JP6901988B2 - Converter control device, electric vehicle control device, and converter control method - Google Patents

Description

The present invention relates to a converter control device and the like in an electric vehicle provided with a converter, an inverter, and a storage battery.

Development of an electric vehicle is underway in which a storage battery is connected to the main circuit and mounted, and the main electric motor is driven by one or both of the power supplied from the overhead wire and the discharge power of the storage battery. Such electric vehicles are also called hybrid electric vehicles or hybrid vehicles, and charge the storage battery by the power supplied from the overhead wire or regenerative energy, or drive the traction motor by the discharge power of the storage battery in the non-electrified section. It has a feature that it can run (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-64397

However, in order to use the storage battery in an electric vehicle safely and for a long life, there are the following two problems.

Since the storage battery has a disadvantage that the capacity decreases at low temperatures, it is necessary to heat the storage battery when driving in cold regions or in winter. As a method of heating the storage battery, there are a method of installing a heater outside and a method of charging or discharging the storage battery (collectively referred to as "energization") to generate heat internally. In the former method, an external device is additionally installed, and there is a problem that it takes time for the storage battery to warm up sufficiently as compared with the internal heat generation, in addition to the installation space and cost. In the latter method, there is a problem that the charging rate is lowered by discharging, and there is a problem that the current value of the charging current is restricted when the charging is close to full charge.

In addition, it is necessary to know the degree of deterioration of the storage battery and the internal resistance of the storage battery, which is a measure of the life of the storage battery. The internal resistance can be accurately calculated from the change in the storage battery voltage at that time by changing the energizing current. Since charging and discharging of the storage battery are performed with constant DC power, it is necessary to temporarily suspend charging and discharging and to change the energizing current in order to calculate the internal resistance. That is, it is difficult to accurately calculate the internal resistance while charging and discharging the storage battery, and if an external device that changes the energizing current is required for measuring the internal resistance, problems of installation space and cost also occur.

The present invention has been made in view of the above circumstances, and a first object of the present invention is to propose a new technique for effectively heating a storage battery connected to a main circuit. The second object is to propose a new technology that enables the internal resistance of the storage battery to be calculated more accurately and at an arbitrary timing.

The first invention for solving the above problems is
In an electric vehicle including a converter, an inverter for driving and controlling a main electric motor, and a storage battery connected to a DC intermediate circuit between the converter and the inverter, a converter current and a given converter current command value are used. A converter control device that controls the converter.
Ripple current control unit that generates a reactive current command value consisting of a reactive current waveform with respect to the overhead wire voltage based on the voltage phase of the overhead wire voltage.
The converter control device is provided with the above, and controls to superimpose the reactive current command value on the converter current command value for a given time, and superimpose the ripple component on the charging current of the storage battery.

As another invention
In an electric vehicle including a converter, an inverter for driving and controlling a main electric motor, and a storage battery connected to a DC intermediate circuit between the converter and the inverter, a converter current and a given converter current command value are used. This is a converter control method for controlling the converter.
To generate a reactive current command value consisting of a reactive current waveform with respect to the overhead wire voltage based on the voltage phase of the overhead wire voltage.
Control is performed to superimpose the reactive current command value on the converter current command value for a given time, and the ripple component is superposed on the charging current of the storage battery.
A converter control method including the above may be configured.

According to the first invention or the like, it is possible to increase the ripple component contained in the charging current of the storage battery by generating a reactive current command value consisting of a reactive current waveform with respect to the overhead wire voltage and superimposing it on the converter current command value. it can. By increasing the ripple component superimposed on the charging current of the storage battery, the internal heat generation of the storage battery can be increased and the storage battery can be effectively heated. The average value of the charging current of the storage battery does not change due to the ripple current superimposed on the charging current.

The second invention is the converter control device of the first invention.
The ripple current control unit has an effective value of the ripple component of the storage battery current detected by the detector that detects the current of the storage battery (hereinafter referred to as “storage battery ripple current effective value”) and a command value of the storage battery ripple current effective value. The amplitude of the invalid current waveform is determined based on the difference from a given command value.
A converter control device may be configured.

According to the second invention, the amplitude of the reactive current waveform, which is the reactive current command value, is determined based on the difference between the detected reactive current storage battery ripple current effective value and the command value of the reactive current ripple current effective value. .. As a result, for example, the storage battery can be heated as needed by changing the command value of the effective value of the ripple current of the storage battery according to the desired heating speed, environmental temperature, and the like.

The third invention is the converter control device of the second invention.
A storage battery internal resistance calculation unit that calculates the internal resistance of the storage battery using the effective value of the ripple component of the storage battery voltage detected by the detector that detects the voltage of the storage battery and the effective value of the storage battery ripple current.
A converter control device further provided with the above may be configured.

According to the third invention, the internal resistance of the storage battery can be calculated by using the detected effective value of the ripple component of the storage battery voltage and the effective value of the ripple current of the storage battery. As a result, the internal resistance of the storage battery can be calculated while charging and discharging the storage battery.

The fourth invention is
An electric vehicle control device including the converter control device according to any one of the first to third aspects, wherein the converter current command is given to the converter control device during warm-up operation at the time of starting the electric vehicle. It is an electric vehicle control device that controls superimposing the invalid current command value on the value.

According to the fourth invention, during the warm-up operation at the time of starting the electric vehicle, the converter current command value is superposed with the reactive current command value to control the increase of the storage battery ripple current, and the storage battery is heated internally. Can be heated.

Schematic diagram of the main circuit configuration of an electric vehicle. The control block diagram of the converter control device. Waveform diagram of voltage and current when reactive current control is executed / not executed.

[Circuit configuration]
FIG. 1 is a schematic diagram of a main circuit configuration of an electric vehicle according to the present embodiment. The electric train of the present embodiment is an electric train that runs in an AC electrified section, and includes a converter 12, an inverter 16, a traction motor 18, a storage battery 20, and an electric train control device 30 as main circuits. doing. The electric vehicle of the present embodiment may be an AC electric vehicle or an AC / DC electric vehicle as long as it can travel in an AC electrified section.

The converter 12 is a PWM converter, and the input side is connected to the secondary winding of the main transformer 10 and the output side is connected to the DC intermediate circuit 14. The DC intermediate circuit 14 is also called a DC stage, and is a circuit portion related to direct current between the converter 12 and the inverter 16. The converter 12 converts the single-phase AC power supplied from the overhead wire 1 via the main transformer 10 into DC power. The operation of the converter 12 is realized by PWM control according to the converter voltage command value v _{c_ref from the electric vehicle control device 30.}

In the present embodiment, for the sake of simplification of the explanation, the converter control device 32 of the electric vehicle control device 30 _{generates and outputs the converter voltage command value v c_ref} , and the converter 12 internally generates the gate pulse signal. It described as, but together with the converter control unit 32 generates a converter voltage command value v _{C_ref,} outputs the converter voltage command value v _{C_ref} generates a gate pulse signal by comparing a triangular wave carrier, a gate pulse signal to the converter 12 Of course, it may be configured to be used.

A filter capacitor C _dc is provided in the DC intermediate circuit 14. The input side of the inverter 16 is connected to the DC intermediate circuit 14, and the output side is connected to the traction motor 18. The inverter 16 _{inputs the DC stage voltage vdc} , which is the voltage of the DC intermediate circuit 14, via the _{filter capacitor Cdc} , converts it into a three-phase AC voltage, and supplies it to the main electric power 18 as driving power.

Battery 20 is connected to a DC intermediate circuit 14 via a series-connected filter reactor L _f, to charge or discharge the relative potential difference between the DC stage voltage v _dc.

The electric vehicle control device 30 includes a converter control device 32 that controls the converter 12, a charge control unit 34, and a reactive current control unit 36.

FIG. 2 is a control block diagram of the converter control device 32. The converter control device 32 includes a converter control unit 100, a ripple current control unit 120, and an internal resistance calculation unit 140.

The converter control unit 100 inputs _{the storage battery current i b} , the DC stage voltage v _dc , the overhead wire voltage v _p , the converter current i _c , the storage battery current command value i _{b_ref,} and the invalid current command value i _{c_refq.} The converter 12 is controlled by generating a converter voltage command value v _{c_ref} for the converter 12. The storage battery current i _b is a value measured by a current meter connected in series to the storage battery 20, the DC stage voltage v _dc is a value measured by a voltmeter connected in parallel to the filter capacitor C _{dc , and the overhead wire voltage v p} is. , A value measured by a voltmeter via an instrument transformer connected in parallel to the primary winding of the main transformer 10 or an estimated value based on other winding voltages, and the converter current _ic is the input side of the converter 12. It is a measured value by a current meter connected in series to (AC side). Further, the storage battery current command value i _{b_ref} is input from the charge control unit 34, and the reactive current command value i _{c_refq} is input from the ripple current control unit 120.

The configuration of each calculation block of the converter control unit 100 will be described in order of calculation. That is, first, the storage battery average current control unit 104 determines the DC stage voltage command value based on the _{storage battery current command value i b_ref} and the storage battery average current i _{ba of the storage battery current i b} extracted by the LPF (Low Pass Filter) 102. Generate v _{dc_ref.} Battery average current control unit 104, for example, a battery current command value _{i B_ref,} the PI control for the difference .DELTA.i _b of the battery average current _{i ba,} as battery average current _{i ba} to follow the battery current command value _{i B_ref} , DC stage voltage command value v _{dc_ref} is generated.

Next, the DC stage voltage control unit 106 generates the d-axis current command value _{icd_ref} of the converter current _{ic based on the DC stage voltage command value v dc_ref} and the DC stage voltage v _dc. DC stage voltage controller 106, for example, a DC stage voltage command value _{v dc_ref,} the PI control for the difference Delta] v _dc of the DC stage voltage _{v dc,} dc stage voltage _{v dc} follows the DC stage voltage command value _{v dc_ref} As described above, the d-axis current command value _{icd_ref} of the converter current i _c is generated.

Also, PLL (Phase Locked Loop) 108 is, detect and output phase θ of trolley voltage _{v p,} sin calculator 110 generates an in-phase waveform value matched with the phase θ of the overhead line voltage _{v p.} Then, the multiplier 112, the d-axis current command value _{i Cd_ref} the converter current _{i c} which is generated by the DC stage voltage control unit 106, the converter current command value by multiplying the in-phase waveform values generated by sin calculator 110 i _{c_refd} is generated. Subsequently, the adder 114, the converter current command value _{i C_refd,} generates the to the converter current command value _{i C_ref} adding the reactive current command value _{i C_refq} input from the ripple current control unit 120.

The converter current control unit 116, the converter current command value _{i C_ref,} based on the converter current _{i c,} generates a converter voltage command _{v c_ref.} Converter current control unit 116, for example, by the PI control for the difference .DELTA.i _c of the converter current command value _{i C_ref} and converter current _{i c,} as the converter current _{i c} to follow the converter current command value _{i C_ref,} the converter voltage command Generate the value v _{c_ref.}

Ripple current control unit 120, a battery current _{i b,} a battery ripple current effective value command value _{I Br_ref,} the execution selection signal S1, and inputs the phase selection signal S2, generates a reactive current command value _{i C_refq,} the reactive current command value _{i C_refq} superimposed on the converter current command value _{i C_ref} of converter control unit 100 controls the ripple component of the storage battery current _{i b.} The storage battery ripple current effective value command value I _{br_ref} , the execution selection signal S1 and the phase selection signal S2 are input from the reactive current control unit 36.

The configuration of each calculation block of the ripple current control unit 120 will be described in order of calculation. That is, first, BPF (Band Pass Filter) 122 is a frequency filter extracts from the storage battery current _{i b} of the double frequency component of the frequency 2f _p of the frequency _{f p} of the overhead line voltage _{v p} as a ripple component _{i br.} Then, the extracted effective value of the ripple component i _br the effective value calculator 124 calculates the battery ripple current effective value I _br. Next, the adder 126 subtracts the storage battery ripple current effective value I _br from the storage battery ripple current effective value command value I _{br_ref} to calculate the _{difference ΔI b.} Subsequently, the PI controller 128 _{performs PI control with respect to this difference ΔI b,} and generates a command value I _q so that the storage battery ripple current effective value I _br follows the storage battery ripple current effective value command value I _{br_ref.} .. Further, the limiter 130 _{limits the command value I q} so as not to exceed the upper limit value I _qmax , and outputs the output to one input terminal of the selector 132.

The selector 132 has an output value of the limiter 130 input to one input terminal and a fixed value "0" input to the other input terminal, and selectively outputs any of the input terminals according to the execution selection signal S1. Connect to the terminal. The execution selection signal S1 is a signal instructing whether or not to execute reactive current control. When "execution" is instructed by the execution selection signal S1, the selector 132 outputs the command value _Iq to the coefficient calculator 134 by connecting one of the input terminals to the output terminal. When "non-execution" is instructed, "0" is output to the coefficient calculator 134 by connecting the other input terminal to the output terminal.

The coefficient calculator 134 multiplies the output value from the selector 132 by a predetermined coefficient K to generate the q-axis current command value i _{cq_ref of the converter current i c.} As the coefficient K, "-1" or "1" is selected according to the phase selection signal S2. The phase selection signal S2 is _{a signal instructing whether the reactive current command value i c_refq} is the delayed reactive current or the leading reactive current. The coefficient calculator 134 selects "-1" when the phase selection signal S2 indicates a "lag" reactive current, and selects "1" when it indicates a "lead" reactive current. , Multiplies the output value from selector 132.

Furthermore, cos calculator 136 generates the waveform value advances is advanced 90 degrees phase θ of trolley voltage _{v p} detected by PLL108 of converter control unit 100. Then, the multiplier 138 generates the reactive current command value i _{c_refq} by multiplying the lead waveform value by the q-axis current command value i _{cq_ref of the converter current i c.}

That is, reactive current command value i _{C_refq} is reactive current waveform of the delay with respect to the overhead line voltage v _p, or a reactive current waveform of the advance, the amplitude, the effective value I _br battery ripple current, battery ripple current effective value command The value _corresponds to the difference from the value I br_ref.

Internal resistance calculation unit 140 inputs the battery voltage _{v b,} and calculates the internal resistance value _{Z b} of the battery 20. The configuration of each calculation block of the internal resistance calculation unit 140 will be described in order of calculation. That, BPF142 extracts the frequency component twice the frequency 2f _p of the frequency _{f p} of the overhead line voltage _{v p} from the battery voltage _{v b} as ripple component _{v br.} Then, the extracted effective value of the ripple component v _br effective value calculator 144 calculates a battery ripple voltage effective value V _br. Then, the multiplier 146 divides the storage battery ripple voltage effective value V _br by the storage battery ripple current effective value I _br to calculate the internal resistance value Z _{b of the storage battery 20.}

Returning to FIG. 1, the charge control unit 34 _{outputs the storage battery current command value I c_ref} to the converter control device 32 to control the charge of the storage battery 20 by the converter control device 32.

Reactive current control unit 36, a storage battery ripple current effective value command value _{I Br_ref,} the execution selection signal S1, by outputting a phase selection signal S2 to the converter control unit 32, by the converter control unit 32, battery current _{i b} Controls the execution of invalid current control that superimposes the ripple component on. Specifically, by setting the execution selection signal S1 to "execute", the reactive current control can be executed, and by setting the execution selection signal S1 to "non-execution", the reactive current control can be prevented from being executed. it can. When the reactive current control is executed, the phase selection signal S2 _{can be used to instruct whether the reactive current command value ic_refq} is the “lag” current command value or the “advance” current command value. Also, the storage battery ripple current effective value command value I _{Br_ref} can be set according to the magnitude of the effective value of the ripple component of the desired battery current i _b. When executing the reactive current control, that reactive current command value i _{C_refq} is superimposed on the converter current command value i _{C_ref,} so that the ripple component is superimposed, increased DC stage voltage v _dc. As a result, the ripple component increases superimposing and the battery current i _b. The battery 20 is internally heated by the ripple component of the battery current i _b, whereby it is possible to battery 20 is warmed.

Further, since _{the ripple component of the storage battery current i b} also causes the ripple component of the storage battery voltage v _{b , the internal resistance value Z b} of the storage battery 20 can be calculated by the internal resistance calculation unit 140. When the invalid current control is not executed, since the DC stage voltage _vdc is a DC voltage, _{the ripple components of the storage battery current i b} and the storage battery voltage v _b are absent or very small, and the internal resistance calculation unit 140 determines. The calculation of the internal resistance value Z _b using the demultiplexer 146 has low accuracy.

From these facts, the reactive current control unit 36 needs an additional device by executing the reactive current control when the storage battery 20 needs to be heated, for example, during warm-up operation at the time of starting the electric vehicle. The storage battery 20 can be heated without using it. _{Further, the internal resistance value Z b} of the storage battery 20 is calculated by executing the invalid current control periodically or irregularly such as every predetermined time (for example, several hours) in addition to the warm-up operation at the start of the electric vehicle. Then, for example, the deteriorated state of the storage battery 20 can be grasped.

[motion]
Figure 3 is a diagram for explaining the operation in the reactive current control, overhead wire voltage v _p, the converter current i _c in the converter control device 32 as determined by circuit _simulation, and shows the respective waveform example battery current i _b ing. Figure 3 (a) ~ (c) is a battery 20, a waveform example when charged with a relatively small battery current _{i b} (low current charging), FIG. 3 (d) ~ (f) is, battery 20 the is a waveform example of a case of charging (high current charging) with a relatively large battery current i _b. Further, FIGS. 3A and 3D are waveform examples when the reactive current control is not performed, that is, when the execution selection signal S1 is set to “non-execution”. 3 (b) and 3 (e) show the case where the invalid current is controlled and the delay invalid current command value i _{c_refq} is set, that is, the execution selection signal S1 is "execution" and the phase selection signal S2 is "delay". This is an example of a waveform in the case of. 3 (c) and 3 (f) show the case where the invalid current is controlled and the lead invalid current command value i _{c_refq} is set, that is, the execution selection signal S1 is set to "execution" and the phase selection signal S2 is set to "lead". This is an example of a waveform in the case of. Further, FIG. 3 (a) ~ (f) are each, together with the mean value _{I ba} battery current _{i b} is performing battery average current control to match the battery current command value _{i B_ref,} FIG 3 (b ), (c), (e ), (f) is performed reactive current control such that the effective value _{I br} ripple component of the battery current _{i b} matches the battery ripple current effective value command value _{I br_ref.}

3 (a) and 3 (d) show the case where the reactive current control is not performed, and the storage battery is more in the case of the large current charging in FIG. 3 (d) than in the case of the small current charging in FIG. 3 (a). The average current i _ba is large. Further, a FIGS. 3 (a) small current charging, since 3 (d) is a large current charging, the converter current i _c and accumulators current i _b amplitude 3 large current charging (d) Is bigger. Moreover, the trolley voltage _{v p,} the converter current _{i c} in phase. Furthermore, the ripple component contained in the battery current i _b is a little in the case of a small current charging in FIG. 3 (a), in the case of a large current charging of FIG. 3 (d), the storage battery average current i _ba Because of the large size, the amount of ripple component contained is also large.

FIG. 3 (a), a comparison of (b), by performing reactive current control, it can be seen that the ripple component of the storage battery current i _b is increased. However, the average current _iba of the storage battery is the same regardless of whether the reactive current control is performed or not, and the effective value of the charging current of the storage battery 20 does not change even if the reactive current control is performed. Further, in FIG. 3 (b), the order reactive current command value _{i C_refq} delay is superimposed on the converter current command value _{i C_ref,} together with the amplitude increase of the converter current _{i c,} the converter current to the overhead wire voltage _{v p} The phase of _{ic is delayed.} Then, by a current delay converter current i _c, the amplitude of the overhead line voltage v _p is slightly reduced.

FIG. 3 (a), a comparison of (c), likewise, by performing the reactive current control, the ripple component of the battery current i _b is increased. However, the average current _iba of the storage battery is the same whether or not the reactive current control is performed. Further, in FIG. 3 (c), the order reactive current command value _{i C_refq} the advance is superimposed on the converter current command value _{i C_refq,} with increasing amplitude of the converter current _{i c,} the converter current to the overhead wire voltage _{v p} The phase of _{ic is advanced.} Then, by the current progress in the converter current i _c, the amplitude of the overhead line voltage v _p is slightly increased.

Further, the comparison of FIGS. 3 (d) and 3 (e) and the comparison of FIGS. 3 (d) and 3 (f) are the same even when the large current is charged in FIGS. 3 (d) to 3 (f). In other words, by performing a reactive current control, the ripple component of the battery current i _b is increased. With a delay of reactive current command value _{i c_refq,} converter current _{i c} is delayed relative to the trolley voltage _{v p,} the amplitude of the overhead line voltage _{v p} decreases slightly. On the other hand, by a reactive current command value _{i C_refq} the advance, the converter current _{i c} advances against the overhead wire voltage _{v p,} the amplitude of the overhead line voltage _{v p} is slightly increased.

[Action effect]
Thus, according to this embodiment, by superimposing the generated reactive current command value i _{C_refq} consisting of reactive current waveform for trolley voltage v _p converter current command value i _{C_ref,} ripples contained in the battery current i _b The components can be increased, the internal heat generation generated in the storage battery 20 can be increased, and the storage battery 20 can be effectively heated. Ripple current superimposed on battery current i _b is because it is ineffective current with respect to the overhead line voltage v _p, the effective value i _ba battery current i _b is not changed by the superimposition of the ripple component. Further, by superimposing the ripple component on the storage battery current i _b , the internal resistance of the storage battery 20 is calculated using _{the effective value V br} of the ripple component of the _{storage battery voltage v b} and the effective value I _{br of the storage battery ripple current.} Can be done. That is, the internal resistance of the storage battery 20 can be calculated while charging and discharging the storage battery 20. Further, these effects are similarly exhibited when the storage battery 20 is charged with a small current and when it is charged with a large current. Therefore, the storage battery 20 can be heated and the internal resistance can be calculated at an arbitrary timing.

1 Overhead line 10 Main transformer 12 Converter 14 DC intermediate circuit (DC stage)
16 Inverter 18 Traction motor 20 Storage battery 30 Electric vehicle control device 32 Converter control device 100 Converter control unit, 120 Ripple current control unit, 140 Internal resistance calculation unit 34 Charge control unit 36 Invalid current control unit

Claims (4)

In an electric vehicle including a converter, an inverter for driving and controlling a main electric motor, and a storage battery connected to a DC intermediate circuit between the converter and the inverter, a converter current and a given converter current command value are used. A converter control device that controls the converter.
A ripple current control unit that generates an invalid current command value consisting of an invalid current waveform with respect to the overhead wire voltage based on the voltage phase of the overhead wire voltage, and is a detector that detects the amplitude of the invalid current waveform and the current of the storage battery. Ripple determined based on the difference between the effective value of the ripple component of the storage battery current detected by (hereinafter referred to as "storage battery ripple current effective value") and the given command value which is the command value of the storage battery ripple current effective value. Current control unit ,
A converter control device that controls to superimpose the reactive current command value on the converter current command value for a given time, and superimposes a ripple component on the charging current of the storage battery. A storage battery internal resistance calculation unit that calculates the internal resistance of the storage battery using the effective value of the ripple component of the storage battery voltage detected by the detector that detects the voltage of the storage battery and the effective value of the storage battery ripple current.
Furthermore converter control apparatus according to claim 1 comprising a. The electric vehicle control device provided with the converter control device according to claim 1 or 2 , wherein the converter current command value is set to the converter control device during warm-up operation at the time of starting the electric vehicle. An electric vehicle control device that controls superimposition of invalid current command values. In an electric vehicle including a converter, an inverter for driving and controlling a main electric motor, and a storage battery connected to a DC intermediate circuit between the converter and the inverter, a converter current and a given converter current command value are used. This is a converter control method for controlling the converter.
It is to generate an invalid current command value consisting of an invalid current waveform with respect to the overhead wire voltage based on the voltage phase of the overhead wire voltage, and the amplitude of the invalid current waveform is detected by a detector that detects the current of the storage battery. The invalidity is determined based on the difference between the effective value of the ripple component of the storage battery current (hereinafter referred to as "effective value of the storage battery ripple current") and the given command value which is the command value of the effective value of the storage battery ripple current. Generating the current command value and
Control is performed to superimpose the reactive current command value on the converter current command value for a given time, and the ripple component is superposed on the charging current of the storage battery.
Converter control method including.

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