Data generation device, battery monitoring device, data generation method, and data generation program

Abstract

To provide a data generation device capable of generating digital data of sine wave and cosine wave frequencies so that errors can be suppressed as much as possible even when the number of operations is increased and DC components are not generated, a battery monitoring device using the data generation device, a data generation method, and a data generation program.SOLUTION: A data generation device 10 generates digital data of a sine wave and a cosine wave. Initial values are given to registers 11s and 11c. A generation unit S1 generates digital data by multiplying the stored values of the registers 11s and 11c by a predetermined coefficient to rotate the unit vector on the two-dimensional complex plane at every predetermined step angle of the sine wave and cosine wave at a predetermined operation interval shorter than a basic period of the sine wave and cosine wave.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a data generation device, a battery monitoring device, a data generation method, and a data generation program.

Background Art

[0002] When generating digital data of the frequencies of a sine wave and a cosine wave, there have been proposed a method of storing digital data of a sine wave and a cosine wave in a ROM at a predetermined step angle and reading out the digital data to generate data (see, for example, Patent Document 1), and a method of generating the data by calculation (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method described in Patent Document 1, a large amount of memory is required and the circuit scale becomes large, which is not preferable. Further, since the generable frequency is determined depending on the digital data, the flexibility of the generable frequency becomes low, which is not preferable. When generating a low-frequency, it is necessary to interpolate the digital data when there is no stored data in the ROM, resulting in the inclusion of harmonics, which is not preferable.

[0005] The present invention has been made in view of the above circumstances, and an object thereof is to provide a data generation device, a battery monitoring device using the data generation device, a data generation method, and a data generation program that can generate digital data of the frequency of a sine wave or a cosine wave as accurately as possible without the need to interpolate digital data using stored data.

Means for Solving the Problem

[0006] The invention according to claim 1 is directed to a data generation device that generates digital data of at least a part of a sine wave (SIN) or a cosine wave (COS) (hereinafter referred to as a predetermined wave). The invention according to claim 1 includes a storage unit in which an initial value is stored, and a generation unit that generates digital data by multiplying a stored value in the storage unit by a predetermined coefficient so as to rotate a unit vector by a predetermined step angle of the predetermined wave at a predetermined calculation interval shorter than the basic period of the predetermined wave on a two-dimensional complex plane.

[0007] According to the invention of claim 1, since the generation unit generates digital data by multiplying a stored value in the storage unit by a predetermined coefficient so as to rotate a unit vector by a predetermined step angle of the predetermined wave on a two-dimensional complex plane, digital data can be generated by calculating without using stored data, and digital data constituting the frequency of a sine wave or a cosine wave can be generated as accurately as possible.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Modes for Carrying Out the Invention

[0009] Hereinafter, several embodiments of the data generation device and the battery monitoring device will be described with reference to the drawings. For the embodiments described later, the same reference numerals or similar reference numerals may be assigned to the components of the previously described embodiments, and the description may be omitted.

[0010] (First Embodiment) The first embodiment will be described with reference to FIGS. 1 to 3. The data generation device 10 is configured as a device that generates digital data of a sine wave (SIN) and a cosine wave (COS). Hereinafter, one period of the digital data of the sine wave and the cosine wave generated by the data generation device 10 will be defined as the "basic period" and described.

[0011] First, the data generation device 10 includes registers 11s and 11c in which initial values are stored. The registers 11s and 11c correspond to a storage unit. The data generation device 10 also includes selectors 12s and 12c, real part coefficient multipliers 13r and 15r, imaginary part coefficient multipliers 13i and 15i, and adders 14 and 16. The real part coefficient multipliers 13r and 15r, the imaginary part coefficient multipliers 13i and 15i, and the adders 14 and 16 constitute a generation unit S1.

[0012] The real - part coefficient multiplier 13r multiplies the stored value in the register 11c by the real - part coefficient A and outputs it to the adder 14. The imaginary - part coefficient multiplier 13i multiplies the stored value in the register 11s by the negative value -B of the imaginary - part coefficient and outputs it to the adder 14. The adder 14 adds the output data of the real - part coefficient multiplier 13r and the output digital data of the imaginary - part coefficient multiplier 13i to output the digital data of the cosine wave (COS). The digital data of the cosine wave is input to the selector 12c.

[0013] The real - part coefficient multiplier 15r multiplies the stored value in the register 11s by the real - part coefficient A and outputs it to the adder 16. The imaginary - part coefficient multiplier 15i multiplies the stored value in the register 11c by the positive value B of the imaginary - part coefficient and outputs it to the adder 16. The adder 14 adds the output data of the real - part coefficient multiplier 15r and the output digital data of the imaginary - part coefficient multiplier 15i to output the digital data of the sine wave (SIN). The digital data of the sine wave is input to the selector 12s.

[0014] The real - part coefficients A of the real - part coefficient multipliers 13r and 15r and the imaginary - part coefficients B of the imaginary - part coefficient multipliers 13i and 15i are predetermined for each of the frequencies f1, f2,.... These coefficients A and B may be preset in each multiplier 13r, 13i, 15r, 15i if the output frequency f (for example, f1) is predetermined. Also, these coefficients A and B may be configured to be externally set from other circuits when the data generation device 10 is connected to other control circuits (for example, the control unit 30 described later). It is desirable to set the coefficients A and B under the condition that A^2 + B^2 = 1. As the frequencies f1, f2,... become smaller, the real - part coefficient A is set larger and the imaginary - part coefficient B is set smaller.

[0015] The upper diagram of FIG. 3 shows an explanatory diagram of the principle of the digital data generation method. The generation unit S1 generates digital data by multiplying the stored values of the registers 11s and 11c by a predetermined coefficient (A + jB) at a predetermined step period T (T0 → T1 → T2 →... in FIG. 3) that is shorter than the basic period of the predetermined wave so as to rotate a unit vector by a predetermined step angle θ on the two-dimensional complex plane. Referring to the upper diagram of FIG. 3 for explanation, it is generated so as to rotate counterclockwise by the step angle θ on the two-dimensional complex plane. By configuring in this way, digital data of a sine wave (SIN) and a cosine wave (COS) can be output as shown in FIG. 2.

[0016] In mathematical formula, it can be expressed as follows. Here, X n is the real component, Y n is the imaginary component, A is the real coefficient, and B is the imaginary coefficient. Since it rotates counterclockwise, by multiplying by the coefficient (A + jB) as in equation (1), the real component X n-1 , the imaginary component Y n-1 from the current step can be used to represent the real component X n , the imaginary component Y n of the next step angle θ.

Number

[0017] Also, since the real and imaginary parts of this equation (1) are the same, it can be expressed as in equation (2). If the equation of this equation (2) is configured by hardware, it can be configured as shown in the data generation device 10 of FIG. 1.

Number

[0018] Since the coefficients A and B are set by digital data, there is a limit to the number of bits. Also, when storing the result of multiplying the coefficient A + jB in registers 11s and 11c, there is a limit to the number of bits and a rounding error occurs. This rounding error accumulates as the calculation progresses. As shown in the lower figure of Fig. 3, which shows the simulation results and experimental results, the absolute value of the data error also accumulates significantly by accumulating the output digital data. It is desirable to reset this error. Therefore, as shown in Fig. 1, the data generation device 10 is provided with a reset counter 17.

[0019] The reset counter 17 represents a circuit that starts counting from an initial value and outputs a reset signal R to selectors 12s and 12c every time a predetermined threshold value is reached. When the selector 12s receives the reset signal R, it temporarily switches the input and outputs a reset value (initial value S) to the register 11s. When the selector 12c receives the reset signal R, it temporarily switches the input and outputs a reset value (initial value C) to the register 11c. As a result, due to the action as a reset unit by the reset counter 17, selectors 12s and 12c, the generation result of the digital data of the generation unit S1 can be reset at periodic timings, and as a result, the error can be reset.

[0020] For example, as shown in Fig. 2, it may be configured to give a reset signal R1 every 360° (2π [rad]) of the basic periods of the sine wave and cosine wave to clear the initial values S and C. In this case, the initial values are S = 0 and C = 1. Also, if the initial values S and C are periodically changed and set, the reset signals R1 to R4 may be repeatedly given every 90° (π / 4 [rad]).

[0021] In this case, it is advisable to set the initial values of S and C as follows: (initial value S = 0, C = 1 @ reset signal R1), (initial value S = 1, C = 0 @ reset signal R2), (initial value S = 0, C = -1 @ reset signal R3), (initial value S = -1, C = 0 @ reset signal R4). Here, a form has been described in which the reset signal R1 or R1 to R4 is periodically applied every 360° or 90° by the action of the reset section to clear the initial values of S and C. However, it may also be reset at any other arbitrary timing (for example, arbitrary timings such as 30°, 10°, 45°, etc.).

[0022] Note that in the method described in Patent Document 2 described in the background art section, as the number of operations increases, the operation error becomes large, which is not preferable. Also, since a DC component is generated as the number of operations increases, it is not preferable. As in this embodiment, by using the reset counter 17 to reset the generation result of the generation section S1 at an arbitrary timing, error components can be cleared, and sine waves (SIN) and cosine waves (COS) can be generated without generating a DC component as much as possible.

[0023] <Summary of this embodiment> As described above, according to this embodiment, since the generation section S1 generates digital data by multiplying the stored values of the registers 11s and 11c by a predetermined coefficient (A + jB) so as to rotate the unit vector on the two-dimensional complex plane at every predetermined step angle θ, digital data can be generated by operating the digital data without using stored data, and the digital data constituting the frequency of the sine wave or cosine wave can be generated as accurately as possible.

[0024] (Second Embodiment) The second embodiment will be described with reference to FIGS. 4 and 5. The data generation device 210 includes a control section 30, sign inverters 18s and 18c, and selectors 19s and 19c, in addition to the configuration of the data generation device 10. The control section 30 is composed of a digital control circuit and a counter, and generates the reset signals R1 and R3 to be given to the selectors 12s and 12c, and also generates selection signals to be given to the selectors 19a and 19c.

[0025] Also, the sign inverter 18s receives the addition result of the adder 16, inverts the sign of the input digital data, and outputs it to the selector 19s. The selector 19s selects whether to output the addition result of the adder 16 as it is or after inverting the sign based on the selection signal from the control unit 30, and outputs it as the digital data of the sine wave (SIN).

[0026] Also, the sign inverter 18c receives the addition result of the adder 14, inverts the sign of the input digital data, and outputs it to the selector 19c. The selector 19c selects whether to output the addition result of the adder 14 as it is or after inverting the sign based on the selection signal from the control unit 30, and outputs it as the digital data of the cosine wave (COS).

[0027] The generation unit S2 of the second embodiment includes the sign inverters 18s and 18c and the selectors 19s and 19c in addition to the configuration of the generation unit S1 of the first embodiment. Note that the generation unit S2 may be defined to include the control unit 30. After the control unit 30 outputs the reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1, the generation unit S2 generates the digital data of the sine wave and the cosine wave at the operation interval T (T0 → T1 → T2 →...) as in the first embodiment during the first half of the basic period of the sine wave and the cosine wave. During this first half (180°) of the basic period, the selectors 19s and 19c output the addition results of the adders 16 and 14 as they are.

[0028] After the generation unit S2 generates the digital data for the first half of the basic period, the control unit 30 outputs the reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1. Also, the control unit 30 outputs a selection signal to the selectors 19s and 19c to output the addition results of the adders 14 and 16 with the sign inverted by the sign inverters 18s and 18c as the digital data of the sine wave and the cosine wave.

[0029] Then, the generation unit S2 reverses the signs of the digital data while regenerating the first half 1 / 2 (corresponding to 180°) of the originally generated digital data, and outputs them as digital data of sine wave and cosine wave respectively. As a result, when the generation unit S2 generates digital data for one basic period of the sine wave and the cosine wave, it repeats the generation of the first half 1 / 2 (corresponding to 180°) of the original digital data twice. During the first half, it outputs the data without reversing the sign, and during the second half, it outputs the data with the sign reversed.

[0030] <Summary of this Embodiment> As described above, the generation unit S2 of the second embodiment generates digital data of sine wave and cosine wave at the operation intervals T (T0→T1→T2→…) during the first half of the basic period of the sine wave and the cosine wave. Then, during the remaining half of the basic period of the sine wave and the cosine wave, the generation unit S2 performs sign swapping of the digital data of the sine wave and the cosine wave, thereby generating digital data of the sine wave and the cosine wave during one basic period. As a result, a waveform that generates as little DC component as possible can be generated. In particular, by the control unit 30 outputting the reset signal R1 to the selectors 12s and 12c, it becomes possible to clear to the initial values S = 0 and C = 1 every half of the basic period, and the generation error can be reduced.

[0031] (Third Embodiment) The third embodiment will be described with reference to FIGS. 6 and 7. The data generation device 310 shown in FIG. 6 includes selectors 20s and 20c in addition to the configuration of the data generation device 210. The control unit 30 generates the reset signal R1 given to the selectors 12s and 12c, and also generates selection signals given to the selectors 19a, 19c, 20s, and 20c.

[0032] Selector 20s is provided to select digital data for a sine wave. Based on a selection signal input from control unit 30, it selects one of the addition results of adders 14 and 16 and outputs it to selector 19s and sign inverter 18s. When sign inverter 18s receives the output digital data of selector 20s as input, it inverts the sign of the input digital data and outputs it to selector 19s. Selector 19s selects whether to output the output digital data of selector 20s as it is or to invert the sign by sign inverter 18s based on the selection signal of control unit 30, and outputs it as digital data of a sine wave (SIN).

[0033] Selector 20c is provided to select digital data for a cosine wave. Based on a selection signal input from control unit 30, it selects one of the addition results of adders 14 and 16 and outputs it to selector 19c and sign inverter 18c. Sign inverter 18c receives the output digital data of selector 20c as input, inverts the sign of the input digital data, and outputs it to selector 19c. Selector 19c selects whether to output the output digital data of selector 20c as it is or to invert the sign by sign inverter 18c based on the selection signal of control unit 30, and outputs it as digital data of a cosine wave (COS).

[0034] The generation unit S3 of the third embodiment includes selectors 20s and 20c together with the generation unit S2 of the second embodiment. After control unit 30 outputs a reset signal R1 to selectors 12s and 12c to clear the output values of selectors 12s and 12c to the initial values S = 0 and C = 1, generation unit S3 generates digital data of a sine wave and a cosine wave at an operation interval T (T0 → T1 → T2 →...) as in the first embodiment during the initial 1 / 4 of the basic period of the sine wave and the cosine wave.

[0035] <From 0° to 90°> During the first 1 / 4 (90°) of the initial basic period, based on the selection signal from the control unit 30, the selector 20s selects and outputs the addition result of the adder 16, and the selector 20c selects and outputs the addition result of the adder 14. Also, the selectors 19s and 19c output the addition results of the adders 14 and 16 as they are. That is, the generation unit S3 outputs the addition results of the adders 16 and 14, which are the same as those in the first embodiment, as digital data of a sine wave and a cosine wave, respectively, during the first 1 / 4 of the basic period (see (D1) and (D2) in FIG. 7).

[0036] After the generation unit S3 generates digital data for the first 1 / 4 of the initial basic period, the control unit 30 outputs a reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1.

[0037] <From 90° to 180°> Also, in the next 1 / 4 of the basic period, the control unit 30 outputs a selection signal to the selectors 20s and 20c to swap the data of the sine wave and the cosine wave. That is, the generation unit S3 outputs the addition result of the adder 14 to the selector 19s and the sign inverter 18s, and outputs the addition result of the adder 16 to the selector 19c and the sign inverter 18c. Further, the control unit 30 outputs a selection signal to the selector 19c, and the sign inverter 18c outputs the addition result of the adder 16 with the sign inverted as digital data of a cosine wave (see (D3) in FIG. 7). At the same time, the selector 19s outputs the output of the selector 20s that has received the addition result of the adder 14 as digital data of a sine wave as it is (see (D4) in FIG. 7).

[0038] After the generation unit S3 generates digital data for the first 2 / 4 (180°) of the initial basic period, the control unit 30 outputs a reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1.

[0039] <From 180° to 270°> Also, in the next 1 / 4 of the basic period, the control unit 30 outputs selection signals to the selectors 20s and 20c from the immediately previous state to perform data swapping between the sine wave and the cosine wave, and returns the data swapping state to its original state. That is, the generation unit S3 outputs the addition result of the adder 16 to the selector 19s and the sign inverter 18s, and outputs the addition result of the adder 14 to the selector 19c and the sign inverter 18c. Further, the selector 19c outputs the addition result of the adder 14 whose sign has been inverted by the sign inverter 18c as the digital data of the cosine wave (see (D5) in FIG. 7). At the same time, the control unit 30 outputs a selection signal to the selector 19s from the immediately previous state, and outputs the addition result of the adder 16 whose sign has been inverted by the sign inverter 18s as the digital data of the sine wave (see (D6) in FIG. 7).

[0040] After the generation unit S3 generates digital data for 3 / 4 (270°) of the initial basic period, the control unit 30 outputs a reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1.

[0041] <From 180° to 270°> Also, in the next 1 / 4 of the basic period, the control unit 30 outputs selection signals to the selectors 20s and 20c from the immediately previous state to perform data swapping between the sine wave and the cosine wave. That is, the generation unit S3 outputs the addition result of the adder 14 to the selector 19s and the sign inverter 18s, and outputs the addition result of the adder 16 to the selector 19c and the sign inverter 18c. Further, the selector 19c outputs the addition result of the adder 16 as the digital data of the cosine wave as it is (see (D7) in FIG. 7). At the same time, the selector 19s outputs the addition result of the adder 14 whose sign has been inverted by the sign inverter 18s as the digital data of the sine wave (see (D8) in FIG. 7).

[0042] After the generation unit S3 generates digital data for 4 / 4 (corresponding to 360°) of the initial basic period, the control unit 30 outputs a reset signal R1 to the selectors 12s and 12c to clear the output values of the selectors 12s and 12c to the initial values S = 0 and C = 1. Then, it returns to the original state and repeats the control (see (D1) in FIG. 7). By repeating the control in the same way, the generation unit S3 can periodically generate digital data of sine waves and cosine waves.

[0043] <Summary of this Embodiment> As described above, the generation unit S3 of the third embodiment generates digital data of sine waves and cosine waves at the operation interval T during the initial 1 / 4 of the basic period of the sine wave and cosine wave. Then, during the remaining period of the basic period of the sine wave and cosine wave (that is, during 3 / 4 of the basic period), the generation unit S3 performs sign inversion of the digital data of the sine wave and cosine wave and data swapping between the sine wave and the cosine wave to generate digital data of the sine wave and cosine wave during the basic period. Thereby, a waveform that does not generate a DC component as much as possible can be generated. Also, by the control unit 30 outputting the reset signal R1 every 1 / 4 of the basic period, it becomes possible to clear to the initial values S = 0 and C = 1 every 1 / 4 of the basic period, and the generation error can be reduced.

[0044] (Fourth Embodiment) The fourth embodiment will be described with reference to FIGS. 8 to 10. FIG. 8 shows an electrical configuration example of a battery monitoring system 401 in which the data generation device 310 shown in the third embodiment is incorporated as a SIN / COS generation unit 310a. Note that only the parts related to the features of this embodiment are extracted and shown, and it should be noted that other block configurations are omitted. The SIN / COS generation unit 310a in FIG. 8 has the same configuration as the generation unit S3 of the data generation device 310, and the description thereof is omitted.

[0045] The battery monitoring system 401 includes a battery monitoring master device 2 and a plurality of battery monitoring slave devices 51, 52, …. The battery monitoring master device 2 includes an MPU 3 and an external interface 4, and is configured to be communicable with the plurality of battery monitoring slave devices 51, 52 via the external interface 4.

[0046] The battery monitoring slave devices 51, 52 respectively monitor the inter-terminal voltages of unit cells Ce1, Ce2, …, Cen of n secondary batteries connected in series. The series connection circuit of the unit cells Ce1, Ce2, …, Cen constitutes a battery pack, and the voltage of the series connection circuit of the battery pack is applied to the current load 40.

[0047] The current load 40 is constituted by an inverter or a DC-DC converter, etc. and is connected in series to the unit cells Ce1, Ce2, …, Cen. The battery monitoring slave device 51 includes RC filters 32, 320, a FET_M, and an integrated circuit IC. The battery monitoring slave device 51 or the integrated circuit IC is configured as a device equivalent to a battery monitoring device.

[0048] RC filters 32 are respectively connected to the unit cells Ce1, Ce2, …, Cen. The RC filter 32 is configured by connecting a resistor Rs and a capacitor Cs in a low-pass type as shown in FIG. 8, and the inter-terminal voltage of the n capacitors Cs is input to the integrated circuit IC. The integrated circuit IC has a lock-in amplifier type battery impedance measurement function. The battery monitoring slave devices 51, 52 are configured to generate an excitation signal to the unit cells Ce1, Ce2, …, Cen using the FET_M at a predetermined excitation frequency fexc regardless of the operation of the aforementioned current load 40. When measuring the battery impedance, the integrated circuit IC measures the impedance at the excitation frequency fexc.

[0049] The integrated circuit IC includes n delta-sigma A / D converters 33, a digital filter 34, a lock-in amplifier 35, a control unit 30, and an external interface 31. The n delta-sigma A / D converters 33 input the inter-terminal voltages of each unit cell Ce1, Ce2... Cen via an RC filter 32 and perform A / D conversion. The digital filter 34 uses a CIC (Cascaded Integrator-Comb) filter, reduces the sampling frequency, and converts it into a multi-bit digital value.

[0050] The lock-in amplifier 35 inputs the output digital data of the digital filter 34. As shown in FIG. 9, the lock-in amplifier 35 includes multipliers 36c, 36s that respectively input the IQ signals obtained by branching the output of the digital filter 34, and LPFs 37c, 37s that respectively input the outputs of the multipliers 36c, 36s, cut the high frequency, and pass the low frequency.

[0051] The multipliers 36c, 36s respectively input the cosine wave (COS) and sine wave (SIN) signals generated by the SIN / COS generation unit 310a and perform orthogonal conversion. When the LPFs 37c, 37s input the outputs of the multipliers 36c, 36s, they cut the high frequency, obtain the desired DC data, and output the real part and the imaginary part (equivalent to a complex signal) to the control unit 30 respectively. Therefore, the lock-in amplifier 35 converts the data generated by the SIN / COS generation unit 310a into a complex signal.

[0052] The control unit 30 can obtain information on the inter-terminal voltages of the unit cells Ce1... Cen from the complex signal input from the lock-in amplifier 35. The external interface 31 is connected to the external interface 4 of the battery monitoring master device 2, enabling communication between the master and slave. The battery monitoring master device 2 can obtain information on the inter-terminal voltages of the unit cells Ce1, Ce2... Cen responsible for each battery monitoring slave device 51, 52 by communicating with each battery monitoring slave device 51, 52.

[0053] In addition, the combination of the RC filter 320, the delta-sigma A / D converter 330, the digital filter 340, and the lock-in amplifier 350 is also provided for the shunt resistor Rsh. The terminal voltage across the shunt resistor Rsh is input to the A / D converter 330 via the RC filter 320 composed of the resistor element Rs0 and the capacitor Cs0 (Vcp - Vcm in FIG. 8). The drain-source terminals of the FET_M are connected in series to the shunt resistor Rsh, and further, a series connection circuit of the unit cells Ce1, Ce2... Cen is connected via the current limiting resistor Rz. The FET_M is composed of an N-channel MOS transistor.

[0054] <Impedance Measurement> When the MPU 3 of the battery monitoring master device 2 measures the impedance of the battery pack at the excitation frequency fexc of the current load 40, it sets the excitation frequency fexc of the SIN / COS generation unit 310a, etc., and transmits it to the target battery monitoring slave device (for example, 51). Further, the MPU 3 transmits a measurement start command via the external interface 4, so that the battery monitoring slave device 51 starts operating, and the SIN / COS generation unit 310a outputs an excitation signal at the excitation frequency fexc set above. A sine wave signal output by the SIN / COS generation unit 310a is applied to the gate of the FET_M through the DA converter 36.

[0055] When the FET_M turns on and off, the A / D converter 330 detects and digitally converts the terminal voltage corresponding to the excitation signal current flowing through the shunt resistor Rsh via the unit cells Ce1, Ce2... Cen. The digital filter 340 decimates the digital data, and the lock-in amplifier 350 performs orthogonal conversion and cuts off the high frequency to obtain a complex signal of the excitation signal current by DC data. The integrated circuit IC can measure the impedance based on the terminal voltage between each of the unit cells Ce1, Ce2... Cen and the excitation signal current obtained. The measurement result of this impedance is transmitted to the battery monitoring master device 2 of the host device through the external interfaces 31 and 4.

[0056] <Explanation of the frequency spectrum and the technical significance of the SIN / COS generation unit 310a> Next, with reference to FIGS. 9 and 10, the frequency spectrum distribution of the internal nodes of the lock-in amplifier 35 will be described. As defined in FIG. 9, let the output node of the digital filter 34 be node NA, the output node of the SIN / COS generation unit 310a be node NB, and the output node of the multiplier 36c (or 36s) be node NC.

[0057] In principle, as described above, the impedance of the battery will be measured, but components of the excitation frequency fexc and its harmonics are generated at the internal nodes of the lock-in amplifier 35. As shown in FIG. 10, at node NA during impedance measurement, the floor noise FN is superimposed at a low level on the components of the excitation signal current / voltage. As described above, since the external RC filter 32 is used, the floor noise FN is cut off in a predetermined high-frequency band.

[0058] At node NA, the excitation signal component DS of the output of the digital filter 34, its second harmonic component DSd, and the DC components DC of the unit cells Ce1, Ce2... Cen appear superimposed in the frequency band of the floor noise FN. Also, at node NB, the main component SC of the SIN / COS generation unit 310a is generated, and its harmonic component SCd and DC error component DCn are also slightly included.

[0059] The multipliers 36c and 36s multiply the sine wave and cosine wave of the excitation frequency fexc of the excitation signal, thereby converting to the frequencies of their sum and difference. Therefore, at node NC, the DC component DC1 (dotted line in FIG. 10) obtained by multiplying the excitation signal component DS of the excitation frequency fexc at node NA and the main component SC of node NB can be obtained as the desired component.

[0060] In addition, at node NC, a DC error component DC2 (solid line in FIG. 10) due to the multiplication result of the DC component DC and the DC error component DCn is also extracted. Further, a DC error component DC3 (dashed-dotted line in FIG. 10) obtained by multiplying the second harmonic component DSd of the excitation signal of the excitation frequency fexc and the harmonic component SCd of the SIN / COS generation unit 310a is also extracted as an unwanted component.

[0061] LPFs 37c and 37s provided at the subsequent stage of node NC can extract only low-frequency components by cutting components of a predetermined high-frequency, and can greatly reduce the floor noise FL, but cannot cut the DC error components DC2 and DC3.

[0062] In this case, if the SIN / COS generation unit 310a generates a large amount of the DC error component DCn and the harmonic component SCd having the same frequency as the component generated at node NA at node NB, the DC error components DC2 and DC3 will be generated to such an extent that they cannot be ignored, which is not preferable. In particular, in order for the integrated circuit IC to accurately measure the DC component DC1 of the unit cells Ce1, Ce2... Cen of the battery, it is desirable to reduce the DC error components DC2 and DC3 as much as possible.

[0063] <Summary of this embodiment> In this embodiment, since the SIN / COS generation unit 310a is configured as shown in the data generation device 310 described in the third embodiment, digital data of the sine wave and cosine wave of the basic period can be generated at node NB so as not to generate the DC error component DCn and the harmonic component SCd as much as possible. Therefore, only the desired main component SC can be generated while suppressing the generation of the DC error component DCn and the harmonic component SCd at node NB. As a result, the DC error components DC2 and DC3 appearing at node NC can be reduced. Thereby, the DC component DC1 of the unit cells Ce1, Ce2... Cen of the battery can be measured as accurately as possible.

[0064] (Fifth Embodiment) The fifth embodiment will be described with reference to FIGS. 11 and 12. FIG. 11 shows an electrical configuration example of a battery monitoring system 501 in which the data generation device 310 shown in the third embodiment is incorporated as SIN / COS generation units 310a and 310b.

[0065] The SIN / COS generation units 310a and 310b shown in FIG. 11 have the same configuration as the generation unit S3 of the data generation device 310, and the configurations of the control units 30a and 30b are the same as those of the control unit 30, and thus the description thereof is omitted. Note that only the parts related to the features of this embodiment are extracted and presented, and it should be noted that the other block configurations are omitted.

[0066] The battery monitoring system 501 includes a battery monitoring master device 2 and a plurality of battery monitoring slave devices 51a, 51b, 52,.... The difference between the fifth embodiment and the fourth embodiment is that the function of the battery monitoring slave device 51 in the fourth embodiment is divided into two battery monitoring slave devices 51a and 51b.

[0067] The battery monitoring slave devices 51a, 51b, 52,... are used in a system in which an external current load 40 is excited at an excitation frequency fexc. The battery monitoring slave device 51a is provided with respect to the shunt resistor Rsh. The battery monitoring slave device 51b is a device that monitors the terminal voltage between the unit cells Ce1, Ce2,... Cen of n secondary batteries connected in series. The series connection circuit of the unit cells Ce1, Ce2,... Cen constitutes a battery pack, and the voltage of the series connection circuit is applied to the current load 40.

[0068] The current load 40 is constituted by an inverter or a DC / DC converter or the like and operates at a relatively low-frequency excitation frequency fexc (for example, about 0.1 Hz to 1 kHz). The battery monitoring slave device 51a includes an RC filter 320 and an integrated circuit ICa. The battery monitoring slave device 51b includes an RC filter 32 and an integrated circuit ICb. The battery monitoring slave devices 51a, 51b, or the integrated circuits ICa, ICb are configured as equivalent to a battery monitoring device.

[0069] The integrated circuits ICa and ICb have a lock-in amplifier type battery impedance measurement function by cooperating with each other. When measuring the battery impedance, the integrated circuit ICa measures the excitation signal current at the excitation frequency fexc of the aforementioned current load 40 through the shunt resistor Rsh. Also, the integrated circuit ICb measures the terminal voltage between the unit cells Ce1, Ce2... Cen at the excitation frequency fexc of the current load 40, and measures the impedance of the battery based on these measurement results.

[0070] That is, in the fourth embodiment, the excitation signal current at the excitation frequency fexc from the SIN / COS generation unit 310a was intentionally passed through the unit cells Ce1, Ce2... Cen to measure the impedance of the battery, but in the fifth embodiment, it is different in that the impedance of the battery is measured when the excitation signal current at the excitation frequency fexc applied to the current load 40 flows through the unit cells Ce1, Ce2... Cen.

[0071] The integrated circuit ICa includes a delta-sigma A / D converter 330, a digital filter 340, a lock-in amplifier 350, a control unit 30a, and an external interface 31a. The integrated circuit ICb includes n delta-sigma A / D converters 33, digital filters 34, lock-in amplifiers 35, a control unit 30b, and an external interface 31b. The configurations of the delta-sigma A / D converters 33, 330, digital filters 34, 340, lock-in amplifiers 35, 350 are the same as those in the fourth embodiment and the description thereof is omitted. Also, the configurations of the control units 30a, 30b, external interfaces 31a, 31b are the same as those of the control unit 30 and the external interface 31 in the fourth embodiment and the description thereof is omitted.

[0072] As a result, the battery monitoring master device 2 can obtain information on the excitation signal current for which each of the battery monitoring slave devices 51a, 51b, 52... is responsible and information on the terminal voltage between the unit cells Ce1, Ce2... Cen by communicating with each of the battery monitoring slave devices 51a, 51b.

[0073] <Explanation of the significance of this embodiment> It is difficult to exactly match the excitation frequency fexc of the inverter or DCDC converter that constitutes the current load 40 with the measurement frequencies fmeas of the sine wave and cosine wave of the SIN / COS generation units 310a and 310b of the integrated circuits ICa and ICb that constitute the battery monitoring system 501 from the default. When these excitation frequency fexc and measurement frequency fmeas do not match, it becomes difficult to detect the DC component DC1 by the lock-in amplifiers 35 and 350.

[0074] Therefore, in the present embodiment, the measurement frequency fmeas of the excitation signal of the SIN / COS generation units 310a and 310b is swept, the excitation frequency fexc of the current load 40 is searched, and the measurement frequency fmeas that matches or is close to the excitation frequency fexc is explored. The operation at this time will be described with reference to the flowchart of FIG. 12.

[0075] As shown in FIG. 12, the battery monitoring master device 2 of the battery monitoring system 501 first excites an alternating current of the excitation frequency fexc by operating the inverter or DCDC converter that constitutes the current load 40 in S1. Then, the excitation signal current flows through the unit cells Ce1, Ce2... Cen and the shunt resistor Rsh.

[0076] Next, the battery monitoring slave devices 51a and 51b generate a sine wave and a cosine wave of the start measurement frequency fmeas_start lower than the excitation frequency fexc by the SIN / COS generation units 310a and 310b in S2. Then, in S3, the control unit 30b measures the AC voltage related to the unit cells Ce1, Ce2... Cen, and the control unit 30a measures the AC current based on the shunt resistor Rsh and obtains the signal intensity. Here, the control units 30a and 30b monitor the intensities of the real part and the imaginary part (complex signal) obtained by converting the terminal voltage and the energizing current of the unit cells Ce1, Ce2... Cen by the lock-in amplifiers 35 and 350 based on the signal excited by the current load 40 of the battery monitoring system 501.

[0077] The control units 30a and 30b of the battery monitoring slave devices 51a and 51b transmit information on the measurement results of the signal strength to the MPU 3 of the battery monitoring master device 2. The MPU 3 sequentially records information on the signal strength of the AC voltage and AC current in the internal memory, and determines whether or not these monitored strengths have become smaller than the previous value (S4).

[0078] If the MPU 3 determines in S4 that it is at a large or equal value (NO in S4), it issues a command to the SIN / COS generation units 310a and 310b in S5 to increase the measurement frequency fmeas. Then, the SIN / COS generation units 310a and 310b change the measurement frequency fmeas and output a sine wave and a cosine wave to the lock-in amplifiers 35 and 350. Thereafter, the processes of S4 and S5 are repeatedly executed and the system waits until the monitored signal strength becomes smaller than the previous value (YES in S4).

[0079] In other words, while the battery monitoring slave devices 51a and 51b sweep the measurement frequency fmeas of the sine wave and cosine wave by the SIN / COS generation units 310a and 310b, the control units 30a and 30b monitor the strength of the received signal of the real part and the imaginary part (complex signal) obtained by converting the signal excited in the battery monitoring system 501 by the lock-in amplifiers 35 and 350 (function as a monitor unit). Then, the processes of S4 and S5 are repeatedly executed and the system waits until the monitored signal strength becomes smaller than the previous value (YES in S4). Thereby, the excitation frequency fexc can be searched based on the strength of the monitored signal.

[0080] Then, if the monitored signal strength becomes smaller than the previous value (YES in S4), the MPU 3 adopts the measurement result of the previous measurement frequency fmeas, commands that value as the measurement frequency fmeas of the SIN / COS generation units 310a and 310b, and the SIN / COS generation units 310a and 310b use that value thereafter. Thereby, the measurement frequency fmeas that provides the condition with the highest monitored signal strength can be set for the SIN / COS generation units 310a and 310b. As a result, the lock-in amplifiers 35 and 350 can easily detect the desired DC component DC1.

[0081] By finely setting the real - part coefficient A and the imaginary - part coefficient B shown in FIG. 1 for each measurement frequency fmeas (f1, f2...), the SIN / COS generation units 310a and 310b can slightly change the frequency setting. Therefore, as shown in this embodiment, even if the measurement frequency fmeas is swept at very small frequencies, it can flexibly respond.

[0082] Here, the mode in which the MPU3 of the battery monitoring master device 2 commands the measurement frequency fmeas has been described, but it is not limited to this. Either the control unit 30a or 30b of the battery monitoring slave devices 51a and 51b may command and sweep the measurement frequency fmeas with each other as the main body.

[0083] (Other Embodiments) It is not limited to the form shown in the foregoing embodiment. For example, the following modifications or expansions are possible. In the foregoing embodiment, the data generation devices 10, 210, and 310 have been described in the form of periodically generating data of a predetermined wave by a sine wave (SIN) and a cosine wave (COS) over one or more periods. However, it is not limited to this, and it may be applied to those that output data of only one of the sine wave or the cosine wave, or it may be applied to those that generate data of at least a part of one period of these sine waves or cosine waves, for example, data for 30°, 60°, 90°, 180°, 270°.

[0084] The form of rotating the unit vector counter - clockwise on the two - dimensional complex plane at each predetermined step angle has been described, but it is not limited to this, and it may be applied to the form of rotating clockwise. When rotating counter - clockwise, the coefficient B is set to a positive value and the coefficient - B is set to a negative value. When rotating clockwise, the coefficient B is set to a negative value and the coefficient - B is set to a positive value. Digital data of a predetermined wave can also be generated in such a form.

[0085] The data generation devices 10, 210, 310 and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the data generation devices 10, 210, 310 and the method thereof described in the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0086] Or, the data generation devices 10, 210, 310 and the method thereof described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executable by a computer.

[0087] That is, the means and / or functions provided by the processor or the like can be provided by software recorded in a physical memory device and a computer that executes the software, software only, hardware only, or a combination thereof. For example, some or all of the functions provided by the processor may be realized as hardware. Modes of realizing a certain function as hardware include modes of realizing it using one or more ICs or the like.

[0088] The present disclosure includes the following disclosure in addition to the content of the invention described in the claims. [1] A data generation device that generates at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave), a storage unit (11s, 11c) to which an initial value is given, A generating unit (S1; S2; S3) that generates digital data by multiplying a stored value in the storage unit by a coefficient predetermined to rotate a unit vector on a two-dimensional complex plane at each predetermined step angle of the predetermined wave at a predetermined operation interval shorter than the basic period of the predetermined wave; A data generation device comprising the same.

[0089] [2] A data generation device according to [1], further comprising a reset unit (17, 12c, 12s) that resets an error by resetting a generation result of the generation unit at an arbitrary timing.

[0090] [3] The generation unit generates the sine wave and the cosine wave as the predetermined wave, The generation unit repeats generation of digital data of the sine wave and the cosine wave at the operation interval during the first half of the basic period of the sine wave and the cosine wave, The data generation device according to [1] or [2], wherein during the remaining period of the basic period of the sine wave and the cosine wave, digital data of the sine wave and the cosine wave are generated by performing sign inversion of the digital data of the sine wave and the cosine wave.

[0091] [4] The generation unit generates the sine wave and the cosine wave as the predetermined wave, The generation unit repeats generation of digital data of the sine wave and the cosine wave at the operation interval during the first quarter of the basic period of the sine wave and the cosine wave, The data generation device according to [1] or [2], wherein during the remaining period of the basic period of the sine wave and the cosine wave, digital data of the sine wave and the cosine wave are generated by performing sign inversion of the digital data of the sine wave and the cosine wave and swapping the data between the sine wave and the cosine wave.

[0092] [5] Comprising the data generation device according to any one of [1] to [4], A battery monitoring device comprising a lock-in amplifier (35; 350) that converts digital data generated by the data generation device into a complex signal.

[0093] [6] A battery monitoring device used in a system where an external load (40) is excited at an excitation frequency, The data generation device is configured to sweep the measurement frequencies of the sine wave and the cosine wave, Comprising a monitor unit (30a, 30b) that monitors the intensity of the complex signal obtained by converting the signal excited in the system by the lock-in amplifier, A battery monitoring device that searches for the excitation frequency based on the intensity of the monitored signal.

[0094] [7] A data generation method for generating at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave), The data generation device has initial values in a storage unit (11s, 11c), A data generation method in which a generation unit (S; S2; S3) multiplies the stored value in the storage unit by a predetermined coefficient at a predetermined operation interval shorter than the basic period of the predetermined wave to rotate a unit vector at each predetermined step angle of the predetermined wave on a two-dimensional complex plane to generate digital data.

[0095] [8] A data generation program for generating at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave) by a data generation device, The data generation device includes a storage unit (11s, 11c) to which an initial value is given, A procedure for giving an initial value to the storage unit, A procedure for a generation unit (S; S2; S3) to generate digital data by multiplying the stored value in the storage unit by a predetermined coefficient at a predetermined operation interval shorter than the basic period of the predetermined wave to rotate a unit vector at each predetermined step angle of the predetermined wave on a two-dimensional complex plane. A data generation program for causing execution.

[0096] Although the present disclosure has been described in accordance with embodiments, it is understood that the present disclosure is not limited to such embodiments or structures. The present disclosure also includes various modifications and variations within the equivalent scope. In addition, various combinations and forms, and further other combinations and forms including only one element, more than one element, or less than one element thereof, are within the scope and spirit of the present disclosure.

Description of Reference Numerals

[0097] In the drawings, 10, 210, and 310 denote data generation devices, 11s and 11c denote registers (storage units), 310a and 310b denote SIN / COS generation units (data generation devices), S1, S2, and S3 denote generation units, IC, ICa, and ICb denote integrated circuits (battery monitoring devices), and 51, 51a, 51b, and 52 denote battery monitoring slave devices (battery monitoring devices).

Claims

1. A data generation device that generates at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave), a storage unit (11s, 11c) to which an initial value is given, a generation unit (S1; S2; S3) that generates digital data by multiplying a storage value of the storage unit at a predetermined operation interval shorter than a basic period of the predetermined wave by a coefficient predetermined to rotate a unit vector on a two-dimensional complex plane for each predetermined step angle of the predetermined wave, A data generation device comprising:

2. The data generation device according to claim 1, further comprising a reset unit (17, 12c, 12s) that resets an error by resetting a generation result of the generation unit at an arbitrary timing.

3. The generation unit generates the sine wave and the cosine wave as the predetermined wave, The generation unit repeats generation of digital data of the sine wave and the cosine wave at the operation interval during an initial 1 / 2 of the basic period of the sine wave and the cosine wave, The data generation device according to claim 1, wherein during a remaining period of the basic period of the sine wave and the cosine wave, digital data of the sine wave and the cosine wave are generated by performing sign inversion of the digital data of the sine wave and the cosine wave.

4. The generation unit generates the sine wave and the cosine wave as the predetermined wave, The generation unit repeats generation of digital data of the sine wave and the cosine wave at the operation interval during an initial 1 / 4 of the basic period of the sine wave and the cosine wave, The data generation device according to claim 1, wherein during a remaining period of the basic period of the sine wave and the cosine wave, sign inversion of the digital data of the sine wave and the cosine wave and data exchange between the sine wave and the cosine wave are performed to generate digital data of the sine wave and the cosine wave during the basic period.

5. A battery monitoring device comprising the data generation device according to any one of claims 1 to 4, and a lock-in amplifier (35; 350) that converts digital data generated by the data generation device into a complex signal.

6. A battery monitoring device used in a system in which an external load (40) is excited at an excitation frequency, wherein the data generation device is configured to sweep the measurement frequencies of the sine wave and the cosine wave, and a monitor unit (30a, 30b) that monitors the intensity of the complex signal obtained by converting the signal excited in the system by the lock-in amplifier, The battery monitoring device according to claim 5, which searches for the excitation frequency based on the intensity of the monitored signal.

7. A data generation method for generating at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave), wherein the data generation device has initial values in a storage unit (11s, 11c), and a generation unit (S; S2; S3) multiplies a storage value in the storage unit by a predetermined coefficient at a predetermined calculation interval shorter than a basic period of the predetermined wave so as to rotate a unit vector by a predetermined step angle of the predetermined wave on a two-dimensional complex plane to generate digital data.

8. A data generation program for generating at least partial digital data of a sine wave (SIN) or a cosine wave (COS) (hereinafter abbreviated as a predetermined wave) by a data generation device, wherein the data generation device has a storage unit (11s, 11c) to which an initial value is given, a procedure for giving an initial value to the storage unit, A procedure for generating digital data by multiplying, in a generation unit (S; S2; S3), a stored value in the storage unit by a coefficient predetermined to rotate a unit vector on a two-dimensional complex plane by a predetermined step angle of the predetermined wave at a predetermined operation interval shorter than a basic period of the predetermined wave, A data generation program for causing the above to be executed.

Images