JP2014039383A - Power supply device and on-vehicle power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized and inexpensive power supply device having high responsiveness of output voltage to input voltage.SOLUTION: A power supply device comprises a power supply main circuit and a power supply control circuit. The power supply main circuit supplies power to a load by performing voltage conversion operation for converting DC input voltage of an input power supply to predetermined DC output voltage, and applying the predetermined DC output voltage to the load. The power supply control circuit creates a control amount for the voltage conversion operation of the power supply main circuit, and controls the voltage conversion operation, where the predetermined DC output voltage of the power supply main circuit is proportional to the product of a control amount of the power supply main circuit and the input voltage in normal operation, and the control amount of the power supply main circuit includes the reciprocal of the DC input voltage as a factor.

Description

  The present invention relates to a power supply device and a vehicle-mounted power supply device equipped with the power supply device.

  An in-vehicle power supply device used in a hybrid electric vehicle (HEV) or an electric vehicle (EV) receives an output voltage such as a high voltage battery composed of a lithium battery or the like, and is a low voltage battery composed of a lead battery or the like. It is a power supply device which outputs the output voltage. Therefore, a step-down DC-DC converter is used in this in-vehicle device power supply device. Since an inverter for driving a motor such as HEV or EV is often connected in parallel to the output terminal of the lithium battery, the input voltage to the on-vehicle equipment power supply device, that is, the DC-DC converter varies greatly.

  As a typical control method for stabilizing the output voltage with a DC-DC converter, there is a method using PI control. In this output voltage control method, first, the voltage command value is compared with the output voltage to obtain a voltage difference. Next, the voltage difference is subjected to PI control to obtain a control amount. Finally, the switching semiconductor element of the DC-DC converter circuit is driven according to the control amount. A DC-DC converter using this PI control does not normally have an input voltage as a parameter, and the control amount is performed by feeding back the output voltage as a control result. large.

  In order to suppress the fluctuation of the output voltage, a method of incorporating the input voltage as a control parameter for PI control is known (see, for example, Patent Document 1).

JP 2011-223729 A

  In the power supply device described in Patent Literature 1, a value determined by the ratio of the input voltage (Vin) and the output voltage (Vout) is added as a feedforward term to the control amount (duty: Duty) of the PI control result. If the transfer function from the controlled variable to the output voltage of the power supply circuit is G (s), Vout = G (s) * (Duty + Vin / Vout). Therefore, the term G (s) * Duty is the input voltage fluctuation. The output voltage fluctuation responds after feedback, and the output voltage fluctuation response is poor. As a result, an excessive capacity is required for the capacitor for suppressing output oscillation and ringing, or a program is added such as providing a separate algorithm at the time of startup, which increases the size and cost of the power supply device.

(1) The invention according to claim 1 includes a power supply main circuit and a power supply control circuit, and the power supply main circuit performs a voltage conversion operation for converting the DC input voltage of the input power supply into a predetermined DC output voltage. The power is supplied to the load by applying a predetermined DC output voltage to the load, and the power supply control circuit generates a control amount of the voltage conversion operation of the power supply main circuit to control the voltage conversion operation. The predetermined DC output voltage is proportional to the product of the control amount of the power supply main circuit and the input voltage during steady operation, and the control amount of the power supply main circuit includes the inverse of the input DC voltage as a factor. Device.
(2) The invention according to claim 11 is an in-vehicle power supply device equipped with the power supply device according to any one of claims 1 to 10, wherein the input power source is an inverter that drives a vehicle drive motor. A high-voltage battery that supplies DC power, and the load is an on-vehicle auxiliary device and a low-voltage battery that supplies DC power to the on-vehicle auxiliary device. The controller of the power supply control circuit, the controller of the high-voltage battery, An in-vehicle power supply device comprising a host controller for controlling a controller of a machine and a controller of a low voltage battery.
(3) The invention according to claim 15 includes a power supply main circuit and a power supply control circuit, and the power supply main circuit performs a voltage conversion operation for converting the DC input voltage of the input power supply into a predetermined DC output voltage. The power is supplied by applying a predetermined DC output voltage to the load, and the power supply control circuit generates a control amount of the voltage conversion operation of the power supply main circuit to control the voltage conversion operation. The DC output voltage is proportional to the product of the control amount of the power supply main circuit and the input voltage during steady operation, and the input voltage and the control amount are output to the output voltage terminal of the power supply main circuit and the output fed back to the power supply control circuit. When the value of the input voltage terminal of the control circuit is changed while the equivalent value is input to the voltage command value terminal and the output voltage terminal fed back to the power supply control circuit, the voltage terminal is disconnected. Special to be in a relationship In the power source apparatus for the.

  By using the power supply device according to the present invention, a small and inexpensive power supply device with high output voltage response to an input voltage can be obtained.

1 is a schematic diagram of an electric drive device including a power supply device according to a first embodiment of the present invention. It is the schematic of the electric drive device containing the power supply device of 2nd Embodiment which concerns on this invention. It is the schematic of the electric drive device containing the modification of the power supply device of 2nd Embodiment which concerns on this invention. It is the schematic of the electric drive device containing the power supply device of 3rd Embodiment which concerns on this invention. It is the schematic of the electric drive device containing the power supply device of 4th Embodiment which concerns on this invention. It is the schematic of the electric drive device containing the power supply device of 5th Embodiment which concerns on this invention. It is the schematic of the electric drive device containing the power supply device of 6th Embodiment which concerns on this invention. It is a block diagram of the test apparatus which confirms the operating characteristic of a power supply device. It is the figure of the operating characteristic of the conventional common power supply device confirmed using the test apparatus of FIG. It is a figure of the operating characteristic of the power supply device of the conventional Vin addition control system using the test apparatus of FIG. It is the figure of the operating characteristic of the power supply device of the Vin division control system which concerns on this invention confirmed using the test apparatus of FIG. It is a figure which shows the outline of the example of the data transmission / reception path | route between these controllers which control the power supply system of an electric vehicle containing the power supply device by this invention, and these controllers. Each controller is controlled by the host controller 10. As in FIG. 12, an outline of another example of a controller that controls the power supply system of the electric vehicle and a data transmission / reception path between these controllers is shown. The power supply controller 3a directly controls other controllers in the power supply device 1.

Hereinafter, an embodiment of a power supply device according to the present invention will be described with reference to FIGS.
(First embodiment)
The power supply device 1 of FIG. 1 includes a power supply main circuit 2, a power supply control circuit 3, an input power supply (VHV) 6, and a load power supply (VLV) 7.

  The input power source (VHV) 6 is assumed to be a high voltage battery including a plurality of lithium ion batteries, for example, and the load power source (VLV) 7 is assumed to be a low voltage battery such as a lead storage battery. Yes. VHV and VLV represent the voltages between the terminals of the input power supply 6 or the load power supply 7, respectively. The input power supply 6 supplies power to the power supply main circuit 2 and the inverter 8. The load power source 7 is driven by being connected to an auxiliary device such as an air conditioner or a car navigation system (see FIG. 12). However, these auxiliary devices are omitted in the load power source 7 shown in FIGS. Therefore, the load power supply 7 and auxiliary equipment such as an air conditioner and a car navigation system connected to the load power supply 7 act as a load for the power supply main circuit 2.

  The power supply main circuit 2 illustrated in FIG. 1 includes an insulated step-down DC-DC converter having a full-bridge circuit with a phase shift operation on the high voltage side and a current doubler circuit on the low voltage side. In the following description of the power supply device according to the present invention, the case of a step-down DC-DC converter will be described. However, the method of the present invention is also applicable to a step-up DC-DC converter.

  The full bridge circuit includes an input capacitor Cin, switching elements Q1, Q2, Q3, and Q4, and a resonant inductor Lr. The resonant inductor Lr is the sum of the inductance value of the external inductor and the leakage inductance value of the transformer Tr. The input capacitor Cin is connected in parallel with the input power supply 6 (VHV), but in reality, a parasitic inductance or the like exists between the input power supply (VHV) 6 and the input capacitor Cin, and therefore the potentials are different. In the present embodiment, the voltage across the input capacitor Cin that is closer to the voltage across the switching elements Q1 to Q4 is taken as the input voltage Vin.

  The full bridge circuit and the current doubler circuit are insulated by a transformer Tr. When the number of turns on the high voltage side of the transformer Tr is N1 and the number of turns on the low voltage side is N2, the voltage N2 / N1 of the voltage generated on the high voltage side (primary side) of the transformer Tr is Occurs on the low voltage side.

  The current doubler circuit includes rectifier diodes D1 and D2, inductors L1 and L2, and an output capacitor Cout. The difference between the pulse voltage generated on the low voltage side of the transformer Tr and the output voltage Vout which is the voltage across the output capacitor Cout determines the increase / decrease of the currents in the inductors L1 and L2, and the current to the load power supply (VLV) 7 Supply. VLV represents the voltage between the terminals of this load power supply.

  The inverter (INV) 8 converts DC power supplied from the input power supply (VHV) 6 into AC power and supplies AC power required by the motor (MOT) 9. In the case where the input power supply 6 is composed of an electricity storage device such as a lithium ion secondary battery or a large-capacity capacitor, the voltage across the input power supply 6 varies greatly when the inverter 8 requires a large amount of power.

  The power control circuit 3 includes a power control block 4 and a power drive signal generation block and drive circuit 5. The power supply control circuit 3 can be configured as an analog circuit using an operational amplifier or the like, or can be configured as a digital circuit using an FPGA, a DSP, or the like. Here, in order to facilitate understanding, blocks will be divided for each function, and explanation will be made on the premise of digital processing.

  The power supply control circuit 3 receives the voltage command value Vref from the host controller 10, and receives the input voltage Vin and the output voltage Vout from the power supply main circuit 2. The output of the power supply control circuit 3 is a drive signal for the power supply main circuit 2. In the first embodiment, the power supply main circuit 2 including a full bridge circuit is provided, and the switching elements Q1 to Q4 are elements that drive the full bridge circuit in phase shift. The gates of switching elements Q1 to Q4 are controlled to turn on / off these elements by signals Vg1 to Vg4, respectively.

Although not shown in FIGS. 1 to 8, the input voltage Vin of the power supply main circuit 2 and the input voltage value of the output voltage Vout to the power supply control block 4 are input to an insulated transfer element (for example, a photocoupler). (Not shown). When the voltage value of Vin or Vout is large, the voltage is divided as appropriate, or the voltage value is converted into a digital signal and input to the power supply control block 4. These voltage dividing circuits, voltage detection circuits, and voltage value digitizing circuits are omitted.
Similarly, the signals Vg1 to Vg4 are transmitted to a driver circuit (not shown) that drives the gates of the switching elements Q1 to Q4 using an insulated transmission element (not shown) such as a photocoupler.

  The power supply control block 4 first calculates a difference Verr between the voltage command value Vref and the output voltage Vout. The sum of the proportional calculation result obtained by multiplying Verr by the proportional constant Kp and the integral calculation result obtained by integrating (1 / s) and multiplying by the integral constant Ki is normally calculated by the switching elements Q1 to Q4 of the full bridge circuit. An on / off control amount (duty) is assumed. However, in this embodiment, the sum of the proportional calculation result and the integral calculation result is multiplied by the average value Vina of the input voltage, and the result of dividing the input voltage Vin is defined as a control amount (duty: Duty). The power supply device according to the present invention is characterized by adopting control using such calculation, and the characteristics of this control method will be described later.

・・・（１） The switching signal generation block 5 generates a drive signal for controlling the switching elements Q1 to Q4 of the power supply main circuit 2 according to the control amount Duty.
Here, the steady state of the power supply device 1 is considered. In a steady state, the control amount Duty determines the relationship between the input voltage Vin and the output voltage Vout. In other words, Vin becomes a pulse voltage at the duty ratio, and is applied alternately to the high voltage side of the transformer Tr, and a voltage N2 / N1 times that voltage is generated on the low voltage side of the transformer Tr. Since only the voltages generated in the positive direction are applied to L2 and Cout, the relationship between the steady state Duty and Vout is expressed by Equation (1).

... (1)

Expression (1) is a function in which a control amount Duty, which is an output signal of the power supply control block 4, is transmitted to the switching signal generation block 5 and the power supply main circuit 2, and is converted into Vout, which is output information of the power supply main circuit. Vin / 2) · (N2 / N1). N2 / N1 is a constant because it is the turn ratio of the transformer Tr. Therefore, it can be seen that the variation in Vin is directly linked to the variation in Vout.
From this, it can be seen that in order to remove the variation of Vin in the feedback loop, it is necessary to cancel Vin by adjusting the gain corresponding to Vin in the calculation of the control amount (duty: Duty).

  In the first embodiment, Vina / Vin is multiplied by the result of PI control of Verr. The reason for dividing by Vin is to cancel the effect because the function of the power supply main circuit 2 depends on Vin. Multiplying Vina has the meaning of negating the weight of Vin division because the value becomes smaller when it is simply divided by Vin. Vina is described as an average value of the input voltage for the sake of convenience, but is a constant of the effect of canceling the weight of Vin division, and can be any minimum value or maximum value of the input voltage, or any numerical value between the minimum value and the maximum value. There is no particular limitation.

(Second Embodiment)
FIG. 2 shows a second embodiment of the power supply device according to the present invention.
In the second embodiment, the configuration of the rectifier circuit on the low voltage side of the power supply main circuit 2 inside the power supply device 1 described in the first embodiment is changed. Switching elements S1 and S2 are used instead of the rectifying diodes D1 and D2 of the first embodiment, and when the current flows, the switching elements S1 and S2 are turned on to perform synchronous rectification. Further, in order to temporarily store energy of the surge voltage generated at both ends of S1 in the active clamp capacitor Cc during the ON-OFF state transition of the switching elements S1 and S2, and gently regenerate the energy in the inductors L1 and L2. The switching elements S3 and S4 are driven. In the present specification, a circuit including the switching elements S3 and S4 and the active clamp capacitor Cc is referred to as an active clamp circuit.

  That is, in the second embodiment, the rectifier circuit on the low voltage side is a current doubler circuit with an active clamp circuit. By using such a rectifier circuit, the conduction loss of the power supply main circuit 2 can be reduced. The reason will be described below.

In this current doubler circuit with an active clamp circuit, the on / off timing of the switching elements S3 and S4 depends on Vin, so that the Vin detection circuit is one of the control of the present invention and the control of the switching elements S3 and S4. Plays two roles on the stand.
The on-timing of the switching elements S3 and S4 needs to avoid a period in which a voltage is applied to the resonant inductor Lr. This period is called a commutation overlap period and is inversely proportional to Vin. Therefore, in order to control the active clamp circuit at an appropriate timing, it is necessary to perform arithmetic processing using the reciprocal of Vin, and the reciprocal of Vin can be easily used for the control of the present invention.

  Similarly, the off timing of the switching elements S3 and S4 is also correlated with Vin. The off timing may be synchronized with the timing of any of the switching elements Q1, Q2, Q3, and Q4 on the high voltage side. However, even when the high-voltage side voltage is not applied to the transformer Tr, the switching elements S3 and S4 are maintained in the ON state to reduce the circulating current on the high-voltage side of the transformer Tr (for example, Japanese Patent Laid-Open No. 2006-187147). It is desirable to implement ( By this circulating current reduction control, energy is supplied from the active clamp capacitor Cc to the inductors L1 and L2, and the current circulating to the high voltage side decreases, so that the conduction loss of the power supply main circuit 2 decreases.

  Note that if the period during which the switching elements S3 and S4 maintain the ON state even when the high-voltage side voltage is not applied to the transformer Tr is a circulating current reduction period, the circulating current reduction period is short when Vin is large. However, when Vin is small, it needs to be long. This is because the voltage applied to the active clamp capacitor Cc is substantially proportional to Vin, and therefore, if the circulating current reduction period is constant, Vin and the circulating current reduction amount have an inversely proportional correlation. From the above, it can be seen that it is desirable to detect the information of Vin for the control of the active clamp circuit.

As shown in FIG. 3, even if the current doubler circuit with an active clamp circuit is changed to a center tap circuit with an active clamp circuit, the operation principle of the active clamp circuit is the same, so Vin is a center tap circuit with an active clamp circuit. It is also used for control. N21 and N22 indicate the number of turns of the transformer Tr.
Therefore, it can be said that the present invention is particularly effective for the power supply main circuit 2 using the active clamp circuit.

(Third embodiment)
FIG. 4 shows a third embodiment of the power supply device according to the present invention.
The third embodiment is an example in which a resonance capacitor Cr is arranged in series with the primary side of the resonance inductor Lr or the transformer Tr in the power supply main circuit 2 of FIG. 3 described in the second embodiment. There are two reasons for arranging the resonant capacitor Cr, which will be described below.

The first is the case of driving as a resonant converter. FIG. 4 shows a series resonance type resonance converter.
Using the resonance characteristics of the resonant inductor Lr and the resonant capacitor Cr, the voltage or current is converted into a sine wave. The power supply control block 4 obtains the switching frequency Fsw. In the case of a resonant converter, the switching frequency Fsw is a controlled variable. The switching element is turned on and off at the timing when the voltage or current sine wave crosses zero. A time for applying a voltage to the primary side of the transformer Tr is fixed, and a desired output voltage is generated by controlling the switching frequency Fsw.

  The power supply device of the third embodiment can also be used when the output of the power supply control block 4 is other than Duty like a resonant converter. This is because the product of Duty and Vin and Vout are proportional to each other in the steady state as in the equation (1) also in the resonant converter.

・・・（２）

上記式（２）から、制御量であるＦｓｗにＶｉｎａ／Ｖｉｎの重みを因子として持たせることで、Ｖｏｕｔに対するＶｉｎの影響を相殺できることが分かる。 Assuming that the switching period is T and the time during which the voltage is applied to the primary side of the transformer Tr is ton, Duty = ton / T and T = 1 / Fsw. Considering that the circuit on the low voltage side is a center tap circuit, the relationship of Expression (2) is established. However, N21 = N22.

... (2)

From the above equation (2), it can be understood that the influence of Vin on Vout can be offset by giving the weight of Vina / Vin as a factor to the control amount Fsw.

  Note that when the control amount is the switching cycle T, it is equivalent to multiplying T by Vin / Vina. When the control amount is set to the off time toff, the ton + toff is calculated once in the power supply control block 4 to obtain the switching period T (T = ton + toff), and ton is subtracted from the switching period T ′ multiplied by Vin / Vina. The final control variable toff ′ (= T′−ton = T * Vin / Vina−ton = (ton + toff) * Vin / Vina−ton) can be used to implement the present invention.

The second reason for disposing the resonance capacitor Cr is to suppress the direct current component of the current flowing through the transformer Tr and to avoid magnetic saturation due to magnetic bias.
For example, when driven as a full bridge circuit of a phase shift operation with a fixed frequency, a voltage of Vin is applied to both ends of the primary side of Lr and Tr while the switching elements Q1 and Q4 are on. At this time, the current flowing through Lr is defined as a positive current. Conversely, when the switching elements Q2 and Q3 are on, a voltage of −Vin is applied to both ends of the primary side of Lr and Tr. At this time, the current flowing through Lr is a negative current. At this time, the ON resistance variation between the switching elements and the time lag in which Q2 and Q3 are on with respect to the time in which Q1 and Q4 are on appear as the difference between the positive current and the negative current. As it manifests.

  However, by arranging the resonant capacitor Cr, the difference between the positive current and the negative current is generated as a voltage across Cr, and the difference between the positive current and the negative current is suppressed, and the direct current flowing through the transformer Tr is reduced. The component disappears and does not demagnetize. This bias is particularly likely to occur due to discretization of the pulse width due to the clock limit of the digital control power supply. The duty control of the power supply apparatus according to the present invention is easier to perform by digital arithmetic processing, but when this digital arithmetic processing is adopted, the bias of the transformer Tr is likely to occur. Therefore, when the present invention is applied to a digital control power supply as in the third embodiment, it is desirable to reduce the bias of the transformer Tr by arranging a resonance capacitor.

FIG. 5 shows a fourth embodiment of the power supply device according to the present invention.
The fourth embodiment is an example in which a power control block 4 having a configuration different from that of the power supply device 1 described in the first embodiment is employed. The reason why Verr may be multiplied by Vina / Vin as in the fourth embodiment is that the effect of eliminating the variation of Vin in the feedback loop described in the first to third embodiments is that the control amount Duty is Vin. This is because it is established if it is inversely proportional.

・・・（３） That is, if the integral calculation is described by Σ, the following formula (3) is established in the first embodiment and the fourth embodiment.

... (3)

  As in the expression (3), as another configuration of the power supply control block 4 in which the control amount Duty is inversely proportional to Vin, Kp is set to Kp * Vina / Vin and Ki is set to Ki * Vina / Vin. A system or a system in which Vref is multiplied by Vina / Vin and Vout is also multiplied by Vina / Vin may be used, and similar effects can be obtained by these systems.

  Furthermore, in this embodiment, the description is limited to the PI control. However, even if the gain and the phase margin are adjusted by the PID control or the analog control, the control amount (duty: Duty) is finally in an inversely proportional relationship with Vin. The same effect can be obtained.

FIG. 6 shows a fifth embodiment of the power supply device according to the present invention.
The fifth embodiment is an example of a power supply main circuit 2 having a configuration different from that of the power supply device 1 described in the first embodiment. The power supply device according to the present invention can be effectively used for a non-insulated step-down DC-DC converter as in the fifth embodiment.

・・・（４） The relational expression between the duty (Duty) at the steady state of the non-insulated step-down DC-DC converter and Vout and Vin is the following expression (4).

... (4)

If the relational expression of Vout, Vin, and Duty in a steady state is described as in the first embodiment and the fifth embodiment, if the power supply main circuit 2 can be expressed as a function of the product of Duty and Vin The power supply circuit according to the present invention can be used effectively.
For example, in the first embodiment, the high-voltage side full-bridge circuit and the low-voltage side current doubler circuit insulation type step-down DC-DC converter are taken as an example, but the high-voltage side half-bridge circuit and the low-voltage side center tap circuit are insulated. The present invention is effective even with a DC-DC converter, and the present invention is also effective with an insulated DC-DC converter having a high-voltage side full bridge circuit and a low-voltage side center tap circuit as in the third embodiment. The present invention is also effective in an insulated DC-DC converter of a bridge circuit and a low-voltage current doubler circuit.

FIG. 7 shows a sixth embodiment of the power supply device according to the present invention.
The sixth embodiment is an example in which the control amount adjustment described in the first embodiment is performed not by the power supply control block 4 but by the switching signal generation block 5.

In the first to fifth embodiments, in order to facilitate understanding, the control amount (duty: Duty) is controlled in inverse proportion to Vin. However, Duty is finally converted into a drive signal for the switching element. Therefore, even if the same processing is added to the switching signal generation block 5, the same effect can be obtained.
For example, in the first embodiment, the timing at which the on times of Vg1 and Vg4 overlap and the timing at which the on times of Vg3 and Vg2 overlap are periods corresponding to the control amount, and these periods are inversely proportional to Vin according to Vin. The same effect can be obtained by performing processing with correlation.

8 to 11 are diagrams for explaining the operating characteristics of the power supply device according to the present invention.
FIG. 8 is a block schematic diagram of a test apparatus for confirming the operating characteristics of the power supply apparatus.

  The feedback loop of Vout from the power supply main circuit 2 is disconnected, and signals equal to Vref and Vout are input. By configuring the circuit in this way, Verr becomes 0, and the integrator settles at a certain integral value, so that the control amount (duty: Duty) takes a certain constant value. This fixed value of Duty is set to α. At this time, it is a condition that the integral value or the control amount (Duty) is not saturated. In this state, when Vin is changed as a parameter, the power supply device according to the present invention shows a characteristic correlation between Vin and the control amount Duty as described below. Note that, as described in the sixth embodiment, it can be confirmed that the same operation is performed also by checking the timing of the ON times of the drive signals such as Vg1 and Vg4.

  FIG. 9 is a correlation graph in the case of a conventional general power supply device that does not use Vin information for control calculation. The control amount does not change with respect to the change in Vin.

  FIG. 10 is a control using conventional PI control, and is a correlation graph in the case of a power supply device in which the inverse of Vin is added to the control amount Duty. Actually, an upper limit value and a lower limit value are set in a practical range for Vin and the control amount Duty. However, as is easy to understand in FIG. 10, Vin and Vin when changing Vin in a wide range are used. A duty relationship curve is shown. When Vin is infinite, the control amount (Duty) approaches a value obtained by subtracting Vout / Vin ′ from α, and when Vin is brought close to 0, a curve is obtained in which Duty approaches infinity. Here, Vin ′ is the value of Vin when α is obtained. This is because an inverse proportional curve of Vin is added to the PI calculation result. The difference from the present invention described below is that even when Vin is brought to infinity, Duty approaches a value other than 0.

  FIG. 11 is a correlation graph of Vin and Duty when the power supply device according to the present invention is used. There are upper and lower limits for Vin and Duty, but Vin and Duty are inversely proportional, and when Vin approaches infinity, Duty approaches 0, and when Vin approaches 0, Duty approximates infinity. can get.

  As described above with reference to FIGS. 8 to 11, the present invention is characterized in that Vin and Duty are in an inversely proportional relationship. In the case of the resonant converter according to the third embodiment, the same phenomenon can be obtained by measuring the duty in FIGS. 8 to 11 as Fsw.

FIG. 12 shows a seventh embodiment of the power supply device according to the present invention. When this power supply device is mounted on an electric vehicle, the movement of electric energy in the power supply system including this power supply device and the various types constituting this power supply system are shown. It is a figure for demonstrating the movement of the control information between the control apparatuses (controller) of the circuit of this.
Electric energy is stored in the input power source (VHV) 2 composed of a lithium battery or the like from the external power system 12 via the charger 13. The input power source (VLV) 6 is a power source that supplies an appropriate voltage to an inverter 8 that drives a motor (MOT) 9 connected to a wheel (not shown) of an electric vehicle and a load power source (VLV) 7 that drives an auxiliary device 14. Power is supplied to the main circuit 2.

  Since the charger 13 does not supply power to the input power supply 6 when the electric vehicle is traveling, the voltage between the terminals of the input power supply 6 affects only the driving status of the inverter 8 and the power supply main circuit 2. Therefore, particularly when the electric vehicle is accelerated, the inverter 8 draws a large current from the input power supply 6. At this time, in addition to the effect that the amount of power stored in the input power supply 6 decreases and the voltage decreases due to the extraction of the large current, a large current flows through the internal resistance of the input power supply 6 to generate a voltage, and the voltage across the input power supply 6 is instantaneous. Greatly decreases.

Since a general power supply device does not need to take into account fluctuations in input voltage instantaneously, special control for fluctuations in input voltage is not usually incorporated in a power supply control circuit.
On the other hand, in the case of an in-vehicle power supply device, the above phenomenon becomes remarkable, and the function of adjusting the control amount of the power supply main circuit 2 in the present invention with respect to the voltage fluctuation of the input power supply as in the present invention 3 must be incorporated. If this function is not incorporated in the power supply control circuit 3, the voltage applied to the auxiliary device 14 may be excessive or low, and the auxiliary device 14 may be damaged.

  FIG. 12 shows communication between each controller and the host controller 10. The power supply controller 3a performs calculations in the power supply control block 4, calculations in the switching signal generation block 5, and the like. Vref shown in the first to sixth embodiments is a part of a signal sent from the host controller 10 to the power supply controller 3a. Vref depends on a deterioration state, a charging state, a connection state, and the like of the load power source 7. For example, when the load power supply 7 is deteriorated, it becomes impossible to chemically charge to the voltage at the time of initial shipment, so that Vref is lowered. This information is transmitted from the battery controller of the load power supply 7 to the host controller 10, and is transmitted from the host controller 10 to the power supply controller 3a. At this time, in the first to sixth embodiments, Vref acts as a disturbance on the control loop. Control is realized. When the inverse number of Vin mentioned as the background art is added to the control amount, the term Vin / Vout affects from the outside of the control loop, so that appropriate control cannot be performed and Vout response to Vref is poor. Therefore, the present invention can be said to be an effective invention even when a variable Vref is given from the host controller 10.

  FIG. 13 shows an example of a configuration in which the battery controller 7a of the load power supply 7 can directly transmit Vref information to the power supply controller 3a without going through the host controller 10. Since the state of the load power supply 7 is directly grasped and the control of the supply of DC power to the load power supply 7 is directly performed, the auxiliary machine 14 and the like are compared with the case of controlling the power supply to the load power supply 7 via the host controller 10. Responsiveness when the load changes.

  Assuming that Vin is equal to the terminal voltage VHV of the input power supply, as shown in FIG. 13, it is also possible to directly transmit Vin information from the battery controller 6a of the input power supply 6 to the power supply controller 3a. Of course, the host controller 10 may be used. In the configuration as shown in FIG. 12, a voltage detection circuit is required for detecting the voltage of VHV and Vin, respectively, but in the configuration of FIG. 13, the voltage detection circuit of either VHV or Vin can be reduced. However, as described in the first embodiment, it is desirable to detect the input voltage Vin from the voltage across the input capacitor Cin that is closer to the voltage across the switching elements Q1 to Q4.

As mentioned above, although the example of 6 embodiment of the power supply device by this invention was demonstrated, it is also possible to use combining these embodiment.
Further, the power supply device according to the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the gist thereof. For example, the power storage device described as the input power supply (VHV) 6 may be connected to another load other than the inverter 8. The input power supply 6 may be a diode rectified voltage of the power system 12.

The effects of the DC-DC converter and the DC power supply device according to the present invention described above are summarized as follows.
In the DC-DC converter according to the present invention, the control amount is changed so as to cancel the change in the transfer function of the power supply circuit due to the input voltage. Therefore, the output voltage can respond at high speed to the change of the input voltage.
Furthermore, due to this effect, fluctuations in the output voltage can be suppressed, the capacity of the output capacitor of the power supply circuit can be reduced, and a small, lightweight and inexpensive power supply device can be realized.
Therefore, the power supply device according to the present invention can be effectively used for a power supply device for an electric construction machine or a power supply device for an electric tool.

  The above description is examples of the embodiments and modified embodiments of the present invention, and the present invention is not limited to these embodiments and modified examples. Those skilled in the art can implement various modifications without impairing the features of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Power supply device 2 ... Power supply main circuit 3 ... Power supply control circuit 3a ... Power supply controller 4 ... Power supply control block 5 ... Switching signal generation block 6 ... Input power supply (VHV)
6a: Input power controller 7: Load power supply (VLV)
7a ... Load power supply controller 8 ... Inverter (INV)
8a ... Inverter controller 9 ... Motor (MOT)
DESCRIPTION OF SYMBOLS 10 ... Host controller 11 ... Test apparatus 12 ... External electric power system 13 ... Charger 13a ... Charger controller 14 ... Auxiliary machine 14a ... Auxiliary machine controller Q1, Q2, Q3, Q4, Q5, Q6, S1, S2, S3, S4 ... Switching elements D1, D2 ... Rectifier diode Lr ... Resonant inductors L1, L2, L3 ... Inductors Cin ... Input capacitors Cout ... Output capacitors Cc ... Active clamp capacitors Cr ... Resonant capacitors Tr ... Transformers N1, N2, N21, N22 ... Number of turns Vref ... Voltage command value Vin ... Input voltage Vout ... Output voltage Verr ... Differential voltage between voltage command value and output voltage 1 / s ... Integrator Kp ... Proportional constant Ki ... Integral constant Vina ... Weighs about the average value of input voltage Constant Duty ... Control amount Fsw ... Switching frequency ( Control amount in the vibration converter synonymous)
Vg1, Vg2, Vg3, Vg4, Vg5, Vg6... Switching element gate drive signal Vin '... Initial value of Vin when the measurement shown in FIG. 4 is performed α... When the measurement shown in FIG. Duty value

Claims (16)

Power supply main circuit and power supply control circuit
The power supply main circuit performs a voltage conversion operation for converting a DC input voltage of an input power supply into a predetermined DC output voltage, and supplies the load with power by applying the predetermined DC output voltage to a load.
The power supply control circuit generates a control amount of the voltage conversion operation of the power supply main circuit to control the voltage conversion operation;
The predetermined DC output voltage of the power supply main circuit is proportional to the product of the control amount of the power supply main circuit and the input voltage during steady operation.
The control amount of the power supply main circuit includes a reciprocal of the input DC voltage as a factor. The power supply device according to claim 1,
The power supply apparatus further includes the input power supply and the load. The power supply device according to claim 1 or 2,
In the power supply main circuit, the input side and the output side are insulated by a transformer,
The power supply apparatus according to claim 1, wherein the input side or output side circuit includes a low voltage side circuit formed of a current doubler circuit. The power supply device according to claim 1 or 2,
In the power supply main circuit, the input side and the output side are insulated by a transformer,
A power supply apparatus comprising: a circuit on the input side or an output side, and a circuit on a low voltage side formed of a center tap circuit. The power supply device according to any one of claims 1 to 4,
In the power supply main circuit, the input side and the output side are insulated by a transformer,
The circuit on the high voltage side of the power supply main circuit is composed of a full bridge circuit,
A power supply device. The power supply device according to any one of claims 1 to 5,
In the power source main circuit, the low voltage side circuit includes an active clamp circuit. The power supply device according to any one of claims 1 to 6,
A power supply device comprising a resonance capacitor arranged in series with a primary winding of a transformer of the power supply main circuit. The power supply device according to any one of claims 1 to 7,
The power source main circuit has a switching circuit having a plurality of switching elements,
A power control block for generating a control amount for the voltage conversion operation; and a switching signal generation for generating a switching control signal for controlling on / off of each of the plurality of switching elements from the control amount for the voltage conversion operation. A power supply device comprising a block. The power supply device according to claim 8, wherein
The power source control block includes a digital arithmetic circuit, and a control amount of the main power circuit output from the power source control block is divided by the input voltage. The power supply device according to claim 9,
The control amount of the power supply main circuit output from the power supply control block is multiplied by a certain value from a minimum value to a maximum value of the input voltage. It is a vehicle-mounted power supply device mounting the power supply device according to any one of claims 1 to 10, wherein the input power supply is a high-voltage battery that supplies DC power to an inverter that drives a vehicle drive motor,
The load is a low voltage battery that supplies DC power to the in-vehicle auxiliary machine,
An in-vehicle power supply device comprising: a controller of the power supply control circuit; a controller of the high-voltage battery; a controller of the in-vehicle auxiliary machine; and a controller of the low-voltage battery. The in-vehicle power supply device according to claim 11,
The in-vehicle power supply apparatus, wherein the voltage command value of the power supply control block is transmitted from a host controller to the controller of the power supply control circuit. The in-vehicle power supply device according to claim 11,
The load includes a load power source and an auxiliary device connected thereto,
The in-vehicle power supply device, wherein the voltage command value of the power supply control block is transmitted as a variable value from the controller of the load power supply to the controller of the power supply control circuit. The in-vehicle power supply device according to claim 12 or 13,
The in-vehicle power supply device characterized in that the input voltage value of the power supply control block is transmitted as a variable value from the controller of the input power supply to the controller of the power supply control circuit. Power supply main circuit and power supply control circuit
The power source main circuit performs a voltage conversion operation for converting a DC input voltage of an input power source into a predetermined DC output voltage, and supplies power by applying the predetermined DC output voltage to a load.
The power supply control circuit generates a control amount of the voltage conversion operation of the power supply main circuit to control the voltage conversion operation;
In the power supply apparatus, the predetermined DC output voltage of the power supply main circuit is proportional to a product of a control amount of the power supply main circuit and the input voltage during steady operation.
The input voltage and the controlled variable are separated from the output voltage terminal of the power supply main circuit and the output voltage terminal fed back to the power supply control circuit, and are fed back to the voltage command value terminal and the power supply control circuit. A power supply apparatus having an inversely proportional relationship when a value of an input voltage terminal of the control circuit is changed while an equivalent value is input to a voltage terminal. The power supply device according to claim 15,
The power supply apparatus further includes the input power supply and the load.

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