RU2721227C1 - Energy accumulation system and method of control thereof - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: group of inventions relates to an energy storage system and a method of controlling said energy. Proposed system consists of power section, power section conditioners and control means equipped with data interface. Power section comprises power terminals of power accumulation system, accumulator battery, capacitor bank and converter with control input of converter, which are connected so that P_out=P_ab+P_cb-P_c, where: P_out - output electric power of power accumulation system, measured at its power terminals, P_ab - output electric power of accumulator battery, P_cb is the output power of the capacitor bank, P_c is the loss power in the converter, and the power ratio P_ab, P_cb and P_c depends on the setting Ref at the control input of the converter. At the same time the control means include an input data array and an optimum control program. Wherein the array of input data can be filled through an information interface and comprises a prediction P_f of power P_out, and the optimum control program is connected to the input data array by the power part condition evaluation means and the converter control input and serves to generate the Ref setting, which minimizes the W function from the energy losses expected in the prediction lead period P_f.

EFFECT: higher efficiency of energy accumulation system by minimizing energy losses due to consideration of system requirements in output power, both current and prospective in the short term.

9 cl, 8 dwg

Description

The invention relates to the field of electrical engineering, in particular to electric power plants of transport vehicles, mainly unmanned vehicles.

Transport vehicles with electric power plants, such as hybrid cars with internal combustion engines or fuel cells, electric cars and electric buses, are finding wider application. They include rechargeable batteries, the efficiency of use of which largely determines the cost and technical characteristics of transport vehicles.

Known methods of energy management in hybrid vehicles (WO 2013/131735 A3; U.S. Pat. No. 8,606,513 B2; U.S. Pat. No. 10,131,341 B2) based on the characteristics of the movement of cars in various road conditions. These methods can improve the efficiency of use of rechargeable batteries, however, to an insufficient extent. This is due to the fact that the batteries have a relatively low specific power, and it is necessary to increase their mass in order to ensure sufficiently intense acceleration or regenerative braking of the transport vehicle.

Known energy storage systems for electric power plants of transport vehicles, which include a combination of two energy storage devices: the first is a rechargeable battery (secondary chemical current source) with high specific energy, the second is a capacitor bank (capacitor bank with a double electric layer, also referred to as supercapacitors), which has a high power density. In this case, various means and methods of energy distribution between the storage and capacitor batteries are used (US Pat. No. 5,373,195; US Pat. No. 7,258,183 B2; US Pat. No. 7,780,562 B2; US Pat. No. 7,791,216 B2; US Pat. No. 7,936,083 B2; US Pat. No. 8,434,578 B2; US Pat. No. 8,860,359 B2; US Pat. No. 9,162,669 B2; US Pat. No. 9,895,983 B2; US Pat. No. 10,050,439 B2; US Pat. No. 10,293,702 B2).

In the above technical solutions, energy delivery / reception by the capacitor bank occurs as a reaction to the current need arising from acceleration or regenerative braking of the transport vehicle, and the amount of energy stored in the capacitor bank deviates from the previously set initial level E ₀ to a smaller or larger side, and then returns to him; the operational energy capacity of a capacitor bank is

E _cb = E _max -E _min = E _ret + E _rec ,

where E _max , E _min are the maximum and minimum acceptable levels of energy stored by the capacitor bank, E _ret = E ₀ -E _min is the potential need for energy supplied by the capacitor bank, E _rec = E _max -E ₀ is the potential need for the received capacitor bank energy. A common drawback of these solutions is the inefficient use of a capacitor bank, which should have a substantial (up to two times at E _ret = E _rec ) excess operational energy intensity in relation to the potential demand for energy supplied or received by it.

From among the above technical solutions, as a prototype of the claimed invention, a method and a system for energy storage of a transport vehicle (U.S. Pat. No. 7,791,216 B2) were selected. This system is part of the electric power plant of the transport machine and consists of a power unit and a controller containing means for assessing the status of the power unit, control means and an information interface, the power unit containing power terminals of the system (a bus for connecting drive wheels to an electric drive), a battery , a capacitor bank and a converter with a control input of the converter, which are connected so that

P _out = P _ab + P _cb -P _c ,

where P _out is the output electric power of the energy storage system measured at its power terminals, P _ab is the output electric power of the battery, P _cb is the output electric power of the capacitor bank, P _c is the power loss in the converter, and the power ratio is P _ab , P _cb and P _c depend on the setting on the control input of the converter.

The control in the prototype is carried out so that the power ratio P _ab , P _cb and P _c is determined by the amount of energy E stored in the capacitor bank, in particular, when P _out > 0:

- if E ₁ <E, then P _ab = 0, P _cb > 0, P _c = 0;

- if E ₂ <E <E ₁ , then P _ab > 0, P _cb > 0, P _c >0;

- if E <E ₂ , then P _ab > 0, P _cb = 0, P _c > 0,

where E ₁ , E ₂ are threshold levels.

Thus, in the prototype, the process of energy delivery / reception includes stages in which the entire output electric power of the energy storage system is provided exclusively by capacitor or rechargeable batteries — energy losses at the internal resistances of the batteries are proportional to the square of their output currents and can be minimized by uniform distribution of these currents, which is not satisfied in this case.

The objectives of the invention are to reduce the weight and cost of the energy storage system, increase its resource.

Technical results that allow us to solve the problem: reducing the energy consumption of the capacitor bank, improving the operating modes of the converter, battery and capacitor banks by minimizing energy losses in them.

Technical results are achieved by the fact that in the energy storage system (hereinafter referred to as the system), consisting of the power unit, means for assessing the status of the power unit and control means equipped with an information interface, the power unit comprising power system terminals, a battery, a capacitor bank and a converter with the control input of the converter, which are connected so that

P _out = P _ab + P _cb -P _c ,

where P _out is the electrical output of the system, measured at its power terminals, P _ab is the electrical output of the battery, P _cb is the electrical output of the capacitor battery, P _c is the power loss in the converter, and the power ratio is P _ab , P _cb and P _c depends on the Ref setting at the control input of the converter, according to the claimed invention, an array of input data and an optimal control program are included in the control means, moreover:

- the input data array has the ability to fill through the information interface and contains a forecast P _f power P _out ;

- the optimal control program is connected with the input data array, means for assessing the state of the power unit and controlling the input of the converter and serves to form a Ref setting that minimizes the value of the function W from energy losses expected during the forecast lead P _f .

The system can be implemented in such a way that the formation of the Ref set point consists in choosing one of the many forecast variants of its change based on dynamic programming methods, and the criterion for choosing is the minimum value of the function

W = W _ab + k ₁ ⋅ W _cb + k ₂ ⋅ W _c ,

where k ₁ , k ₂ are weight factors, W _ab is the amount of energy loss at the internal resistance of the battery, W _cb is the amount of energy loss at the internal resistance of the capacitor bank, W _c is the amount of energy loss in the converter.

In the converter circuit, half-bridges can be used, each of which has a half-bridge control input, a first key, a second key, a positive output, a negative output and a switched output, a positive output connected to a switched output through the first key, a negative output connected to a switched output through a second key, the switched output has the ability to connect to the positive or negative output by a signal at the control input of the half-bridge.

The first version of the converter contains two half-bridge, a choke with a current sensor of the choke and a regulator, moreover:

- the positive and negative terminals of the first half-bridge are connected in parallel to the battery, the negative terminal of the first half-bridge is connected to the negative terminal of the second half-bridge, the switched output of the first half-bridge is connected via a choke to the switched output of the second half-bridge, the positive and negative terminals of which are connected in parallel to the capacitor bank;

- the regulator has three inputs and two outputs, the first feedback from the means for assessing the state of the power unit receives a signal of general feedback on the open circuit voltage of the capacitor bank, the second input of the regulator is the control input of the converter, and the local feedback from the sensor is fed to the third input of the regulator throttle current, the controller outputs are connected to the control inputs of the half-bridge.

In the first version of the converter, the power terminals of the system can be the plus and minus terminals of any of the two half-bridges.

The second version of the converter contains a half-bridge, a choke with a choke current sensor and a regulator, moreover:

- the positive and negative terminals of the half-bridge are power terminals of the energy storage system, the negative terminal of the half-bridge is connected to the negative terminal of the battery, the switched half-bridge output through the inductor is connected to the positive terminal of the battery and the negative terminal of the capacitor battery, the positive terminal of which is connected to the positive terminal of the half-bridge;

- the regulator has three inputs and an output, a general feedback signal for the open circuit voltage of the capacitor bank is fed to the first input of the regulator from the power unit state assessment means, the second input of the regulator is the control input of the converter, the local feedback signal from the current sensor is fed to the third input of the regulator throttle, the regulator output is connected to the control input of the half-bridge.

The regulator in both versions of the converter is designed so that the general feedback signal at the first input of the regulator strives for the Ref setting at the second input of the regulator.

The system can be placed on an electric vehicle with navigation and traffic assessment tools, and the program of cyclic forecast formation P _f based on the analysis of data from navigation tools and traffic assessment is included in the control tools.

The specified electric vehicle may contain a heat-insulating compartment, while:

- the battery has a capacity that provides no more than 100 kilometers of electric vehicle without recharging, and is placed in the insulating compartment so that it can be quickly replaced;

- on the territory of the alleged operation of the electric vehicle, a network of stations is located for the rapid replacement of batteries and their charging, combined with heating or cooling the batteries to optimal operating temperatures.

When controlling a system comprising a battery, a capacitor bank, and a converter with a control input of the converter, which are connected so that

P _out = P _ab + P _cb -P _c ,

where P _out is the electrical output of the system, P _ab is the electrical output of the battery, P _cb is the electrical output of the capacitor battery, P _c is the power loss in the converter, and the power ratio P _ab , P _cb and P _c depends on the Ref setting at the control input of the converter, according to the claimed method, a finite set U of voltage values is set and then the following actions are cyclically performed:

- form a forecast P _f power P _out and break the forecast lead time P _f into many time intervals;

- at each time interval, a set of predictive options for changing the voltage of the open circuit of the capacitor bank is formed so that at the borders of the time interval the magnitude of this voltage belongs to a given finite set U, and for each option, the loss w corresponding to the forecast P _{f is} calculated by the formula

w = w _ab + k ₁ ⋅w _cb + k ₂ ⋅w _c ,

where k ₁ , k ₂ are weighting factors, w _ab is the amount of energy loss at the internal resistance of the battery, w _cb is the amount of energy loss at the internal resistance of the capacitor battery, w _c is the amount of energy loss in the converter;

- from the set of generated forecast options, a sequence is selected that forms a continuous function u _f (t) with a minimum loss amount w, then the setting Ref is applied to the converter control input such that the open circuit voltage of the capacitor bank tends to u _f (t).

The inventive control method can be applied so that the cyclic execution of these actions is carried out with a repetition period many times smaller than the forecast lead time P _f .

The inventive control method can be applied on an electric vehicle with navigation aids, the data of which are used to compose a route, and means of assessing the traffic situation, the data of which are used to predict the electric vehicle’s traffic route along a route, and the forecast P _f is formed by the formula

P _f = (m⋅v⋅dv / dt + m⋅g⋅dh / dt + P _w ) / η,

where m is the mass of the electric vehicle, v, h are the predicted speed and height of the position of the electric vehicle, g is the acceleration of gravity, P _w is the predicted power loss due to rolling friction and aerodynamic resistance of the electric vehicle, η is the efficiency of the electric drive wheels of the electric vehicle, and the forecast lead time P _{f is} set so that it exceeds the value

(E _max -E _min ) / P _av ,

where E _max , E _min is the maximum and minimum possible energy reserves of the capacitor bank, P _av is the average power P _out when the electric vehicle moves along the main road with high-quality coating.

The essential features of the proposed solutions affect the achievement of the technical result as follows:

The battery has a high specific energy, and a capacitor bank has a high specific power. A system having high specific indicators of energy and power consists of a power unit, means for assessing the status of the power unit and control means, and the power unit contains power terminals of the system, a storage battery, a capacitor bank and a converter with a control input of the converter, which are connected in a certain way. The listed features are known from the prior art and offer the potential for optimizing the distribution process of the electrical output of the system between the battery and capacitor banks.

A new sign: “the input data array ... contains a forecast P _{f of} power P _out ” allows you to plan the return or reception of energy by a capacitor bank not only as a reaction to the current need that occurs during surges in the electrical output of the system, but also prepare the capacitor bank for such surges, and namely, to discharge it before the reception of energy, or to charge before the release of energy. At the same time, the capacitor bank will be used as efficiently as possible, since its operational energy intensity will not be excessive in relation to the potential need for energy to be supplied or received.

The realization of the above possibility is provided by a new feature: “an optimal control program ... for setting the Ref setting minimizing the value of the function W from energy losses expected during the forecast lead time P _f ”.

The formation algorithm is disclosed in the sign: “the formation of the Ref setting is to select one of the many predictive options for changing it, based on dynamic programming methods”. The latter are widely known (Bellman R. // Dynamic programming. - M .: Publishing house of foreign literature, 1960 .; Kormen T., Leiserson Ch., Rivest R., Stein K. // Algorithms: construction and analysis. - M .: William, 2005.).

Symptom: “minimum function value

W = W _ab + k ₁ ⋅ W _cb + k ₂ ⋅ W _c ,

where k ₁ , k ₂ are weight coefficients, W _ab is the amount of energy loss at the internal resistance of the battery, W _cb is the amount of energy loss at the internal resistance of the capacitor bank, W _c is the amount of energy loss in the converter ”reveals one of the possible selection criteria . For a person skilled in the art it should be clear that the weights are set depending on the specific parameters of the system, in particular, these factors can be set to zero if the operating temperatures of the capacitor bank and converter do not exceed a safe level. In this case, the operating mode of the battery will be maximally improved by minimizing energy losses at its internal resistance. Since the rechargeable battery is the most heavy, expensive and short-lived element of the system, the tasks set for reducing weight, cost, and increasing the life of the system will be solved.

Signs that reveal the options for constructing the Converter are known from the existing level of technology and are explanatory.

Signs: “The system ... is located on an electric vehicle with navigation and traffic assessment tools, and the control program includes a cyclic forecasting program P _f based on the analysis of data from navigation tools and traffic assessment” are obvious to a person skilled in the art and are explanatory.

The introduction of the sign: "the battery ... is located in the insulating compartment" was made possible by minimizing the energy loss on the internal resistance of the battery. With minimal energy loss, the heat capacity of the battery is sufficient to prevent overheating, which eliminates the need for forced cooling. By placing the battery in the insulating compartment, the effects of such harmful factors as reduced or elevated ambient temperatures are reduced.

The introduction of the sign: “the battery has a capacity that provides no more than 100 kilometers of electric vehicle without recharging” was made possible by reducing the battery power requirements (due to the presence of a capacitor bank). The low capacity of the battery allows you to make it light and small, that is, to implement the sign: "the battery ... is placed ... so that it is possible to quickly replace it."

The symptom: “in the territory of the alleged operation of the electric vehicle there is a network of stations for the rapid replacement of batteries and their charging ...” is obvious to a person skilled in the art and is explanatory.

A new sign: “... charging combined with heating or cooling the batteries to optimal operating temperatures” allows (in combination with the placement of the battery in the heat-insulating compartment) to improve the battery mode.

A new set of features of the control method: "set a finite set U of voltage values ... divide the forecast lead time P _f into many time intervals;

- at each time interval, a set of predictive options for changing the voltage of the open circuit of the capacitor bank is formed so that at the boundaries of the time interval the magnitude of this voltage belongs to a given finite set U, and for each option, the loss w ... is calculated;

- from a set of generated forecast options, choose a sequence that forms a continuous function u _f (t) with a minimum loss amount w ”allows us to reduce the problem of finding optimal control to the well-known problem of finding the shortest path in an oriented acyclic graph (see page 197 in the book by Christofides N. // Graph theory. Algorithmic approach. - M.: Mir, 1978.).

The symptom: "the cyclical implementation of these actions is carried out with a repetition period many times shorter than the forecast lead time P _f " allows you to make timely adjustments to the power distribution process when changing the forecast P _f .

A method for generating a forecast P _{f is} disclosed in the features characterizing the claimed solution in relation to an electric vehicle, mainly unmanned - in this case, the method is the simplest and is given as an illustrative example. The scope of the proposed solution is not limited to the above example. In particular, the formation of forecasts of the output electric power of systems designed for hybrid transport vehicles, industrial drives, autonomous electric power devices, etc. relates to individual tasks that are not the subject of this application. The achievement of the technical result in the claimed solution is provided regardless of the method for generating a forecast of the electrical output of the system.

Thus, the claimed technical solution contains features unknown from the prior art and affecting the achievement of the technical result, that is, meets the criteria of "novelty" and "inventive step".

The claimed technical solution is illustrated by drawings.

FIG. 1 contains a block diagram of a system.

FIG. 2, 3, 4 contain variants of the power section of the system.

FIG. 5 illustrates an optimal control process.

FIG. 6 illustrates a path in a directed acyclic graph.

FIG. 7 illustrates an example implementation of a control method.

FIG. 8 illustrates an embodiment of an unmanned electric vehicle.

The structural diagram (Fig. 1) presents:

- power unit 1;

- means 2 assessment of the state of the power unit;

- management tools 3 with an information interface 4;

- plus 5 and minus 6 power terminals of the system;

- battery 7;

- capacitor bank 8;

- Converter 9 with a control input 10 of the converter;

- an array of 11 input data;

- optimal control program 12;

- program 13 cyclic formation of a forecast of the electrical output of the system;

- Means 14 of navigation and traffic assessment.

The battery 7 is connected to the capacitor bank 8 through the converter 9, these elements together with the terminals 5, 6 form the power part 1, which is controlled by the control input 10 of the converter; the power unit 1 is associated with means 2 for assessing the state of the power unit.

Means 2 for assessing the state of the power unit contain at least:

- means for evaluating the open circuit voltage and the internal resistance of the battery 7;

- means for evaluating the voltage of the open circuit and the internal resistance of the capacitor bank 8.

Well-known algorithms can be used to evaluate states, such as the Kalman filter or the Luenberger observer (Andreev Yu. N. // Control of finite-dimensional linear objects.- M.: Main edition of the physics and mathematics literature of the Nauka publishing house, 1976.).

The composition of the control means 3 includes an input data array 11, an optimal control program 12, a program 13 for cyclically generating a forecast of the output electric power of the system; the program 13 has the ability to receive data from the means 14 of navigation and traffic assessment, as well as recording data into the array 11 through the information interface 4; program 12 has the ability to receive data from array 11 and from means 2 for assessing the status of the power unit, as well as transmitting data to the control input 10 of the converter.

The diagrams (Fig. 2, 3) show the power unit 1 with the first version of the converter 9, which includes:

- the first and second half-bridge 20.21, each of which has a control input, positive output, negative output and switch output;

- inductor 22 with a sensor 23 of the inductor current;

- regulator 24 with three inputs 25, 10, 26 and outputs 27, 28.

The first input 25 of the regulator receives a signal of general feedback on the voltage and open circuit of the capacitor bank, the second input of the regulator is the input 10 of the converter, the third input 26 of the regulator receives a local feedback signal from the sensor 23 of the inductor current, the outputs 27, 28 of the regulator are connected to half-bridge control inputs; the positive and negative terminals of the first half-bridge 20 are connected in parallel to the battery 7, the negative terminal of the first half-bridge 20 is connected to the negative terminal of the second half-bridge 21, the switched output of the first half-bridge 20 through the inductor 22 is connected to the switched output of the second half-bridge 21, the positive and negative outputs of which are connected in parallel to capacitor bank 8.

In the power part 1 containing the first version of the converter, the system power terminals 5, 6 can be: the plus and minus terminals of the second half-bridge 21 (as shown in Fig. 2), or the plus and minus terminals of the first half-bridge 20 (as shown in Fig. 3 )

The diagram (Fig. 4) shows the power unit 1 with the second version of the converter 9, which includes:

- half-bridge 30, which has a control input, positive output, negative output and switch output;

- a choke 31 with a sensor 32 of the choke current;

- controller 33 with three inputs 34, 10, 35 and output 36.

The first input 34 of the controller is fed a signal of general feedback on the voltage and open circuit of the capacitor bank, the second input of the controller is the control input 10 of the converter, the third input 36 of the controller is fed a local feedback signal from the sensor 32 of the inductor current, the output 36 of the controller is connected to the control input half bridge 30; the positive and negative terminals of the half-bridge 30 are power terminals 5, 6 of the system, the negative terminal of the half-bridge 30 is connected to the negative terminal of the battery 7, the switched output of the half-bridge 30 through the inductor 31 is connected to the positive terminal of the battery 7 and the negative terminal of the capacitor battery 8, the positive terminal of which connected to the positive terminal of the half-bridge 30.

The choice of power unit option 1 is determined by the specific parameters of the system:

- in cases where the output power of the capacitor bank 8 is significantly (more than 3 times) higher than the power of the battery 7 (for example, in a hybrid car), the circuit shown in FIG. 2;

- in cases where the output power of the capacitor bank 8 is approximately equal to the power of the battery 7 (for example, in an electric bus), the circuit shown in FIG. 3;

- in other cases (for example, in an electric vehicle), the circuit shown in FIG. 4.

In all these variants, the principle of operation of converter 9 is the same, and is illustrated by the example of the circuit of FIG. 4:

When applying from the output of the 36 controller to the control input of the half-bridge 30 periodic rectangular pulses, the switched output of the half-bridge 30 is periodically connected to its positive or negative terminals. In this case, the average voltage at the switched output of the half-bridge 30 depends on the duty cycle of the pulses at the output of the 36 controller. The change in current of the inductor 31 is determined by the voltage difference at its terminals and, therefore, also depends on the duty cycle of the pulses at the output 36 of the controller. The inductor current affects the distribution of the electrical output of the system between the battery 7 and capacitor 8 batteries. The voltage and open circuit of the capacitor bank 8 varies depending on its output electrical power. The controller 33 is designed so that the voltage at the input 34 tends to the Ref setting at the input 10. The principle of operation of the controller is known and does not require additional explanation.

An example implementation of the inventive control method is illustrated in FIG. 5, 6 and is described below.

Program 12 receives from the means 2 data on the state of the power unit (open circuit voltage and internal resistance of the rechargeable 7 and capacitor 8 batteries), and from the array 11 the forecast P _{f of the} output electric power of the system. Note that the internal resistance of the capacitor bank 8, as well as the open circuit voltage and the internal resistance of the battery 7 change quite slowly, and during the forecast lead P _f they can be considered constant. Program 12 solves the problem of finding optimal control using the following algorithm:

1) Inside the operating range (u _min , u _max ), a finite set U of the open circuit voltage of the capacitor bank is set.

2) The forecast forecast period P _{f is divided} into time intervals (t _i-1 , t _i ), where i is the number of the interval from 1 to N.

3) At each time interval, a set of forecast options Ref _ijk changes the settings Ref. In accordance with the principle of operation of the converter, the open circuit voltage of the capacitor bank should tend to the Ref setting - the formation of forecast variants is carried out in such a way that each time moment t _i corresponds to the value u _ij of the open circuit voltage of the capacitor bank from a given finite set U.

4) For each forecast option Ref _{ijk, the} loss w _{ijk is calculated} (for example, the energy loss on the internal resistance of the battery) corresponding to the forecast Pf using data on the state of the power unit and its mathematical model.

5) Present forecast variants in the form of an oriented acyclic graph (Fig. 6) with many vertices (i, j) and many arcs (i, j, k). Arcs (i, j, k) are directed to the vertex (i, j) from the vertices (i-1, j '), the index k takes values from 1 to K, where K is the number of arcs directed to the vertex (i, j) . The vertices correspond to the values of u _ij , arcs - Ref _ijk and w _ijk .

6) Successively increasing i from 1 to N, assign the vertices (i, j) the marks W (i, j) equal to the minimum amount of losses on the way to them:

where (i, j, k) runs over the set of all arcs directed to the vertex (i, j), W (i-1, j ') are the marks previously assigned to the vertices from which the arcs (i, j, k) are directed, W (0, 0) = 0 - the mark assigned to the beginning of the graph. Of all the vertices (N, j), one (N, M) with the least mark is selected. From all arcs (N, M, k), one (N, M, L) is selected that satisfies formula (1). The arc (N, M, L) lies in the path with the least amount of loss.

7) Moving sequentially from the peak (N, M) to the peak (0, 0) along arcs satisfying formula (1), one obtains the path with the smallest sum of losses (indicated by arrows in Fig. 6). This path corresponds to the sequence of settings Ref _ijk , which provides optimal control, and is transmitted by program 12 to the control input 10 of the converter.

In connection with possible unpredictable changes in road conditions, the cycle shown in FIG. 5 should be carried out as often as possible - in order to avoid significant discrepancies between the output electric power P _out and its forecast P _f .

In FIG. 7 shows an example of the system when the electric vehicle is moving. The route of movement is divided into sections by points 40, 41, 42, 43, 44, 45. At each point, the forecast is updated. Forecast periods of forecasts intersect (each of them corresponds to two sections of the route). Graph energy (E = S⋅u ^2/2) stored in the capacitor bank (solid thickened line) is formed by a plurality of overlapping fragments corresponding to various portions of the route:

- fragment 50 corresponds to the section to paragraph 41;

- fragment 51 corresponds to the section 40 ÷ 42;

- fragment 52 corresponds to section 41 ÷ 43;

- fragment 53 corresponds to section 42 ÷ 44;

- fragment 54 corresponds to the section 43 ÷ 45.

The Ref setting at the control input of the converter is formed on the basis of the latest forecast, while the E chart is updated, which may differ from the previous one (dashed line):

- the forecast formed in paragraph 40 takes into account the descent of the electric vehicle in section 41 ÷ 42, therefore, in section 40 + 41, the updated fragment 51 is lower than the previous fragment 50, which ensures the preparation of a capacitor bank for receiving energy on the descent;

- section 42 ÷ 43 does not contain significant changes in the terrain, nor does it imply acceleration / deceleration of the electric vehicle, therefore, in section 41 ÷ 42, the updated fragment 52 differs little from the previous fragment 51;

- the forecast formed in paragraph 42 takes into account the rise of the electric vehicle in the section 43 ÷ 44, therefore, in the section 42 ÷ 43 the updated fragment 53 is higher than the previous fragment 52, which ensures the preparation of the capacitor bank for energy transfer on the rise;

- the forecast formed in paragraph 43 takes into account the braking of the electric vehicle before the intersection 45, therefore, at section 43 ÷ 44, the updated fragment 54 is higher than the previous fragment 53.

Thus, the optimal control program takes into account not only the current needs for the electrical output of the system, but also those needs that may arise in the short term.

A variant of unmanned electric vehicle 60 (Fig. 8) has drive wheels 61 mechanically connected to electric machines 62. Electric machines 62 are connected to AC / DC converters 63, which are powered by the energy storage system with the power section shown in FIG. 4. The electric car 60 contains a heat-insulating compartment 64 in which the battery 7 is located.

This option allows you to solve two main problems inherent in electric vehicles - a long charging time and unreliable operation at low ambient temperatures. Due to a significant reduction in energy losses on the internal resistance of the battery, the proposed option allows, in comparison with traditional ones, to reduce the weight and size of the battery by at least three times. At the same time, the electric vehicle’s mileage without recharging decreases, but its dynamics do not deteriorate. After discharge, a small battery can be easily and quickly replaced with a fresh one.

The network of stations 65 is used for operational robotic replacement of discharged batteries with fresh ones. A fresh (charged) battery has an electrolyte temperature close to optimal. During a short run (not more than 100 km), the temperature of the electrolyte of the battery 5, placed in the heat-insulating compartment 61, does not have time to change significantly, which increases the reliability of the battery in winter and eliminates the need for forced cooling in summer. Thus, the proposed embodiment of the electric vehicle 60 provides the accumulation of not only electric but also thermal energy.

An unmanned electric vehicle 60 is preferable to use as a city taxi, the route of which is compiled automatically and involves visiting robotic points for the rapid replacement of batteries.

Claims (35)

1. The energy storage system, consisting of a power unit, means for assessing the status of the power unit and controls equipped with an information interface, the power unit comprising power terminals of the energy storage system, a battery, a capacitor bank and a converter with a control input of the converter, which are connected in such a way what P _out = P _ab + P _cb -P _c , where P _out is the output electric power of the energy storage system measured at its power terminals, P _ab is the output electric power of the battery, P _cb is the output electric power of the capacitor bank, P _c is the power loss in the converter, and the power ratio is P _ab , P _cb and P _c depend on the Ref setting at the control input of the converter, characterized in that an array of input data and an optimal control program are included in the control means, moreover: - the input data array has the ability to fill through the information interface and contains a forecast P _f power P _out ; - the optimal control program is connected with the input data array, means for assessing the state of the power unit and the control input of the converter and serves to form the Ref setting that minimizes the value of the function W from energy losses expected during the forecast lead P _f . 2. The system according to p. 1, characterized in that the formation of the set point Ref consists in choosing one of the many predictive options for changing it, based on the methods of dynamic programming, and W = W _ab + k ₁ ⋅ W _cb + k ₂ ⋅ W _c , where k ₁ , k ₂ are weight factors, W _ab is the amount of energy loss at the internal resistance of the battery, W _cb is the amount of energy loss at the internal resistance of the capacitor bank, W _c is the amount of energy loss in the converter. 3. The system according to p. 1, characterized in that the converter contains two half-bridge, a choke with a current sensor of the choke and a regulator, moreover: - each half-bridge has a half-bridge control input, a first key, a second key, a positive output, a negative output and a switched output, a positive output connected to a switched output through a first key, a negative output connected to a switched output through a second key, a switched output has the ability to connect to a positive or negative output by a signal at the control input of the half-bridge; - the positive and negative terminals of the first half-bridge are connected in parallel to the battery, the negative terminal of the first half-bridge is connected to the negative terminal of the second half-bridge, the switched output of the first half-bridge is connected via a choke to the switched output of the second half-bridge, the positive and negative terminals of which are connected in parallel to the capacitor bank; - the plus and minus terminals of the first or second half-bridge are power terminals of the energy storage system; - the regulator has three inputs and two outputs, the first input of the regulator from the means for assessing the state of the power unit receives a signal of general feedback on the open circuit voltage of the capacitor bank, the second input of the regulator is the control input of the converter, the local feedback signal from the sensor is fed to the third input of the regulator throttle current, the controller outputs are connected to the control inputs of the half-bridge. 4. The system according to claim 1, characterized in that the converter comprises a half-bridge, a choke with a current sensor of the choke and a regulator, moreover: - the half-bridge has a control input, a first key, a second key, a positive output, a negative output and a switched output, a positive output connected to a switched output through a first key, a negative output connected to a switched output through a second key, a switched output can be connected to positive or negative output signal on the control input of the half-bridge; - the positive and negative terminals of the half-bridge are power terminals of the energy storage system, the negative terminal of the half-bridge is connected to the negative terminal of the battery, the switched half-bridge output through the inductor is connected to the positive terminal of the battery and the negative terminal of the capacitor battery, the positive terminal of which is connected to the positive terminal of the half-bridge; - the regulator has three inputs and an output, a general feedback signal for the open circuit voltage of the capacitor bank is fed to the first input of the regulator from the power unit state assessment means, the second input of the regulator is the control input of the converter, the local feedback signal from the current sensor is fed to the third input of the regulator throttle, the regulator output is connected to the control input of the half-bridge. 5. The system according to claim 1, characterized in that it is located on an electric vehicle having navigation and traffic assessment tools, and the control program includes a cyclic forecasting program P _f based on an analysis of the data of navigation tools and traffic assessment. 6. The system according to p. 5, characterized in that the electric vehicle contains a heat-insulating compartment, moreover: - the battery has a capacity that provides no more than 100 kilometers of electric vehicle without recharging, and is placed in the insulating compartment so that it can be replaced quickly; - on the territory of the alleged operation of the electric vehicle, a network of stations is located for the rapid replacement of batteries and their charging, combined with heating or cooling the batteries to optimal operating temperatures. 7. A method for controlling an energy storage system comprising a battery, a capacitor bank, and a converter with a control input of the converter, which are connected so that P _out = P _ab + P _cb -P _c , where P _out is the output electric power of the energy storage system, P _ab is the output electric power of the battery, P _cb is the output electric power of the capacitor bank, P _c is the power loss in the converter, and the power ratio P _ab , P _cb and P _c depends on the Ref settings at the control input of the converter, characterized in that they specify a finite set U of voltage values and then cyclically perform the following actions: - form a forecast P _f power P _out and break the forecast lead time P _f into many time intervals; - at each time interval, a set of predictive options for changing the voltage of the open circuit of the capacitor bank is formed so that at the borders of the time interval the magnitude of this voltage belongs to a given finite set U, and for each option, the loss w corresponding to the forecast P _{f is} calculated by the formula w = w _ab + k ₁ ⋅w _cb + k ₂ ⋅w _c , where k ₁ , k ₂ are weighting factors, w _ab is the amount of energy loss at the internal resistance of the battery, w _cb is the amount of energy loss at the internal resistance of the capacitor battery, w _c is the amount of energy loss in the converter; - from the set of generated forecast options, a sequence is selected that forms a continuous function u _f (t) with a minimum loss amount w, then the setting Ref is applied to the converter control input such that the open circuit voltage of the capacitor bank tends to u _f (t). 8. The method according to p. 7, characterized in that the cyclic execution of these actions is carried out with a repetition period many times smaller than the forecast lead time P _f . 9. The method according to p. 7, characterized in that it is used on an electric vehicle with navigation aids, the data of which are used to compose a route, and means for assessing the road situation, the data of which are used to predict the electric vehicle’s traffic schedule along the route, and the forecast P _f according to the formula P _f = (m⋅v⋅dv / dt + m⋅g⋅dh / dt + P _w ) / η, where m is the mass of the electric vehicle, v, h are the predicted speed and height of the position of the electric vehicle, g is the acceleration of gravity, P _w is the predicted power of losses due to rolling friction and aerodynamic resistance of the electric vehicle, η is the efficiency of the electric drive wheels of the electric vehicle, and the period forecast anticipations P _f set so that it exceeds the value (E _max -E _min ) / P _av , where E _max , E _min are the maximum and minimum possible energy reserves of the capacitor bank, P _av is the average power P _out when the electric vehicle moves along the main road with high-quality coating.

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