CN107147201A - A Hybrid Energy Storage Power Supply Instantaneous Current Control System - Google Patents

Abstract

The invention discloses a kind of hybrid energy-storing power supply transient current control system, belong to dc source energy storage field.The control system of the present invention, including hybrid energy-storing power supply, DC/AC inverters, current detection module, digital control module and voltage detection module, the electric current of current detection module detection load simultaneously sends digital control module to, voltage detection module detection hybrid energy-storing power supply in batteries and super capacitor group port voltage and send digital control module to, transient current of the digital control module according to needed for the port voltage of batteries and super capacitor group, load drives DC/AC inverters, and hybrid energy-storing power supply provides transient current by DC/AC inverters to load.The present invention exports steady-state current by batteries, and peak point current is exported by super capacitor group, and takes into full account the port voltage range of operation of batteries and super capacitor group, and system effectiveness is high, controllability is strong, long lifespan, it is adaptable to the occasion of impact load.

Description

A Hybrid Energy Storage Power Supply Instantaneous Current Control System

technical field

The invention relates to a control system of a hybrid energy storage power supply, and more specifically relates to an instantaneous current control system of a hybrid energy storage power supply, which is suitable for applications with impact loads.

Background technique

DC energy storage is an important technology in the application fields of new energy vehicles and mobile energy storage power stations. A single battery energy storage has the characteristics of high energy density, but it also has the problem of difficult charging and discharging of large currents; supercapacitors have high specific power, It can charge and discharge with high current, and has the advantages of fast charge and discharge reaction time and long cycle life, but its disadvantages are low specific energy and short cruising range. The hybrid energy storage power supply combined with battery pack and supercapacitor pack has the advantages of high energy density and high power density, can solve the problem of instantaneous large current demand of impact load, and has a good application prospect in the field of industrial production. For example, Chinese Patent No. ZL201420099721.8, the authorized announcement date is July 30, 2014, and the name of the invention is: Adaptive filter power split control hybrid power supply, the application involves an adaptive filter power split Controlled Hybrid Electric Vehicle Composite Power. The composite power supply includes a battery, a supercapacitor and a bidirectional DC/DC converter. The battery is directly connected to the power bus as the main power source; the supercapacitor is connected to the power bus through a bidirectional DC/DC converter, and connected in series with the bidirectional DC-DC converter to form an auxiliary power source. The bidirectional DC-DC converter adopts a non-isolated half-bridge structure. In the composite power supply in this application, the supercapacitor compensates the battery for power, and the overall efficiency of the composite power supply is significantly improved; the supercapacitor can quickly and efficiently charge and discharge large currents, and maximize the recovery of regenerative braking energy.

Although the hybrid energy storage power supply composed of batteries and supercapacitors has the above-mentioned advantages, for hybrid energy storage power supplies, how to give full play to the advantages of batteries and supercapacitors to achieve better control effects is a problem that those skilled in the art are facing. technical problems. In order to ensure that the hybrid energy storage power supply can output a steady-state current and meet the instantaneous current demand of the impact load, it is urgent to design an instantaneous current control system for the above hybrid energy storage power supply.

Contents of the invention

1. The technical problem to be solved by the invention

The object of the present invention is to provide an instantaneous current control system for a hybrid energy storage power supply. By adopting the technical solution of the present invention, the battery pack of the hybrid energy storage power supply outputs a steady-state current, and the supercapacitor bank of the hybrid energy storage power supply outputs a peak current. The instantaneous current demand of the impact load, and fully consider the port voltage operating range of the battery pack and the super capacitor pack, limit the output current of the battery pack, avoid the over-current discharge of the battery pack, and ensure that the discharge current of the battery pack is within its safe operating range Inside, the system has high efficiency, strong controllability, and long service life of energy storage power supply, especially suitable for applications with impact loads.

2. Technical solution

In order to achieve the above object, the technical scheme provided by the invention is:

An instantaneous current control system for a hybrid energy storage power supply of the present invention includes a hybrid energy storage power supply, a DC/AC inverter, a current detection module, a digital control module and a voltage detection module, the current detection module detects the current of the load and It is sent to the digital control module, and the voltage detection module detects the port voltage of the battery pack and the supercapacitor pack in the hybrid energy storage power supply and sends it to the digital control module, and the said digital control module is based on the port voltage of the battery pack and the supercapacitor pack 1. The instantaneous current required by the load drives the DC/AC inverter, and the hybrid energy storage power supply provides the instantaneous current to the load through the DC/AC inverter.

Furthermore, the driving rule of the digital control module for the DC/AC inverter is:

(a) When the terminal voltage u _bat (t) of the battery pack < u _{bat min} , the output current i _bat (t) of the battery pack = 0;

(b) When the terminal voltage u _su (t) of the super capacitor group < u _{su min} , the output current i _su (t) of the super capacitor group = 0;

(c) When the port voltage u _{bat min} < u _bat (t) < u _{bat max} of the storage battery pack, the port voltage u _{su min} < u _su (t) < u _{su max} of the supercapacitor pack, and when the load required When the instantaneous current i(t)≤i _{bat max} , then i _bat (t)=i(t);

(d) When the port voltage u _{bat min} < u _bat (t) < u _{bat max} of the storage battery pack, the port voltage u _{su min} < u _su (t) < u _{su max} of the supercapacitor pack, and when the load required When the instantaneous current i(t)>i _{bat max} , i _bat (t)=i _{bat max} ; i _su (t)=i(t)-i _{bat max} ;

(e) When the terminal voltage u _su (t) of the super capacitor group <u _{su min} , the battery pack charges the super capacitor group;

In the formula, u _{bat max} is the maximum voltage of the battery pack, u _{bat min} is the minimum voltage of the battery pack, u _{su max} is the maximum voltage of the supercapacitor pack, u _{su min} is the minimum voltage of the supercapacitor pack, and i _{bat max} is the released energy of the battery pack The maximum current, i _su (t) is the current output by the supercapacitor pack, and i _bat (t) is the current output by the battery pack; among them, u _{bat min} , u _{bat max} and i _{bat max} are based on the electrochemical performance of the battery pack and the battery pack The remaining capacity of the group is determined; u _{su min} and u _{su max} are determined according to the performance of the super capacitor group.

Furthermore, the hybrid energy storage power supply is composed of a storage battery pack, a supercapacitor pack and a bidirectional DC/DC inverter, and the supercapacitor pack is connected in series with the bidirectional DC/DC inverter and connected to the battery pack respectively. DC/AC inverter.

Furthermore, the battery pack is composed of n battery cells connected in series; the supercapacitor group is composed of m supercapacitor cells connected in series.

Furthermore, the battery pack is an electrochemical energy storage battery pack, and the DC/AC inverter and load are single-phase or three-phase.

Furthermore, the electrochemical energy storage battery pack is a lead-acid battery pack, a nickel-metal hydride battery pack or a lithium-ion battery pack.

3. Beneficial effect

Compared with the existing known technology, the technical solution provided by the invention has the following remarkable effects:

(1) A kind of instantaneous current control system of a hybrid energy storage power supply of the present invention, which outputs a steady-state current through the storage battery pack of the hybrid energy storage power supply, and realizes the instantaneous current of the impact load through the output peak current of the supercapacitor bank of the hybrid energy storage power supply Requirements, and fully consider the port voltage operating range of the battery pack and the super capacitor pack, limit the output current of the battery pack, avoid the over-current discharge of the battery pack, and ensure that the discharge current of the battery pack is within its safe operating range, the system efficiency is high, Strong controllability and long service life of energy storage power supply, especially suitable for applications with impact loads;

(2) In the instantaneous current control system of a hybrid energy storage power supply of the present invention, the driving rules of the DC/AC inverter by the digital control module take into account the port voltages of the battery pack and the supercapacitor pack, effectively protecting the battery pack and the supercapacitor pack. Capacitor pack, effectively prolonging the service life of the battery pack while meeting the instantaneous current demand of the load;

(3) A kind of hybrid energy storage power supply instantaneous current control system of the present invention, its hybrid energy storage power supply is made up of storage battery pack, supercapacitor pack and bidirectional DC/DC inverter, and supercapacitor pack and bidirectional DC/DC inverter After being connected in series, the battery pack is connected to the DC/AC inverter respectively; the hybrid energy storage power supply can reduce the number of high-current charging and discharging of the battery pack and improve the service life of the battery pack; moreover, the battery pack is composed of n battery cells in series, The supercapacitor bank is composed of m supercapacitor units connected in series, and has a high degree of structural integration and a compact structure. Compared with a parallel structure, it can better utilize the advantages of the two energy storage elements.

Description of drawings

Fig. 1 is a functional block diagram of a hybrid energy storage power supply instantaneous current control system of the present invention;

Fig. 2 is the schematic diagram of the principle of the hybrid energy storage power supply in the present invention;

Fig. 3 is a schematic diagram of the serial structure of the battery pack in the hybrid energy storage power supply in the present invention;

Fig. 4 is a schematic diagram of the series structure of supercapacitor banks in the hybrid energy storage power supply in the present invention.

Explanation of the labels in the schematic diagram:

1. Hybrid energy storage power supply; 2. DC/AC inverter; 3. Load; 4. Current detection module; 5. Digital control module; 6. Voltage detection module; 1-1. Battery pack; 1-2. Super Capacitor bank; 1-3, bidirectional DC/DC inverter.

detailed description

In order to further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, a hybrid energy storage power supply instantaneous current control system of the present invention outputs a steady-state current through the battery pack 1-1 of the hybrid energy storage power supply 1, and passes through the supercapacitor bank of the hybrid energy storage power supply 1 1-2 outputs the peak current to realize the instantaneous current demand of the impact load 3, and fully considers the port voltage operating range of the battery pack 1-1 and the supercapacitor pack 1-2, which limits the output current of the battery pack 1-1 and avoids The overcurrent discharge of the battery pack 1-1 ensures that the discharge current of the battery pack 1-1 is within its safe operating range, the system has high efficiency, strong controllability, and long service life of the energy storage power supply, and is especially suitable for applications with impact loads.

The specific solution is: including a hybrid energy storage power supply 1, a DC/AC inverter 2, a current detection module 4, a digital control module 5 and a voltage detection module 6, the current detection module 4 detects the current of the load 3 and transmits it to the digital control module 5 , the voltage detection module 6 detects the port voltages of the battery pack 1-1 and the supercapacitor pack 1-2 in the hybrid energy storage power supply 1 and transmits it to the digital control module 5, and the digital control module 5 according to the battery pack 1-1 and the supercapacitor pack 1 The port voltage of -2 and the instantaneous current required by the load 3 drive the DC/AC inverter 2, and the hybrid energy storage power supply 1 supplies the instantaneous current to the load 3 through the DC/AC inverter 2. As shown in Figure 2, the above-mentioned hybrid energy storage power supply 1 is composed of a battery pack 1-1, a supercapacitor pack 1-2 and a bidirectional DC/DC inverter 1-3, and the supercapacitor pack 1-2 and the bidirectional DC/DC The inverter 1-3 is connected in series with the battery pack 1-1 to the DC/AC inverter 2 respectively. As shown in FIG. 3 and FIG. 4 , the battery pack 1-1 is composed of n battery cells connected in series; the supercapacitor group 1-2 is composed of m supercapacitor cells connected in series.

The present invention will be further described below in conjunction with embodiment.

Example

Referring to Fig. 1 and Fig. 2, a hybrid energy storage power supply instantaneous current control system in this embodiment includes a hybrid energy storage power supply 1, a DC/AC inverter 2, a current detection module 4, a digital control module 5 and a voltage detection module Module 6, wherein the hybrid energy storage power supply 1 is composed of a battery pack 1-1, a supercapacitor pack 1-2 and a bidirectional DC/DC inverter 1-3, and a supercapacitor pack 1-2 and a bidirectional DC/DC inverter 1 -3 is connected in series with the battery pack 1-1 to the DC/AC inverter 2 respectively. In the hybrid energy storage power supply 1, the battery pack 1-1 is used as the main power supply, and the supercapacitor pack 1-2 and the bidirectional DC/DC The inverters 1-3 are connected in series to form an auxiliary power supply. The hybrid energy storage power supply 1 can reduce the number of high-current charging and discharging of the battery pack 1-1 and improve the service life of the battery pack 1-1. The current detection module 4 detects the current required by the load 3 and transmits it to the digital control module 5, and the voltage detection module 6 detects the port voltage of the battery pack 1-1 and the supercapacitor pack 1-2 in the hybrid energy storage power supply 1 and transmits it to the digital control module Module 5, the digital control module 5 drives the DC/AC inverter 2 according to the port voltage of the battery pack 1-1 and the supercapacitor pack 1-2, and the instantaneous current required by the load 3, and the hybrid energy storage power supply 1 passes through the DC/AC inverter The converter 2 supplies the instantaneous current to the load 3 .

In this embodiment, the driving rule of the digital control module 5 for the DC/AC inverter 2 is:

(a) When the port voltage u _bat (t) of the battery pack 1-1 < u _{bat min} , the output current i _bat (t) of the battery pack 1-1 = 0;

(b) When the port voltage u _su (t) of the super capacitor group 1-2<u _{su min} , the output current i _su (t) of the super capacitor group 1-2=0;

(c) When the port voltage u _{bat min} < u _bat (t) < u _{bat max} of the battery pack 1-1 and the port voltage u _{su min} < u _su (t) < u _{su max} of the supercapacitor pack 1-2, And when the instantaneous current i(t) required by the load 3≤i _{bat max} , then i _bat (t)=i(t);

(d) When the port voltage u _{bat min} < u _bat (t) < u _{bat max} of the battery pack 1-1, and the port voltage u _{su min} < u _su (t) < u _{su max} of the supercapacitor pack 1-2, And when the instantaneous current i(t) required by the load 3>i _{bat max} , i _bat (t)=i _{bat max} ; i _su (t)=i(t)-i _{bat max} ;

(e) When the port voltage u _su (t) of the super capacitor group 1-2<u _{su min} , the storage battery group 1-1 charges the super capacitor group 1-2;

In the formula, u _{bat max} is the maximum voltage of battery pack 1-1, u _{bat min} is the minimum voltage of battery pack 1-1, u _{su max} is the maximum voltage of super capacitor group 1-2, u _{su min} is the super capacitor group 1-2 Minimum voltage, i _{bat max} is the maximum current that battery pack 1-1 can release, i _su (t) is the current output by supercapacitor pack 1-2, and i _bat (t) is the current output by battery pack 1-1; where , u _{bat min} , u _{bat max} and i _{bat max} are determined according to the electrochemical performance of the battery pack 1-1 and the remaining capacity of the battery pack 1-1; u _{su min} and u _{su max} are determined according to the performance of the supercapacitor pack 1-2.

That is to say, in this embodiment, when the port voltage of the battery pack 1-1 is less than its minimum voltage, the output current of the battery pack 1-1 is zero; when the port voltage of the super capacitor pack 1-2 is less than its minimum voltage , the output current of the supercapacitor bank 1-2 is zero; when the port voltage of the battery pack 1-1 is within the appropriate port voltage range, the port of the supercapacitor bank 1-2 is within the appropriate port voltage range, and when the load 3 When the required instantaneous current is less than the maximum current that the battery pack 1-1 can output, the current required by the load 3 is provided by the battery pack 1-1; when the port voltage of the battery pack 1-1 is within the appropriate port voltage range, the supercapacitor When the port voltage of group 1-2 is within the appropriate port voltage range, and when the instantaneous current required by load 3 is greater than the maximum current that battery group 1-1 can output, the output current of battery group 1-1 is equal to the output current of battery group 1-1. The maximum current, the output current of the supercapacitor group 1-2 is equal to the instantaneous current required by the load 3 minus the output current of the battery group 1-1; when the terminal voltage of the supercapacitor group 1-2 is less than its minimum voltage, the battery group 1-1 charges the supercapacitor bank 1-2. The driving rules of the above-mentioned digital control module 5 for the DC/AC inverter 2 take into account the port voltages of the battery pack 1-1 and the supercapacitor pack 1-2, effectively protecting the battery pack 1-1 and the supercapacitor pack 1-2 , in the case of meeting the instantaneous current demand of the load 3, the service life of the battery pack 1-1 is effectively prolonged.

As shown in Fig. 3 and Fig. 4, in this embodiment, the storage battery pack 1-1 is composed of n storage battery cells connected in series; It has high integration and compact structure. Compared with the parallel structure, it can give full play to the advantages of the two energy storage elements. In addition, the battery pack 1-1 adopts an electrochemical energy storage battery pack, and the DC/AC inverter 2 and the load 3 are single-phase or three-phase; or lithium-ion battery packs.

The instantaneous current control system of a hybrid energy storage power supply in this embodiment is realized by outputting a steady-state current through the battery pack 1-1 of the hybrid energy storage power supply 1, and outputting a peak current through the supercapacitor group 1-2 of the hybrid energy storage power supply 1. The instantaneous current demand of the impact load 3, so as to control the current output of the battery pack 1-1, reduce the current impact on the battery pack 1-1, and at the same time solve the problem of insufficient instantaneous current supply of the energy storage power supply after the aging of the battery pack 1-1 problem; and fully consider the port voltage operating range of battery pack 1-1 and supercapacitor pack 1-2, which limits the output current of battery pack 1-1, avoids the overcurrent discharge of battery pack 1-1, and ensures that battery pack 1 -1 The discharge current is within its safe operating range, the system has high efficiency, strong controllability, and long service life of the energy storage power supply, especially suitable for applications with impact loads, such as new energy vehicles, mobile energy storage power stations and grid energy storage It has a good application prospect in the field of DC power storage such as system.

The present invention and its implementations have been schematically described above, and the description is not restrictive. What is shown in the drawings is only one of the implementations of the present invention, and the actual structure is not limited thereto. Therefore, if a person of ordinary skill in the art is inspired by it, without departing from the inventive concept of the present invention, without creatively designing a structure and an embodiment similar to the technical solution, it shall fall within the scope of protection of the present invention .

Claims (6)

1. a kind of hybrid energy-storing power supply transient current control system, including hybrid energy-storing power supply (1) and DC/AC inverters (2), its It is characterised by：Also include current detection module (4), digital control module (5) and voltage detection module (6), described electric current inspection Survey the electric current of module (4) detection load (3) and send digital control module (5) to, described voltage detection module (6) detection is mixed Close in accumulation power supply (1) port voltage of batteries (1-1) and super capacitor group (1-2) and send digital control module to (5), described digital control module (5) is according to the port voltage of batteries (1-1) and super capacitor group (1-2), load (3) Required transient current driving DC/AC inverters (2), described hybrid energy-storing power supply (1) is by DC/AC inverters (2) to negative Carry (3) and transient current is provided.

2. a kind of hybrid energy-storing power supply transient current control system according to claim 1, it is characterised in that：Described number Word control module (5) is to the driving rule of DC/AC inverters (2)：

(a) as the port voltage u of batteries (1-1)_bat(t) ＜ u_{bat min}When, the output current i of batteries (1-1)_bat(t) =0；

(b) as the port voltage u of super capacitor group (1-2)_su(t) ＜ u_{su min}When, the output current i of super capacitor group (1-2)_su (t)=0；

(c) as the port voltage u of batteries (1-1)_{bat min}＜ u_bat(t) ＜ u_{bat max}, the port electricity of super capacitor group (1-2) Press u_{su min}＜ u_su(t) ＜ u_{su max}When, and as transient current i (t)≤i needed for load (3)_{bat max}When, then i_bat(t)=i (t)；

(d) as the port voltage u of batteries (1-1)_{bat min}＜ u_bat(t) ＜ u_{bat max}, the port electricity of super capacitor group (1-2) Press u_{su min}＜ u_su(t) ＜ u_{su max}When, and as transient current i (t) the ＞ i needed for load (3)_{bat max}When, i_bat(t)= i_{bat max}；i_su(t)=i (t)-i_{bat max}；

(e) as the port voltage u of super capacitor group (1-2)_su(t) ＜ u_{su min}When, then batteries (1-1) are to super capacitor group (1-2) charges；

In formula, u_{bat max}For batteries (1-1) maximum voltage, u_{bat min}For batteries (1-1) minimum voltage, u_{su max}It is super Level capacitance group (1-2) maximum voltage, u_{su min}For super capacitor group (1-2) minimum voltage, i_{bat max}For batteries (1-1) energy The maximum current enough discharged, i_su(t) electric current exported for super capacitor group (1-2), i_bat(t) exported for batteries (1-1) Electric current；Wherein, u_{bat min}、u_{bat max}And i_{bat max}It is surplus according to the chemical property of batteries (1-1) and batteries (1-1) Covolume amount is determined；u_{su min}And u_{su max}Determined according to the performance of super capacitor group (1-2).

3. a kind of hybrid energy-storing power supply transient current control system according to claim 1 or 2, it is characterised in that：It is described Hybrid energy-storing power supply (1) be made up of batteries (1-1), super capacitor group (1-2) and two-way DC/DC inverters (1-3), institute The super capacitor group (1-2) stated is respectively connecting to DC/AC after being connected with two-way DC/DC inverters (1-3) with batteries (1-1) Inverter (2).

4. a kind of hybrid energy-storing power supply transient current control system according to claim 3, it is characterised in that：Described storage Battery pack (1-1) is in series by n secondary battery unit；Described super capacitor group (1-2) is connected by m supercapacitive cell Form.

5. a kind of hybrid energy-storing power supply transient current control system according to claim 4, it is characterised in that：Described storage Battery pack (1-1) uses electrochemical energy storage cell group, and described DC/AC inverters (2) and load (3) is single-phase or three-phase.

6. a kind of hybrid energy-storing power supply transient current control system according to claim 5, it is characterised in that：Described electricity Chemical energy storage battery pack is lead-acid batteries, Ni-MH battery group or Li-ion batteries piles.