CN115991123B

CN115991123B - Power load state identification method, system, equipment and medium

Info

Publication number: CN115991123B
Application number: CN202310284920.XA
Authority: CN
Inventors: 曾韬; 苏忠; 陈金锐; 肖龙; 李煜
Original assignee: Changan New Energy Nanjing Research Institute Co Ltd
Current assignee: Shenzhen Blue Automobile Nanjing Research Institute Co ltd
Priority date: 2023-03-22
Filing date: 2023-03-22
Publication date: 2023-07-18
Anticipated expiration: 2043-03-22
Also published as: CN115991123A

Abstract

The application provides a power load state identification method, a system, equipment and a medium, wherein the method comprises the following steps: acquiring net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment; if the change amount of the net power request value is in a preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value to determine that the power load state of the fuel cell engine at the current sampling moment reaches a steady state when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment. The method and the device can effectively improve the state identification accuracy and the anti-interference capability.

Description

Power load state identification method, system, equipment and medium

Technical Field

The application relates to the field of new energy automobile application, in particular to a power load state identification method, a system, equipment and a medium.

Background

Fuel cell automobiles are considered as the most effective solution for future green energy vehicles because of their advantages of zero emissions, high efficiency, fast hydrogenation, etc. Fuel cell engines play an important role as power units for mainly supplying driving power in fuel cell automobiles. The fuel cell engine has complex structure composition and mainly comprises a fuel cell stack, an air supply subsystem, a water heat management subsystem, a hydrogen supply subsystem, a DCDC subsystem and the like, wherein each subsystem except the electric stack consists of a plurality of parts. During operation of a fuel cell vehicle, the fuel cell engine will follow the power demand in response to the vehicle powertrain, and therefore the power output of the fuel cell engine is typically repeatedly variable.

In order for the fuel cell engine to maintain a high performance output, the fuel cell engine needs to control the subsystems to rapidly meet the operating conditions required for efficient reaction of the fuel cell stack, such as air flow, air pressure, water temperature, hydrogen pressure, etc., during operation. However, the fuel cell engine has complex composition, the dynamic response characteristics of key parts of each subsystem are different, and the dynamic response of each operating condition has strong nonlinear characteristics, so that the response speed of most operating conditions lags behind the power change of the fuel cell. In order to improve the dynamic response speed of the operation condition, the control parameters of closed-loop control of a sensor-actuator can be adjusted, the control integral function is increased, and the action speed of the actuator is accelerated, so that the aim of quickly reducing the control error of the operation condition is fulfilled. However, control parameters that ensure a fast dynamic response of operating conditions tend to degrade the anti-tamper capability of the closed loop control at steady state, which is detrimental to maintaining a stable power output of the fuel cell engine.

The Chinese patent [ CN113782791A ] determines whether the automobile is currently in a transient working condition or a steady working condition according to the change rate of the required power of the whole automobile, and then decides whether to start the air storage tank unit to supply oxygen for the fuel cell stack or start the screw air compressor to supply oxygen for the fuel cell stack according to the identified working condition of the whole automobile. However, simply judging whether the steady state or the transient state is higher than the threshold value according to the change rate of the required power of the whole vehicle can cause frequent false tripping of the identification result. The power change rate calculated by the controller is easy to exceed a set judgment threshold value, so that false jump of the identification result occurs. In addition, in actual hardware, errors, ripples and occasional unreasonable values of the signal acquisition can exist, and these can lead to false jumps of the recognition result. Therefore, the method for judging the steady-state or transient-state working condition only according to the calculated power change rate is weak in robustness, and misjudgment and repeated jump of unexpected recognition results are easy to occur.

The chinese patent [ CN114883609a ] determines a steady-state operating period of the fuel cell system according to the time when an air flow curve reaches an upper limit and a lower limit of a flow error interval, wherein the air flow curve is a curve of air flow change with time in a power rising process of the fuel cell system, and the flow error interval is the upper limit and the lower limit of a current target air flow. The method comprises the following specific principles: firstly, distinguishing whether an air flow curve is monotonically rising or decaying oscillation; aiming at the monotone rising condition, taking the moment when the air flow curve reaches the lower limit value of the flow error interval as the moment of entering a steady state, and taking the time period before the steady state moment as a transient working time period; for the damping vibration, the air flow curve can enter and exit the flow error interval for a plurality of times, at the moment, the moment when the air flow curve enters the flow error interval last time is taken as the moment when the air flow curve enters a steady state, and similarly, the time period before the steady state moment is taken as the transient working time period. However, this method can only distinguish between steady-state and transient operating time periods by means of offline analysis after obtaining or recording experimental data, and cannot calculate in real time on line, because the time when the air flow curve enters the flow error interval last time in real time operation is unknown, that is, it cannot be judged whether the entering flow error interval is the last time, and whether the entering flow error interval deviates from the error interval again in the future, so that the time when the transient is converted into steady-state cannot be determined unbiased.

Disclosure of Invention

In view of the problems in the prior art, the application provides a power load state identification method, a system, equipment and a medium, which mainly solve the problems that the steady state identification accuracy of the existing method is poor, and the existing method is easily influenced by actual power signal jump, so that the control accuracy of the power output of a vehicle is influenced by repeated jump between different power load states.

In order to achieve the above and other objects, the technical solutions adopted in the present application are as follows.

The application provides a power load state identification method, which comprises the following steps:

obtaining net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment, wherein the plurality of continuous sampling moments comprise: a current sampling instant and at least one preceding sampling instant;

if the change amount of the net power request value is in a preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value to determine that the power load state of the fuel cell engine at the current sampling moment reaches a steady state when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

In an embodiment of the present application, after obtaining the net power request values and the actual power values at a plurality of consecutive sampling moments, the method further includes:

and if the change amount of the net power request value exceeds the preset change range, determining that the power load state of the fuel cell engine is in a loading state or a load-reducing state according to the change amount of the net power request value, the net power request value and the corresponding actual power value.

In an embodiment of the present application, determining a power control error according to the net power request value and the actual power value includes:

the net power request value of the current sampling moment is recorded as a first request value, and the actual power value in the neighborhood time range of the current sampling moment is used as a first power value;

and calculating a first difference value between the first request value and the first power value, and taking the ratio of the absolute value of the first difference value to the first request value as the power control error.

In an embodiment of the present application, after determining the power control error according to the net power request value and the actual power value, the method further includes:

if the power control error is greater than or equal to a preset error threshold value within a preset first time limit, waiting for the power control error to be smaller than the preset error threshold value, and if the power control error is continuously smaller than the preset error threshold value and the duration exceeds a preset second time limit, assigning a first numerical value to a preset first zone bit;

If the duration of the power control error smaller than the preset error threshold is smaller than the preset second implementation, a second value is assigned to the first flag bit;

determining that the battery engine load power state reaches a steady state when the first flag bit is equal to the first value; and when the first flag bit is equal to the second value, the battery engine load power state is kept unchanged.

In an embodiment of the present application, before determining that the power load state of the fuel cell engine reaches the steady state at the current sampling time, the method further includes:

and if the change amount of the net power request value is in the preset change range, setting the change amount of the net power request value to zero.

In an embodiment of the present application, determining the load state of the power of the fuel cell engine as the loading state or the load-reducing state according to the change amount of the net power request value, the net power request value and the corresponding actual power value includes:

if the absolute value of the change quantity of the net power request value is larger than zero, calculating a second difference value between the net power request value and the actual power value at the current sampling moment;

if the second difference is greater than zero, the fuel cell engine power load state is a loaded state;

And if the second difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment of the present application, determining the power load state of the fuel cell engine as the loading state or the load-reducing state according to the net power request value variation, the net power request value, and the corresponding actual power value further includes:

if the change amount of the net power request value is equal to zero, calculating a third difference value between the net power request value at the current sampling moment and the actual power value at the previous sampling moment;

if the third difference value is greater than zero, the power load state of the fuel cell engine is a loading state;

and if the third difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment of the present application, the process of comparing the power control error with a preset error threshold includes:

and if the absolute value of the change quantity of the net power request value is larger than zero, resetting the count value of the current sampling moment, and if the count value does not exceed the preset first time limit and the power control error is larger than or equal to the preset error threshold, keeping the original state of the power of the fuel cell engine unchanged.

In an embodiment of the present application, the process of comparing the power control error with a preset error threshold further includes:

if the change amount of the net power request value is equal to zero, a sampling duration is newly increased on the basis of the count value of the last sampling time as the count value of the current sampling time, so that the count value of the current sampling time exceeds the preset first time limit, and the power state of the fuel cell engine is kept unchanged at the moment.

The application also provides a power load state identification system, comprising:

the power data acquisition module is configured to acquire net power request values of a plurality of consecutive sampling moments and actual power values in a neighborhood time range of each sampling moment, where the plurality of consecutive sampling moments include: a current sampling instant and at least one preceding sampling instant;

and the load state identification module is used for determining a power control error according to the net power request value and the actual power value if the net power request value variation is in a preset variation range, comparing the power control error with a preset error threshold value, and determining that the power state of the fuel cell engine reaches a steady state at the current sampling moment when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the net power request value variation is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

The present application also provides a computer device comprising: the system comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor realizes the steps of the power load state identification method when executing the computer program.

The present application also provides a computer readable storage medium having stored thereon a computer program which when executed by a processor implements the steps of the power load state identification method.

As described above, the power load state identification method, system, device and medium have the following beneficial effects.

The method comprises the steps of obtaining net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment, wherein the plurality of continuous sampling moments comprise: a current sampling instant and at least one preceding sampling instant; if the change amount of the net power request value is in a preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value to determine that the power load state of the fuel cell engine at the current sampling moment reaches a steady state when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment. When the net power request value variation is in a preset variation range, the power control error is limited by a preset error threshold value, so that the phenomenon of repeated jump of an identification result caused by oscillation attenuation of the power control error is prevented, the steady-state anti-interference capability is enhanced, and the transient response performance of the stable wing control parameters of the system operation is ensured.

Drawings

Fig. 1 is a flowchart of a power load status recognition method according to an embodiment of the present application.

FIG. 2 is a schematic diagram of an overall flow of power load status identification in an embodiment of the present application.

Fig. 3 is a schematic diagram of an acquisition flow of status flags recorded or down loaded in an embodiment of the present application.

Fig. 4 is a flow chart illustrating power control error determination in an embodiment of the present application.

Fig. 5 is a schematic diagram of a judgment flow after exceeding a preset error threshold in an embodiment of the present application.

FIG. 6 is a flow chart illustrating steady state determination according to an embodiment of the present application.

Fig. 7 is a schematic diagram illustrating an implementation effect of the power load status recognition method according to an embodiment of the present application.

FIG. 8 is a comparison diagram of the difference between the recognition results of the error-proofing and the error-proofing in an embodiment of the present application.

FIG. 9 is a block diagram of a power load status recognition system according to an embodiment of the present application.

Fig. 10 is a schematic structural diagram of an apparatus according to an embodiment of the present application.

Description of the embodiments

Other advantages and effects of the present application will become apparent to those skilled in the art from the present disclosure, when the following description of the embodiments is taken in conjunction with the accompanying drawings. The present application may be embodied or carried out in other specific embodiments, and the details of the present application may be modified or changed from various points of view and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict.

It should be noted that, the illustrations provided in the following embodiments merely illustrate the basic concepts of the application by way of illustration, and only the components related to the application are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

In order to balance the following response speed of each operation condition of the fuel cell engine in the transient process of the power load and the control stability of the power steady state, the power load state of the fuel cell engine needs to be identified, the fuel cell engine is distinguished to be in loading, load reduction or steady state, and then the control parameters of each subsystem are adaptively adjusted according to the power load state of the fuel cell engine, so that the aim of accurate control is achieved. On one hand, the transient following response effect of each operation condition in the loading and unloading processes is good, and the overshoot phenomenon is avoided; on the other hand, the steady-state control precision is improved, and the anti-interference capability is enhanced. Therefore, the technical problem that transient response performance and steady-state anti-interference performance are contradicted due to the adoption of fixed control parameters is solved.

Further, in order to make the control parameters of each subsystem of the fuel cell engine adaptively change with the power load state, the primary problem is to solve the problem of power load state identification. However, the process of transitioning the fuel cell engine power load state from dynamic (loaded, unloaded) to steady state is difficult to determine, and is embodied as:

the actual power in the loading process is continuously close to the set target value, and the steady state can be judged to be reached after the error between the actual power and the set target value is lower than a certain degree, however, the possible overshoot phenomenon at the tail end of the loading process can cause the power load state of the fuel cell engine to be judged to reach the steady state too early, and the control error convergence speed and stability of the power of the fuel cell engine at the tail end of the loading process and each operation condition are affected;

the response speed of the subsystem control operation condition is lagged or the occasional state abnormal fluctuation of the actuator can cause occasional fluctuation when the actual power of the fuel cell engine is close to the set target value, so that the judgment result of the load state of the fuel cell engine is jumped;

after the load state of the fuel cell engine is judged to reach a steady state, the power of the fuel cell engine is greatly deviated from a set target value in a very short time due to sudden changes of certain external factors such as vehicle speed, wind speed and ambient temperature or sporadic abnormal state fluctuation of an actuator, so that a judgment result is jumped.

Based on the above problems in the prior art, the present application provides a power load status identification method, system, device and medium. The technical scheme of the present application is described in detail below in connection with specific embodiments.

In an embodiment, the fuel cell engine in the embodiments of the present application has a complete control function, specifically has basic subsystem functions, including an air supply subsystem, a hydrogen supply subsystem, a hydrothermal management subsystem, DCDC, and a fuel cell engine controller FCCU. Through CAN communication configuration of the DCDC and the FCCU, the DCDC CAN be guaranteed to receive a DCDC input end current request value signal sent by the FCCU, meanwhile, the FCCU CAN be guaranteed to receive a DCDC output end current and voltage actual value signal sent by the DCDC, and the FCCU software obtains a system net power actual value signal by calculating the product of the DCDC output end current and voltage. The hydrogen inlet pipe of the fuel cell engine is connected with the hydrogen supply pipe of the test system, and the main water path and the auxiliary water path are connected with the cooling water path of the test system, so that continuous hydrogen supply and cooling water circulation are ensured during the operation of the fuel cell engine. After the setting is finished, the power load state identification method can be adopted to identify the power load state, so that the system parameter is precisely controlled according to the identified power load state, the stability of power output is ensured, and the influence of repeated jump of the power load state on the reliability of corresponding components at the vehicle end is avoided.

Referring to fig. 1, the present application provides a power load status identifying method, which includes the following steps:

step S100, obtaining net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment, wherein the plurality of continuous sampling moments include: a current sampling instant and at least one preceding sampling instant;

step S110, if the change amount of the net power request value is within the preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value, so as to determine that the power load state of the fuel cell engine reaches a steady state at the current sampling moment when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

In step S100, after the fuel cell engine is started, the power demand of the whole vehicle power system at different sampling moments, that is, the net power demand value, is obtained through the set sampling interval. While the actual power value of the fuel cell engine may be collected. The output power of a fuel cell engine typically exists in three states: load, steady state, and load-down states. The net power request value is taken as target power, the actual power value of the fuel cell engine gradually approaches to the net power request value, the actual power of the loading process is continuously close to the target power, the steady state can be judged to be reached after the error between the actual power and the target power is lower than a certain degree, however, the possible overshoot phenomenon at the tail end of the loading process can cause the power load state of the fuel cell engine to be judged to reach the steady state too early, and the control error convergence speed and stability of the power of the fuel cell engine at the tail end of the loading process and each operation condition are influenced.

In step S110, since the actual power is easily interfered by external factors and has transient mutation, there may be a problem that the actual power value is determined to be steady state prematurely or jumps between steady state and loading or unloading state in the process of identifying whether the actual power value reaches steady state, which affects the accuracy of final identification. The method and the device judge through combining the net power request value with the actual power value and the power control error so as to solve the problem that steady state judgment is easy to be interfered.

In one embodiment, after obtaining the net power request value and the actual power value at a plurality of consecutive sampling moments, the method further includes:

Referring to fig. 2, fig. 2 is an overall flowchart illustrating power load status identification according to an embodiment of the present application. The power load status identification includes the steps of:

s1, starting a fuel cell engine, and inputting a net power request value P of a fuel cell engine system _req Step S2, jumping to the step S2;

s2, judging a request value P of the current moment of the net power of the system _req (t) request value P with last sampling time _req （t-t _s ) Whether or not the difference of (2) exceeds the interval [ -delta, delta]Wherein t is _s The step length, i.e. the sampling time, is calculated for the controller, and δ is a set value, which can be set according to the actual application requirements, without limitation. If the difference exceeds the preset variation range, the net power request value of the system changes by an amount P _chg = P _req （t）- P _req （t-t _s ) Otherwise, the net power request value of the system changes by an amount P _chg =0, proceed to steps S3 and S4 in parallel; in step S2, small-amplitude changes in the system net power request value are filtered by taking the allowable interval, i.e. if the system net power request value P _req If the change amplitude relative to the last sampling time is not more than + -delta, the system net power request value is regarded as unchanged, and the change quantity P of the system net power request value is made _chg Otherwise, as the change, the net power request value of the system changes by an amount P _chg = P _req （t）- P _req （t-t _s ). Such an approach may allow for a small range of power requests to be varied without changing the recognition state results, avoiding unnecessary repeated changes in system control parameters, enhancing system robustness.

S3, according to the change quantity P of the net power request value of the system _chg Net system power request value P _req And system net power actual value P _act And judging and determining the loading and unloading state flag bit LoadFlg. If load is load, loadflg=1, if load is load-reducing, loadflg= -1, jump to step S8;

S4, according to the change quantity P of the net power request value of the system _chg Net system power request value P _req And system net power actual value P _act Judging at the set time T _PwrChgHold Internal power control error e _Pwr Whether or not the set threshold e is exceeded _ctrl If yes, the power error overrun flag bit S _PwrErr =0, jump to step S5, otherwise, S _PwrErr =1, jump to step S7;

s5, when the actual power is suddenly changed instantaneously, controlling the power to be in error e _Pwr Gradually converging with time to decrease, at this time, keep S _PwrErr =0, until e _Pwr <e _ctrl Is activated, the determination logic: determining a power control error e _Pwr Whether or not to be continuously lower thanSetting a threshold e _ctrl And the duration exceeds the set time T _ErrSat If yes, outputting a process flag bit h (t) =0, otherwise, h (t) =1, and jumping to step S6;

s6, judging whether the process flag bit h (t) =0 is true, if yes, S _PwrErr =1, otherwise, S _PwrErr Keeping 0 unchanged, and jumping to the step S7;

s7, according to the change quantity P of the net power request value of the system _chg And power error overrun flag bit S _PwrErr Judging whether the net power of the system reaches a steady state or not, and determining a steady state flag bit StdyFlg. If the steady state is reached, stdyflg=1, and if the steady state is not reached, stdyflg=0, the process goes to step S8;

and S8, determining a final power load state flag bit LoadStateFlg according to the steady state flag bit StdyFlg and the loading and unloading state flag bit LoadFlg. Judging whether stdyflg=1 is true, if yes, loadstateflg=0, otherwise, loadstateflg=loadflg. Returning to step S2, the loop is executed until the fuel cell engine is stopped.

By executing steps S1 to S8, a function of automatically judging the power load state of the fuel cell engine can be realized. If loadstateflg=1, then the fuel cell engine is in a power load state; if loadstateflg= -1, the fuel cell engine is in a power load off-state; if loadstateflg=0, the fuel cell engine power load reaches the request value P _req And is in steady state.

In an embodiment, determining the fuel cell engine power load state as a loaded state or a down-loaded state according to the net power request value variation, the net power request value, and the corresponding actual power value includes:

In an embodiment, determining the power load state of the fuel cell engine as the loaded state or the down load state according to the net power request value variation amount, the net power request value, and the corresponding actual power value further includes:

Referring to fig. 3, fig. 3 is a schematic diagram illustrating an acquisition flow of status flags recorded or downloaded in an embodiment of the present application. The method comprises the following specific steps:

s31, inputting a net power request value variation quantity P of the system _chg Jump to step S32;

s32, judging absolute value |P of system net power request value variation _chg If the I is greater than 0, if yes, jumping to the step S33, otherwise, jumping to the step S34;

s33, updating the process variable b to be the actual value of the net power of the system at the current moment, namely, let b (t) =P _act (t) jumping to step S35;

s34, the process variable b maintains the last time state value, i.e. let b (t) =b (t-t) _s ) Jump to step S35;

s35, calculating a system net power request value P at the current moment _req The difference c from the process variable b, i.e. c (t) =p _req (t) -b (t), jumping to step S36;

S36, determining whether c (t) >0 is true, if yes, setting loadflg=1, otherwise, setting loadflg= -1.

In one embodiment, the process of comparing the power control error to a preset error threshold comprises:

In an embodiment, the process of comparing the power control error with a preset error threshold further comprises:

Referring to fig. 4, fig. 4 is a flow chart illustrating a power control error determination in an embodiment of the present application. The method comprises the following specific steps:

s41, inputting a net power request value variation quantity P of the system _chg Jump to step S42;

s42, judging absolute value |P of system net power request value variation _chg If the I is greater than 0, if yes, jumping to step S43, otherwise, jumping to step S44;

s43, counting the counter at the current moment ₁ Zero the value of (t), namely make Count ₁ (t) =0, jumping to step S45;

s44, counting the counter at the current moment ₁ The value of (t) is increased by t on the basis of the last moment _s Order Count ₁ （t）= Count ₁ （t-t _s ）+t _s Jump to step S45;

s45, according to formula e _Pwr =|P _act -P _req |/P _req Calculating the power control error e at the current moment _Pwr (t) jumping to step S46;

s46, judging whether the counter value has not overflowed for the set time T _PwrChgHold I.e. judge Count ₁ （t）≤T _PwrChgHold If yes, jumping to step S47, otherwise jumping to step S48;

s47, judgment e _Pwr (t)≥e _ctrl (t) if so, making the power error overrun flag bit S _PwrErr =0, ending the flow of step S4, otherwise, S _PwrErr =1, jump to step S42;

s48, order S _PwrErr =1, and the flow of step S4 ends.

In an embodiment, after determining the power control error according to the net power request value and the actual power value, the method further includes:

Referring to fig. 5, fig. 5 is a schematic diagram of a judgment flow after exceeding a preset error threshold in an embodiment of the present application. The method comprises the following specific steps:

s51, inputting the power control error e calculated in the step S45 _Pwr Jump to step S52;

s52, judgment e _Pwr (t)≥e _ctrl (t) if yes, then the process variable d at the current moment is assigned to 0, i.e. d (t) =0, and the process jumps to step S53, otherwise, d (t) =1, and jumps to step S54;

s53, assigning an output process flag bit h (t), enabling h (t) =1, and returning to the step S52;

s54, judging whether the current time value of the process variable d is not equal to the previous valueA sampling time value, i.e. determining d (t) noteqd (t-t) _s ) If so, the process variable f at the current time is assigned 0, i.e. f (t) =0, otherwise, f (t) =f (t-t) _s ）+t _s Jump to step S55;

s55, judging whether the process variable d (t) +.0 is true, if yes, the process variable g (t) =f (t) at the current moment, otherwise, g (t) =0, jumping to step S56;

s56, judging the process variable g (T) > T _ErrSat If yes, outputting a flag bit h (t) =0, otherwise, h (t) =h (t-t) _s ) Returning to step S52, the loop is executed.

Referring to fig. 6, fig. 6 is a flow chart illustrating steady state determination according to an embodiment of the present application, and the specific steps are as follows:

s71, inputting a net power request value variation quantity P of the system _chg And power error overrun flag bit S _PwrErr Jump to step S72;

s72, judging the net power request value variation P of the system _chg If not, jumping to step S73 if yes, otherwise jumping to step S74;

s73, counting a counter at the current moment ₂ Zero the value of (t), namely make Count ₂ (t) =0, jumping to step S75;

s74, counting the counter at the current moment ₂ The value of (t) is increased by t on the basis of the last moment _s Order Count ₂ (t)= Count ₂ (t-t _s )+t _s Jump to step S75;

s75, judging power error overrun flag bit S _PwrErr Not 0, if yes, then the process variable k (t) =0 at the current time, otherwise, k (t) =count ₂ (t) jump to step S76;

s76, determining whether the process variable k (t) +.0 is true, if yes, stdyflg=0, otherwise stdyflg=1.

Based on the steps, the step S2 and the step S4 can realize an error proofing function, and can avoid power caused by certain factors in the steady-state operation processThe false jump phenomenon of the identification result caused by the flash difference. The implementation principle of this function is specifically described as follows: assuming that the current state of the system is steady state, stdyFlg=1, S at this time _PwrErr =1; if the system power is flashed due to some factors, but the system net power request value P _req And does not change, P _chg=0 The method comprises the steps of carrying out a first treatment on the surface of the Will P _chg=0 The condition is substituted into step S4, more specifically step S41 to step S48 will be performed; according to step S42, at this time |P _chg If 0 is not true, the process jumps to step S44; the counter value is incremented by t _s I.e. Count ₁ （t）= Count ₁ （t-t _s ）+t _s Jump to step S45; calculating the power control error e at the current moment _Pwr (t) jumping to step S46; at this time, it should be noted that the counter value has overflowed for the set time T _PwrChgHold I.e. Count ₁ （t）≤T _PwrChgHold If not, jumping to step S48; let S _PwrErr =1, and the flow of step S4 ends. As can be seen from the specific step S75 in the step S7, when S _PwrErr When=1, the process variable k (t) =0, further according to step S76, where k (t) +.0 is not satisfied, stdyflg=1, and it can be found that the StdyFlg state is not changed, so that the system power load state recognition result still remains in a steady state, and a false jump phenomenon of the recognition result is avoided.

The combination of the step S4, the step S5 and the step S6 can avoid the phenomenon of repeated jump of the identification result caused by the oscillation attenuation of the power control error in the process of converting the loading/unloading state into the steady state. The implementation principle of this function is specifically described as follows: suppose the current system net power request value P _req With variation exceeding the allowable range, i.e. |P _req I > 0, and power control error e _Pwr At a set time T _PwrChgHold Exceeds a set threshold e _ctrl According to step S4, S _PwrErr =0, at this time, the power load state recognition result is loading or unloading, and the system power control error e _Pwr Will exceed the set threshold e _ctrl Then gradually converging and reducing along with time, and the program further jumps to step S5; gradual power control errorReduced, when e _Pwr <e _ctrl If e _Pwr Continuously lower than the set threshold e _ctrl And the duration exceeds the set time T _ErrSat The process flag bit h (t) =0, provided that oscillations occur during the power control error reduction resulting in e _Pwr ＞e _ctrl If the judgment condition in step S5 cannot be satisfied, let h (t) =1, and the process jumps to step S6; according to step S6, when h (t) =0, S _PwrErr =1, otherwise, S _PwrErr And remains unchanged at 0. Therefore, the situation that the oscillation occurs in the process of reducing the power control error and the error exceeds the threshold again will not lead to the jump of the power load state identification result to the steady state, and the waiting for e is needed _Pwr Continuously lower than the set threshold e _ctrl And the duration exceeds the set time T _ErrSat And when the condition is satisfied, the system jumps to a steady state, so that the phenomenon of repeated jump of the identification result caused by oscillation attenuation of the power control error is avoided.

In one embodiment, according to the method principles of the present invention described in step S1-step S8, more specifically, the method includes step S31-step S36, step S41-step S48, step S51-step S56, and step S71-step S76, and an application layer software model is built in Matlab/Simulink;

c code compiling is carried out on an application layer software model built in Matlab/Simulink, and the C code is uploaded to a controller through USBCANN equipment, so that automatic identification control is realized.

In one embodiment, the method provided in the foregoing embodiment may be used to perform experimental verification, and the FCCU software of the fuel cell engine controller will identify the power load state of the fuel cell engine in real time on line according to the principles of the method of the present invention described in steps S1-S8, where the identification result is recorded and stored in the INCA software, and at the same time, the net power request value P of the fuel cell engine needs to be recorded and stored _req And an actual value P _act And the power control error e calculated in step S45 _Pwr The method comprises the steps of carrying out a first treatment on the surface of the And (5) carrying out an algorithm effect verification experiment. Requesting fuel cell engine net power by INCA software, P _req Is set in the range of 10% to 90% of rated power (i.e. 10% PE-90% PE range)) Changing, and storing the data required to be recorded during the test; and carrying out a recognition result difference comparison experiment of whether error prevention fault tolerance measures exist or not. Wherein no error-proofing fault-tolerant measures refer to the following only e _Pwr ＞e _ctrl Whether or not it is established to perform load/load-down and steady state judgment and conversion, i.e. when e _Pwr ＞e _ctrl When e, the identification result is load/load reduction _Pwr ≤e _ctrl When the identification result is steady state; the fault-tolerant measures refer to the effects of the combination of the steps S2, S4, S5 and S6 mentioned in the method according to the invention. The data to be recorded during the test is saved.

Referring to fig. 7, fig. 7 is a schematic diagram illustrating an implementation effect of a power load status recognition method according to an embodiment of the present application. According to FIG. 7 (a), when the system net power request value P _req After the change, the net power actual value P of the system is obtained through a power closed loop program in the FCCU software of the fuel cell engine controller _act Will follow the request value P _req And (3) a change. As shown in FIG. 7, when the request value P _req After the step up, according to FIG. 7 (c), the power control error e _Pwr The power load state recognition result in fig. 7 (b) is changed from state 0 to state 1 to be recognized as the power loading state by exceeding the control threshold line, and then the power control error e in fig. 7 (c) _Pwr After a period of time, the power load state recognition result in fig. 7 (b) is changed from state 1 to state 0, the recognition result is changed from the power load state to the steady state, and then only at the request value P _req In the absence of variation, only the power control error e occurs _Pwr Occasional exceeding of the control threshold line does not cause the recognition result to become loaded again from steady state; equivalent request value P _req As does the step down.

Referring to fig. 8, fig. 8 is a comparison diagram of differences between recognition results of error-proofing measures and error-proofing measures in an embodiment of the present application. Wherein fig. 8 (a) -8 (c) show the recognition results of the error-free fault-tolerant measures, and fig. 8 (d) -8 (f) show the recognition results of the error-tolerant measures. As shown in fig. 8 (b), it is apparent that in the case of no error-proof fault-tolerant measures, i.e.To make the system power load state reach steady state, sporadic power control error e _Pwr Exceeding the control threshold line may also trigger the recognition result to erroneously deviate from a steady state condition. Furthermore, in the absence of error-proofing fault-tolerant measures, the value P is requested _req Control error e after change _Pwr Repeated jumps in the recognition result occur during the damping of the oscillations. Comparing fig. 8 (b) and fig. 8 (e), it can be seen that the above two phenomena can be significantly improved by adopting the error-proofing and fault-tolerant measures of the present invention.

Based on the technical scheme, the method and the device can distinguish and identify the power load state of the fuel cell engine on line according to loading, load reduction and steady state, and the conversion of different identification states is completely and automatically completed by a program algorithm, so that the method and the device have the characteristics of high automation and intelligence; the repeated jump phenomenon of the identification result caused by the oscillation attenuation of the power control error in the process of converting the loading/unloading state into the steady state can be avoided; the device has an error prevention function, and can avoid the phenomenon of false jump of the identification result caused by power flash difference caused by certain factors in the steady-state operation process; the small-range change of the power request does not change the recognition state result, so that the robustness and the anti-interference capability of the recognition method are enhanced; the method is beneficial to realizing parameter self-adaptive control of key actuators of all subsystems of the fuel cell engine according to different engine power load states, thereby improving the control effect of key operation parameters of the fuel cell engine, improving the output performance of the system and prolonging the service life of the system.

Referring to fig. 9, fig. 9 is a block diagram of a power load status recognition system according to an embodiment of the present application, the system includes: a power data acquisition module 10, configured to acquire a net power request value at a plurality of consecutive sampling moments and an actual power value in a neighborhood time range of each sampling moment, where the plurality of consecutive sampling moments includes: a current sampling instant and at least one preceding sampling instant; the load state identification module 11 is configured to determine a power control error according to the net power request value and the actual power value if the net power request value variation is within a preset variation range, and compare the power control error with a preset error threshold, so as to determine that the power state of the fuel cell engine reaches a steady state at the current sampling moment when the power control error is smaller than the preset error threshold within a preset first time limit, where the net power request value variation is a difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

In an embodiment, the load status identifying module 11 is further configured to, after obtaining the net power request values and the actual power values at a plurality of consecutive sampling moments, further include: and if the change amount of the net power request value exceeds the preset change range, determining that the power load state of the fuel cell engine is in a loading state or a load-reducing state according to the change amount of the net power request value, the net power request value and the corresponding actual power value.

In an embodiment, the load status identification module 11 is further configured to determine a power control error according to the net power request value and the actual power value, including: the net power request value of the current sampling moment is recorded as a first request value, and the actual power value in the neighborhood time range of the current sampling moment is used as a first power value; and calculating a first difference value between the first request value and the first power value, and taking the ratio of the absolute value of the first difference value to the first request value as the power control error.

In an embodiment, the load status identifying module 11 is further configured to, after determining the power control error according to the net power request value and the actual power value, further include: if the power control error is greater than or equal to a preset error threshold value within a preset first time limit, waiting for the power control error to be smaller than the preset error threshold value, and if the power control error is continuously smaller than the preset error threshold value and the duration exceeds a preset second time limit, assigning a first numerical value to a preset first zone bit; if the duration of the power control error smaller than the preset error threshold is smaller than the preset second implementation, a second value is assigned to the first flag bit; determining that the battery engine load power state reaches a steady state when the first flag bit is equal to the first value; and when the first flag bit is equal to the second value, the battery engine load power state is kept unchanged.

In one embodiment, the load state identification module 11 is further configured to determine that the current sampling time before the power load state of the fuel cell engine reaches a steady state, further includes: and if the change amount of the net power request value is in the preset change range, setting the change amount of the net power request value to zero.

In an embodiment, the load state identification module 11 is further configured to determine that the load state of the fuel cell engine is a loading state or a load-down state according to the change amount of the net power request value, the net power request value and the corresponding actual power value, and includes: if the absolute value of the change quantity of the net power request value is larger than zero, calculating a second difference value between the net power request value and the actual power value at the current sampling moment; if the second difference is greater than zero, the fuel cell engine power load state is a loaded state; and if the second difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment, the load state identification module 11 is further configured to determine that the load state of the fuel cell engine is a loading state or a load-down state according to the change amount of the net power request value, and the corresponding actual power value, and further includes: if the change amount of the net power request value is equal to zero, calculating a third difference value between the net power request value at the current sampling moment and the actual power value at the previous sampling moment; if the third difference value is greater than zero, the power load state of the fuel cell engine is a loading state; and if the third difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment, the load status identifying module 11 is further configured to implement a process of comparing the power control error with a preset error threshold value, including: and if the absolute value of the change quantity of the net power request value is larger than zero, resetting the count value of the current sampling moment, and if the count value does not exceed the preset first time limit and the power control error is larger than or equal to the preset error threshold, keeping the original state of the power of the fuel cell engine unchanged.

In an embodiment, the load status identifying module 11 is further configured to implement a process of comparing the power control error with a preset error threshold value, and further includes: if the change amount of the net power request value is equal to zero, a sampling duration is newly increased on the basis of the count value of the last sampling time as the count value of the current sampling time, so that the count value of the current sampling time exceeds the preset first time limit, and the power state of the fuel cell engine is kept unchanged at the moment.

The power load condition identification system described above may be implemented in the form of a computer program that is executable on a computer device as shown in fig. 10. A computer device, comprising: memory, a processor, and a computer program stored on the memory and executable on the processor.

The various modules in the power load state identification system described above may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules can be embedded in the memory of the terminal in a hardware form or independent of the terminal, and can also be stored in the memory of the terminal in a software form, so that the processor can call and execute the operations corresponding to the above modules. The processor may be a Central Processing Unit (CPU), microprocessor, single-chip microcomputer, etc.

FIG. 10 is a schematic diagram of the internal structure of a computer device in one embodiment. There is provided a computer device comprising: a memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the steps of: obtaining net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment, wherein the plurality of continuous sampling moments comprise: a current sampling instant and at least one preceding sampling instant; if the change amount of the net power request value is in a preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value to determine that the power load state of the fuel cell engine at the current sampling moment reaches a steady state when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

In an embodiment, after the processor executes the obtained net power request values and actual power values at a plurality of consecutive sampling moments, the method further includes: and if the change amount of the net power request value exceeds the preset change range, determining that the power load state of the fuel cell engine is in a loading state or a load-reducing state according to the change amount of the net power request value, the net power request value and the corresponding actual power value.

In an embodiment, the determining the power control error according to the net power request value and the actual power value includes: the net power request value of the current sampling moment is recorded as a first request value, and the actual power value in the neighborhood time range of the current sampling moment is used as a first power value; and calculating a first difference value between the first request value and the first power value, and taking the ratio of the absolute value of the first difference value to the first request value as the power control error.

In an embodiment, when the processor executes the foregoing method, the determining a power control error according to the net power request value and the actual power value further includes: if the power control error is greater than or equal to a preset error threshold value within a preset first time limit, waiting for the power control error to be smaller than the preset error threshold value, and if the power control error is continuously smaller than the preset error threshold value and the duration exceeds a preset second time limit, assigning a first numerical value to a preset first zone bit; if the duration of the power control error smaller than the preset error threshold is smaller than the preset second implementation, a second value is assigned to the first flag bit; determining that the battery engine load power state reaches a steady state when the first flag bit is equal to the first value; and when the first flag bit is equal to the second value, the battery engine load power state is kept unchanged.

In one embodiment, when the processor executes, the determining performed before the current sampling time reaches the steady state, further includes: and if the change amount of the net power request value is in the preset change range, setting the change amount of the net power request value to zero.

In an embodiment, when the processor executes the above, the determining that the power load state of the fuel cell engine is the loading state or the load-down state according to the net power request value variation, the net power request value and the corresponding actual power value includes: if the absolute value of the change quantity of the net power request value is larger than zero, calculating a second difference value between the net power request value and the actual power value at the current sampling moment; if the second difference is greater than zero, the fuel cell engine power load state is a loaded state; and if the second difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment, when the processor executes the above, the determining that the power load state of the fuel cell engine is the loading state or the load-down state according to the net power request value variation, the net power request value and the corresponding actual power value further includes: if the change amount of the net power request value is equal to zero, calculating a third difference value between the net power request value at the current sampling moment and the actual power value at the previous sampling moment; if the third difference value is greater than zero, the power load state of the fuel cell engine is a loading state; and if the third difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment, when the processor executes the process of comparing the power control error with a preset error threshold, the process includes: and if the absolute value of the change quantity of the net power request value is larger than zero, resetting the count value of the current sampling moment, and if the count value does not exceed the preset first time limit and the power control error is larger than or equal to the preset error threshold, keeping the original state of the power of the fuel cell engine unchanged.

In an embodiment, when the processor executes the foregoing process, the implemented process of comparing the power control error with a preset error threshold further includes: if the change amount of the net power request value is equal to zero, a sampling duration is newly increased on the basis of the count value of the last sampling time as the count value of the current sampling time, so that the count value of the current sampling time exceeds the preset first time limit, and the power state of the fuel cell engine is kept unchanged at the moment.

In one embodiment, the computer device may be used as a server, including but not limited to a stand-alone physical server, or a server cluster formed by a plurality of physical servers, and may also be used as a terminal, including but not limited to a mobile phone, a tablet computer, a personal digital assistant, a smart device, or the like. As shown in FIG. 10, the computer device includes a processor, a non-volatile storage medium, an internal memory, a display screen, and a network interface connected by a system bus.

Wherein the processor of the computer device is configured to provide computing and control capabilities to support the operation of the entire computer device. The non-volatile storage medium of the computer device stores an operating system and a computer program. The computer program is executable by a processor for implementing a power load state identification method provided by the above embodiments. Internal memory in a computer device provides a cached operating environment for an operating system and computer programs in a non-volatile storage medium. The display interface can display data through the display screen. The display screen may be a touch screen, such as a capacitive screen or an electronic screen, and the corresponding instruction may be generated by receiving a click operation on a control displayed on the touch screen.

It will be appreciated by those skilled in the art that the architecture of the computer device illustrated in fig. 10 is merely a block diagram of some of the structures associated with the present application and is not limiting of the computer device to which the present application may be applied, and that a particular computer device may include more or fewer components than those illustrated, or may combine some components, or have a different arrangement of components.

In one embodiment, a computer readable storage medium is provided having stored thereon a computer program which when executed by a processor performs the steps of: obtaining net power request values of a plurality of continuous sampling moments and actual power values in a neighborhood time range of each sampling moment, wherein the plurality of continuous sampling moments comprise: a current sampling instant and at least one preceding sampling instant; if the change amount of the net power request value is in a preset change range, determining a power control error according to the net power request value and the actual power value, and comparing the power control error with a preset error threshold value to determine that the power load state of the fuel cell engine at the current sampling moment reaches a steady state when the power control error is smaller than the preset error threshold value within a preset first time limit, wherein the change amount of the net power request value is the difference between the net power request value at the current sampling moment and the net power request value at the previous sampling moment.

In one embodiment, the computer program, when executed by the processor, is configured to obtain the net power request value and the actual power value at a plurality of consecutive sampling instants, and then further includes: and if the change amount of the net power request value exceeds the preset change range, determining that the power load state of the fuel cell engine is in a loading state or a load-reducing state according to the change amount of the net power request value, the net power request value and the corresponding actual power value.

In one embodiment, the computer program, when executed by the processor, is implemented to determine a power control error based on the net power request value and the actual power value, comprising: the net power request value of the current sampling moment is recorded as a first request value, and the actual power value in the neighborhood time range of the current sampling moment is used as a first power value; and calculating a first difference value between the first request value and the first power value, and taking the ratio of the absolute value of the first difference value to the first request value as the power control error.

In an embodiment, the computer program, when executed by the processor, is implemented to determine a power control error based on the net power request value and the actual power value, further comprising: if the power control error is greater than or equal to a preset error threshold value within a preset first time limit, waiting for the power control error to be smaller than the preset error threshold value, and if the power control error is continuously smaller than the preset error threshold value and the duration exceeds a preset second time limit, assigning a first numerical value to a preset first zone bit; if the duration of the power control error smaller than the preset error threshold is smaller than the preset second implementation, a second value is assigned to the first flag bit; determining that the battery engine load power state reaches a steady state when the first flag bit is equal to the first value; and when the first flag bit is equal to the second value, the battery engine load power state is kept unchanged.

In one embodiment, the computer program, when executed by the processor, performs the determining that the fuel cell engine power load state reaches a steady state prior to the current sampling time, further comprising: and if the change amount of the net power request value is in the preset change range, setting the change amount of the net power request value to zero.

In an embodiment, the computer program, when executed by the processor, is implemented to determine that the fuel cell engine power load state is a loaded state or a down-loaded state according to the net power request value variation, the net power request value, and the corresponding actual power value, comprising: if the absolute value of the change quantity of the net power request value is larger than zero, calculating a second difference value between the net power request value and the actual power value at the current sampling moment; if the second difference is greater than zero, the fuel cell engine power load state is a loaded state; and if the second difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In an embodiment, the determining that the fuel cell engine power load state is the loaded state or the unloaded state according to the net power request value variation, the net power request value, and the corresponding actual power value implemented when the instructions are executed by the processor further comprises: if the change amount of the net power request value is equal to zero, calculating a third difference value between the net power request value at the current sampling moment and the actual power value at the previous sampling moment; if the third difference value is greater than zero, the power load state of the fuel cell engine is a loading state; and if the third difference value is smaller than zero, the power load state of the fuel cell engine is in a load-reducing state.

In one embodiment, the instructions, when executed by the processor, implement a process for comparing the power control error to a preset error threshold comprising: and if the absolute value of the change quantity of the net power request value is larger than zero, resetting the count value of the current sampling moment, and if the count value does not exceed the preset first time limit and the power control error is larger than or equal to the preset error threshold, keeping the original state of the power of the fuel cell engine unchanged.

In one embodiment, the process implemented to compare the power control error to a preset error threshold when the instructions are executed by the processor further comprises: if the change amount of the net power request value is equal to zero, a sampling duration is newly increased on the basis of the count value of the last sampling time as the count value of the current sampling time, so that the count value of the current sampling time exceeds the preset first time limit, and the power state of the fuel cell engine is kept unchanged at the moment.

The foregoing embodiments are merely illustrative of the principles of the present application and their effectiveness, and are not intended to limit the application. Modifications and variations may be made to the above-described embodiments by those of ordinary skill in the art without departing from the spirit and scope of the present application. Accordingly, it is intended that all equivalent modifications and variations which may be accomplished by persons skilled in the art without departing from the spirit and technical spirit of the disclosure be covered by the claims of this application.

Claims

1. A method for identifying a power load condition, comprising:

2. The method of claim 1, further comprising, after obtaining the net power request value and the actual power value at a plurality of consecutive sampling instants:

3. The power load state identification method of claim 1, wherein determining a power control error from the net power request value and the actual power value comprises:

4. The power load state identification method of claim 1, further comprising, after determining a power control error from the net power request value and the actual power value:

if the duration of the power control error smaller than the preset error threshold is smaller than the preset second time limit, a second value is assigned to the first flag bit;

5. The power load condition identification method of claim 1, wherein determining that the fuel cell engine power load condition has reached steady state at the current sampling time further comprises:

6. The power load state identification method according to claim 2 or 5, characterized in that determining the fuel cell engine power load state as a loaded state or a down-loaded state from the net power request value variation amount, the net power request value, and the corresponding actual power value, comprises:

7. The power load state identification method of claim 6, wherein determining the fuel cell engine power load state as a loaded state or a down-loaded state based on the net power request value variation, the net power request value, and a corresponding actual power value, further comprises:

8. The method of claim 1, wherein comparing the power control error to a preset error threshold comprises:

9. The method of claim 1, wherein comparing the power control error to a preset error threshold further comprises:

10. A power load condition identification system, comprising:

11. A computer device, comprising: memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the steps of the power load state identification method according to any of claims 1 to 9 when the computer program is executed by the processor.

12. A computer readable storage medium, on which a computer program is stored, characterized in that the computer program, when being executed by a processor, implements the steps of the power load state identification method of any of claims 1 to 9.