JP6971649B2 - Synchronous motor system and control device for synchronous motor system - Google Patents

Description

Embodiments of the present invention relate to a synchronous motor system and a control device for the synchronous motor system.

In recent years, synchronous motors have been used as a power source in automobiles and ships. In a system for using a synchronous motor as a power source for an automobile or the like, the electric power stored in a storage battery is supplied to the synchronous motor via an inverter.

In a system using a storage battery, a safety device such as a circuit breaker or a fuse having a capacity corresponding to the rated output of the synchronous motor or the inverter is provided. Therefore, in automobiles and ships that require a large propulsion force, a synchronous motor having a large rated output is required, and the safety device is inevitably increased in size. In this case, the system becomes large, and the manufacturing cost and running cost also increase.

Japanese Unexamined Patent Publication No. 2016-25720

The present invention has been made under the above-mentioned circumstances, and an object of the present invention is to reduce the size of a synchronous motor system.

In order to solve the above problems, the synchronous motor system according to the present embodiment includes a first inverter device and a second inverter device including a storage battery and an inverter that receives power from the storage battery and outputs multi-phase AC power. The inverter device, the control device that controls the multi-phase AC power output from the first inverter device and the second inverter device, and the multi-phase AC power from the first inverter device and the second inverter device. It is equipped with a synchronous motor that operates under the supply of. The storage battery includes a remaining capacity measuring unit that measures the remaining capacity of the storage battery and notifies the control device of the remaining capacity. The control device includes a control signal creating unit that creates a control signal for controlling the power output by the first inverter device and the second inverter device with a pulse width corresponding to the rotation angle of the rotor of the synchronous motor. A remaining capacity comparison unit that compares the remaining capacity of the storage batteries of the first inverter device and the second inverter device, and a pulse width correction unit that corrects the pulse width of the control signal based on the remaining capacity. Be prepared. The pulse width correction unit corrects the pulse width of the control signal so that the power output by the inverter device having a small remaining capacity of the storage battery is smaller than the power output by the inverter device having a large remaining capacity of the storage battery. The synchronous motor includes a first stator coil that receives polymorphic AC power from the first inverter device and a second stator coil that receives polyphase AC power from the second inverter device. , Have. The first inverter device does not supply polymorphic AC power to the second stator coil, and the second inverter device does not supply polyphase AC power to the first stator coil. ..

It is a figure which shows the structure of the synchronous motor system which concerns on 1st Embodiment. It is a figure for demonstrating the AC voltage applied to the synchronous motor which concerns on 1st Embodiment. It is a figure which shows the structure of the storage battery which concerns on 1st Embodiment. It is a figure which shows the structure of the inverter which concerns on 1st Embodiment. It is a figure which shows the structure of the control device which concerns on 1st Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 1st Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 1st Embodiment. It is a flowchart for demonstrating the control signal creation process by the control apparatus which concerns on 1st Embodiment. It is a figure which shows the structure of the synchronous motor system which concerns on 2nd Embodiment. It is a figure for demonstrating the AC voltage applied to the synchronous motor which concerns on 2nd Embodiment. It is a figure which shows the structure of the inverter which concerns on 2nd Embodiment. It is a figure which shows the structure of the control device which concerns on 2nd Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating the creation of the control signal by the control apparatus which concerns on 2nd Embodiment. It is a flowchart for demonstrating the control signal creation process by the control apparatus which concerns on 2nd Embodiment.

<< First Embodiment >>
FIG. 1 is a diagram showing a configuration of a synchronous motor system 100 according to a first embodiment. The synchronous motor system 100 is a system for driving a synchronous motor by polyphase AC power output from a plurality of inverter devices. Here, a case where the synchronous motor is driven by two inverter devices that output three-phase AC power will be described. Hereinafter, the first embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the synchronous motor system 100 controls the inverter devices 10a and 10b so that the phases of the voltages output from the plurality of inverter devices 10a and 10b are synchronized with the inverter devices 10a and 10b. A synchronous motor 1 driven by the inverter devices 10a and 10b, and a rotation angle sensor 40 are provided.

The synchronous motor 1 is a synchronous motor in which the rotor is made of a permanent magnet. The synchronous motor 1 includes a stator 2 and a rotor 3 as shown in FIG. The stator 2 is a cylindrical member made of, for example, iron or silicon steel plate. Six stator cores 2a to 2f protruding toward the rotor 3 are formed on the inner peripheral surface of the stator 2. The stator cores 2a to 2f are arranged around the rotor 3 at equal intervals. Stator coils U1, V1, W1, U2, V2, W2 are attached to the stator cores 2a to 2f, respectively. Further, the stator coils U1, V1, W1 and the stator coils U2, V2, W2 are star-connected. The stator coils U2, V2 and W2 are arranged so as to oppose the stator coils U1, V1 and W1 via the rotor 3. The stator coils U1, V1 and W1 are connected to the inverter device 10a, and the stator coils U2, V2 and W2 are connected to the inverter device 10b.

An image diagram of the AC voltage applied to each stator coil is shown in FIG. The waveform shown by the solid line in FIG. 2 is the waveform of the AC voltage applied to the stator coils U1 and U2. The waveform shown by the alternate long and short dash line in FIG. 2 is the waveform of the AC voltage applied to the stator coils V1 and V2. The waveform shown by the dotted line in FIG. 2 is the waveform of the AC voltage applied to the stator coils W1 and W2. AC voltages having different phases of 120 degrees are applied to the stator coils U1, V1, W1 and the stator coils U2, V2, W2, respectively. The phases of the voltages applied to the stator coils U1 and U2 are equal to each other. Further, the phases of the voltages applied to the stator coils V1 and V2 are also equal to each other, and the phases of the voltages applied to the stator coils W1 and W2 are also equal to each other. When voltages having different phases of 120 degrees are applied to the stator coils U1 and U2, the stator coils V1 and V2, and the stator coils W1 and W2, a rotating magnetic field is generated inside the stator 2.

The rotor 3 is a member in which N poles and S poles are alternately formed along the outer peripheral surface. In the rotor 3, four magnetic poles are formed along the outer peripheral surface. The rotor 3 rotates due to an electromagnetic interaction with a rotating magnetic field generated inside the stator 2.

In the synchronous motor 1 configured as described above, the stator coils U1, V1, W1 connected to the inverter device 10a and the stator coils U2, V2, W2 connected to the inverter device 10b are alternately arranged. As a result, the adjacent stator coils are supplied with power from different inverter devices 10a and 10b, respectively.

The reason for supplying AC power from different inverter devices 10 to the stator coils wound around the adjacent stator core is to suppress the vibration of the synchronous motor 1 when the magnitudes of the power output from the inverter devices 10a and 10b are different. Because. When the magnitudes of the electric power output from the inverter devices 10a and 10b are different, when AC power is supplied from the same inverter device 10 to the stator coil wound around the adjacent stator core, the magnetic flux is generated every time the rotor 3 rotates 180 °. The density will fluctuate greatly. By supplying AC power from different inverter devices 10 to the stator coil wound around the adjacent stator core, the fluctuation of the magnetic flux density becomes the rotation angle of the rotor 3 with a period of 60 °, so that the vibration of the synchronous motor 1 is suppressed. be able to.

Returning to FIG. 1, the inverter device 10 (10a, 10b) supplies the three-phase AC power to the synchronous motor 1. The inverter device 10 (10a, 10b) includes a storage battery 20 (20a, 20b) and an inverter 30 (30a, 30b).

The storage battery 20 supplies DC power to the inverter 30. As shown in FIG. 3, the storage battery 20 includes a battery 21, a circuit breaker 22, a fuse 23, and a remaining capacity measuring unit 24.

The battery 21 has a configuration in which a plurality of power storage elements are connected in series and in parallel. This is to secure the required voltage and power. The circuit breaker 22 is composed of a breaker or the like. The circuit breaker 22 detects an abnormal current due to a short circuit, a ground fault, or the like, and cuts off the power supply path. The fuse 23 is blown by an abnormal current due to a short circuit, a ground fault, or the like, and cuts off the power supply path. The circuit breaker 22 and the fuse 23 have a characteristic that they do not react to the inrush current at the time of starting the synchronous motor 1. Further, the circuit breaker 22 and the fuse 23 have an abnormal current detection characteristic and a breaking characteristic at the time of abnormal current detection according to the required specifications at the time of a failure such as a ground fault. The remaining capacity measuring unit 24 measures the remaining capacity of the battery 21 and informs the control device 50 of the remaining capacity of the battery 21.

The inverter 30 converts the DC power supplied from the storage battery 20 into three-phase AC power. As shown in FIG. 4, the inverter 30 includes a power conversion unit 31 and a gate drive circuit 32.

The power conversion unit 31 is composed of a plurality of switching elements SW11, SW12, SW21, SW22, SW31, and SW32. Each switching element is, for example, an IGBT (Insulated Gate Bipolar Transistor). Each switching element is on / off controlled by a drive signal output from the gate drive circuit 32. As a result, the power conversion unit 31 converts DC power into three-phase AC power and supplies it to the synchronous motor 1. The creation of AC power by the power conversion unit 31 will be described later.

The gate drive circuit 32 drives each switching element of the power conversion unit 31 according to a control signal input from the control device 50.

Returning to FIG. 1, the rotation angle sensor 40 detects the rotation angle θ of the rotor 3 of the synchronous motor 1. The rotation angle sensor 40 supplies the detected rotation angle θ data to the control device 50. The rotation angle sensor 40 is, for example, a resolver.

The control device 50 creates a control signal according to the load of the synchronous motor 1. Further, the control device 50 controls the inverter devices 10a and 10b so that the voltage phases of the three-phase AC power output from the inverter devices 10a and 10b are in phase as shown in FIG. Further, the control device 50 controls the inverter devices 10a and 10b so that the remaining capacities of the storage batteries of the inverter devices 10a and 10b are about the same. Therefore, as shown in FIG. 5, the control device 50 includes an angular velocity difference detection unit 51, a control signal creation unit 52, a remaining capacity comparison unit 53, and a pulse width correction unit 54. Here, a case where the rotation speed (angular velocity) is used as the command value will be described.

The angular velocity difference detection unit 51 calculates the rotational angular velocity (rotational velocity) of the rotor 3 by differentiating the rotational angle θ of the rotor 3 of the synchronous motor 1 acquired from the rotational angle sensor 40. Then, the angular velocity difference detection unit 51 compares with a reference angular velocity command signal (for example, 50 Hz), and obtains a difference from the reference angular velocity.

The control signal creating unit 52 drives the switching element SW of the inverter device 10 (10a, 10b) so that the angular velocity of the rotor 3 becomes the same as the reference angular velocity, and the control signal I1 (U) corresponding to the rotor position shown in FIG. ), I1 (V), I1 (W), I2 (U), I2 (V), I2 (W).

Specifically, the control signal creating unit 52 outputs an AC voltage having a frequency, a phase, and an amplitude corresponding to the positional relationship (rotation angle θ) between the stator 2 and the rotor 3 detected by the rotation angle sensor 40 by the inverter device 10. Create a control signal to do so. I1 (U) is a control signal that controls the power conversion unit 31 via the gate drive circuit 32 of the inverter device 10a and specifies a period for applying a positive voltage to the stator coil U1 of the synchronous motor 1. The detailed waveform of the control signal will be described later. Similarly, I1 (V) is a stator coil V1 and I1 (W) is a control signal for designating a period during which a positive voltage is applied to the stator coil W1. Similarly, I2 (U), I2 (V), and I2 (W) are control signals that specify a period during which a positive voltage is applied to the stator coils U2, V2, and W2. Although not shown, the control signal creation unit 52 controls the power conversion unit 31 via the gate drive circuit 32 of the inverter device 10a, and specifies a period for applying a negative voltage to the stator coil U1 of the synchronous motor 1. A control signal whose phase is 180 degrees out of phase with that of I1 (U) is created. Similarly, the control signal generation unit 52 is an inverter device 10a, b that is 180 degrees out of phase with respect to each of I1 (V), I1 (W), I2 (U), I2 (V), and I2 (W). Create a control signal that outputs a negative voltage to the inverter. In this way, the control signal creation unit 52 creates twelve control signals.

The period of one cycle of AC power supplied to the synchronous motor 1 is defined as the period T. I1 (U), I1 (V), and I1 (W) are each 120 ° out of phase. Further, I1 (U) and I2 (U), I1 (V) and I2 (V), and I1 (W) and I2 (W) are in phase with each other.

FIG. 7 shows a detailed waveform of the control signal I1 (U) that causes the inverter device 10 to output a positive voltage. The same applies to the detailed waveform of the control signal that causes the inverter device 10 to output a negative voltage. As shown in FIG. 7, the control signal I1 (U) is formed by a plurality of pulses. Here, the case where the number of pulses is 5 will be described. The longer the ON time of the switching element SW, the larger the current can flow in the inverter 30. In the control signal creating unit 52, the pulse width of the control signal gradually widens from t01 to t03 and then from t03 to t05 so that the inverter devices 10a and 10b output the AC voltage having the waveform as shown in FIG. Create a control signal that gradually narrows.

Specifically, when the pulse width t0 of t03, which has the widest pulse width, is used as a reference, the control signal creation unit 52 multiplies the reference pulse width t0 by a coefficient gi to obtain each pulse width from t01 to t05. Specifically, it is calculated as t01 = t0 × g1, t02 = t0 × g2. The coefficient gi is calculated in advance so that the waveform of the AC voltage output by the inverter 30 becomes a predetermined waveform, and is stored in the storage unit. The same applies to the detailed waveforms of other control signals.

When increasing the AC power output by the inverter device 10, the control signal creating unit 52 sets the on-time t0 shown in FIG. 7 to be long. Further, when the AC power output by the inverter device 10 is reduced, the control signal creating unit 52 sets the on-time t0 shown in FIG. 7 to be short.

Returning to FIG. 5, the remaining capacity comparison unit 53 compares the remaining capacity of the batteries 21 of the inverter devices 10a and 10b. Specifically, the remaining capacity comparison unit 53 obtains the value of SOC1 / SOC2 based on the SOC (State of Charge) signals acquired from the inverter devices 10a and 10b, and corresponds to the value as shown in FIG. Calculate the correction amount of the pulse width of the control signal. The correction amount of the pulse width shown in FIG. 8 corresponding to the value of SOC1 / SOC2 is stored in the storage unit in advance.

The pulse width correction unit 54 corrects the pulse width of the control signal created by the control signal creation unit 52 based on the correction amount of the pulse width calculated by the remaining capacity comparison unit 53. Specifically, the pulse width correction unit 54 sets the on-time t0 of the control signal so that the output power of the inverter device having a small remaining capacity of the storage battery is smaller than the output power of the inverter device having a large remaining capacity of the storage battery. to correct. For example, when the signal SOC1 indicating the remaining capacity of the battery 21 of the inverter device 10a is larger than the signal SOC2 indicating the remaining capacity of the battery 21 of the inverter device 10b, the pulse width correction unit 54 uses the inverter device 54 as shown in FIG. The on-time t1 for gate-driving 10a is corrected to be longer than the on-time t2 for gate-driving the inverter device 10b. In order to keep the angular velocity of the rotor 3 at a predetermined speed, t1 + t2 = 2 × t0. That is, since the electric power supplied to the synchronous motor 1 is the same before and after the correction, the synchronous motor 1 can maintain a desired output. FIG. 9 shows an example of the control signal corrected by the pulse width correction unit 54.

As shown in FIG. 10, by setting t1> t2, the AC power output from the inverter device 10a becomes larger than the AC power output from the inverter device 10b. As a result, the remaining capacity of the battery 21 of the inverter device 10a decreases faster than the remaining capacity of the battery 21 of the inverter device 10b. In this way, the synchronous motor system 100 controls so that the remaining capacity of the battery 21 of the inverter device 10a and the remaining capacity of the battery 21 of the inverter device 10b are equal to each other.

Here, how to set Δt = | t1-t2 | is important. By increasing Δt, the remaining capacity of the battery 21 of the inverter device 10a and the remaining capacity of the battery 21 of the inverter device 10b can be controlled to be equal in a short time. On the other hand, the magnetic flux density fluctuates greatly each time the rotor 3 rotates by 60 °. As a result, the torque of the synchronous motor 1 becomes non-uniform, so that the vibration of the synchronous motor 1 becomes large.

Specifically, the smaller the coefficient K shown in FIG. 8, the smaller the change in the magnetic flux density can be, and the smaller the vibration of the synchronous motor 1. For example, when the coefficient K is K = 0.1 and SOC1 / SOC2 = 1.1, the magnetic flux density due to the stator coil U1 is 1.5% × 2 = 3 with respect to the magnetic flux density due to the stator coil U2. % Will be higher. Assuming that the coefficient K is K = 1, when SOC1 / SOC2 = 1.1, the magnetic flux density due to the stator coil U1 is 15% × 2 = 30% higher than the magnetic flux density due to the stator coil U2. As a preliminary process, the vibration of the synchronous motor 1 is measured experimentally with the coefficient K as a parameter. Then, the coefficient K is determined based on the allowable vibration magnitude and stored in the storage unit.

In FIG. 8, the reason why the increase / decrease correction of the pulse width is not performed in the range of SOC1 / SOC2 = 0.9 to 1.1 is that when the difference in the remaining capacity of the battery 21 is small, the power supplied from the inverter devices 10a and 10b is the same. This is to reduce the vibration of the synchronous motor 1. The order of each process in FIG. 5 may be changed.

Next, the process of creating the control signal by the control device 50 will be described with reference to FIG. When the user performs an activation operation from an operation unit (not shown) of the synchronous motor system 100, the control signal creation process shown in FIG. 11 is started.

When the user activates the synchronous motor system 100, the control device 50 creates a control signal as shown in FIGS. 6 and 7 at a preset on time and supplies the control signal to the inverter devices 10a and 10b. The inverter devices 10a and 10b that have received the control signal from the control device 50 generate three-phase AC power in which the mutual voltage phases are synchronized and supply the three-phase AC power to the synchronous motor 1. The synchronous motor 1 supplied with the three-phase AC power rotates the rotor 3 to generate a predetermined torque.

When the synchronous motor 1 starts operation, the rotation angle sensor 40 measures the rotation angle θ of the rotor 3 and supplies the rotation angle θ to the control device 50 (step S11). Further, the inverter device 10a transmits a signal SOC1 indicating the remaining capacity of the battery 21 to the control device 50. Further, the inverter device 10b transmits a signal SOC2 indicating the remaining capacity of the battery 21 to the control device 50.

The angular velocity difference detecting unit 51 of the control device 50 detects the difference between the reference angular velocity and the rotational speed of the rotor 3 based on the information supplied from the rotational angle sensor 40. Further, the control signal creating unit 52 acquires the positional relationship between the stator 2 and the rotor 3. Then, the control signal creating unit 52 creates the control signal shown in FIG. 7 having the on-time t0 required to drive the synchronous motor 1 at a predetermined rotation speed (step S12).

In addition to this processing, the control device 50 turns on the on time t1 of the control signal 1 and the on of the control signal 2 based on the rule shown in FIG. 8 so that the remaining battery capacities of the inverter devices 10a and 10b are about the same. The pulse width at time t2 is corrected. Specifically, the remaining capacity comparison unit 53 of the control device 50 compares the remaining battery capacity of the inverter devices 10a and 10b based on the signals SOC1 and SOC2 representing the remaining capacity of the battery 21 of the inverter devices 10a and 10b (). Step S13).

For example, when the value of SOC1 / SOC2 is 1.1 or more and less than 1.2 (step S14: Yes), the pulse width correction unit 54 sets the on-time t1 of the control signal 1 that gate drives the inverter device 10a. T1 = t0 × 1.015 and t2 = t0 × 0.985 (step S15). When the value of SOC1 / SOC2 is 1.2 or more and less than 1.3 (step S16: Yes), the pulse width correction unit 54 sets the on-time t1 of the control signal 1 for gate-driving the inverter device 10a to t1 =. T0 × 1.025 and t2 = t0 × 0.975 (step S17). The description after SOC1 / SOC2 ≧ 1.3 is omitted.

On the other hand, when the value of SOC1 / SOC2 is 0.8 or more and less than 0.9 (step S18: Yes), the pulse width correction unit 54 sets the on-time t1 of the control signal 1 that gate drives the inverter device 10a. T1 = t0 × 0.985 and t2 = t0 × 1.015 (step S19). When the value of SOC1 / SOC2 is 0.7 or more and less than 0.8 (step S20: Yes), the pulse width correction unit 54 sets the on-time t1 of the control signal 1 for gate-driving the inverter device 10a to t1 =. T0 × 0.975 and t2 = t0 × 1.025 (step S21). The description of SOC1 / SOC2 <0.7 will be omitted.

On the other hand, when the value of SOC1 / SOC2 is 0.9 or more and less than 1.1 (step S20: No), the pulse width correction unit 54 sets the on-time t1 of the control signal 1 that gate drives the inverter device 10a to t1. = T0 is left, and the on-time t2 of the control signal 1 that gate-drives the inverter device 10b is left at t2 = t0 (step S22).

The control device 50 transmits the control signals 1 and 2 created as described above to the inverter devices 10a and 10b (step S23). The inverter devices 10a and 10b output a three-phase AC voltage based on the newly acquired control signals 1 and 2. The synchronous motor 1 rotates in synchronization with this three-phase AC voltage. The order of processing from step S14 to step S22 is arbitrary.

By the above processing, when the remaining battery capacity of the inverter device 10a is larger than the remaining battery capacity of the inverter device 10b, for example, the control device 50 has "on time t1 of the control signal 1> control signal 2" as shown in FIG. The control signals 1 and 2 "on time t2" are transmitted. By setting t1> t2 in this way, as shown in FIG. 10, the output power of the inverter device 10a can be made larger than the output power of the inverter device 10b. Then, the remaining capacity of the battery 21 of the inverter device 10a decreases faster than the remaining capacity of the battery 21 of the inverter device 10b, and the remaining capacity of both batteries 21 is controlled to be equal.

The synchronous motor system 100 repeats the above process until the user stops the synchronous motor system 100.

As described above, the synchronous motor system 100 according to the present embodiment includes a plurality of inverter devices 10 including an inverter 30 that receives power from the storage battery 20 and outputs three-phase AC power, and these plurality of inverter devices 10 3 phase AC power is supplied to the synchronous motor 1. With such a configuration, the electric power supplied from one battery 21 to the inverter 30 can be reduced. Therefore, the circuit breaker 22 and the safety device such as the fuse included in the storage battery 20 can be miniaturized, and the synchronous motor system 100 can be miniaturized.

Further, the synchronous motor system 100 includes a remaining capacity measuring unit 24 for measuring the remaining capacity of electric power in the storage battery 20. Further, the control device 50 corrects the pulse width of the control signal for controlling the AC power output by the inverter device 10 based on the remaining capacity comparison unit 53 for comparing the remaining capacity of the storage battery 20 of the inverter device 10 and the remaining capacity. The pulse width correction unit 54 is provided. As a result, the synchronous motor system 100 can consume the electric power remaining in the battery 21 included in the inverter devices 10a and 10b so that the remaining capacities of the batteries 21 of the inverter devices 10a and 10b are equal to each other. The time during which 100 can be driven can be extended.

The synchronous motor 1 includes stator cores 2a to 2f around which a stator coil that allows AC power supplied from the inverter device 10 to flow as a magnetization current is wound. Then, AC power is supplied from different inverter devices 10 to the stator coils wound around the adjacent stator cores. Thereby, the synchronous motor system 100 can reduce the vibration of the synchronous motor 1.

In the above description, the case where the number of the inverter devices 10 is two has been described, but it is not necessary to limit the number of the inverter devices 10. For example, 4 or 10 units may be used. The number of inverter devices 10 is determined by considering the power supplied to the synchronous motor 1, the time during which the power can be supplied from the battery 21, the conditions of the protection circuit in the storage battery 20 suitable for the power, and the like, and the manufacturing cost of the device and the device. The size of the power may be determined so as to satisfy the required specifications.

Further, in the above description, the case where the synchronous motor 1 is driven by the three-phase AC power has been described, but the present invention can also be applied to the synchronous motor driven by the two-phase AC power, the six-phase AC power, or the like.

Further, the synchronous motor 1 may be a permanent magnet synchronous motor having a permanent magnet in the rotor 3, a synchronous motor without a permanent magnet, or a relaxation motor (the configuration may change).

Further, in the above description, as shown in FIG. 8, the case where the remaining capacity ratio (SOC1 / SOC2) is specified in increments of 0.1 has been described, but the method of this specification is arbitrary and is specified in more detail. You may. The condition for operating the synchronous motor system 100 for the longest time is that the time when SC1 = 0 and the time when SOC2 = 0 are the same time. The step size may be determined in consideration of the remaining capacity ratio (SOC1 / SOC2) for starting the correction of the pulse width of the control signal, the coefficient K, and the power supplied to the synchronous motor 1. Further, the section (SOC1 / SOC2 = 0.9 to 1.1) in which the pulse width of the control signal shown in FIG. 8 is not corrected may be eliminated.

Further, when the ratio is unexpected such as SC1 / SC2> 1.3 or SOC1 / SOC2 <0.7, there is a possibility that a failure such as a short circuit or a ground fault has occurred. Therefore, when such a ratio is reached, the synchronous motor system 100 may be stopped.

Further, in the above description, the correction of the pulse width of the control signal is started based on the remaining capacity ratio (SOC1 / SOC2). However, the condition of the remaining battery capacity may be added to the condition for correcting the pulse width of the control signal. That is, when the remaining capacity of the battery is large, the pulse width is not corrected even when the difference between SOC1 and SOC2 is large. This is because the electric power supplied from the inverter devices 10a and 10b is made the same to prolong the period during which the vibration of the synchronous motor 1 can be reduced. The condition for starting the correction of the pulse width is calculated based on the power supplied to the synchronous motor 1, the difference in the remaining capacity of the battery 21, and the coefficient K so that the remaining battery levels of the inverter devices 10a and 10b become zero at the same time. do.

Further, in the above description, the control signal for controlling the inverter device 10 is created by digital signal processing, but the method for creating the control signal is not limited to this. For example, a control signal for controlling the inverter device 10 may be created by comparing a reference triangular wave and a desired sine wave corresponding to a voltage waveform applied to the synchronous motor with a comparator.

<< Second Embodiment >>
Next, the second embodiment will be described with reference to the drawings. For the same or equivalent configuration as that of the first embodiment, the same reference numerals are used, and the description thereof will be omitted or abbreviated.

FIG. 12 is a diagram showing the configuration of the synchronous motor system 200 according to the second embodiment. As shown in FIG. 12, the synchronous motor system 200 includes a plurality of inverter devices 210 (210a to 210f) including a single-phase inverter 230 that receives power from the storage battery 20 and outputs single-phase AC power. Further, the synchronous motor system 200 controls the voltage phase of the single-phase AC power output by the single-phase inverter 230 so that the single-phase AC power output from the plurality of inverter devices 210 is combined to form a three-phase AC power. The control device 250 is provided. Further, the synchronous motor system 200 includes a synchronous motor 201 that operates by receiving supply of single-phase AC power from a plurality of inverter devices 210.

The synchronous motor 201 is a synchronous motor in which the rotor 3 is made of a permanent magnet. The synchronous motor 201 is driven by the single-phase AC power output from the inverter devices 210a, 210b, 210c, 210d, 210e, 210f. The single-phase AC power supplied from the inverter devices 210a to 210f is supplied to each of the stator coils C1 to C6 shown in FIG. These stator coils C1 to C6 are wound around the stator cores 2a to 2f of the synchronous motor 201. The stator cores 2a to 2f are formed around the rotor 3 of the synchronous motor 201. An image diagram of the AC voltage applied to each stator coil is shown in FIG. The voltage applied to the stator coil C1 is _{V C1.} The voltage applied to the stator coil C2 is _{V C2.} The same applies hereinafter. A rotating magnetic field is generated inside the stator 2 by the three-phase AC power supplied to the synchronous motor 201. The rotor 3 rotates due to an electromagnetic interaction with a rotating magnetic field generated inside the stator 2.

The configuration of the storage battery 20 of the inverter device 210 is the same as the configuration shown in FIG. The configuration of the single-phase inverter 230 is shown in FIG. Since the inverter device 210 according to the second embodiment outputs single-phase AC power, the configuration of the power conversion unit 231 is configured to output single-phase AC power.

The configuration of the control device 250 is shown in FIG. The description of the angular velocity difference detecting unit 51 is the same as the description of the first embodiment. The control signal creation unit 252 outputs control signals 1 to 6 as shown in FIG. 16 according to the rotor position for driving the switching element SW of the inverter devices 210a to 210f so that the angular velocity of the rotor 3 becomes the same as the reference angular velocity. create.

Specifically, the control signal creation unit 252 outputs an AC voltage having a frequency, a phase, and an amplitude according to the positional relationship (rotation angle θ) between the stator 2 and the rotor 3 detected by the rotation angle sensor 40 by the inverter device 210. Create a control signal to do so. The control signal 1 shown in FIG. 16 is a control signal that controls the power conversion unit 231 via the gate drive circuit 32 of the inverter device 210a and specifies a period for applying a positive voltage to the stator coil C1 of the synchronous motor 201. be. The detailed waveform of the control signal is the same as the waveform shown in FIG. Similarly, the control signals 2 to 6 are control signals that specify a period during which a positive voltage is applied to the stator coils C2 to C6. Although not shown, the control signal creation unit 252 also creates a control signal for outputting a negative voltage to the inverter device 210a which is 180 degrees out of phase with the control signal 1. Similarly, the control signal creation unit 252 creates a control signal that outputs a negative voltage to the inverter devices 210b to 210f that are 180 degrees out of phase with each of the control signals 2 to 6. In this way, the control signal creation unit 252 creates twelve control signals. Since the synchronous motor 201 according to the second embodiment is a three-phase synchronous motor, the control signals 1 to 3 and the control signals 4 to 6 are control signals whose phases are shifted by 120 °. The control signals 1 and 4, the control signals 2 and 5, and the control signals 3 and 6 are in phase, respectively. The waveform is such that the pulse width is controlled so that the outputs of the inverter devices 210a to 210f have the waveform shown in FIG.

The synchronous motor system 200 includes a plurality of inverter devices 210, and the remaining capacity of the storage battery 20 of each inverter device 210 varies. The control device 250 controls the inverter devices 210a to 210f so that the remaining capacity of the storage batteries 20 included in the inverter devices 210a to 210f becomes zero at the same time.

Therefore, the remaining capacity comparison unit 253 obtains the ratio (remaining capacity ratio) of each SOC based on the value of the SOC having the largest remaining capacity among the SOCs 1 to 6, and obtains the ratio (remaining capacity ratio) of each SOC as shown in FIG. Calculate the correction amount of the pulse width. For example, as shown in FIG. 17, when the value indicated by SOC1 is the largest, the remaining capacity comparison unit 253 obtains the remaining capacity ratio of each inverter device 210 with reference to SOC1.

The pulse width correction unit 54 corrects the pulse width of the control signal at the on-time t0 based on the correction amount of the pulse width shown in FIG. 17 calculated by the remaining capacity comparison unit 253. Specifically, the remaining capacity ratio of the battery 21 is the value shown in FIG. 17, and when K = 0.1, the control signal creating unit 252 sets the pulse width t2 of the control signal 2 to t2 = t1 × 0.99. Correct to. The pulse width t3 of the control signal 3 is corrected to t3 = t1 × 0.97. Similarly, the control signal creation unit 52 corrects the pulse width of the control signal based on the remaining capacity ratio. The method for setting the coefficient K is the same as that described in the first embodiment. The corrected on-time is (t1 + t2 + t3 + t4 + t5 + t6) = 6 × t0.

Next, the process of creating the control signal by the control device 250 will be described with reference to FIG. The start condition of the control signal creation process, the process of step S11, and the process of step S12 are the same as those of the first embodiment.

Next, the control device 250 extracts the largest SOC (maximum SOC) and the smallest SOC (minimum SOC) among the SOCs 1 to 6 received from the inverter devices 210a to 210f (step S33).

The control device 250 determines whether or not the minimum SOC / maximum SOC value is a predetermined value (for example, 0.9) or more (step S34). When the minimum SOC / maximum SOC value is a predetermined value (for example, 0.9) or more (step S34: Yes), the control device 250 does not perform the correction processing of the pulse width of the control signal.

On the other hand, when the minimum SOC / maximum SOC is less than a predetermined value (for example, 0.9) (step S34: No), the control device 250 performs correction processing for the pulse width of the control signal. Specifically, the remaining capacity comparison unit 253 calculates the remaining capacity ratio as shown in FIG. 17 based on the SOC received from each inverter device 210 (step S35). Then, the remaining capacity comparison unit 253 calculates the correction amount of the pulse width of the control signal as shown in FIG. The pulse width correction unit 54 corrects the pulse width of each control signal based on this correction amount (step S36).

The control device 250 outputs the control signals 1 to 6 created as described above to the inverter devices 210a to 210f (step S37). In this way, the synchronous motor system 100 controls the on-time t0 of the control signals 1 to 6 so that the remaining capacities of the batteries 21 of the inverter devices 210a to 210f become equal by correcting the on-time t0 according to the remaining capacity of the battery 21. do. The synchronous motor system 100 repeats the above process until the user stops the synchronous motor system 200.

As described above, the synchronous motor system 200 according to the second embodiment includes a plurality of inverter devices 210 including a single-phase inverter 230 that receives power from the storage battery 20 and outputs single-phase AC power. The output from the inverter device 210 is combined to supply the three-phase AC power to the synchronous motor 201. With such a configuration, the power supplied from one battery 21 to the single-phase inverter 230 can be reduced. Therefore, the safety devices such as the circuit breaker 22 and the fuse 23 included in the storage battery 20 can be miniaturized, and the synchronous motor system 200 can be miniaturized.

Further, the synchronous motor system 200 includes a remaining capacity measuring unit 24 for measuring the remaining capacity of electric power in the storage battery 20. Further, the control device 250 includes a remaining capacity comparison unit 253 that compares the remaining capacity of the storage battery 20 of the inverter device 210, and a pulse width correction unit 54 that corrects the pulse width of the control signal based on the remaining capacity of the inverter device 210. To prepare for. As a result, the synchronous motor system 200 can consume the electric power remaining in the batteries 21 of the inverter devices 210a to 210f so that the remaining capacities of the batteries 21 of the inverter devices 210a to 210f are equal, and the synchronous motor system 200 can be used. The driveable time can be extended.

In the above description, when the remaining capacity ratio (minimum SOC / maximum SOC) <0.9, the pulse width of the control signal is not corrected, but the remaining capacity ratio (minimum SOC / maximum SOC) < Even in the case of 0.9, the pulse width of the control signal may be corrected.

Further, the flowchart shown in FIG. 18 is an example, and it is not necessary to limit the flow chart to this. For example, the process of step S35 may be performed after step S33, and then the process of step S34 may be performed.

Further, in the above description, the case where the present invention is applied to a synchronous motor has been described as an example, but the present invention can be similarly applied to a linear motor, a linear actuator, or the like.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

1, 201 ... Synchronous motor 2 ... Stator 2a to 2f ... Stator core 3 ... Rotor 10, 10a, 10b ... Inverter device 210, 210a to 210f ... Inverter device 20, 20a, 20b ... Storage battery 21 ... Battery 22 ... Breaker 23 ... Hughes 30, 30a, 30b ... Inverter 230, 230a-230f ... Single-phase inverter 31,231 ... Power conversion unit 32 ... Gate drive circuit 40 ... Rotation angle sensor 50, 250 ... Control device 51 ... Angle speed difference detection unit 511 ... Voltage conversion unit 52, 252 ... Control signal creation unit 521 ... Triangular wave creation unit 522 ... Comparative device 53,253 ... Remaining capacity comparison unit 54 ... Pulse width correction unit U1, U2, V1, V2, W1, W2 ... Controller coil C1, C2 C3, C4, C5, C6 ... Controller coil SW11, SW12, SW21, SW22, SW31, SW32 ... Switching element

Claims (6)

A first inverter device and a second inverter device including a storage battery and an inverter that receives power from the storage battery and outputs multi-phase AC power.
A control device that controls the multi-phase AC power output from the first inverter device and the second inverter device, and
A synchronous motor that operates by receiving polyphase AC power from the first inverter device and the second inverter device, and
Equipped with
The storage battery includes a remaining capacity measuring unit that measures the remaining capacity of the storage battery and notifies the control device.
The control device is
A control signal creating unit that creates a control signal for controlling the electric power output by the first inverter device and the second inverter device with a pulse width corresponding to the rotation angle of the rotor of the synchronous motor.
A remaining capacity comparison unit for comparing the remaining capacities of the storage batteries of the first inverter device and the second inverter device, and
A pulse width correction unit that corrects the pulse width of the control signal based on the remaining capacitance,
Equipped with
The pulse width correction unit corrects the pulse width of the control signal so that the power output by the inverter device having a small remaining capacity of the storage battery is smaller than the power output by the inverter device having a large remaining capacity of the storage battery.
The synchronous motor includes a first stator coil that receives polymorphic AC power from the first inverter device and a second stator coil that receives polyphase AC power from the second inverter device. , Has,
The first inverter device does not supply polymorphic AC power to the second stator coil, and the second inverter device does not supply polyphase AC power to the first stator coil. Synchronous motor system featuring that. A first inverter device and a second inverter device including a storage battery and an inverter that receives power from the storage battery and outputs single-phase AC power.
The first inverter device and the second inverter device are controlled so as to control the phase of the single-phase AC power output from the first inverter device and the second inverter device to obtain multi-phase AC power. Control device and
A synchronous motor that operates by receiving supply of single-phase AC power from the first inverter device and the second inverter device, and
Equipped with
The storage battery includes a remaining capacity measuring unit that measures the remaining capacity of the storage battery and notifies the control device.
The control device is
A control signal creating unit that creates a control signal for controlling the electric power output by the first inverter device and the second inverter device with a pulse width corresponding to the rotation angle of the rotor of the synchronous motor.
A remaining capacity comparison unit for comparing the remaining capacities of the storage batteries of the first inverter device and the second inverter device, and
A pulse width correction unit that corrects the pulse width of the control signal based on the remaining capacitance,
Equipped with
The pulse width correction unit corrects the pulse width of the control signal so that the power output by the inverter device having a small remaining capacity of the storage battery is smaller than the power output by the inverter device having a large remaining capacity of the storage battery.
The synchronous motor includes a first stator coil that receives single-phase AC power from the first inverter device and a second stator coil that receives single-phase AC power from the second inverter device. , Has,
The first inverter device does not supply single-phase AC power to the second stator coil, and the second inverter device does not supply single-phase AC power to the first stator coil. Synchronous motor system featuring that. The synchronous motor includes a stator and has a stator.
The stator has a plurality of stator cores which are divided and arranged on the circumference about the rotation axis.
The stator core is wound with the first stator coil and the second stator coil that flow AC power supplied from the first inverter device or the second inverter device as a magnetization current. ,
The stator coils wound around the stator cores facing each other across the rotating shaft are supplied with AC voltages of the same phase from different inverter devices.
The synchronous motor system according to claim 1. A control device that controls the plurality of inverter devices in a synchronous motor system that operates a common synchronous motor with polymorphic AC power supplied from a plurality of inverter devices.
A control signal creation unit that creates control signals that control the power output by multiple inverter devices,
A remaining capacity comparison unit that receives signals representing the remaining capacity of the electric power remaining in the storage batteries of the plurality of inverter devices from the plurality of inverter devices and compares the remaining capacities of the storage batteries of the plurality of inverter devices.
A pulse width correction unit that corrects the pulse width of the control signal based on the remaining capacitance,
A control device for a synchronous motor system. A control device that controls the plurality of inverter devices in a synchronous motor system that operates a common synchronous motor with polymorphic AC power supplied from a plurality of inverter devices.
A control signal creation unit that creates a control signal that controls the power output by multiple inverter devices with a pulse width that corresponds to the rotation angle of the rotor of the synchronous motor.
A remaining capacity comparison unit that receives signals representing the remaining capacity of the electric power remaining in the storage batteries of the plurality of inverter devices from the plurality of inverter devices and compares the remaining capacities of the storage batteries of the plurality of inverter devices.
A pulse width correction unit that corrects the pulse width of the control signal based on the remaining capacitance,
Equipped with
The control signal creating unit controls the phase of the single-phase AC power output from the plurality of inverter devices to create the control signal so as to be the multi-phase AC power.
Control device for synchronous motor system. The pulse width correction unit corrects the pulse width of the control signal so that the power output by the inverter device having a small remaining capacity of the storage battery is smaller than the power output by the inverter device having a large remaining capacity of the storage battery.
The control device for a synchronous motor system according to claim 4 or 5.

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