JP2016167939A - Power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply system performing efficient power supply control reflecting the capacity of each power supply appropriately, depending on the request characteristics of a high voltage load, in a power supply system including two power supplies.SOLUTION: The high voltage power supply 50 of a power supply system 12 is constituted by connecting a plurality of high voltage modules 51, 52 in series, and can supply a DC power to a rotary machine system 6 for driving a rotary machine as a main machine. Low voltage power supplies 31, 32 can supply a DC power to an auxiliary load 2 other than the rotary machine. Substation machines 401, 402 are provided corresponding to the plurality of high voltage modules 51, 52 individually, and connect the plurality of high voltage modules 51, 52 and low voltage power supplies 31, 32 so as to be able to transform bi-directionally. When the capacity or the I/O of the low voltage power supplies deviates from a proper range, a substation machine controller 70 controls the substation machines 401, 402 so as to complement by means of a high voltage module, and when the total of the capacity or the I/O of the plurality of high voltage modules deviates from a proper range, controls the substation machines 401, 402 so as to complement by means of a low voltage power supply.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power supply system including dual power supplies.

  Conventionally, in a power supply system that supplies DC power to a high-voltage load such as an inverter that drives the main unit of a hybrid vehicle, an output type power supply that outputs high power in a short time and a capacity type power supply that outputs low power over a long period of time A device having two power sources is known. For example, in a power supply system (power supply device) described in Patent Document 1, an instantaneous storage battery that can output a large amount of power instantaneously and a persistent storage battery that can output a constant voltage continuously are connected in parallel. Yes.

JP-A-11-252711

The instantaneous storage battery represented by the capacitor has a large voltage change depending on the amount of stored electricity. The power supply system of Patent Document 1 is based on the premise that a similar voltage is applied to a common output terminal from the persistent storage battery and the instantaneous storage battery, and as a second embodiment, voltage fluctuation of the instantaneous battery is suppressed. Therefore, a current control device is provided between the instantaneous storage battery and the output terminal.
As a result, since the maximum output supplied to the load via the output terminal is regulated by the output capability of the current control device, the responsiveness of the instantaneous battery is reduced. Further, if a large amount of power output from the instantaneous battery is to be supplied to the load, the required output of the current control device must be increased. Therefore, there is a problem that the current control device is enlarged and the cost is increased.

Furthermore, in the power supply system of Patent Document 1, when the current direction with respect to the load is switched, that is, when high-output high-frequency power whose current crosses the zero point is transformed, the passing current of the current control device increases, and the power efficiency decreases. In addition, when a high-output transformer is used with a small output, the efficiency decreases.
In addition, there is no mention in Patent Document 1 about the configuration when the capacity of the instantaneous storage battery is insufficient and the configuration for notifying the high-voltage load-side control device such as the main engine drive device of the information on the power supply system side. . Therefore, efficient power supply control that appropriately reflects the capability of each power supply cannot be sufficiently performed according to the required characteristics of the high-voltage load.

  The present invention has been created in view of the above points, and an object of the present invention is to efficiently reflect the capability of each power supply according to the required characteristics of the high-voltage load in a power supply system including two power supplies. An object of the present invention is to provide a power supply system that performs power supply control.

A power supply system according to the present invention includes a high-voltage power source configured by connecting a plurality of high-voltage modules in series, at least one low-voltage power source, a plurality of transformers, and a transformer controller.
A high-voltage power source composed of a plurality of high-voltage modules can supply DC power to a rotating machine system that drives a rotating machine as a main machine. At least one low-voltage power supply can supply DC power to auxiliary loads other than the main engine. The plurality of transformers are provided individually corresponding to the plurality of high-voltage modules, and connect the plurality of high-voltage modules and the low-voltage power supply so as to be capable of bidirectional transformation.
When the capacity or input / output of the low-voltage power supply is out of the proper range, the substation controller is supplemented by the high-voltage module, and when the total capacity or input / output of multiple high-voltage modules is out of the proper range, it is supplemented by the low-voltage power supply. To control the transformer.
Here, “when input / output is out of the proper range” includes when output is insufficient and when input is excessive.

  As a rotating machine system that is a high-pressure load, an inverter that drives a rotating machine as a main machine is applicable. In addition, the “main machine” that is the driving target of the rotating machine system is not limited to the rotating machine used as the driving power source of the hybrid vehicle, but refers to a device that is a main power supply target of the power supply system. An auxiliary machine other than the main machine is not limited to a device mounted on a vehicle, but refers to all devices driven by electric power supplied from a low-voltage power source. In this specification, the auxiliary machine is referred to as “auxiliary machine load” in order to clearly indicate the load of the power supply system.

In the present invention, when the capacity or input / output of the low-voltage power source is out of the proper range, it is supplemented by the high-voltage module, and when the total capacity or input / output of the plurality of high-voltage modules is out of the proper range, it is supplemented by the low-voltage power source. In addition, since the transformer is controlled, the disadvantages can be compensated while taking advantage of the advantages of each power source.
Further, by dividing the high-voltage power source into a plurality of high-voltage modules, the output and transformation ratio per transformer can be set low. Therefore, the balance between output and capacity can be optimized according to the required characteristics of the high-voltage load without excessively increasing the power supply specification. Therefore, a small and low-cost power supply system can be provided.

Preferably, the substation control device includes a plurality of substations having a maximum conversion efficiency in accordance with the relationship between the “target power per unit” and the “conversion efficiency for each number of operating units” of the plurality of substations. If the number of substations is less than the number of substations, the number of substations is “alternately operated”, and if the number of substations with the maximum conversion efficiency is the total number of substations, "
As described above, the conversion efficiency can be maximized by selecting the number of operating sub-machines as needed according to the target power per sub-machine.

The plurality of high-voltage modules of the power supply system are preferably configured by an output type power supply capable of outputting a relatively large amount of power, and the low-voltage power source is preferably configured by a capacity-type power supply having a relatively large capacity.
Thereby, it is possible to provide an optimum power supply specification for a required specification of high output and low capacity in a hybrid vehicle or the like. Therefore, energy consumption in the entire system is reduced by reducing charging / discharging loss due to frequent input / output to the power supply, improving the thermal efficiency of the internal combustion engine by improving the power input / output with the rotating machine, and improving the regeneration efficiency by improving the input from the rotating machine. Efficiency is improved.

1 is an overall configuration diagram of a power supply system according to a first embodiment of the present invention. The control block diagram of the power supply system of FIG. (A) Ragon plot of various power sources. (B) Relationship diagram between capacity and output for explaining power supply specifications targeted by the present invention. The whole block diagram of the power supply system of a comparative example. The main flowchart of the normal process by the power supply system of FIG. (A) A map showing the relationship between the low pressure capacity and the input / output limit value. (B) A map showing the relationship between the high voltage capacity and the input / output limit value. The map which shows the relationship between the open circuit voltage of a high voltage power supply, and a high voltage capacity. The map which shows the relationship between low voltage capacity and low voltage power supply demand power. The map which shows the relationship between the ratio of a high voltage capacity | capacitance to a low voltage capacity | capacitance, and transformation required electric power. The figure explaining prediction of high voltage power supply required power. The flowchart which determines the capacity | capacitance order of several high voltage | pressure modules. The characteristic view which shows the relationship between the target electric power per 1 substation and the conversion efficiency for every operation number when the number k of substations is (a) k = 2 and (b) k = 3. The flowchart which determines alternating operation / simultaneous operation. The figure which shows the one-side driving | operation when one unit | set fails among two substations. The main flowchart of the process at the time of a failure by the power supply system of FIG. FIG. 16 is a sub-flowchart for determining a low-voltage internal resistance in FIG. 15. FIG. 16 is a sub-flowchart of high-voltage internal resistance determination in FIG. 15. The whole power supply system lineblock diagram by a 2nd embodiment of the present invention.

Hereinafter, a power supply system according to a plurality of embodiments of the present invention will be described with reference to the drawings. In the configurations of the plurality of embodiments and the comparative example, substantially the same configurations are denoted by the same reference numerals and description thereof is omitted.
The power supply system of the following embodiment is mounted on a hybrid vehicle that uses an internal combustion engine and a rotating machine (motor generator) as a main engine as a power source, and supplies high-voltage DC power to the rotating machine system that drives the rotating machine. The power supply system supplies low-voltage DC power to various auxiliary loads.

(First embodiment)
The power supply system of 1st Embodiment of this invention is demonstrated with reference to FIGS.
First, FIG. 1 will be referred to regarding the overall configuration of the power supply system. The power supply system 12 is provided between the rotating machine system 6 as a high pressure load and the auxiliary load 2 as a low pressure load.
The rotating machine system 6 is a system that drives a rotating machine as a main machine that is a power source of a vehicle, and typically corresponds to an inverter that converts DC power into AC power and supplies the AC power to the rotating machine. Depending on the system, a boost converter may be further provided on the input side of the inverter.
The auxiliary load 2 is a device that bears various functions other than the main engine, such as an electric power steering device, a power window device, a blower, and a fan.

The power supply system 12 includes a plurality of high voltage modules 51 and 52 connected in series, a high voltage power supply 50, a plurality of low voltage power supplies 31 and 32, a plurality of transformation machines 401 and 402, and a transformation machine control device 70 (FIG. 2). Reference). In the example of FIG. 1, the number of high-voltage modules 51 and 52 and transformers 401 and 402 is two.
Hereinafter, the number of high voltage modules and transformers is represented by the symbol k. That is, FIG. 1 shows an example of “k = 2”. Also, the variable “i” that takes a value from 1 to k for each of the k pieces is represented. For example, “i = 1, 2” when “k = 2”, “i = 1, 2, 3” when “k = 3”, “i = 1, 2,... N when“ k = n ” "Means. Furthermore, since the number of the low-voltage power supplies 31 and 32 is two in the first embodiment, the symbols “k” and “i” are similarly applied to the low-voltage power supplies 31 and 32.
Hereinafter, depending on the content of the description, description will be made with an example of “k ≧ 3” as appropriate.

  The high-voltage power supply 50 is directly connected to the rotating machine system 6 and can supply high-voltage power exceeding, for example, 100 V to the rotating machine system 6. The low voltage power supplies 31 and 32 can supply low voltage power of, for example, about 14 V to the auxiliary load 2. In the first embodiment, the high voltage modules 51 and 52 are configured by an output power source such as LiC (lithium ion capacitor), and the low voltage power sources 31 and 32 are configured by a capacitive power source such as LiB (lithium ion secondary battery). Has been.

The two transformers 401 and 402 are provided corresponding to the two high-voltage modules 51 and 52 individually, and are connected to the low-voltage power supplies 31 and 32 and the high-voltage modules 51 and 52 so that they can be transformed bidirectionally. Device. The transformers 401 and 402 are generally called DC-DC converters (DDC).
In each of the transformers 401 and 402, transformers 451 and 452 are provided between the low voltage parts (LV) 441 and 442 and the intermediate voltage parts (MV) 461 and 462, respectively. The voltage of the low voltage parts 441 and 442 is 12 to 14 V, for example, and a voltage corresponding to this is supplied to the auxiliary load 2. The voltages of the intermediate pressure portions 461 and 462 are generally in the range of 24 to 60V. The voltage of the high-voltage power supply (stack) 50 configured by connecting the high-voltage modules 51 and 52 in series is in the range of more than 60 V to several hundred V, and typically exceeds 100 V.

Hereinafter, when referring to the power balance in the configuration of FIG. 1, the sign of each output variable is defined by the direction of the arrow. As shown in FIG. 1, the sign (= direction of the arrow) of power from the auxiliary machine load 2 side to the rotating machine system 6 side is positive, and the sign of power in the opposite direction is negative.
Regarding the power in each part, the power input / output by the auxiliary load 2 is Po, the power input / output by the low voltage power supplies 31 and 32 is PL_1, PL_2, the power input / output by the high voltage modules 51, 52 is PH_1, PH_2, and the transformer 401. , 402 is referred to as PDCtgt_1, PDCtgt_2, and target power supplied to the rotating machine system 6 is referred to as PItgt. In the following description, “* _1, * _2 (* is each variable)” is included and described as “* _i”.

High-voltage output PHout_i when the high-voltage modules 51 and 52 are discharged during powering operation of the rotating machine or power supply to the low-voltage power supplies 31 and 32, and power supply to the high-voltage modules 51 and 52 when driving the auxiliary load 2 Therefore, the low-voltage output PLout_i when the low-voltage power supplies 31 and 32 are discharged is represented by 0 or a positive value (PHout_i ≧ 0, PLout_i ≧ 0).
On the other hand, the high-voltage input PHin_i when the high-voltage module 51, 52 is charged during the regenerative operation of the rotating machine or the power supply from the low-voltage power supply 31, 32, the output of the auxiliary load 2, and the high-voltage module 51, 52 The low-voltage output PLin_i when the low-voltage power supplies 31 and 32 are charged by power supply is represented by 0 or a negative value (PHin_i ≦ 0, PLin_i ≦ 0).

Next, the control configuration of the power supply system 12 will be described with reference to FIG. In the description of the output variable, the paired output and input are appropriately described as “* out / * in”.
The substation control device 70 includes low voltage arithmetic devices 731, 732, high voltage arithmetic devices 751, 752 corresponding to the low voltage power supplies 31, 32 and high voltage modules 51, 52, and a substation arithmetic device 74 corresponding to the substations 401, 402. have.
The substation arithmetic unit 74 acquires the input / output limit values PLout_i / PLin_i of the low-voltage power supplies 31 and 32 from the low-voltage arithmetic units 731 and 732, and the input / output limit values PHout_i / PHin_i of the high-voltage modules 51 and 52 from the high-voltage arithmetic units 751 and 752. To get.

  The rotating machine control device 8 is a control device that controls energization of the rotating machine by controlling the drive of the inverter of the rotating machine system 6, and corresponds to a so-called MG-ECU. Hereinafter, the driving power of the rotating machine system 6 is referred to as “high-pressure power PI”. The rotating machine control device 8 calculates the required power PIreq of the high voltage power and further calculates the target output PItgt for the high voltage power.

The power supply system 12 is characterized in that the processing is executed between the variable electrical machine control device 70 and the rotating machine control device 8 while mutually communicating calculation values as described below. Here, only the outline of the processing is described, and details of each calculation will be described later.
(I) Based on the input / output limit values PLout_i / PLin_i, PHout_i / PHin_i, and the auxiliary machine output Po, the transformation machine control device 70 to the rotating machine control device 8 are represented by the equations (1.1) and (1.2). The power supply system output guard value PSout and the power supply system input guard value PSin calculated by the above are notified.

PSout = k × {min (PHout_i) + min (PLout_i)} + Po
... (1.1)
PSin = k × {max (PHin_i) + max (PLin_i)} + Po
... (1.2)
In the above formula, based on the idea of surely limiting, the calculation is simplified using the minimum value for the output limit values PLout_i and PHout_i (≧ 0) and the maximum value for the input limit values PLin_i and PHin_i (≦ 0). ing. However, k input / output limit values PLout_i / PLin_i and PHout_i / PHin_i may be added.

(II) The rotating machine control device 8 calculates the supply target power PItgt of the high-voltage power based on the required power PIreq of the high-voltage power and the notified guard value PSout / PSin.
(III) The variable electrical machine control device 70 acquires the supply target power PItgt of the high voltage power from the rotating machine control device 8 and calculates the target output PDCtgt_i of the variable electrical machinery 401, 402. And electric power is converted between the low voltage power supplies 31 and 32 and the high voltage modules 51 and 52 based on the calculation result.

Here, the basic concept of the present invention will be described with reference to FIG.
FIG. 3A is a Ragon plot showing the relationship between the capacity density and the output density of a capacitor or battery used as a power source. The electric double layer capacitor (EDLC) and LiC in the short broken line region have a low capacitance density and a high output density. The output type LiB and the nickel metal hydride battery (NiMH) in the long broken line region have medium capacity density and output density. The capacitive LiB in the one-dot chain line region has a high capacity density and a low output density.

In this way, the output / capacity ratio is determined by the power supply type. Therefore, if the power supply characteristics are set so as to match the required output / capacity ratio, a wasteful power supply specification can be realized. This leads to downsizing and cost reduction. Therefore, in the present invention, the power supply specification is minimized by optimizing the output / capacity ratio by cooperation of two power supplies.
FIG. 3B is a relationship diagram between the capacity and the output for explaining the power supply specification targeted by the present invention. Here, description will be made assuming an example in which the low-voltage power supplies 31 and 32 in FIG. 1 are capacitive LiB and the high-voltage modules 51 and 52 are LiC.

  First, a power supply system of a comparative example compared with the present invention will be described with reference to FIG. In the power supply system 19 of the comparative example, a low voltage unit (LV) 44 connected to, for example, a 14V auxiliary battery 39 and a high voltage unit (HV) 48 connected to a high voltage power supply 59 of, for example, more than 100V are connected to the transformer 409. Are connected via the transformer 49. The high voltage power supply 59 is composed of an output type LiB. In this power supply system 19, since it is necessary to select a power supply having a specification shown by a long broken line in order to obtain a required output / capacity ratio, the capacity becomes excessive (overspec).

  On the other hand, in the present invention, two power sources of LiC indicated by a short broken line and a capacitive LiB indicated by a one-dot chain line are used in combination while taking advantage of each advantage. That is, while the electric power is supplied to the rotating machine system 6 based on LiC capable of generating a high output, the capacity shortage of LiC is compensated with the capacitive LiB.

  By the way, in the prior art of patent document 1 (Unexamined-Japanese-Patent No. 11-252711), the current control apparatus is provided between the instantaneous storage battery and the output terminal. Thus, when a transformer is interposed between the LiC and the rotating machine system 6, the maximum output that can be supplied to the rotating machine system 6 is regulated by the output capability of the transformer, so that the response that is an advantage of LiC It will reduce the nature. Therefore, it is preferable that the high-voltage power supply 50 configured by connecting LiC high-voltage modules 51 and 52 in series is directly connected to the rotating machine system 6.

On the other hand, in order to eliminate the shortage of capacity of the LiC high voltage modules 51 and 52 constituting the high voltage power supply 50, the LiC is fed from the low voltage power supplies 31 and 32 of the capacitive LiB via the transformers 401 and 402, and the capacity of the LiC Adjust (SOC).
In FIG. 3B, the relationship among the LiC capacity Ec, the capacity type LiB capacity Eb, and the required capacity Er is set to satisfy “Ec + Eb ≧ Er”.

Next, referring to the flowchart of FIG. 5, the characteristic diagrams (maps) of FIGS. 6 to 10, and the other FIGS. 11 to 13 for normal processing executed in the transformer control device 70 and the rotating machine control device 8. To explain. In the following description of the flowchart, the symbol S represents “step”.
Here, the “normal processing” is processing when the low-voltage power supplies 31 and 32 and the high-voltage modules 51 and 52 are all normal with respect to “failure processing” described later. The normal process is repeated at a predetermined cycle while at least one of the rotating machine system 6 or the auxiliary machine load 2 is operating. An object of the present embodiment is to efficiently supply power from the power supply system 12 to the rotating machine system 6 mainly when the vehicle is idling or traveling.

The substation control device 70 first has a capacity (hereinafter referred to as “low voltage capacity”) EL_i of each of the current low voltage power supplies 31 and 32 and a capacity (hereinafter referred to as “high voltage capacity”) EH_i of each of the high voltage modules 51 and 52. And the input / output limit values PLout_i / PLin_i and PHout_i / PHin_i are calculated. Here, the capacitances EL_i and EH_i correspond to a so-called SOC (amount of stored electricity).
The input / output limit values PLout_i / PLin_i of the low-voltage power supplies 31 and 32 change according to the low-voltage capacity EL_i, and the input-output limit values PHout_i / PHin_i of the high-voltage modules 51 and 52 change according to the high-voltage capacity EH_i. Hereinafter, the dependency relationship of the output variable is expressed by appropriately describing the variable on which the variable depends in () after the variable symbol as an argument of the function.

In S201, the low voltage capacity EL_i is estimated. Separately, information on the temperature T of the low-voltage power supplies 31 and 32 is acquired.
In S202, the input / output limit values PLout_i (EL_i, T) / PLin_i (EL_i, T) of the low-voltage power sources 31, 32 depending on the low-voltage capacity EL_i and the temperature T are calculated using the map of FIG. . The input limit value PLin_i corresponds to a so-called allowable charge power Win, and the output limit value PLout_i corresponds to a so-called discharge allowable power Wout.
As shown in FIG. 6A, when EL_i ≧ ELmax_i, PLin_i = 0 is set to prevent overcharge. Further, when EL_i ≦ ELmin_i, PLout_i = 0 is set to prevent overdischarge.

Similarly, in S401, the high voltage capacity EH_i is estimated. Separately, information on the temperature T of the high-voltage modules 51 and 52 is acquired.
In S402, the input / output limit value PHout_i (EH_i, T) / PHin_i (EH_i, T) of the high voltage modules 51 and 52 depending on the high voltage capacity EH_i and the temperature T is calculated using the map of FIG. . The input limit value PHin_i corresponds to the so-called charge allowable power Win, and the output limit value PHout_i corresponds to the so-called discharge allowable power Wout.
As shown in FIG. 6B, when EH_i ≧ EHmax_i, PHin_i = 0 is set to prevent overcharge. Further, when EH_i ≦ EHmin_i, PHout_i = 0 is set to prevent overdischarge.

  By the way, as shown in FIG. 7, the high voltage capacity EH_i is expressed as a function of the open circuit voltage OCV_H_i of the high voltage modules 51 and 52, and the open circuit voltage OCV_H_i is the voltage VH_i of the high voltage modules 51 and 52, the internal resistance RH_i, and Using the current IH_i, “OCV_H_i = VH_i−RH_i × IH_i” is defined. From this relationship, the state of the high voltage modules 51 and 52 can also be determined based on the voltage VH_i instead of the capacitor EH_i.

Subsequently, in S502, the low-voltage power requirement power PLreq_i (PL_i) that depends on the low-voltage power PL_i is calculated. The low-voltage power request power PLreq_i indicates an input / output request according to the capacity EL_i (SOC) of the low-voltage power supplies 31 and 32 that are the maximum power storage devices in the power supply system 12.
In FIG. 8, the low voltage capacity EL_i corresponding to SOC = 0% is EL ₀ , and the low voltage capacity EL_i corresponding to SOC = 100% is EL ₁₀₀ . Further, the absolute value of the auxiliary machine maximum output is Pomax, and the required duration is TcL.

The minimum value ELmin_Ld_i and the maximum value ELmax_Ld_i of the low-pressure capacity EL that can maintain the driving of the auxiliary load 2 are expressed by equations (2.1) and (2.2).
ELmin_Ld_i = EL ₀ + (Pomax / k) × TcL (2.1)
_{ELmax_Ld_i = EL 100 - (Pomax /} k) × TcL ··· (2.2)
When the low voltage capacity EL_i is lower than the minimum value ELmin_Ld_i, the transformer control device 70 requests charging to the low voltage power supplies 31 and 32, and when the low voltage capacity EL exceeds the maximum value ELmax_Ld_i, the transformer control device 70 discharges from the low voltage power supplies 31 and 32. Request.

  In S <b> 503, the transformation machine control device 70 gives the rotating machine control device 8 a total value of “input / output capabilities of the high-voltage modules 51 and 52 and the low-voltage power supplies 31 and 32” corresponding to “capacity of all power sources of the power supply system 12”. The value obtained by adding the auxiliary machine output Po to “high voltage power (rotary machine system 6) power limit” is notified. That is, the power system output guard value PSout calculated by the above formula (1.1) is notified as a discharge limit, and the power system input guard value PSin calculated by the formula (1.2) is notified as a charge limit.

In S504, the required transformation power PDreq_i (EH_i, EL_i) depending on the high voltage capacity EH_i and the low voltage capacity EL_i is calculated. FIG. 9 is a map in which the horizontal axis represents the capacity ratio X_i = (EH_i / EL_i), which is the ratio of the high voltage capacity EH_i to the low voltage capacity EL_i, and the vertical axis represents the required transformation power PDreq_i.
The substation control device 70 determines the substation target power PDCtgt so that the capacity ratio X_i approaches the reference value Xref_i.

When the high-voltage capacity EH_i is smaller than the low-voltage capacity EL_i and the capacity ratio X_i is smaller than the threshold value Xmin_i, the substation control device 70 sets the substation required power PDreq_i to a positive value, and the high-voltage module 51 from the low-voltage power supplies 31 and 32. , 52 is charged. On the other hand, when the low-voltage capacity EL_i is smaller than the high-voltage capacity EH_i and the capacity ratio X_i is larger than the threshold value Xmax_i, the required transformation power PDreq_i is set to a negative value, and the low-voltage power supplies 31 and 32 are charged from the high-voltage modules 51 and 52. . The threshold values Xmin_i and Xmax_i are defined by design and experiment.
In FIG. 8, the low voltage power supplies 31 and 32 are forcibly charged in a region where the low voltage capacity EL_i is lower than the minimum value ELmin_Ld_i. Instead of FIG. 9 based on the capacity ratio X_i = (EH_i / EL_i), a three-dimensional map of “EH_i vs. EL_i vs. PDreq_i” may be used.

  In S505, the high-voltage module required power PHreq_i (PH_i) depending on the high-voltage power PH_i is calculated. In the example shown in FIG. 10, the output PH_i (> 0) of the high-voltage modules 51 and 52 is changed in a mountain shape so as to increase from time t1 to time t2 and decrease from time t2 to time t3. The output limit value PHout_i is exceeded in the straddling period. When the future required power is not predicted, the static required power PHreq_s_i, which is a difference obtained by subtracting the output limit value PHout_i from the high-voltage power PH_i, is indicated by a hatched area of a broken line.

On the other hand, in this embodiment, the transformer control device 70 predicts the future required power based on the power change of the high voltage modules 51, 52, that is, the time differential value (dPH_i / dt) of the power, and the high voltage module required power. PHreq_i is calculated. In FIG. 10, the lead compensation term “α × (dPH_i / dt)” obtained by multiplying the power change (dPH_i / dt) by the adaptive factor α is positive from time t1 to time t2, and negative from time t2 to time t3.
The future required power PHreq_i is calculated by the equation (3) obtained by adding the compensation term to the static required power PHreq_s_i.
PHreq_i = PH_i + α × (dPH_i / dt) −PHout_i
... (3)

As indicated by the hatched area of the solid line, the required power PHreq_i to which the advance compensation term is added shifts to the advance side with respect to the static required power PHreq_s_i.
By performing the prediction in this way, for example, when the output PH_i of the high-voltage modules 51 and 52 exceeds the output limit value PHout_i and the output is predicted to be insufficient, the substation control device 70 is previously connected to the low-voltage power supplies 31 and 32. The transformers 401 and 402 are controlled so as to charge the high voltage modules 51 and 52. Similarly, when it is predicted that the input PH_i (<0) of the high-voltage modules 51 and 52 is lower than the input limit value PHin_i and the input is excessive, the transformer control device 70 receives the low-voltage power supply 31 from the high-voltage modules 51 and 52 in advance. , 32 are controlled to discharge to 32.

S601 and S602 are executed by the rotating machine control device 8.
In S <b> 601, the rotating machine control device 8 calculates a high-voltage power required power PIreq that reflects a request from the driving main engine system such as improvement in thermal efficiency of the internal combustion engine and regenerative power.
In S602, the rotating machine control device 8 calculates the supply target power PItgt to the high voltage power (the rotating machine system 6) according to the equation (4). In this calculation, the high-voltage power demand power PIreq,
The upper limit on the positive side is limited by the power supply system output guard value PSout, and the lower limit on the negative side is limited by the power supply system input guard value PSin with respect to the sum of “low voltage power supply required power PLreq_i from i = 1 to k” To do.

In S700, the substation control device 70 calculates the substation target power PDCtgt_i according to Expression (5) based on the high-voltage power request power PIreq calculated by the rotating machine control device 8.

  The first term of the equation (5) means a current value (real-time value) of the shortage amount of the high-voltage power PH_i with respect to the high-voltage power demand power PIreq. The required transformation power PDreq_i of the second term is obtained in S504, and reflects a request to maintain the capacity ratio X_i = (EH_i / EL_i) between the high voltage modules 51 and 52 and the low voltage power supplies 31 and 32 within a certain range. The high-voltage module required power PHreq_i of the third term is a value obtained in S505 and foreseeing future power prediction.

Here, determination of the capacity order in the plurality of high-voltage modules 51 and 52 will be described with reference to FIG. Even if the plurality of high-voltage modules 51 and 52 are manufactured with equivalent specifications, a capacity difference occurs due to variations in internal resistance and self-discharge rate of the storage battery. Therefore, in order to operate the power supply system 12 more efficiently, it is preferable to compare the capacities of the high-voltage modules 51 and 52 and perform control according to the order. In addition, the several high voltage | pressure modules 51 and 52 assume the condition where it is operating simultaneously instead of the alternating operation mentioned later.
In S701 of FIG. 11, the reciprocal ratio of the capacity EH_i of each high voltage module 51, 52 is calculated. That is, the reciprocal ratio becomes larger as the high voltage module has a lower capacity EH_i.
In S702, the total value of the transformation target power PDCtgt_i is apportioned based on the reciprocal ratio of the capacity EH_i.

As a result, when charging the plurality of high-voltage modules 51 and 52 from the low-voltage power supplies 31 and 32, the high-voltage modules having a relatively low capacity EH_i are preferentially charged. In addition, when discharging from the plurality of high-voltage modules 51 and 52 to the low-voltage power supplies 31 and 32, the high-voltage modules having a relatively high capacity EH_i are preferentially discharged.
In addition, when the substation target power PDCtgt_i after apportionment exceeds the input / output capability of the low-voltage power supply, the shortage may be compensated by another low-voltage power supply. The same applies to the case where the transformation target power PDCtgt_i exceeds the maximum capacity of the transformer.

Next, selection of the alternating operation mode or the simultaneous operation mode of the plurality of transformers 401 and 402 will be described with reference to FIGS. 12 and 13.
When the total number of transformers is two (k = 2), the alternating operation means that the transformers are alternately operated one by one at predetermined intervals. Simultaneous operation means that two transformers are operated simultaneously. When the total number of transformers is three (k = 3), the alternate operation is further divided into alternate operation with one unit and alternate operation with two units. When the total number of transformers is n (k = n), it is possible to select (n-1) alternating operations from alternating operation with one device to alternating operation with (n-1) devices.

FIG. 12 shows the “target power PDCtgt_i” and “conversion efficiency (average of one unit) of a plurality of substations when the total number of substations is (a) 2 and (b) 3 units. FIG. Efficiency characteristic curves Eff1, Eff2, and Eff3 represent average efficiency characteristics during one unit operation, two unit operation, and three unit operation, respectively.
PDC_EffTh1 and PDC_EffTh2 on the horizontal axis are “target power per unit PDCtgt_i” corresponding to the intersection of the efficiency characteristic curves Eff1 and Eff2, and the intersection of the efficiency characteristic curves Eff2 and Eff3, respectively. It is an efficiency threshold in operation.

As shown in FIG. 12, the number of the substations with the maximum conversion efficiency changes according to the target power PDCtgt_i per substation. Therefore, the optimum operation mode is selected according to the flowchart of FIG. In FIG. 13, the total number of transformers is indicated as n (n ≧ 3).
In S801, the success or failure of Formula (6.1) is determined.
PDCtgt_i ≦ PDC_EffTh1 (6.1)
When YES in S801, “single unit alternate operation” is selected in S802.
When NO in S801, the success or failure of the formula (6.2) is determined in S803.
PDC_EffTh1 <PDCtgt_i ≦ PDC_EffTh2 (6.2)
When YES is determined in S803, “two-unit alternate operation” is selected in S804.

Thereafter, the same determination is repeated, and in S805, the success or failure of the formula (6.3) is determined.
PDC_EffTh (n−2) <PDCtgt_i ≦ PDC_EffTh (n−1)
... (6.3)
When YES in S805, “(n-1) vehicle alternate operation” is selected in S806. When NO in S805, Expression (6.4) is established by the erasing method.
PDC_EffTh (n−1) <PDCtgt_i (6.4)
Therefore, “n simultaneous operation” is selected in S807.

  In addition, for example, when the total number of substations is three (k = 3) and two units are operated alternately, substations corresponding to two high-voltage modules having a large high-voltage capacity EH_i are selected during boosting. There is a method of selecting a substation corresponding to two high voltage modules having a small high voltage capacity EH_i at the time of step-down. The switching cycle may be set based on the total capacity of the power supply system 12 or the like.

Returning to FIG. 5, in S900, which is the final step of the normal processing, the circuit switching operation of the transformers 401 and 402 is performed. Since this step is a well-known technique, a detailed description thereof will be omitted.
This is the end of the description of the normal process.

Next, with reference to the system diagram of FIG. 14 and the flowcharts of FIGS. 15 to 17, processing when one of the low voltage power supplies 31 and 32 or one of the high voltage modules 51 and 52 has failed will be described. . In the main flowchart of FIG. 15, step numbers in the normal process of FIG. 5 are used.
FIG. 14 shows a state where, as an example, the high voltage module 52 has failed due to an open failure and cannot store power. In this case, at the time of the power running operation of the rotating machine, the deformed electric machine control device 70 supplies power to the rotating machine system 6 from the changing machine 402 corresponding to the failed high voltage module 52 as indicated by the solid line arrow [H]. The transformer 402 is controlled. Thereby, evacuation driving | running | working is attained.
Further, during the regenerative operation of the rotating machine, power is regenerated to the low-voltage power supplies 31 and 32 via the transformer 401 corresponding to the normal high-voltage module 51 as indicated by the broken line arrow [L].

  As shown in FIG. 15, in the failure process, whether or not the transformers 401 and 402 are normal after the internal resistance determination (S100 and S300) is performed for the low-voltage power supplies 31 and 32 and the high-voltage modules 51 and 52, respectively. Depending on (S501), the following processing is divided into cases.

First, in the low voltage internal resistance determination shown in the sub-flowchart of FIG. 16, the low voltage current IL_i and the voltage VL_i are measured (S101), and the low voltage internal resistance RL_i (= VL_i / IL_i) is calculated (S102).
If the low-voltage internal resistance RL_i is within the range from the lower limit value RLmin_i to the upper limit value RLmax_i (S103: YES, S104: YES), the main flowchart is joined through the route “A”, and S201 to S202 of normal processing are executed. .

If the low-voltage internal resistance RL_i is below the lower limit value RLmin_i (S103: NO), it is determined that the low-voltage power supply is short-circuited, and the failure location is shut off by a fuse, relay, or other breaker (S105), and then S106 Migrate to
If the low voltage internal resistance RL_i exceeds the upper limit value RLmax_i (S104: NO), it is determined that the low voltage power source is disconnected or deteriorated, and the process proceeds to S106. In S106, the low-pressure input / output limit value is set to “PLin_i = 0, PLout_i = 0”, and joins the main flowchart through the route “B”.

In the high-voltage internal resistance determination shown in the sub-flowchart of FIG. 17, the high-voltage current IH_i and the voltage VH_i are measured (S301), and the high-voltage internal resistance RH_i (= VH_i / IH_i) is calculated (S302).
If the high-voltage internal resistance RH_i is within the range from the lower limit value RHmin_i to the upper limit value RHmax_i (S303: YES, S304: YES), the main flow chart is joined through the route “C”, and the normal processes S401 to S402 are executed. .

If the high-voltage internal resistance RH_i is below the lower limit value RHmin_i (S303: NO), it is determined that the high-voltage module is short-circuited, and the failure location is blocked by a fuse, relay, or other breaker (S305), and then S306 Migrate to
If the high voltage internal resistance RH_i exceeds the upper limit value RHmax_i (S304: NO), it is determined that the high voltage module is disconnected or deteriorated, and the process proceeds to S306. In S306, the high-voltage input / output limit value is set to “PHin_i = 0, PHout_i = 0”, and joins the main flowchart through the route “D”.

Next, in S501 of FIG. 15, it is determined whether the transformers 401 and 402 are normal or abnormal.
When both the transformation machine 401 and the transformation machine 402 are normal (S501: YES), the circuit SW operation (S900) is performed after the normal processes S502 to S505, S601 to S602, and S700 are performed.
When the transformer 401 or transformer 402 is abnormal (S501: NO), a warning is displayed to the driver, and power is supplied to the rotating machine system 6 within the allowable range of the high-voltage power supply 50, while the low-voltage power supplies 31 and 32 are supplied. Supplies electric power to the auxiliary load 2 as long as the remaining capacity.

Specifically, the driver is instructed to stop (S506) and set to “low-voltage power requirement power PLreq_i = 0” (S507). Further, “output guard value PSout = k × min (PHout_i)” regarding discharge limitation and “input guard value PSin = k × max (PHin_i)” regarding charging limitation are notified as power limitation of high-voltage power (S508).
Furthermore, “transformation target power PDCtgt_i = 0” and “high-voltage module required power PHreq_i = 0” are set (S509, S510). Then, the steps after S601 to S602 of the normal process are executed.

(effect)
(1) The power supply system 12 of the present embodiment supplies power to a plurality of high-voltage modules 51 and 52 that constitute a high-voltage power supply 50 that can supply a large amount of power to the rotating machine system 6 as a high-voltage load, and to the auxiliary load 2. The low-voltage power sources 31 and 32 are connected to the plurality of high-voltage modules 51 and 52 by transformers 401 and 402 that are individually provided and can be transformed bidirectionally.
When the capacity or input / output of the low voltage power supplies 31 and 32 is out of the appropriate range, the transformer control device 70 complements the high voltage modules 51 and 52, and the total capacity or input / output of the plurality of high voltage modules 51 and 52 is appropriate. Since the transformers 401 and 402 are controlled so as to be supplemented by the low-voltage power supplies 31 and 32 when out of the range, the disadvantages can be compensated while taking advantage of the advantages of each power supply.
Thereby, the balance between the output and the capacity can be optimized according to the required characteristics of the rotating machine system 6 (high voltage load) without excessively increasing the power supply specification. Therefore, a small and low-cost power supply system can be provided.

In addition, the transformer control device 70 notifies the rotating machine control device 8 of the total value of the input / output capabilities of the plurality of high voltage modules 51 and 52 and the low voltage power supplies 31 and 32. Then, the rotating machine control device 8 limits the required power PIreq of the rotating machine system 6 using the notified total values as guard values PSout and PSin, and calculates the supply target power PItgt. Furthermore, the substation control device 70 calculates the substation target power PDCtgt_i based on the supply target power PItgt calculated by the rotating machine control device 8, and executes power conversion.
As described above, since the electrical machine control device 70 and the rotating machine control device 8 exchange information with each other, efficient power supply control that appropriately reflects the capabilities of each power source, particularly when the vehicle is idling or traveling. It can be performed.

(2) The transformation machine control device 70 is a transformation machine having a maximum conversion efficiency in accordance with the relationship between the “target power per unit” of the plurality of transformation machines 401 and 402 and the “conversion efficiency for each number of operating units”. When the number of 401, 402 is less than the number of the plurality of transformers, the number of transformers is “alternately operated”. Further, when the number of the transformers with the maximum conversion efficiency is the total number of the plurality of transformers 401 and 402, all the transformers are “simultaneously operated”.
As described above, the conversion efficiency can be maximized by selecting the number of operating sub-machines as needed according to the target power per sub-machine.

  (3) In the present embodiment, the plurality of high-voltage modules 51 and 52 are configured by a high-output power source such as LiC, and the low-voltage power sources 31 and 32 are configured by a high-capacity power source such as LiB. Thereby, it is possible to provide an optimum power supply specification for a required specification of high output and low capacity in a hybrid vehicle or the like. Therefore, energy consumption in the entire system is reduced by reducing charging / discharging loss due to frequent input / output to the power supply, improving the thermal efficiency of the internal combustion engine by improving the power input / output with the rotating machine, and improving the regeneration efficiency by improving the input from the rotating machine. Efficiency is improved.

(4) When the total of the capacity EH_i or the voltage VH_i of the plurality of high voltage modules 51 and 52 is lower than a predetermined value, the transformer control device 70 charges the plurality of high voltage modules 51 and 52 from the low voltage power sources 31 and 32. Thus, the electric transformers 401 and 402 are controlled.
Further, when the total of the capacity EH_i or the voltage VH_i of the plurality of high voltage modules 51, 52 rises above a predetermined value, the transformer control device 70 discharges from the plurality of high voltage modules 51, 52 to the low voltage power sources 31, 32. The transformers 401 and 402 are controlled.
As a result, overdischarge or overcharge can be prevented in response to a high voltage power request, and the capacity EH of the high voltage power supply 5 can be maintained appropriately.

(5) The transformation machine control device 70 determines the order of the capacities EH_i of the plurality of high voltage modules 51 and 52. When charging the plurality of high-voltage modules 51 and 52 from the low-voltage power supplies 31 and 32, the high-voltage modules having a relatively low capacity EH_i are preferentially charged. Further, when discharging from the plurality of high-voltage modules 51 and 52 to the low-voltage power supplies 31 and 32, the high-voltage modules having relatively high capacity EH_i are preferentially discharged.
Thereby, the difference of the capacity | capacitance (electric storage amount) which generate | occur | produced between several high voltage modules can be eliminated, and it can average.

  (6) The variable electrical machine control device 70 predicts future high-voltage module required power PHreq_i based on the power change (dPH_i / dt) of the high-voltage modules 51 and 52. As a result, for example, the shortage with respect to the high-voltage power requirement can be compensated from the low-voltage power supplies 31 and 32, so that the output specifications of the high-voltage modules 51 and 52 can be reduced.

  (7) When the capacity EL_i of the low-voltage power supplies 31 and 32 is lower than the minimum value ELmin_Ld_i, the variable electrical machine control device 70 requests the rotating machine control device 8 to generate power by the rotating machine. Thereby, the electric power supply to the auxiliary machine load 2 can be maintained appropriately.

(8) When the high voltage module 52 of the plurality of high voltage modules 51 and 52 fails, for example, the variable electric machine control device 70 supplies power to the rotating machine system 6 from the variable electric machine 402 corresponding to the high voltage module 52 that has failed. In this way, the transformer 402 is controlled.
Thereby, an emergency function degenerate operation is possible. In particular, when applied to a hybrid vehicle, retreat travel is possible.

  (9) When the electric machine control device 70 has a power request from the rotating machine control device 8 and at least a part of the plurality of high-voltage modules 51 and 52 has failed, the failed high-voltage module from the low-voltage power supply. The transformer is controlled so as to supply electric power to the rotating machine system 6 via the transformer corresponding to the above. Thereby, even if some or all of the high-pressure modules 51 and 52 fail, the internal combustion engine can be started by cranking the rotating machine.

(Second Embodiment)
As shown in FIG. 18, the power supply system 11 of the second embodiment of the present invention is different from the first embodiment shown in FIG. 1 in that there is one low-voltage power supply 3. The low-voltage parts 441 and 442 of the transformers 401 and 402 are connected to the low-voltage power supply 3 in parallel. Further, corresponding to the single low-voltage power supply 3, the low-voltage arithmetic devices 731 and 732 in the variable electric machine control device 70 of FIG. 2 are integrated into one block.

  In the configuration of the present invention, it is a requirement that the number of high-voltage modules and transformers be the same, but the low-voltage power supply may be set regardless of the number of high-voltage modules and transformers. For example, three high-voltage modules and transformers are provided, and two low-voltage power sources, one low-voltage power source connected to two transformers and one low-voltage power source connected to the remaining one transformer, are provided. There can also be a configuration.

(Other embodiments)
Specific selection of the output power source and the capacitive power source is not limited to those exemplified in the above embodiment. An appropriate power source may be selected according to the required specifications of the high-voltage load (rotary machine system).
Further, when the driving voltage of the auxiliary load is lower than the voltage of the low-voltage power supply, a step-down converter may be further provided between the low-voltage power supply and the auxiliary load.

The power supply system of the present invention is not limited to a rotating machine system and an auxiliary load mounted in a hybrid vehicle, and may be applied to a rotating machine system and an auxiliary load for supplying DC power to an auxiliary load for any other purpose. . For example, the present invention is effectively applied to a system in which a request for outputting high power instantaneously and a request for continuously outputting low power coexist, such as a power source of a heavy machine.
As mentioned above, this invention is not limited to the said embodiment at all, In the range which does not deviate from the meaning of invention, it can implement with a various form.

12, 11 ... power supply system,
2 ... Auxiliary load,
31, 32 ... low voltage power supply,
401, 402 ... transforming machine,
50 ... High voltage power supply,
51, 52 ... high pressure module,
6 ・ ・ ・ Rotary machine system,
70 ... Electric transformer control device,
8: Rotating machine control device.

Claims (12)

A high-voltage power source (50) configured by connecting a plurality of high-voltage modules (51, 52) in series and capable of supplying DC power to a rotating machine system (6) that drives a rotating machine as a main machine, and auxiliary equipment other than the main machine At least one low-voltage power supply (31, 32) capable of supplying DC power to the load (2);
A plurality of transformers (401, 402) provided individually corresponding to the plurality of high-voltage modules and connecting the plurality of high-voltage modules and the low-voltage power supply in a bidirectionally transformable manner;
When the capacity or input / output of the low-voltage power source is out of the proper range, the high-voltage module is supplemented. When the capacity or input / output of the plurality of high-voltage modules is out of the proper range, the low-voltage power source is supplemented. A substation control device (70) for controlling the substation;
A power supply system comprising:   According to the relationship between the target power per unit of the plurality of substations and the conversion efficiency for each number of operating units, the substation control device has the maximum number of substations having the maximum conversion efficiency. If the number of the substations is the total number of the plurality of substations, the total number of substations is operated simultaneously. The power supply system according to claim 1.   The power supply system according to claim 1, wherein the plurality of high-voltage modules are configured by an output power source, and the low-voltage power source is configured by a capacitive power source.   The transformer control device is configured to charge the plurality of high-voltage modules from the low-voltage power source when the total capacity or voltage of the plurality of high-voltage modules is lower than a predetermined value by a power running operation of the rotating machine. The power supply system according to claim 3, wherein the power transformer is controlled.   When the total capacity or voltage of the plurality of high voltage modules rises above a predetermined value by the regenerative operation of the rotating machine, the transformer control device is configured to discharge the plurality of high voltage modules to the low voltage power source. The power supply system according to claim 3 or 4, wherein the power transformer is controlled. The transformer control device determines an order of capacities of the plurality of high-voltage modules;
5. The power supply system according to claim 4, wherein when charging the plurality of high-voltage modules from the low-voltage power supply, the high-voltage modules having a relatively low capacity are preferentially charged. The transformer control device determines an order of capacities of the plurality of high-voltage modules;
6. The power supply system according to claim 5, wherein when discharging from the plurality of high-voltage modules to the low-voltage power supply, the high-voltage modules having a relatively high capacity are preferentially discharged.   The transformer control device predicts the future required power based on the power change of the high voltage module, and when it is predicted that the output of the high voltage module will be insufficient or the input will be excessive, The power supply system according to any one of claims 3 to 7, wherein the transformer is controlled so as to be charged and discharged between the two.   When the capacity of the low-voltage power source is below a predetermined value, the transformer control device requests the rotating machine control device (8) that controls the rotating machine system to generate power by the rotating machine. The power supply system as described in any one of Claims 3-8.   When the capacity or input / output of the low-voltage power source or the capacity or input / output of the plurality of high-voltage modules is out of an appropriate range, the transformer control device controls the rotating machine system ( The power supply system according to any one of claims 1 to 9, wherein a total value of input / output capabilities of the plurality of high-voltage modules and the low-voltage power supply is notified to 8).   When the at least some of the plurality of high-voltage modules have failed, the transformer control device is configured to supply the power to the rotating machine system from the transformer corresponding to the failed high-voltage module. It controls, The power supply system as described in any one of Claims 1-10 characterized by the above-mentioned.   The transformer control device corresponds to the failed high-voltage module from the low-voltage power supply when there is a power request from the rotating machine control device and at least a part of the plurality of high-voltage modules fails. The power supply system according to claim 11, wherein the power transformation system is controlled to supply power to the rotating machine system via the power transformation machine.

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