the present invention breaks through the traditional design concept of electric storage system, adopts a brand-new design method and technology, realizes low-cost, ultra-long-life electric storage system design, and is simple to implement and has wider application fields.

Contents of the invention

The technical problem to be solved by the present invention is to aim at the short-life problem that is generally faced by the design of various existing electric storage systems, and there is no effective solution. The present invention provides a low-cost, ultra-long-life stepped buffer gradual change System, which realizes the premise of low cost and greatly improves the service life of the power storage system. Compared with the traditional power storage design method, the life of the power storage system is increased by 2-4 times.

In order to solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a low-cost, ultra-long-life step-by-step buffer gradual change power storage system. Several buffer power storage areas and initial main power storage areas are set inside the power storage system. These buffer power The storage areas are activated one by one in a stepwise activation manner, that is, when the cycle life of the activated buffer storage area ends or the fault fails to work normally, the next buffer storage area is activated, and so on until all the buffer storage areas are activated. Activated and put into application; the activated buffer storage area is used for high-frequency charging and discharging, the inactive buffer storage area and the initial main storage area constitute the main storage area, and the activated buffer storage area and the main storage area The input end is connected to the primary energy generation system in parallel, and the output end of the activated buffer storage area is connected to the load, and the output end of the main storage area is selectively connected to the load and the input end of the activated buffer storage area.

The low-cost, ultra-long-life step-buffer gradient power storage system is composed of a plurality of single batteries of the same type (lithium batteries, lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, etc.).

The above stepwise gradually activated buffer storage area solves the demand for high-frequency charging and discharging. The main power storage area is used to store part of the electric energy produced by the primary energy power generation system to meet the charging and discharging needs in a long period of time under special conditions. For example, in the solar street lamp power storage system, the charging and discharging of one cycle per day is completed by the activated buffer storage area, which greatly increases the charging and discharging time interval of the main storage area, reduces the frequency of charging and discharging of the main storage area, and improves The service life of the whole power storage system is extended.

Once the primary energy generation system encounters special circumstances, such as a long rainy day or a calm windy day with solar energy and wind energy as the primary energy input, and the power in the buffer storage area is exhausted (the energy is less than 10%-20%), then the The two modes guarantee the normal operation of the energy-using system. Mode 1: The output end of the main storage area is connected to the activated buffer storage area, the main storage area charges the activated buffer storage area, and the activated buffer storage area then supplies power to the load. Mode 2: The output terminal of the main power storage area is connected to the load, and the main power storage area directly supplies power to the load, and the activated buffer power storage area waits for the primary energy generation system to charge.

The calculation of the total design capacity of the power storage system varies according to the purpose of the power storage system, but the common calculation core is the same. That is, according to the longest idle period of the power generation device (that is, the most unfavorable situation possible, such as the time when solar energy is used as the primary energy input and there is no solar radiation for continuous rain), the total energy consumption of electrical equipment * safety factor (1.2-1.5 ) = total design capacity of the power storage system. The value of the safety factor, if the probability of the most unfavorable situation is greater than or equal to 40%, the larger the coefficient selection (choose 1.4-1.5), if the probability of the most unfavorable situation is lower than 40%, the smaller the coefficient selection (choose 1.2- 1.4).

The calculation of the design capacity of the buffer storage area is also different from the use of the storage system, but the common calculation core is the same. That is, according to the normal idle time of the power generation device (such as the time when solar energy is used as the primary energy input, when there is no solar radiation) and the working period (such as when the solar energy is used as the primary energy input, the time when there is solar radiation), the consumption of electrical equipment Total energy * 2.5 = design capacity of the buffer storage area.

The upper limit set for the number of buffer storage areas = the ratio of the total design capacity of the storage system to the design capacity of the buffer storage areas - 1. The recommended number of buffer storage areas is 1-5, and even if there are conditions to set more, it should not exceed 5.

Compared with prior art, the beneficial effect of the present invention is:

1. The low-cost, ultra-long-life stepped buffer storage system provided by the present invention greatly reduces the charging of the main storage area by setting multiple buffer storage areas (recommended value is 1-5) in a stepwise manner. The discharge frequency prolongs the interval between charge and discharge cycles in the main storage area, thereby increasing the service life of the overall storage system by 2-4 times. Moreover, the design method of the power storage system is applicable to many power storage systems, such as lithium batteries, lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and other batteries with a certain cycle life.

2. In the low-cost, ultra-long-life stepped buffer storage system provided by the present invention, the number of divisions of the buffer storage area can be flexibly set, but the recommended limit value (upper limit) should not exceed the total design capacity of the storage system and the buffer storage area The ratio of the design capacity -1 can make the service life match or be similar to the requirements according to the different requirements of the application occasions of the power storage system.

3. The low-cost, super-long-life step-buffering gradient power storage system provided by the present invention has clear ideas, uncomplicated control circuits, simple implementation, and no incremental cost, which is very economical.

4. The low-cost, ultra-long-life step-buffer gradual change power storage system provided by the present invention provides the calculation method and recommended value for the buffer power storage area and the overall power storage system capacity, eliminating the need for tedious capacity calculation. It is suitable for a variety of high-frequency charge and discharge fields, especially the application field of power storage systems that use solar energy and wind energy as primary energy.

Description of drawings

Figure 1. The general diagram of the basic design principle of the low-cost , ultra-long-life stepped buffer and gradual change power storage system;

Figure 2 The basic structure diagram of the solar lawn lamp prototype;

Figure 3. The working principle diagram of the low-cost, ultra-long-life stepped buffer and gradual change power storage system when there is solar radiation;

Fig. 4 The working principle diagram of the low-cost, ultra-long-life step-buffer gradient power storage system at night;

Figure 5. Low-cost, ultra-long-life step buffer gradient power storage system working principle diagram of power depletion in buffer power storage zone 1 (mode 1);

Fig. 6 Low-cost, ultra-long life step buffer gradient power storage system working principle diagram of power depletion in buffer power storage zone 1 (mode 2);

Fig. 7 The working principle diagram of low-cost, ultra-long-life stepped buffer storage system buffer storage zone 1 with end-of-life or failure.

detailed description

The following will take the design of a certain type of solar lawn lamp prototype (CPD-NO.01) power storage system as an example to describe the application and implementation of this low-cost, ultra-long-life stepped buffer and gradual change power storage system in detail.

As shown in Figure 1, it is a general diagram of the basic principles of the design method of the low-cost, ultra-long-life stepped buffer and gradual change storage system. It can be seen from the figure that the present invention is composed of a plurality of single batteries of the same type (lithium batteries, lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, etc.), and these single batteries are divided into several buffer storage areas and initial main storage areas. These buffer storage areas are activated one by one in a stepwise activation manner, that is, when the cycle life of the activated buffer storage area ends or the fault fails to work normally, the next buffer storage area is activated, and so on, until all the buffer storage areas are activated. The buffer storage area is activated and put into use; the activated buffer storage area is used for high-frequency charging and discharging, the inactive buffer storage area and the initial main storage area constitute the main storage area, and the activated buffer storage area and The input end of the main storage area is connected to the primary energy generation system (periodical or high-frequency power generation systems such as solar photovoltaic panels/wind power generation), and the output end of the activated buffer storage area is connected to the load. The main storage area The output terminal of the selectively connects the load and the input terminal of the activated buffer storage area.

As shown in Figure 2, the solar lawn lamp prototype consists of four parts: solar photovoltaic panels (using polysilicon), power storage system (composed of lead-acid battery packs), lighting fixtures (LED single lamp power 3W, working voltage 12V), control system (omitted in the figure).

The selected area for use is Changsha City, which is a fourth or fifth category of solar energy resources. The daily lighting time is usually 4 hours, and the power consumption per night is 1Ah. Assume that the longest continuous rainy days is 7 days, and the probability of occurrence is less than 40%. If the safety factor is selected as 1.2, the total capacity of the power storage system is 8.4Ah (1Ah*7*1.2). The design capacity of the buffer storage area is 2.5Ah (1Ah*2.5). In this power storage system, the number of steps in the buffer storage area is set to 2 (the upper limit does not exceed 8.4Ah/2.5Ah-1=2.36). The power generation capacity of the matching solar photovoltaic panels is designed to be 5W, and the daily photoelectric conversion time is 6 hours.

As shown in Figure 3, when there is solar radiation during the day (and the intensity of solar radiation can produce photoelectric effect), solar photovoltaic panels (PV panels) generate electricity to charge the activated buffer storage area 1, and at the same time charge the main storage area ( The inactive buffer storage area and the initial main storage area are collectively referred to as the main storage area) are also charged.

As shown in FIG. 4 , when it is necessary to provide power to lighting fixtures at night, the activated buffer storage area 1 performs discharge.

As shown in Figure 5, once the number of consecutive rainy days (more than 2.5 days) is encountered, the activated buffer storage area 1 is exhausted (the power is less than 10%). In order to ensure the normal operation of energy-consuming equipment, according to mode 1, the main storage area quickly charges the activated buffer storage area 1 until it is fully charged, and the activated buffer storage area 1 still supplies power to the load. This design model can meet 7 days of normal lighting under the most extreme and harsh conditions (all rainy days).

As shown in Figure 6, once the number of consecutive rainy days (more than 2.5 days) is encountered, the activated buffer storage area 1 is exhausted (the power is less than 10%). In order to ensure the normal operation of energy-consuming equipment, the main power storage area can also provide load energy according to mode 2. The activated buffer storage area 1 waits for the weather to improve to be charged by the solar photovoltaic panels.

As shown in Figure 7, once the cycle life of the activated buffer storage area 1 expires or fails to work for some reason, the buffer storage area 2 is activated according to the stepped buffer and gradual design method of the main storage system, and the above workflow is repeated.

The power storage system of this model is only designed with 2 buffer zones. Overall, this model can increase the service life of the power storage system with the same parameters by about 2.2 times. According to the whole life cycle analysis, the cost of the power storage system of this type is 45% of the cost of the same type of power storage system.

Claims (3)

1. A low-cost, ultra-long-life step-by-step buffer and gradual change power storage system, which is characterized in that several buffer power storage areas and initial main power storage areas are set inside the power storage system, and these buffer power storage areas adopt a stepped activation method Activate one by one, that is, when the cycle life of the activated buffer storage area ends or fails to work normally, the next buffer storage area is activated, and so on, until all the buffer storage areas are activated and put into use; the activated buffer storage area The electric area is used for high-frequency charging and discharging. The inactive buffer storage area and the initial main storage area constitute the main storage area. The input terminals of the activated buffer storage area and the main storage area are connected to the primary energy generation in parallel. system, and the output terminal of the activated buffer storage area is connected to the load, and the output terminal of the main storage area is selectively connected to the load and the input terminal of the activated buffer storage area: when the energy of the activated buffer storage area is lower than 10% When -20%, the output end of the main storage area is connected to the activated buffer storage area, and the main storage area charges the activated buffer storage area, and the activated buffer storage area meets the load energy consumption; or, when activated When the energy of the buffer storage area is lower than 10%-20%, the output end of the main storage area is connected to the load, and the main storage area directly meets the energy consumption of the load, and the activated buffer storage area waits for the primary energy generation system to charge; The total design capacity of the power storage system is the total energy consumption of electrical equipment during the longest idle period of the primary energy power generation system* (1.2-1.5), and the design capacity of the buffer power storage area is the normal idle time of the primary energy power generation system and one working cycle Total energy consumption of internal electrical equipment*2.5; if the occurrence probability of the longest idle period is greater than or equal to 40%, the total design capacity of the power storage system is the total energy consumption of electrical equipment during the longest idle period of the primary energy generation system*( 1.4-1.5), if the probability of occurrence of the longest idle period is less than 40%, the total design capacity of the power storage system is the total energy consumption of electrical equipment during the longest idle period of the primary energy generation system * (1.2-1.4). 2. The low-cost, ultra-long-life step-by-step buffer-gradient power storage system according to claim 1, characterized in that the upper limit of the number of buffer storage areas = the total design capacity of the storage system and the design of the buffer storage areas Capacity ratio -1. 3. The low-cost, super-long-life step-buffered gradual change power storage system according to claim 2, characterized in that the number of buffer power storage areas is 1-5.