JP6679042B2 - Charger and charger - Google Patents

Description

  The present invention relates to a storage cell string configured by connecting a plurality of storage cells (such as a secondary battery and an electric double layer capacitor) in series, and a charger and a charger / charger for charging while equalizing the voltage of each storage cell. (Integrated converter)

  A storage cell such as a secondary battery or an electric double layer capacitor is used by forming a storage cell string by connecting a plurality of cells in series to obtain a desired voltage. During repeated charging / discharging of the storage cell string, variations in cell voltage occur due to variations in capacity, internal resistance, environmental temperature, self-discharge, etc. of each cell. Generally, in an electricity storage cell string in which voltage variation occurs, problems such as accelerated progress of deterioration and reduction of usable energy occur. In order to solve such a problem, various voltage equalization circuits have been proposed.

  As an equalization circuit having a simple circuit configuration, an equalization circuit using the multistage voltage doubler rectifier circuit shown in FIG. 1 has been proposed (Patent Document 1, Non-Patent Document 1). Many conventional systems require a plurality of switches in proportion to the number of cells, whereas an equalization circuit using a multistage voltage doubler rectifier circuit requires only two switches. Therefore, the circuit configuration can be dramatically simplified. Further, as shown in FIG. 2, an integrated system in which an equalizing circuit using this multistage voltage doubler rectifying circuit and a converter (charger / discharger) are integrated has also been reported (Patent Document 2, Non-Patent Document 2). . By driving the multistage voltage doubler rectifier circuit by utilizing the rectangular wave voltage that is secondary generated in the switching node in the converter, a switchless circuit configuration can be achieved as the equalization circuit. Can be simplified. Furthermore, the system configuration can be simplified by integrating the equalization circuit and the converter.

  The integrated method in which the converter and the equalization circuit are integrated is very useful from the viewpoint of simplifying the circuit configuration and system configuration, but the drawback is that a transformer is essential. Can be mentioned. In the integrated method, the voltage amplitude of the rectangular wave voltage generated at the switching node of the converter is once converted into a small rectangular wave voltage by a transformer, and the converted rectangular wave voltage is configured by a capacitor and a diode. It drives a multi-stage voltage doubler rectifier circuit. It is possible to drive a multi-stage voltage doubler rectifier circuit without using a transformer, but because the amplitude of the rectangular wave voltage applied to the multi-stage voltage doubler rectifier circuit is large, an excessive current is generated in the multi-stage voltage doubler rectifier circuit, which is large. It leads to loss and becomes impractical.

  In this regard, adjusting the amplitude of the rectangular wave voltage using a transformer can prevent the generation of excessive current, but the winding ratio of the transformer depends on the number of series-connected storage cells and the input / output voltage of the converter. You need to make an appropriate decision. In other words, if the number of storage cells connected in series changes for some reason, the transformer must be redesigned. In general, there are no transformers that meet arbitrary specifications, that is, there are no catalog products, so it is necessary to design appropriately according to the specifications, but generally transformers are difficult to design. Therefore, it is difficult to quickly change the design when the number of storage cells connected in series changes depending on the application.Therefore, the integrated method that integrates this converter and the equalization circuit is designed in terms of designability and expandability. Challenges remain.

JP, 2013-183557, A JP, 2014-233128, A

Masatoshi uno and Akio Kukita, “Double-switch series-resonant cell-voltage equalizer using a voltage multiplier for series-connected energy storage cells”, Electrical Engineering Japan, Vol. 189, No. 3, pp. 41-51, Nov. 2014. Masatoshi uno and Akio Kukita, “Bidirectional PWM converter integrating cell voltage equalizer using series-resonant voltage multiplier for series-connected energy storage cells”, IEEE Trans. Power Electronics, Vol. 30, No. 6, pp. 3077-3090, Jun . 2015. Masato Uno, Akio Kukita "Futaki-type cell balance circuit using series resonant multi-stage voltage rectifier circuit-Study on operation mode suitable for integration with charger-discharger-," IEICE Energy Research Group), Technical Report vol.114, no.63, pp.7-12.

  The present invention has been made under such a background. INDUSTRIAL APPLICABILITY The present invention provides an integrated system of a converter and an equalization circuit which does not require a transformer between the converter and the multi-stage voltage doubler rectification circuit, and can prevent an excessive current from flowing in the equalization circuit. The challenge is to provide a method.

  In order to solve the above problems, the present invention connects two series-connected diodes in parallel to each of the series-connected first to n-th (n is an integer of 2 or more) capacitors, A multi-stage voltage doubler rectifier circuit in which an intermediate capacitor is connected to an intermediate point in each of two diodes connected in series, and a converter to which a first voltage that operates by switching and that fluctuates according to switching is applied A switching converter including an inductor, an intermediate inductor connected between the output section of the switching converter and the multistage voltage doubler rectifier circuit, on the current path flowing through the switching converter in at least one of the switching states of the switch. The second voltage that fluctuates according to the switching of the switch is applied due to the arrangement An intermediate inductor, and by connecting the series-connected first to n-th capacitors to the output section of the switching converter via the intermediate inductor, the first output voltage from the switching converter is output via the intermediate inductor. It is configured to charge the 1st to nth capacitors and to charge the 1st to nth capacitors by operating the multistage voltage doubler rectifier circuit with the voltage input from the intermediate inductor to the multistage voltage doubler rectifier circuit. , Provide a charger.

  According to the above charger, it is possible to prevent the current flowing through the multi-stage voltage doubler rectifier circuit from becoming excessive without adjusting the ratio of the inductors in the converter and the intermediate inductor.

  As the switching converter, any switching converter such as a step-down PWM (Pulse Width Modulation) converter, a step-up PWM converter, a Zeta converter, or a half-bridge converter can be used.

  By connecting a resonance capacitor between the output section of the switching converter and the multistage voltage doubler rectifier circuit, the charger can be configured such that the intermediate inductor and the resonance capacitor form a resonance circuit.

  The charger may be configured such that the in-converter inductor and the intermediate inductor are wound around the same core to form a coupled inductor.

  Further, by using a bidirectional switching converter as a switching converter in the charger of the present invention, a charger / discharger can be configured.

  According to the transformerless equalization circuit integrated converter taught by the present invention, the converter and the equalization circuit can be integrated without using a transformer. The transformer-less circuit configuration allows flexible and quick design changes even when the number of storage cells connected in series changes, resulting in superior expandability and design flexibility compared to conventional methods. Can be realized.

FIG. 6 is a circuit diagram of a conventional equalization circuit using a multistage voltage doubler rectifier circuit. FIG. 10 is a circuit diagram of a conventional integrated converter in which an equalization circuit using a multistage voltage doubler rectifier circuit and a converter (charger / discharger) are integrated. FIG. 3 is a circuit diagram of a step-down converter that can be used in the charger and the charger / discharger of the present invention. The circuit diagram of a boost converter that can be used in the charger and the charger / discharger of the present invention. The circuit diagram of the buck-boost converter that can be used in the charger and the charger / discharger of the present invention. The circuit diagram of the SEPIC converter which can be used in the charger and charger of the present invention. The circuit diagram of the Zeta converter that can be used in the charger and the charger / discharger of the present invention. FIG. 3 is a circuit diagram of a Cuk converter that can be used in the charger and the charger / discharger of the present invention. The figure which shows the electric current path at the time of operation of a step-down converter when switch Q is ON. The figure which shows the electric current path at the time of operation of a step-down converter when switch Q is OFF. A circuit diagram showing an example of a multistage voltage doubler rectifier circuit. FIG. 6 is a diagram showing a current path of mode 1 when the multi-stage voltage doubler rectifier circuit shown in FIG. 5 operates with a rectangular wave voltage. FIG. 6 is a diagram showing a current path in mode 2 when the multi-stage voltage doubler rectifier circuit shown in FIG. 5 operates with a rectangular wave voltage. FIG. 6 is a circuit diagram of an equivalent circuit of the multistage voltage doubler rectifier circuit shown in FIG. 5. FIG. 6 is a diagram showing a current path of mode 1 when the multistage voltage doubler rectifier circuit shown in FIG. 5 is operated by a rectangular wave voltage from another input position. The figure which shows the current path of the mode 2 at the time of the operation | movement by the rectangular wave voltage from another input position of the multistage voltage doubler rectifier circuit shown in FIG. A circuit diagram of a system in which storage cells B1 to B4 connected in series are connected to a charger with an equalizing function using a step-down converter, a resonance circuit, and a multistage voltage doubler rectifier circuit, which is the first embodiment of the present invention. . 10 is a theoretical operation waveform of the transformerless equalizing circuit integrated converter shown in FIG. 9. Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 1) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 2) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 3) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 4) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 5) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 9 (mode 6) The figure which shows the electric current path at the time of operation | movement of a boost converter when switch Q is ON. The figure which shows the electric current path at the time of operation of a boost converter when switch Q is OFF. 2nd Embodiment of this invention The circuit diagram of the system which connected the series-connected storage cells B1-B4 to the charger with the equalization function which used the boost converter, the resonance circuit, and the multistage voltage doubler rectification circuit which is 2nd Embodiment. . FIG. 14 is a theoretical operation waveform of the transformerless equalization circuit integrated converter shown in FIG. 13. Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 13 (mode 1) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 13 (mode 2) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 13 (mode 3) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 13 (mode 4) Current path during operation of the transformerless equalization circuit integrated converter shown in FIG. 13 (mode 5) The figure which shows the electric current path at the time of operation of a Zeta converter when switch Q is one | on. The figure which shows the electric current path at the time of operation of a Zeta converter when switch Q is OFF. The circuit diagram of the system which connected the storage cells B1-B4 connected in series to the charger with an equalization function which uses the Zeta converter, the resonance circuit, and the multistage voltage doubler rectification circuit which are the 3rd Embodiment of this invention. A circuit diagram of a system in which storage cells B1 to B4 connected in series are connected to a charger with an equalizing function using a half-bridge converter, a resonance circuit, and a multistage voltage doubler rectifier circuit, which is a fourth embodiment of the present invention. . The fifth embodiment of the present invention, in particular, storage cells B1 to B4 connected in series to a charger with an equalizing function, which is composed of a step-down converter, a resonance circuit, and a multistage voltage doubler rectifier circuit, which uses a coupled inductor. Schematic of the system with connected. The sixth embodiment of the present invention, in particular, storage cells B1 to B4 connected in series to a charger with an equalizing function, which includes a step-up converter, a resonance circuit, and a multistage voltage doubler rectifier circuit using a coupled inductor. Schematic of the system with connected. The circuit diagram which connected the inductor Lr and the capacitor Cr to the multistage voltage doubler rectifier circuit, and set it as the series resonance type voltage doubler rectifier circuit. FIG. 6 is a circuit diagram of a non-resonant voltage doubler rectifier circuit in which only the inductor Lr is connected to the multistage voltage doubler rectifier circuit. The circuit diagram which connected the inductor Lr and the capacitor Cr to the multistage voltage doubler rectifier circuit, and set it as the parallel resonance type voltage doubler rectifier circuit. FIG. 6 is a circuit diagram in which an inductor Lr, a capacitor Cr, and an inductor La are connected to a multistage voltage doubler rectifier circuit to form an LLC resonant voltage doubler rectifier circuit. The figure which shows the electric current path at the time of discharge operation of a bidirectional converter when switch QH is OFF and switch QL is ON. The figure which shows the electric current path at the time of discharge operation of a bidirectional converter when switch QH is ON and switch QL is OFF. A circuit diagram of a system in which storage cells B1 to B4 connected in series are connected to a charger / discharger with an equalizing function, which is a bidirectional converter, a resonance circuit, and a multistage voltage doubler rectifier circuit, which is a seventh embodiment of the present invention. .

  The charger and the charger / discharger according to the present invention will now be described with reference to the drawings. However, the configurations of the charger and the charger / discharger according to the present invention are not limited to the specific specific configurations shown in the drawings, and can be appropriately changed within the scope of the present invention. For example, in the following description, each capacitor is mainly described as a single power storage element, and the power storage cell is described as a secondary battery, an electric double layer capacitor, or the like, but these are arbitrary chargeable / dischargeable elements or a plurality of elements. It may be a module consisting of, or any device configured using those modules. In addition, although the multistage voltage doubler rectifier circuit in the following embodiments is shown as a 4-stage voltage doubler rectifier circuit, the number of stages of the multistage voltage doubler rectifier circuit in the present invention, that is, the number n of capacitors connected in series is 2 or more. It can be any integer.

  The charger and the charger / discharger of the present invention having a voltage equalizing function include a switching converter (charging circuit) having an inductor (in the converter), an intermediate inductor (and optionally an element such as an additional capacitor or inductor). , And a multi-stage voltage doubler rectifier circuit. As typical examples that can be used as the converter, FIGS. 3a to 3f show a step-down converter, a step-up converter, an inverting buck-boost converter, a SEPIC converter, a Zeta converter, and a Cuk converter, respectively. The capacitors included in the multistage voltage doubler rectifier circuit can be charged by the output voltages of these converters.

  In FIGS. 3a to 3f, the rectangular wave voltage generated at the switching node in the converter is also shown. As described later, by applying a part of the rectangular wave voltage to the intermediate inductor arranged on the output side of the converter, it becomes possible to operate the multistage voltage doubler rectifier circuit with the input voltage from the intermediate inductor.

  Although an example of a non-isolated PWM (Pulse Width Modulation) converter is shown here, it is also possible to use other non-isolated converters, isolated converters (half bridge, full bridge, etc.), resonant converters, etc. is there. Since all the converters shown here are unidirectional converters using diodes, they can be used only for the charger (or only the discharger). By replacing the diode with a switch and using these converters as bidirectional converters, the charger / discharger of the present invention can be configured as described below.

  As an example, current paths during operation of the step-down converter of FIG. 3a among the converters of FIGS. 3a to 3f are shown in FIGS. 4a and 4b, respectively.

During the period when the switch Q is turned on, a voltage is applied from the capacitors Cin and Cout to the inductor L (V _in −V _out is applied when the input voltage is V _in and the output voltage is V _out ). , The current flowing through the inductor L increases linearly. At this time, the voltage applied to the switch Q is zero (ignoring the on resistance). During the period when the switch Q is off, the current flowing through the inductor L flows to the load side through the diode Do. The voltage applied to the inductor L is −V _out (in FIG. 4a and FIG. 4b, the voltage that causes the current to flow in the direction of the arrow is positive), and the current flowing through the inductor L decreases linearly. In this way, the voltage of the inductor L becomes a rectangular wave voltage due to the switching operation.

  FIG. 5 shows an example of a multi-stage voltage doubler rectifier circuit. The multi-stage voltage doubler rectifier circuit includes two diodes D1, D2, D3, D4, D5, D6, and D7, D8 connected in series to each of the capacitors Cout1 to Cout4 connected in series. The capacitors C1 to C4 are connected in parallel, and the intermediate capacitors C1 to C4 are connected to the intermediate points of the two diodes connected in series.

  The multi-stage voltage doubler rectifier circuit operates by inputting an AC voltage such as a rectangular wave or sine wave voltage. When a rectangular wave voltage is input between the terminals A and B in FIG. 5, a charging / discharging current flows through the capacitors Cout1 to Cout4 according to a change in the input rectangular wave voltage, and an odd-numbered voltage in the multi-stage voltage doubler rectifier circuit Diodes D1, D3, D5, D7 and even-numbered diodes D2, D4, D6, D8 are alternately conducted.

  Specifically, in FIG. 5, when a voltage of a polarity that causes a current to flow from the terminal B to the terminal A (in the direction of the arrow) is input to the multistage voltage doubler rectifier circuit, the current flows through the path as shown in FIG. 6a. Then, in FIG. 5, when the voltage of the polarity that causes the current to flow from the terminal A to the terminal B is input to the multistage voltage doubler rectifier circuit, the current flows through the path as shown in FIG. 6b.

（１） Here, assuming that the capacitances of the capacitors Cout1 to Cout4 are sufficiently larger than the capacitances of the intermediate capacitors C1 to C4, when the operating frequency of the input voltage V _SN is sufficiently high, the voltage V of the capacitors Cout1, Cout2, Cout3, Cout4 is increased. _{Cout1, V Cout2, V Cout3,} V Cout4 can be regarded as invariant in one cycle before and after. If the magnitude of V _SN in mode 1 of FIG. 6a is E and the magnitudes of the voltages of the intermediate capacitors C1, C2, C3 and C4 in mode 1 are V _C1a , V _C2a , V _C3a and V _C4a , FIG. By applying Kirchhoff's second law to the current path of, the following equation (1) is obtained.

(1)

Note that the V _Cout1 ~V _{Cout 4,} city the polarity of the voltage to flow a current in the direction flowing through the capacitor Cout2~Cout4 in Figure 6a _positive, V _c1a ~V c4a (and, V _c1b ~V _C4b below) 6a, the voltage of the polarity that causes the current to flow in the direction in which the intermediate capacitors C1 to C4 flow in FIG. 6a is positive.

（２） Similarly, the magnitude of V _SN in mode 2 of FIG. 6b is set to 0 (for example, the voltage of the inductor L included in the step-down converter of FIG. 3a takes positive and negative values, and the voltage shared by the intermediate inductor will be described later). Also varies in positive and negative, but V _SN in mode 2 may be set to zero by taking the reference point of the voltage as the negative voltage.), And the magnitude of the voltage of the intermediate capacitors C1, C2, C3, C4 is V _C1b. , V _C2b , V _C3b , and V _C4b , the following equation (2) can be obtained by applying Kirchhoff's second law to the current path of FIG. 6b.

(2)

（３） From the above equations (1) and (2), the voltage variation between the mode 1 and the mode 2 in the intermediate capacitors C1 to C4 ΔV _C1 = V _C1b −V _C1a , ΔV _C2 = V _C2b −V _C2a , Δ V _C3 = V _C3b −V _C3a and ΔV _C4 = V _C4b −V _C4a are calculated as follows.

(3)

（４）
となる。ここで、ｆは入力電圧Ｖ_SNの周波数である。ここで、オームの法則から、ｆ×Ｇ１，ｆ×Ｇ２，ｆ×Ｇ３，ｆ×Ｇ４はそれぞれ抵抗の逆数、つまりコンダクタンスの次元であることが分かる。 When the capacitances of the intermediate capacitors C1 to C4 are G1, G2, G3, and G4, respectively, the currents I _C1 , I _C2 , I _C3 , and I _C4 flowing from the intermediate capacitors C1 to C4 to the capacitors Cout1 to Cout4 are: current = frequency × From the relationship of charge amount = frequency × capacity × voltage fluctuation,

(4)
Becomes Here, f is the frequency of the input voltage V _SN . From Ohm's law, it can be seen that f × G1, f × G2, f × G3, and f × G4 are the reciprocal of resistance, that is, the conductance dimension.

  Therefore, from the above equation (4), the circuit of FIG. 5 can be replaced with an equivalent circuit as shown in FIG. Here, the equivalent power source Vdc is a DC power source of the output voltage E, the equivalent resistors R1 to R4 are obtained by replacing the charge / discharge operation of the intermediate capacitors C1 to C4 with equivalent resistors, and the equivalent resistors R1 to R4 have resistance values, respectively. , 1 / (f × G1), 1 / (f × G2), 1 / (f × G3), 1 / (f × G4). When G1 to G4 are equal, the values of R1 to R4 are also equal. Therefore, when the voltages of the capacitors Cout1 to Cout4 are the same in FIG. 7, the currents flowing through the equivalent resistors R1 to R4 are also equal. That is, the capacitors Cout1 to Cout4 are evenly charged.

  As a result, the voltages of the capacitors Cout1 to Cout4 become uniform in the steady state. Each voltage of the capacitors Cout1 to Cout4 in the steady state is E (however, the voltage drop in the diode is ignored. The same applies hereinafter). Note that when G1 to G4 are different, the currents flowing through the equivalent resistances R1 to R4 are also different, but the voltage of the capacitors Cout1 to Cout4 eventually becomes a uniform value of E in a steady state.

  The position where the AC voltage is input to the multistage voltage doubler input circuit is not limited to the position shown in FIG. As an example, an operation when input is performed from the position shown in FIG. 7 of Patent Document 2 will be described according to [0022] to [0030] of Patent Document 2.

  As shown in FIGS. 8a and 8b, a rectangular wave voltage is input between terminals A and B of the input circuit. At this time, a charging / discharging current flows through the capacitors Cout1 to Cout4 according to the change of the input rectangular wave voltage, and the odd-numbered diodes D1, D3, D5, D7 and the even-numbered diodes D2 in the multistage voltage doubler rectifier circuit. D4, D6 and D8 are alternately conducted.

  Specifically, when a voltage of a polarity that causes a current to flow from the terminal B to the terminal A as shown in FIG. 8a is input to the multistage voltage doubler rectifier circuit, the current flows through the path as shown in FIG. When a voltage of a polarity that causes a current to flow from the terminal A to the terminal B as shown in 8b is input to the multistage voltage doubler rectifier circuit, the current flows through the path as shown in FIG. 8b.

（５） Here, assuming that the capacitances of the capacitors Cout1 to Cout4 are sufficiently larger than the capacitances of the intermediate capacitors C1 to C4, when the operating frequency of the input voltage V _SN is sufficiently high, the voltage V of the capacitors Cout1, Cout2, Cout3, Cout4 is increased. _{Cout1, V Cout2, V Cout3,} V Cout4 can be regarded as invariant in one cycle before and after. If the magnitude of V _SN in mode 1 is E and the magnitudes of the voltages of the intermediate capacitors C1, C2, C3 and C4 in mode 1 of FIG. 8a are V _C1a , V _C2a , V _C3a and V _C4a , FIG. By applying Kirchhoff's second law to the current path of, the following equation (5) is obtained.

(5)

Note that the V _Cout1 ~V _{Cout 4,} voltage is positive polarity flowing current in the direction flowing through the capacitor Cout3 in FIG 8a, the _{V c1a} ~V c4a (and, V _c1b ~V _C4b below) is In FIG. 8a, the voltage of the polarity that causes the current to flow in the direction in which the intermediate capacitors C1 to C4 flow is negative.

（６） Similarly, the magnitude of V _SN in mode 2 of FIG. 8B is set to 0 (V _SN in mode 2 may be set to zero by taking the reference point of the voltage as the negative voltage), and the intermediate capacitors C1, C2. If the magnitudes of the voltages of C3 and C4 are V _C1b , V _C2b , V _C3b and V _C4b , the following equation (6) can be obtained by applying Kirchhoff's second law to the current path of FIG. 8b.

(6)

From the above equations (5) and (6), the voltage variation between the modes 1 and 2 in the intermediate capacitors C1 to C4 ΔV _C1 = V _C1a −V _C1b , ΔV _C2 = V _C2a −V _C2b , Δ V _C3 = V _C3a −V _C3b and ΔV _C4 = V _C4a −V _C4b are calculated according to the above equation (3), and therefore even if the voltage is input from the positions shown in FIGS. The operation of the voltage doubler rectifier circuit can be explained by the equivalent circuit of FIG.

  3 series storage cell strings are connected to the charger, which is the first embodiment of the present invention, in which the step-down PWM converter of FIG. 3a and the multistage voltage doubler rectifier circuit are connected via an inductor Lr which is an intermediate inductor. FIG. 9 shows a circuit diagram of a charging system with an equalizing function, in which B1 to B4 are connected. Vin is a DC power supply, Q is a switch, D is a diode, L is an inductor in the converter, Lr is an intermediate inductor, and the multistage voltage doubler rectifier circuit is as shown in FIG. As shown in FIG. 9, a resonance capacitor Cr is further connected between the step-down converter and the multistage voltage doubler rectifier circuit, and the resonance circuit (resonance tank) is formed by the intermediate inductor Lr and the resonance capacitor Cr as described later. (Hereinafter, a circuit formed by connecting a resonance circuit and a multistage voltage doubler rectifier circuit is referred to as a series resonance type voltage doubler rectifier circuit. Further, a switching converter and a series resonance type voltage doubler rectifier circuit, etc. will be described later with reference to FIG. 21d is a charger which is connected to a rectifier circuit of a modified example as shown in FIG. 21d is called a transformerless equalization circuit integrated converter. Note that Rbias is a bias resistor for preventing the voltage value of each capacitor from becoming an indefinite value.

  The two inductors L and Lr behave as filter inductors in the step-down PWM converter. On the other hand, the intermediate inductor Lr also acts as a resonance inductor in the series resonance type voltage doubler rectifier circuit, and resonates with the resonance capacitor Cr to generate a sinusoidal current in the series resonance type voltage doubler rectifier circuit. That is, the intermediate inductor Lr is shared by the two circuit units and plays two roles.

（７） In the transformerless equalization circuit integrated converter (charger) of the first embodiment, the step-down PWM converter charges the entire storage cell string (storage cells B1 to B4 connected in series), while the series resonance type doubler is used. The voltage rectifier circuit equalizes the voltage of the storage cells. The series resonance type voltage doubler rectifier circuit is automatically driven during operation of the step-down PWM converter. The relationship between the input voltage V _in and the output voltage (that is, the string voltage V _string that is the total voltage of the voltages of the storage cells B1 to B4) is similar to that of a general-purpose step-down PWM converter, and the duty ratio of the switch (switching of the switch Q 1 When the ratio of the ON period to the cycle) is D, the change in the magnetic flux in the inductor is expressed by the following equation (7) under the condition that the change amount of the magnetic flux in the inductor is zero in one steady state.

(7)

FIG. 10 shows operation waveforms of current and voltage flowing through each element when the charger of FIG. 9 is operated by switching the switch Q, and current paths in each operation mode 1 to 6 when all the storage cell voltages are uniform. 11a to 11f, respectively. 10 and 11a to 11f show operating waveforms and current paths when operating in the discontinuous current mode, in which one cycle of switching of the switch Q includes two resonance cycles of the resonance circuit. Ts in FIG. 10 is a switching cycle of the switch Q. Note that, in the graph of FIG. 10, for each current, the direction shown in FIG. 9 is positive, and for the voltage V _Cr of the resonance capacitor Cr, the current i _Cr flows in the direction shown in FIG. 9 to be charged. The voltage was positive.

（８）

（９） In the mode 1 shown in FIG. 11A, the switch Q is turned on, and the voltage according to the respective inductance value is applied to the inductor L in the converter and the intermediate inductor Lr. The inductance of the converter in the inductor L and L, if the inductance of the intermediate inductor Lr and L _r, inductor L, the voltage value V _L which is applied to Lr, V _Lr is approximately expressed by the following equation (in FIG. 9, The polarity of the current flowing in the direction of the arrows i _L and i _Lr is positive.).

(8)

(9)

V _Lr causes resonance in the resonance tank, that is, between the intermediate inductor Lr and the resonance capacitor Cr, and a sinusoidal resonance current flows in the series resonance type voltage doubler rectifier circuit. The current i _L flowing through the inductor L in the converter increases almost linearly as already described as the operation of the step-down converter (see the graph of i _{L in} FIG. 10). On the other hand, the current i _Lr flowing through the intermediate inductor Lr, as seen from the current path in FIG. 9, and i _L, to correspond to the difference between the current i _Cr of the resonance capacitor Cr, a sinusoidal to i _L linearly increases The current waveform is a waveform in which the wavy current i _Cr is superimposed (i _L is subtracted from i _Cr ) (see the graph of i _{Lr in} FIG. 10). The current flowing through the intermediate capacitors C1 to C4 in the multi-stage voltage doubler rectifier circuit flows through the even-numbered diodes D2, D4, D6 and D8. The current i _Cr of the resonance capacitor Cr changes sinusoidally due to resonance and becomes zero, and the current polarity is reversed, and at the same time, the operation shifts to the mode 2.

Also in the mode 2 shown in FIG. 11B, the switch Q is in the ON state, and the voltage applied to the inductors L and Lr is almost the same as in the mode 1. The intermediate inductor Lr and the resonance capacitor Cr continue to resonate, and since the polarity of the sinusoidal resonance current i _Cr in mode 2 is opposite to that in mode 1, the odd-numbered diodes D1, D3, D5, and D7 are conductive. To do. Mode 2 is continued until the sinusoidal current i _Cr reaches 0 again. As described above, the voltages applied to the inductors L and Lr are approximately expressed by the equations (8) and (9) as in the mode 1, and the polarity is the same as that in the mode 1, and the positive current i _Cr is It has a flowing polarity.

In mode 3 shown in FIG. 11c, the switch Q is still in the on state, and the voltage applied to the inductors L and Lr is the same as in mode 1. Since the currents in the multistage voltage doubler rectifier circuit are all zero, i _L = i _Lr in mode 3.

（１０）

（１１） When the switch Q is turned off, the current flowing through the inductors L and Lr commutates to the diode D, and the mode 4 current path shown in FIG. 11d is realized. In mode 4, the voltage V _L applied to the inductor _L and the voltage value V _Lr applied to the inductor Lr are approximately expressed by the following equations when the forward drop of the diode is ignored (the definition of the polarity is expressed by the equation (8 ), Same as (9)).

(10)

(11)

V _Lr causes resonance in the resonance tank, that is, between the intermediate inductor Lr and the resonance capacitor Cr, and a sinusoidal resonance current flows again in the series resonance type voltage doubler circuit. The current i _L flowing through the inductor L in the converter decreases almost linearly as already described as the operation of the step-down converter (see the graph of i _{L in} FIG. 10). On the other hand, the current i _Lr flowing through the intermediate inductor Lr, as seen from the current path in FIG. 9, and i _L, to correspond to the difference between the current i _Cr of the resonance capacitor Cr, a sinusoidal to i _L linearly decreases The current waveform is a waveform in which the wavy current i _Cr is superimposed (i _L is subtracted from i _Cr ) (see the graph of i _{Lr in} FIG. 10). The currents in the intermediate capacitors C1 to C4 in the multistage voltage doubler rectifier circuit flow through the odd-numbered diodes D1, D3, D5, and D7. Current i _Cr of the resonance capacitor Cr becomes zero, at the same time the current polarity is reversed, the operation shifts to Mode 5.

Also in mode 5 shown in FIG. 11e, the switch Q is in the off state, and the voltage applied to the inductors L and Lr is almost the same as in mode 4. The intermediate inductor Lr and the resonance capacitor Cr continue to resonate, and in mode 5, the polarity of the sinusoidal current is opposite to that in mode 4, so that the even-numbered diodes D2, D4, D6, and D8 conduct. Mode 5 continues until the sinusoidal current again reaches zero. As described above, the voltages applied to the inductors L and Lr are approximately expressed by the equations (10) and (11) as in the mode 4, and the polarity is the negative current i _Cr as in the mode 4. It has a flowing polarity.

Even in the mode 6 shown in FIG. 11f, the switch Q is still in the off state, and the voltage applied to the inductors L and Lr is the same as that in the mode 4. Since the currents in the multistage voltage doubler rectifier circuit are all zero, i _L = i _Lr in mode 6.

（１２） As described above, as shown in the current paths of FIGS. 11a to 11f and the equations (8) to (11), a voltage corresponding to the inductance ratio between the inductor L in the converter and the intermediate inductor Lr is generated across the intermediate inductor Lr. To do. Assuming that the voltage generated across the intermediate inductor Lr is a rectangular wave voltage for the sake of simplicity, its amplitude V _{Lr_p-p} is expressed by the following equation from equations (9) and (11).

(12)

（１３）
の形式で表わすことができる。ここで、Ｚｒは共振タンクのインピーダンスである。式（１２），（１３）が示すとおり、本発明のトランスレス均等化回路統合型コンバータではインダクタＬ，Ｌｒのインダクタンス比を任意に決定することでｉ_Cr-peakを抑えつつ、蓄電セル電圧の均等化機能を担う多段倍電圧整流回路を駆動することができる。 Generally, the _peak value i _Cr-peak of the resonance current flowing in the resonance tank is proportional to the applied voltage,

(13)
Can be represented in the form of. Here, Zr is the impedance of the resonance tank. As shown in equations (12) and (13), the transformerless equalization circuit integrated converter of the present invention arbitrarily determines the inductance ratio of the inductors L and Lr to suppress i _Cr-peak and reduce the storage cell voltage. It is possible to drive a multi-stage voltage doubler rectifier circuit having an equalizing function.

  The principle of equalizing the voltage of the storage cell by the series resonance type voltage doubler rectifying circuit, which is the equalization circuit for the storage cell, is described in detail in Patent Document 2 and Non-Patent Document 3, and also in this specification. 5 to 8b as described in detail. Here, the operation of the charger shown in the waveform diagram of FIG. 10 is composed of six modes. Modes 1 to 3 are realized when the switch Q is on, and modes 4 to 6 are realized when the switch Q is off. Whether the current has a rectangular wave shape or a sine wave shape, as long as the intermediate capacitors C1 to C4 are charged and discharged through the odd-numbered diodes and the even-numbered diodes, the capacitors Cout1 to The voltage of Cout4 is equalized. Therefore, even when 6-mode operation is performed due to the resonance of the intermediate inductor Lr and the resonance capacitor Cr, the intermediate capacitor is passed through the odd-numbered and even-numbered diodes through one cycle of switching from mode 1 to mode 6. By charging and discharging C1 to C4, the voltages of the capacitors Cout1 to Cout4 are equalized, and it is qualitatively described using the above equations (1) to (4) and the equivalent circuit of FIG. 7. It is considered to be similar to the equalization operation.

  Note that when the charger of FIG. 9 operates in a continuous mode in which one cycle of switching is shorter than the resonance cycle of the resonance tank, the operation is a two-mode operation in which the current paths are shown in FIGS. 11a and 11d. Specifically, it is considered that the equalization operation is described using the above equations (1) to (4) and the equivalent circuits of FIGS. 6a, 6b, and 7. Also, when the resonance capacitor Cr is removed from the charger of FIG. 9 and the portion where the resonance capacitor Cr is present is simply a conducting wire (see FIG. 21b, which will be described later), the operation is the same as the current path shown in FIGS. 11a and 11d. Since the mode operation is performed (the resonance described above does not occur because there is no resonance tank), the equalization operation described using the equations (1) to (4) and the equivalent circuits of FIGS. 6a, 6b, and 7 is performed. Considered to be similar.

  The example in which the step-down PWM converter and the series resonance type voltage doubler rectifier circuit are combined has been described above, but other converters and the resonance type voltage doubler rectifier circuit can be combined. As an example, a charger using the step-up PWM converter of FIG. 3b will be described. It should be noted that, unless otherwise specified, the same reference numerals, variable definitions, and the like as those in the first embodiment are used in the following embodiments.

Current paths during operation of the boost converter of FIG. 3b are shown in FIGS. 12a and 12b, respectively. In the period in which the switch Q is turned on, a voltage is applied from the capacitor Cin to the inductor L (V _in is applied if the input voltage is V _in ), so that the current flowing through the inductor L increases linearly. To do. At this time, the voltage applied to the switch Q is zero (ignoring the on resistance). During the period when the switch Q is off, the current flowing through the inductor L flows to the load side through the diode Do. The voltage applied to the inductor L is − (V _out −V _in ) (in FIGS. 12a and 12b, the voltage that causes the current to flow in the direction of the arrow is positive). The current flowing through the inductor L is linear. Decrease. In this way, the voltage of the inductor L becomes a rectangular wave voltage due to the switching operation.

  A battery charger in which the step-up PWM converter of FIG. 3b and the multi-stage voltage doubler rectifier circuit are connected via an inductor Lr, which is an intermediate inductor, is connected to the charger according to the second embodiment of the present invention in four series storage cell strings. FIG. 13 shows a circuit diagram of a charging system with an equalizing function, in which B1 to B4 are connected. Vin is a DC power supply, Q is a switch, D is a diode, L is an inductor in the converter, Lr is an intermediate inductor, and the multistage voltage doubler rectifier circuit is as shown in FIG. As shown in FIG. 13, a resonance capacitor Cr is further connected between the boost converter and the multi-stage voltage doubler rectifier circuit, and the intermediate inductor Lr and the resonance capacitor Cr are connected to each other as in the case of FIG. 9 of the first embodiment. A resonance circuit (resonance tank) is configured. The operations and roles of the two inductors L and Lr and the resonance capacitor Cr are similar to those of the first embodiment.

（１４） In the transformerless equalization circuit integrated converter (charger) of the second embodiment, the step-up PWM converter charges the entire storage cell string (storage cells B1 to B4 connected in series) while the series resonance type doubler is used. The voltage rectifier circuit equalizes the voltage of the storage cells. The series resonance type voltage doubler rectifier circuit is automatically driven during operation of the step-up PWM converter. The relationship between the input voltage V _in and the output voltage (that is, the string voltage V _string that is the total voltage of the voltages of the storage cells B1 to B4) is similar to that of a general-purpose step-up PWM converter. When the ratio of the ON period to the cycle) is D, the change in the magnetic flux in the inductor is represented by the following equation (14) under the condition that the change amount of the magnetic flux in the inductor is zero in the steady state for one cycle.

(14)

FIG. 14 shows operation waveforms of current and voltage flowing through each element when the charger of FIG. 13 is operated by switching of the switch Q, and FIGS. 15a to 15e show current paths in each operation mode 1 to 5. In the graph of FIG. 14, the direction shown in FIG. 13 is positive for each current, and the voltage V _Cr of the resonance capacitor Cr is the voltage charged by the current i _Cr flowing in the direction shown in FIG. It was positive.

  As shown in the operation waveform of FIG. 14, in the discontinuous mode, the charger of FIG. 13 operates while repeating five operation modes (modes 1 to 5). For convenience, mode 2 will be described.

（１５）

（１６） In mode 2 (FIG. 15b) in which the switch Q is turned on, the inductor L in the converter is charged by the input voltage source Vin, and the current i _L flowing through the inductor L in the converter increases linearly. At this time, no current flows in the resonant voltage doubler rectifier circuit. Voltage value V _L of the mode 2 is applied to the inductor L, _Lr, V Lr is expressed by the following equation.

(15)

(16)

（１７）

（１８） In the mode 3 shown in FIG. 15c, by turning off the switch Q, the current flowing through the switch Q is commutated to the diode D, and the current i _D starts flowing through the diode D. i _D flows through the resonance inductor (intermediate inductor) Lr and the resonance capacitor Cr. In the mode 3, the initial value of the current i _Lr flowing through the resonant inductor Lr is zero, and in general, the current of the inductor cannot rapidly change. Therefore, at the beginning of the mode 3, i _D is all the resonance capacitor Cr. Will flow through. Inductor L in the mode 3, the voltage value V _L which is applied to Lr, V _Lr is expressed by the approximate equation Neglecting the forward drop of the diode.

(17)

(18)

Due to V _Lr , resonance occurs in the resonance tank, that is, between the intermediate inductor Lr and the resonance capacitor Cr, and a resonance current starts flowing in the series resonance type voltage doubler circuit. The current i _L flowing through the inductor L in the converter decreases almost linearly as already described as the operation of the boost converter (see the graph of i _{L in} FIG. 14). On the other hand, as can be seen from the current path in FIG. 13, the current i _Lr flowing through the intermediate inductor Lr corresponds to the difference between i _L and the current i _Cr of the resonance capacitor Cr in mode 3, and therefore decreases linearly. i _L sinusoidal current i _Cr is superimposed on (i minus i _Cr from _L) becomes a current waveform (see the graph in FIG. 14, i _Lr). The current flowing through the intermediate capacitors C1 to C4 in the multi-stage voltage doubler rectifier circuit flows through the even-numbered diodes D2, D4, D6 and D8. The current i _Cr of the resonance capacitor Cr changes sinusoidally due to resonance and becomes zero, and the current polarity is reversed, and at the same time, the operation shifts to the next mode 4.

Also in mode 4 shown in FIG. 15d, the switch Q is in the off state, and the voltage applied to the inductors L and Lr is almost the same as in mode 3. The intermediate inductor Lr and the resonance capacitor Cr continue to resonate, and in mode 4, since the polarity of the sinusoidal resonance current i _Cr is opposite to that in mode 3, the odd-numbered diodes D1, D3, D5, and D7 conduct. To do. Mode 4 continues until the sinusoidal current again reaches zero.

In the mode 5 shown in FIG. 15e, the switch Q is still in the off state, and the voltage applied to the inductors L and Lr is the same as that in the mode 3. Since the currents in the multistage voltage doubler rectifier circuit are all zero, i _L = i _Lr in mode 5.

Turning on switch Q turns off diode D and begins mode 1 shown in Figure 15a. The current i _{L of the} inductor L in the converter starts to flow through the switch Q, while the current i _Lr of the intermediate inductor Lr starts to flow through the resonance capacitor Cr and resonates between the intermediate inductor Lr and the resonance capacitor Cr. Begins. The voltage applied to the inductors L and Lr in mode 1 is almost the same as that in mode 2.

（１９） As described above, as shown in the current paths of FIGS. 15a to 15e and the equations (15) to (18), a voltage corresponding to the inductance ratio between the inductor L in the converter and the intermediate inductor Lr is generated across the intermediate inductor Lr. To do. Assuming that the voltage generated across the intermediate inductor Lr is a rectangular wave voltage for simplification, its amplitude V _{Lr_p-p} is expressed by the following equation from the equations (16) and (18).

(19)

As described above, generally, the _peak value i _Cr-peak of the resonance current flowing in the resonance tank can be expressed in the form of the above equation (13) in proportion to the applied voltage, and therefore the transformerless equalization of the second embodiment is performed. Also in the integrated circuit integrated converter, it is possible to drive the multi-stage voltage doubler rectifier circuit having the equalizing function of the storage cell voltages while suppressing i _Cr-peak by arbitrarily determining the inductance ratio of the inductors L and Lr. .

  The principle of equalizing the voltage of the storage cell by the series resonance type voltage doubler rectifying circuit which is the equalization circuit for the storage cell is as described in detail in the first embodiment. Here, the operation of the charger shown in the waveform diagram of FIG. 14 is composed of five modes, and modes 1 and 2 are realized when the switch Q is on, and modes 3 and 5 are realized when the switch Q is off. As in the first embodiment, the intermediate capacitors C1 to C4 are charged and discharged through the odd-numbered and even-numbered diodes through one cycle of switching, so that the voltages of the capacitors Cout1 to Cout4 are equalized. Even if the 5-mode operation is performed due to the resonance of the intermediate inductor Lr and the resonance capacitor Cr, it is qualitatively equivalent to that described using the above equations (1) to (4) and the equivalent circuit of FIG. 7. It is considered to be the same as the activating operation.

  Note that, when the charger of FIG. 13 operates in a continuous mode in which one cycle of switching is shorter than the resonance cycle of the resonance tank, the operation is a two-mode operation in which the current path is shown in FIGS. 15a and 15c. Specifically, it is considered that the equalization operation is described using the above equations (1) to (4) and the equivalent circuits of FIGS. 6a, 6b, and 7. Also, when the resonance capacitor Cr is removed from the charger of FIG. 13 and the portion where the resonance capacitor Cr was present is simply a conducting wire (see FIG. 21b described later), the operation is represented by the current path shown in FIGS. 15a and 15c. Since the mode operation is performed (the resonance described above does not occur because there is no resonance tank), the equalization operation described using the equations (1) to (4) and the equivalent circuits of FIGS. 6a, 6b, and 7 is performed. Considered to be similar.

  Although the embodiment in which the step-down PWM converter, the step-up PWM converter, and the series resonance type voltage doubler rectifier circuit are combined has been described above, other converters can be combined as a basic circuit. As an example, a charger using the Zeta converter of FIG. 3e will be described.

（２０）
と表わされる。 Current paths during operation of the Zeta converter of FIG. 3e are shown in FIGS. 16a and 16b, respectively. With the switching of the switch Q, the current flowing through the inductor linearly increases or decreases as in the step-down type and step-up type described above. From the condition that the change of the magnetic flux in the inductors L1 and L2 is zero in the steady state for one cycle, the input / output voltage ratio is

(20)
Is represented.

  4 series storage cell strings B1 to the charger which is the third embodiment of the present invention in which the Zeta converter of FIG. 3e and the multistage voltage doubler rectifier circuit are connected via the inductor Lr which is an intermediate inductor. FIG. 17 shows a circuit diagram of a charging system with an equalizing function to which B4 is connected. As shown in FIG. 17, a resonance capacitor Cr is further connected between the Zeta converter and the multistage voltage doubler rectifier circuit, and resonance occurs between the intermediate inductor Lr and the resonance capacitor Cr as in FIG. 9 of the first embodiment. A circuit (resonant tank) is configured. The operations and roles of the inductors L1, L2, Lr and the resonance capacitor Cr are similar to those of the first embodiment.

In the transformerless equalization circuit integrated converter (charger) of the third embodiment, the Zeta converter charges the entire storage cell string (storage cells B1 to B4 connected in series), while series resonant double voltage rectification. The circuit equalizes the storage cell voltages. The series resonance type voltage doubler rectifier circuit is automatically driven when the Zeta converter operates. The relationship between the input voltage V _in and the output voltage V _out (that is, the string voltage V _string that is the total voltage of the voltages of the storage cells B1 to B4) is represented by the above equation (20).

  A rectangular wave voltage is applied to the inductors L1 and L2 in the converter in response to the switching on and off of the switch Q, and accordingly, a rectangular wave voltage is also applied to the intermediate inductor Lr. Since the intermediate inductor Lr and the resonance capacitor Cr form a resonance circuit, a sinusoidal voltage is input to the multistage voltage doubler rectifier circuit. After that, the storage cell voltages are equalized by the operation of the multistage voltage doubler rectifier circuit according to the same principle as in the first and second embodiments. The case where the resonance capacitor Cr is removed is the same as the first and second embodiments (the same applies to the following embodiments).

  FIG. 18 illustrates a charger (fourth embodiment of the present invention) in which a half-bridge converter, which is a type of insulation converter, and a series resonance type voltage doubler rectifier circuit are combined without a transformer, and four series storage cell strings B1. [Fig. 6] Fig. 6 shows a circuit diagram of a charging system with an equalizing function, in which ~ B4 is connected.

  The half-bridge converter includes an input power source Vin, capacitors Ca and Cb, switches Qa and Qb, a converter transformer (insulating transformer), diodes Da, Db, Dc, Dd, and a converter inductor L, and only the switch Qa is in an on state. And a switch Qb are turned on alternately to generate a rectangular wave voltage, which is transformed by a transformer in the converter and further rectified and output by a rectifying circuit composed of diodes Da, Db, Dc, Dd. . An intermediate inductor Lr is connected in series with an in-converter inductor L provided for a filter at the output terminal of the rectifier circuit on the secondary winding side of the insulation transformer, and switches the switches Qa and Qb between on and off. Since a rectangular wave voltage is applied to the intermediate inductor Lr, the resonant voltage doubler rectifier circuit is driven according to the same principle as in the above-described embodiment, and the storage cell voltages are equalized.

（２１）

（２２）

（２３）

（２４） Specifically, since the magnitude of the voltage applied to the primary winding of the converter in the transformer becomes 0.5V _in input voltage as V _in, the number of turns N2 of the number of turns N1 of the primary winding a secondary winding If the winding ratio N2 / N1 = N, the magnitude of the voltage applied to the secondary winding is 0.5 NV _in . Therefore, in the above equations (8) to (11), the following equations (21) to (24) are obtained by replacing V _in with 0.5 NV _in .

(21)

(22)

(23)

(24)

（２５）
で表される振幅Ｖ_{Lr_p-p}の矩形波状電圧が印加される。以降、多段倍電圧整流回路による蓄電セル電圧の均等化は上述の実施例と同様である。 The voltage V _{L of the} inductor L in the converter is a rectangular wave voltage represented by the above equations (21) and (23), and the voltage V _Lr of the intermediate inductor Lr is a rectangle represented by the above equations (22) and (24). It becomes a wavy voltage. By taking the difference between the above equations (22) and (24), the intermediate inductor is approximately

(25)
A rectangular wave voltage having an amplitude V _{Lr_p-p} represented by is applied. After that, the equalization of the storage cell voltage by the multi-stage voltage doubler rectifier circuit is the same as in the above-described embodiment.

  In the above embodiment, since the inductor for the filter and the inductor Lr for the resonance type voltage doubler rectifier circuit are individually required, at least two magnetic elements are required for the entire circuit. However, it is possible to combine these magnetic elements as one element by using a coupled inductor. With a equalizing function, four series storage cell strings B1 to B4 are connected to a charger which is a fifth embodiment of the present invention in which a step-down PWM converter is combined with a resonance type voltage doubler rectifier circuit using a coupled inductor. A circuit diagram of the charging system is shown in FIG.

（２６）

（２７） The circuit configuration of FIG. 19 is generally similar to that of FIG. 9, but two inductors (inductor L in converter and intermediate inductor Lr in FIG. 9) are wound around the same core to form one inductor. It is integrated into a magnetic element (coupled inductor). In FIG. 19, Lmg and Lkg represent the exciting inductance and the leakage inductance of the coupled inductor, respectively. The exciting inductance Lmg behaves as the filter inductor L (see FIG. 9) in the step-down PWM converter, while the leakage inductance Lkg is the series resonance type double. The function of the resonance inductor Lr for the voltage rectification circuit is fulfilled. The coupled inductor is a magnetic element in which one core is provided with a plurality of windings like the transformer, and the voltage applied to each winding is determined by the winding ratio (N1: N2). Since the voltage applied to the leakage inductance Lkg is sufficiently small and can be ignored, the voltage V _N1 applied to the primary winding and the voltage V _N2 applied to the secondary winding while the switch Q is on are approximately represented by the following equation (26 ), (27) (the number of turns of the primary winding is N1, and the number of turns of the secondary winding is N2).

(26)

(27)

（２８）

（２９） Due to V _N2 , resonance occurs between the resonance tank, that is, the leakage Lkg and the resonance capacitor Cr, and a sinusoidal resonance current flows in the series resonance type voltage doubler circuit. On the other hand, the diode D conducts while the switch Q is off. The voltage values applied to the primary winding and the secondary winding are approximately represented by the following equations (28) and (29), ignoring the forward drop of the diode.

(28)

(29)

Even when the switch Q is off, resonance occurs between the resonance tank, that is, the leakage inductance Lkg and the resonance capacitor Cr due to V _N2 , and a sinusoidal resonance current flows in the series resonance type voltage doubler circuit.

（３０） As described above, as shown in equations (27) and (29), a voltage corresponding to the ratio of N1 and N2 is generated across the secondary winding. Assuming that the voltage generated across the secondary winding is a rectangular wave voltage for the sake of simplicity, its amplitude V _{N2 — p-p} is expressed by the following equation from equations (27) and (29).

(30)

（３１）
の形式で表わすことができる。ここで、Ｚｒは共振タンクのインピーダンスである。式（３０），（３１）式が示すように、カップルドインダクタを用いたトランスレス均等化回路統合型コンバータでは、Ｎ１とＮ２の比を任意に決定することでｉ_Cr-peakを抑えつつ、セル電圧の均等化機能を担う倍電圧整流回路を駆動することができる。なお、図１９の充電器の動作原理も実施例１等と同様であり、上式（７）で表わされる降圧型ＰＷＭコンバータの出力電圧によって蓄電セルＢ１〜Ｂ４を充電しつつ、共振タンクの共振電流によって多段倍電圧整流回路を動作させることにより蓄電セル電圧を均等化する。 The _peak value i _Cr-peak of the resonance current flowing in the resonance tank is similar to equation (13) and is proportional to the applied voltage,

(31)
Can be represented in the form of. Here, Zr is the impedance of the resonance tank. As shown in the equations (30) and (31), in the transformerless equalization circuit integrated converter using the coupled inductor, i _Cr-peak is suppressed while arbitrarily determining the ratio of N1 and N2. It is possible to drive a voltage doubler rectifier circuit having a function of equalizing cell voltages. The operating principle of the charger of FIG. 19 is the same as that of the first embodiment and the like, and the storage tanks B1 to B4 are charged by the output voltage of the step-down PWM converter represented by the above formula (7), and the resonance of the resonance tank is generated. By operating the multistage voltage doubler rectifier circuit with the current, the voltage of the storage cells is equalized.

  In the fifth embodiment, the example in which the equalizing circuit is integrated while using the coupled inductor for the step-down PWM converter has been shown, but the integration using the coupled inductor is also possible for other converters. As an example, a series of storage cell strings B1 to B4 are connected to a charger, which is a sixth embodiment of the present invention, in which an equalization circuit is integrated with a step-up PWM converter while using a coupled inductor. FIG. 20 shows a circuit diagram of the charging system with an activating function.

In the configuration of FIG. 20, the inductor L in the converter of the step-up converter shown in FIG. 13 and the intermediate inductor Lr in the resonance-type voltage doubler rectifier circuit are wound around the same core to form a coupled inductor. It corresponds to the embodiment. The basic operation principle is the same as that shown in FIG. 13, and the storage cells B1 to B4 are charged by the output voltage of the step-up PWM converter represented by the above formula (14), while the resonance current of the resonance tank causes the multi-stage operation. The storage cell voltage is equalized by operating the voltage doubler rectifier circuit. According to the same principle as that of the fifth embodiment described with reference to FIG. 19, the amplitude of the rectangular wave voltage generated in each winding depends on the winding ratio of the coupled inductor. Can be arbitrarily determined to drive the voltage doubler rectifier circuit having the cell voltage equalizing function while suppressing the _peak value i _Cr-peak of the resonance current.

Other Modifications In each of the above-described embodiments, the embodiment in which the multistage voltage doubler rectifier circuit is operated by inputting the resonance current mainly from the series resonance type resonance circuit has been described. It is also possible to operate the multi-stage voltage doubler rectifier circuit by the input current from the input section of 1 or other input section of the resonance type.

  21a to 21d show configuration examples of the input unit and the multistage voltage doubler rectifier circuit that can be used in the transformerless equalization circuit integrated converter taught by the present invention. FIG. 21a shows an example of the connection between the series resonance type input section and the multistage voltage doubler rectifier circuit, which is the configuration used in each of the embodiments described so far. FIG. 21b shows an example of connection between the non-resonant type input section and the multistage voltage doubler rectifier circuit, which is equivalent to the form in which the resonance capacitor Cr is removed from the series resonant type circuit of FIG. 21a. The operation of the multistage voltage doubler rectifier circuit when the non-resonant type input section is used is as described with reference to FIGS. Even when the capacitance of the resonance capacitor Cr of FIG. 21a is set to be sufficiently large, it is possible to obtain an operation waveform and characteristics equivalent to those of the non-resonance type of FIG. 21b.

  FIG. 21c shows an example of connection between the parallel resonance type input section and the multistage voltage doubler rectifier circuit, and FIG. 21d shows an example of connection between the LLC resonance type input section and the multistage voltage doubler rectifier circuit. Even when these input sections are used, the multistage voltage doubler rectifier circuit operates in the same manner as in the above-described respective embodiments due to the resonance current. Each of the circuits shown in FIGS. 21a to 21d is a generally well-known resonant / non-resonant circuit system applied to a multi-stage voltage doubler rectifier circuit. It is also possible to apply to.

  In each of the above-described embodiments, the configuration in which the equalizing circuit is integrated without a transformer in the converter for performing unidirectional power transmission, that is, the charging of the storage cell string is used. By using the dischargeable bidirectional converter, the transformerless equalization circuit integrated bidirectional converter can be configured.

Generally, various converters can be applied as bidirectional converters by replacing the diode included in the unidirectional converter with a switch. For the bidirectional converter configured by replacing the diode of the step-down PWM converter of FIG. 3a with a switch, the current path realized according to the switching state of the switch during the discharging operation from the load RL (output) side is shown in FIG. 22a. (Switch QH is off, switch QL is on. Mode 1 is shown.) And FIG. 22b (switch QH is on, switch QL is off. Mode 2 is shown). The output voltage −V _out is applied to the inductor L in the converter in the mode 1 of FIG. 22a, and V _in −V _out corresponding to the input / output voltage difference is applied in the mode 2 of FIG. 22b. Similarly, a rectangular wave voltage is applied. The input / output voltage ratio is also represented by the above equation (7), as in the case of the unidirectional.

  Figure 22a. A storage cell in which the charger / discharger according to the seventh embodiment of the present invention in which the bidirectional step-down PWM converter shown in FIG. 22b is connected to a multistage voltage doubler rectifier circuit via an intermediate inductor Lr is connected in series A circuit diagram of the charging / discharging system connected to B1 to B4 is shown in FIG. The charging / discharging system of FIG. 23 is an embodiment in which the diode D in the embodiment shown in FIG. 9 is replaced with a switch QL to support bidirectional operation. In this embodiment, since the above formulas (8) to (13) are satisfied both during charging and discharging, the equalization of the storage cells is performed by the same principle as in the first embodiment shown in FIG. And in the case of both discharges.

  INDUSTRIAL APPLICABILITY The present invention can be widely applied to power sources and the like that use storage cells such as secondary batteries and electric double layer capacitors.

B1 to B4 Storage cells Cout1 to Cout4 Capacitors C1 to C4 Intermediate capacitors D1 to D8 Diodes Lr Inductors Cr Resonant capacitors Vin, Vdc Power supplies L1, L2 Inductors Q, Qa, Qb Switches Do Diodes Cout, Cin, Cet Capacitors Rbias Bias resistance Lmg Excitation Inductance Lkg Leakage inductance La Inductor QL, QH switch

Claims (7)

Two series-connected diodes are connected in parallel to each of the first to n-th (n is an integer of 2 or more) capacitors connected in series, and each of the two series-connected diodes is further connected. A multi-stage voltage doubler rectifier circuit in which an intermediate capacitor is connected to the intermediate point of
A switching converter that includes an in-converter inductor that operates by switching and that is applied with a first voltage that fluctuates in accordance with switching;
An intermediate inductor connected between the output section of the switching converter and the multistage voltage doubler rectifier circuit, the intermediate inductor being arranged on a current path flowing through the switching converter in at least one of the switching states of the switch. Thus, a second voltage that fluctuates according to the switching of the switch is applied, and an intermediate inductor is provided,
A transformer is not connected between the output section of the switching converter and the multistage voltage doubler rectifier circuit,
By connecting the series-connected first to n-th capacitors to the output section of the switching converter via the intermediate inductor, the voltage output from the switching converter via the intermediate inductor is used. While charging the 1st to nth capacitors,
A charger configured to charge the first to nth capacitors by operating the multistage voltage doubler rectifier circuit with a voltage input from the intermediate inductor to the multistage voltage multiplier rectifier circuit.   The charger according to claim 1, wherein a step-down PWM (Pulse Width Modulation) converter is used as the switching converter.   The charger according to claim 1, wherein a step-up type PWM (Pulse Width Modulation) converter is used as the switching converter.   The charger according to claim 1, wherein a Zeta converter is used as the switching converter.   The charger according to claim 1, wherein a half bridge converter is used as the switching converter.   The resonance capacitor is further connected between the output section of the switching converter and the multi-stage voltage doubler rectifier circuit, so that the intermediate inductor and the resonance capacitor form a resonance circuit. Charger according to item. Constructed by using a bi-directional switching converter as the switching converter in the charger according to any one of claims 1 to 6, the charge and discharge device.

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