WO2021153094A1 - Control device and coil system - Google Patents

Abstract

A control device that controls a power source for supplying electric power to a coil, the control device comprising: an acquisition unit that acquires a measurement value for estimating the state of the atmosphere around the coil; a calculation unit that calculates, on the basis of the measurement value, an output voltage value at which no discharge is generated between the conductors of the coil; and an output unit that outputs, to the power source, a command to output an output voltage at the output voltage value.

Description

Control device and coil system

This disclosure relates to a control device and a coil system.

It is known that the voltage at which a discharge occurs between conductors adjacent to each other in a coil changes depending on the atmospheric conditions such as gas pressure (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-207742

The voltage applied to the coil is limited in order to prevent discharge between the conductors adjacent to each other in the coil. For example, since the atmospheric pressure fluctuates depending on the altitude, etc., the voltage value of the voltage applied to the coil is the most in the fluctuation range of the atmospheric pressure in order to prevent discharge from occurring between the conductors even if the atmospheric pressure fluctuates. May be set to a low voltage limit. When the atmospheric pressure changes due to changes in the usage environment (for example, the altitude and weather of the place where the coil is used in the coil mounted on the moving body), a voltage with a voltage value higher than the voltage limit value is applied to the coil. Even so, there are cases where no discharge occurs between the conductors. However, in the above-mentioned voltage value setting method, since a voltage value equal to or less than the voltage limit value is used, it is not possible to reduce the power loss and increase the output.

The present disclosure describes a control device and a coil system capable of improving power efficiency or increasing output.

The control device according to one aspect of the present disclosure is a device that controls a power source for supplying electric power to a coil. This control device includes an acquisition unit that acquires measured values for estimating the state of the atmosphere around the coil, and a calculation unit that calculates an output voltage value that does not cause discharge between the conductors of the coil based on the measured values. It includes an output unit that outputs a command to output an output voltage of an output voltage value to the power supply.

According to the present disclosure, it is possible to improve power efficiency or increase output.

FIG. 1 is a diagram showing a schematic configuration of a coil system including a control device according to an embodiment. FIG. 2 is a diagram showing a configuration example of the power supply shown in FIG. FIG. 3 is a diagram showing another configuration example of the power supply shown in FIG. FIG. 4 is a diagram showing still another configuration example of the power supply shown in FIG. FIG. 5 is a diagram showing a hardware configuration of the control device shown in FIG. FIG. 6 is a diagram showing a functional configuration of the control device shown in FIG. FIG. 7 is a diagram for explaining the relationship between the measured value and the target voltage value. FIG. 8 is a flowchart showing an example of a table setting method. FIG. 9 is a diagram showing a configuration for obtaining the relationship between the input voltage and the output voltage of the inverter. FIG. 10 is a diagram showing a configuration for acquiring a set of a measured value and a discharge start voltage value. FIG. 11 is a flowchart showing a series of processes of the output voltage setting method performed by the control device shown in FIG. FIG. 12 is a diagram showing an example of the relationship between the atmospheric pressure and the output voltage value.

[1] Outline of Embodiment The control device according to one aspect of the present disclosure is a device that controls a power source for supplying electric power to a coil. This control device includes an acquisition unit that acquires measured values for estimating the state of the atmosphere around the coil, and a calculation unit that calculates an output voltage value that does not cause discharge between the conductors of the coil based on the measured values. It includes an output unit that outputs a command to output an output voltage of an output voltage value to the power supply.

In this control device, an output voltage value that does not cause discharge between the conductors of the coil is calculated based on the measured value for estimating the state of the atmosphere around the coil, and a command to output the output voltage of the output voltage value is issued. It is output to the power supply. Therefore, the output voltage of the output voltage value according to the atmospheric condition is output from the power supply. For example, when the atmospheric pressure is high, even if the output voltage value is raised to some extent, no discharge occurs between the conductors of the coil. By outputting the output voltage of the output voltage value according to the atmospheric condition in this way, it is possible to increase the output as compared with the case where the output voltage value is fixed. Alternatively, when the power supply outputs a constant power, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency.

The output voltage value may be smaller than the minimum output voltage value that causes a discharge between the conductors of the coil in the atmospheric condition around the coil estimated from the measured value. In this case, an output voltage having an output voltage value smaller than the minimum output voltage value that causes discharge between the conductors of the coil is output from the power supply. Therefore, it is possible to at least either improve power efficiency or increase output without causing a discharge between the conductors of the coil.

The output voltage value may be a value obtained by multiplying the above minimum output voltage value by a magnification. In this case, an output voltage value smaller than the minimum output voltage value can be obtained by a simple calculation.

The output voltage value may be a value obtained by subtracting a positive value smaller than the minimum output voltage value from the minimum output voltage value. In this case, an output voltage value smaller than the minimum output voltage value can be obtained by a simple calculation.

The control device may further include a detection unit for detecting an abnormality. When an abnormality is detected by the detection unit, the calculation unit may calculate as an output voltage value a voltage value that does not cause a discharge between the conductors of the coil within the range of the atmospheric condition around the coil in which the coil is used. If an abnormality is detected, the output voltage value according to the atmospheric condition may not be calculated accurately. On the other hand, when an abnormality is detected, a voltage value that does not cause a discharge between the conductors of the coil over the range of the atmospheric condition around the coil in which the coil is used is calculated as an output voltage value. Therefore, even if an abnormality is detected, the possibility of generating an electric discharge between the conductors of the coil can be reduced.

Atmospheric conditions may include atmospheric pressure. In this case, the output voltage of the output voltage value corresponding to the atmospheric pressure is output from the power supply. In this case as well, the output can be increased as compared with the case where the output voltage value is fixed. Alternatively, when the power supply outputs a constant power, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency.

A coil system according to another aspect of the present disclosure includes the above control device, a power source controlled by the control device, and a coil device including a coil that receives power from the power source.

This coil system includes the above-mentioned control device. Therefore, in the coil system, it is possible to improve the power efficiency or increase the output.

The coil system may further include a sensor that outputs measured values. In this case, the output voltage that does not cause discharge between the conductors of the coil is calculated based on the measured value output by the sensor.

Atmospheric conditions may include humidity. The sensor may include a humidity sensor. The minimum output voltage value that causes a discharge between the conductors of the coil can be affected by humidity. According to the above configuration, the output voltage of the output voltage value corresponding to the humidity is output from the power supply. In this case as well, the output can be increased as compared with the case where the output voltage value is fixed. Alternatively, when the power supply outputs a constant power, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency.

[2] Examples of Embodiments Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a diagram showing a schematic configuration of a coil system including a control device according to an embodiment. FIG. 2 is a diagram showing a configuration example of the power supply shown in FIG. FIG. 3 is a diagram showing another configuration example of the power supply shown in FIG. FIG. 4 is a diagram showing still another configuration example of the power supply shown in FIG. FIG. 5 is a diagram showing a hardware configuration of the control device shown in FIG. FIG. 6 is a diagram showing a functional configuration of the control device shown in FIG. FIG. 7 is a diagram for explaining the relationship between the measured value and the target voltage value. The coil system 1 shown in FIG. 1 is a system that drives a coil with a drive voltage according to the atmospheric condition. The coil system 1 includes a power supply 2, an inverter 3, a coil device 4, a sensor 5, and a control device 10.

The power supply 2 is a device for supplying electric power to the coil of the coil device 4. The power supply 2 is controlled by the control device 10. Specifically, the power supply 2 is a variable voltage power supply that receives the output command C from the control device 10 and changes the output voltage value Vdc of the output voltage based on the output command C. The output command C is a command for causing the power supply 2 to output an output voltage having an output voltage value of Vdc. In the present embodiment, the power supply 2 is a DC output power supply, and the DC power Pdc is output to the inverter 3.

The power supply 2 may include, for example, a PFC (Power Factor Correction) circuit. As the PFC circuit, a step-up type, step-down type, or buck-boost type PFC circuit can be used. The power supply 2 receives AC power from, for example, a commercial power source, converts the AC power into power Pdc, and changes the output voltage value Vdc by the PFC circuit.

The power supply 2 may include, for example, a transformer and a rectifier. In this case, the transformer includes a plurality of taps having different numbers of turns and a circuit switch for switching the tap to be connected among the plurality of taps. Examples of circuit switches include contactors and electronic switches. The power supply 2 generates electric power Pdc by receiving an alternating current from a commercial power source, transforming it with a transformer, and rectifying it with a rectifier, for example. The output voltage value Vdc is changed by switching the taps by the circuit switch of the transformer.

The power supply 2 may include, for example, a battery and a DC (Direct Current) -DC converter. The battery may be composed of one battery cell, or may be composed of a plurality of battery cells connected in series. In this case, the output voltage value Vdc is changed by the control of the DC-DC converter.

In the configuration example shown in FIGS. 2 to 4, the power supply 2 includes a plurality of battery cells 21 and a plurality of circuit switches. The battery cell 21 may be a primary battery or a secondary battery. As the battery cell 21, various batteries such as a lead storage battery, a lithium ion battery, and a solar cell can be used. A plurality of types of batteries may be mixed in the plurality of battery cells 21. Examples of circuit switches include contactors and electronic switches. In these configuration examples, the output voltage value Vdc is changed by switching the number of battery cells 21 in series by the circuit switch.

In the configuration example of the power supply 2 shown in FIG. 2, a plurality of (six in this case) battery cells 21 are connected in series, and the positive electrode terminal of the first stage battery cell 21 is a power supply via the circuit switch SW1. It is connected to the terminal 2a of the second stage, and the negative electrode terminal of the battery cell 21 in the sixth stage (final stage) is connected to the terminal 2b of the power supply 2. The connection point between the negative electrode terminal of the first-stage battery cell 21 and the positive electrode terminal of the second-stage battery cell 21 is connected to the terminal 2a via the circuit switch SW2. The connection point between the negative electrode terminal of the second-stage battery cell 21 and the positive electrode terminal of the third-stage battery cell 21 is connected to the terminal 2a via the circuit switch SW3. The connection point between the negative electrode terminal of the third-stage battery cell 21 and the positive electrode terminal of the fourth-stage battery cell 21 is connected to the terminal 2a via the circuit switch SW4.

In this configuration example, when the circuit switch SW1 is set to the closed state and the circuit switches SW2 to SW4 are set to the open state, the output voltage value Vdc of the voltage between the terminals 2a and 2b is in series. The voltage value Vs of the six connected battery cells 21 is obtained. When the circuit switch SW2 is set to the closed state and the circuit switches SW1, SW3, SW4 are set to the open state, the output voltage value Vdc is the voltage value (5Vs) of the five battery cells 21 connected in series. / 6). Similarly, when the circuit switch SW3 is set to the closed state and the circuit switches SW1, SW2, SW4 are set to the open state, the output voltage value Vdc is the voltage of the four battery cells 21 connected in series. It becomes a value (2Vs / 3). When the circuit switch SW4 is set to the closed state and the circuit switches SW1 to SW3 are set to the open state, the output voltage value Vdc is the voltage value (Vs / 2) of the three battery cells 21 connected in series. ). In this way, the output voltage value Vdc of the power supply 2 can be switched by switching the number of battery cells 21 connected in series with the circuit switches SW1 to SW4.

The configuration example of the power supply 2 shown in FIG. 3 is different from the configuration example of FIG. 2 in that the circuit switches SW5 and SW6 are further provided. The circuit switch SW5 is provided between the negative electrode terminal of the third-stage battery cell 21 and the positive electrode terminal of the fourth-stage battery cell 21. The circuit switch SW6 is provided between the negative electrode terminal and the terminal 2b of the third-stage battery cell 21. In this configuration example, the number of battery cells 21 connected in series is switched between 1 and 6. When the circuit switches SW1, SW4, SW6 are set to the closed state and the circuit switches SW2, SW3, SW5 are set to the open state, the series circuit in which the battery cells 21 of the first to third stages are connected in series A series circuit in which the battery cells 21 of the 4th to 6th stages are connected in series is connected in parallel. Also in this case, the output voltage value Vdc is a voltage value of Vs / 2.

The configuration example of the power supply 2 shown in FIG. 4 includes a series circuit in which six battery cells 21 are connected in series, a series circuit in which five battery cells 21 are connected in series, and four battery cells 21. Is equipped with a series circuit connected in series. In a series circuit in which six battery cells 21 are connected in series, the positive electrode terminal of the first stage battery cell 21 is connected to the terminal 2a via the circuit switch SW1, and the negative electrode terminal of the sixth stage battery cell 21 is connected. Is connected to the terminal 2b. In a series circuit in which five battery cells 21 are connected in series, the positive electrode terminal of the first stage battery cell 21 is connected to the terminal 2a via the circuit switch SW2, and the negative electrode terminal of the fifth stage battery cell 21 is connected. Is connected to the terminal 2b. In a series circuit in which four battery cells 21 are connected in series, the positive electrode terminal of the first stage battery cell 21 is connected to the terminal 2a via the circuit switch SW3, and the negative electrode terminal of the fourth stage battery cell 21 is connected. Is connected to the terminal 2b. In this way, the number of battery cells 21 connected in series can be switched by switching the plurality of series circuits having different numbers of battery cells 21 in series by the circuit switches SW1 to SW3. As a result, the output voltage value Vdc of the power supply 2 is switched.

The inverter 3 is a device that converts the electric power Pdc supplied from the power supply 2 into the AC electric power Pac. The inverter 3 supplies the electric power Pac to the coil device 4. The inverter 3 generates electric power Pac by switching the electric power Pdc. The inverter 3 includes, for example, a semiconductor element for performing switching. Examples of such semiconductor elements include MOS FETs (Metal-Oxide-Semiconductor Field-Effect-Transistors) and IGBTs (Insulated Gate Bipolar Transistors).

The switching duty in the inverter 3 and the length of the conduction time of the semiconductor element are changed according to the operating state of the coil device 4. When the coil device 4 is a coil device for non-contact power supply, the operating state of the coil device 4 includes the presence / absence of power supply and the power supply power. When the coil device 4 is a motor, the operating state of the coil device 4 includes the rotation speed of the motor and the torque. Although the positive and negative polarities change due to switching, the input and output of the inverter 3 are conducted by switching, so that the input voltage of the inverter 3 appears in the output voltage of the inverter 3. Therefore, if the output voltage value Vdc of the power supply 2 is high, the voltage value (absolute value) of the output voltage of the inverter 3, that is, the voltage value (absolute value) of the drive voltage of the coil device 4 is high, and the output of the power supply 2 is high. If the voltage value Vdc is low, the voltage value (absolute value) of the output voltage of the inverter 3, that is, the voltage value (absolute value) of the drive voltage of the coil device 4 is low.

The coil device 4 includes a coil that receives power from the power source 2. Specifically, the coil receives electric power Pac from the inverter 3. The coil device 4 may further include a passive electrical circuit electrically connected to the coil. Examples of the coil device 4 include a coil device for non-contact power feeding and a motor.

When the coil device 4 is a coil device for non-contact power feeding, the coil device 4 may include a circuit for grounding, which is a passive electric circuit, and a matching circuit in addition to the coil. The matching circuit may consist of an inductor, a capacitor, or a combination of an inductor and a capacitor. When the coil device 4 is a motor, the coil device 4 may include a circuit for grounding, which is a passive electric circuit, and a filter circuit in addition to the coil. The filter circuit is provided, for example, as a measure against EMC (Electro Magnetic Compatibility), and may be composed of an inductor, a capacitor, or a combination of an inductor and a capacitor.

The sensor 5 outputs a measured value M for estimating the state of the atmosphere around the coil included in the coil device 4. The atmosphere around the coil is the atmosphere to which the coil is exposed. Examples of atmospheric conditions include atmospheric pressure and humidity. The measured value for estimating the atmospheric condition may be a value obtained by directly measuring the atmospheric condition or a value capable of estimating the atmospheric condition. For example, since the atmospheric pressure changes depending on the altitude (altitude), the altitude may be used as the measured value. Examples of the sensor 5 include a pressure sensor, a humidity sensor, and an altitude sensor. An example of an altitude sensor is a sensor that uses GPS (Global Positioning System). The sensor 5 outputs the measured value M to the control device 10. The sensor 5 may be provided adjacent to the coil device 4 (coil). When the coil device 4 is arranged in a place where the air flow is good, the sensor 5 may be separated from the coil device 4 as long as the atmospheric conditions can be regarded as the same. For example, the coil device 4 may be installed on the floor surface of the parking lot, and the sensor 5 may be attached to a pole in the parking lot.

The control device 10 is a device that controls the power supply 2. The control device 10 calculates the output voltage value Vdc according to the measured value M received from the sensor 5, and transmits an output command C for outputting the output voltage of the output voltage value Vdc to the power supply 2.

As shown in FIG. 5, the control device 10 physically includes hardware such as one or more processors 101, a main storage device 102, an auxiliary storage device 103, an input device 104, an output device 105, and a communication device 106. It can be configured as a computer with hardware. An example of the processor 101 is a CPU (Central Processing Unit). The main storage device 102 is composed of, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory). The auxiliary storage device 103 is composed of, for example, a hard disk device or a flash memory, and is generally non-volatile and has a capacity capable of storing a larger amount of data than the main storage device 102. The input device 104 includes, for example, a keyboard, a mouse, a touch panel, and operation buttons. The output device 105 is composed of, for example, a display and a speaker. The communication device 106 is composed of, for example, a network interface card (NIC) or a wireless communication module.

Each function shown in FIG. 6 of the control device 10 is performed under the control of one or a plurality of processors 101 by causing hardware such as the main storage device 102 to read one or a plurality of predetermined computer programs. This is realized by operating the hardware and reading and writing data in the main storage device 102 and the auxiliary storage device 103.

As shown in FIG. 6, the control device 10 functionally includes an acquisition unit 11, a detection unit 12, a storage unit 13, a calculation unit 14, and an output unit 15.

The acquisition unit 11 acquires the measured value M. Specifically, the acquisition unit 11 acquires the measured value M from the sensor 5 and outputs the measured value M to the calculation unit 14. For example, when the sensor 5 is an analog output sensor, the acquisition unit 11 is an A / D (Analog to Digital) conversion circuit. When the sensor 5 is a GPS receiver, the acquisition unit 11 is a communication interface with the GPS receiver. The acquisition unit 11 converts the measured value M acquired from the sensor 5 into digital data that can be processed by the calculation unit 14, and outputs the digital data to the calculation unit 14.

The detection unit 12 detects an abnormality. The detection unit 12 detects, for example, an abnormality of the sensor 5 and an abnormality of the control device 10. When the detection unit 12 detects an abnormality, the detection unit 12 outputs the abnormality information indicating the abnormality to the calculation unit 14. For example, if the sensor 5 is a GPS receiver, the detection unit 12 may determine that the sensor 5 is abnormal when the sensor 5 and the acquisition unit 11 cannot communicate with each other for a certain period of time or longer. In a configuration in which a plurality of sensors are used as the sensor 5, the detection unit 12 may determine that the sensor 5 is abnormal when the difference between the measured values of the plurality of sensors exceeds the range of the measurement error. For example, in a configuration in which a watchdog timer is provided and the processor 101 resets the watchdog timer at regular intervals, the detection unit 12 determines that the control device 10 is abnormal when the watchdog timer is not reset. You may.

The storage unit 13 stores a table 13a that defines the relationship between the measured value M and the target voltage value Vt. The target voltage value Vt is a value of the output voltage value Vdc to be output from the power supply 2, and is smaller than the voltage value Vdis. The voltage value Vdis is the minimum output voltage value of the output voltage that causes a discharge between the conductors of the coil in the state of the atmosphere around the coil estimated from the measured value M. In the table 13a, a set of various measured values M and corresponding target voltage values Vt is set. The setting method of the table 13a will be described later.

The calculation unit 14 calculates the output voltage (output voltage value Vdc) that does not cause a discharge between the conductors of the coil based on the measured value M. When the calculation unit 14 receives the measurement value M from the acquisition unit 11, the calculation unit 14 refers to the table 13a stored in the storage unit 13 and acquires the target voltage value Vt corresponding to the measurement value M. When the measured value M corresponding to the measured value M acquired by the acquisition unit 11 does not exist in the table 13a, the calculation unit 14 corresponds to the measured value closest to the measured value M among the measured values smaller than the measured value M. The smaller value of the target voltage value and the target voltage value corresponding to the measurement value closest to the measurement value M among the measurement values larger than the measurement value M is set as the target voltage value Vt. By using the smaller of the target voltage values corresponding to the two measured values closest to the measured value M as the target voltage value Vt, an output voltage that does not cause discharge between the conductors of the coil can be obtained.

More specifically with reference to FIG. 7, when the measured value M is the measured value M ₀ or more and _{smaller than the measured value M 1} , the smaller target voltage value of the target voltage value Vt_0 and the target voltage value Vt_1 Vt_1 is used as the target voltage value Vt. Similarly, when the measured value M is the measured value M ₁ or more and _{smaller than the measured value M 2} , the smaller target voltage value Vt_1 of the target voltage value Vt_1 and the target voltage value Vt_1 is used as the target voltage value Vt. .. When the measured value M is the measured value M ₂ or more and _{smaller than the measured value M 3} , the smaller target voltage value Vt_2 of the target voltage value Vt_2 and the target voltage value Vt_3 is used as the target voltage value Vt. When the measured value M is the measured value _MN-2 or more and _{smaller than the measured value MN-1} , the smaller target of the target voltage value Vt_ (N-2) and the target voltage value Vt_ (N-1) The voltage value Vt_ (N-2) is used as the target voltage value Vt. When the measured value M is the measured value _MN-1 or more and the measured value _MN or less, the smaller target voltage value Vt_ (N-1) of the target voltage value Vt_ (N-1) and the target voltage value Vt_N ) Is used as the target voltage value Vt. The same applies when the measured value M is included in another range.

As described above, when the power supply 2 can continuously change the output power value, the calculation unit 14 calculates the target voltage value Vt as the output voltage value Vdc. When the power supply 2 can change the output power value discretely, the calculation unit 14 calculates the maximum output voltage value that is equal to or less than the target voltage value Vt among the output voltage values that the power supply 2 can output as the output voltage value Vdc. do. That is, the output voltage value Vdc is smaller than the voltage value Vdis.

When an abnormality is detected by the detection unit 12, the calculation unit 14 calculates the voltage value Vlim1 (see FIG. 12) as the output voltage value Vdc. The voltage value Vlim1 is a voltage value of an output voltage that does not cause a discharge between the conductors of the coil over the entire range of use of the coil device 4. The range of use is the range of atmospheric conditions around the coil in which the coil may be used. The voltage value Vlim1 is predetermined and stored in the storage unit 13. The calculation unit 14 outputs the output voltage value Vdc to the output unit 15.

The output unit 15 outputs (transmits) the output command C to the power supply 2. When the output unit 15 receives the output voltage value Vdc from the calculation unit 14, it generates an output command C for causing the power supply 2 to output the output voltage of the output voltage value Vdc, and outputs the output command C to the power supply 2.

Next, the setting method of the table 13a will be described in detail. FIG. 8 is a flowchart showing an example of a table setting method. FIG. 9 is a diagram showing a configuration for obtaining the relationship between the input voltage and the output voltage of the inverter. FIG. 10 is a diagram showing a configuration for acquiring a set of a measured value and a discharge start voltage value. The following procedure is performed before the operation of the coil device 4 is started. The table 13a may be reset by performing the following procedure during the operation period of the coil device 4.

As shown in FIG. 8, first, the relationship between the input voltage and the output voltage of the inverter 3 is obtained (step S1). In step S1, as shown in FIG. 9, the power supply 2 is connected to the coil device 4 via the inverter 3. A voltage measuring instrument 51 is connected between the inputs of the coil device 4 (that is, between the outputs of the inverter 3) in order to measure the drive voltage of the coil device 4. Then, the output command C is transmitted to the power supply 2 so that the output voltage value of the power supply 2 (that is, the input voltage value of the inverter 3) becomes the voltage value Vtest. The voltage value Vtest is a voltage value that does not cause a discharge between the conductors of the coil of the coil device 4. The voltage value Vtest is estimated from the configuration and operation of the inverter 3, the shape and dimensions of the coil of the coil device 4, and the like. For example, the voltage value Vtest is set to the lowest voltage value that the power supply 2 can output.

At this time, the duty ratio of the inverter 3 is fixed at a constant value. When the inverter 3 can operate at a plurality of duty ratios, the duty ratio at which the output voltage of the inverter 3 is the highest with respect to the input voltage of the same inverter 3 is used. That is, the duty ratio with the longest duration of conduction of either the upper arm or the lower arm of the leg of the inverter 3 is used. In this state, the voltage measuring instrument 51 measures the voltage value Vrms1. The voltage value measured by the voltage measuring instrument 51 is, for example, an effective value.

If the duty ratio of the inverter 3 is constant, the input voltage (output voltage value Vdc) of the inverter 3 and the output voltage (voltage value Vac) of the inverter 3 are proportional to each other, so that the relational expression (1) can be obtained.

Subsequently, a measured value _{M i} and the discharge starting voltage value Vrms2_i is measured and recorded (step S2). The variable i is an integer of 0 or more and N (N is an integer of 1 or more) or less. In step S2, the coil device 4 and the sensor 5 are housed in the chamber 52, as shown in FIG. In this embodiment, the pressure value is used as the measured value M. The chamber 52 is configured so that the pressure in the chamber 52 can be changed by a pump or the like for intake and exhaust. The chamber 52 can change the pressure in the chamber 52 in a range wider than the range of use of the coil device 4. The range of use of the coil device 4 is the range from the lowest atmospheric pressure to the highest atmospheric pressure in which the coil device 4 is used.

Further, the partial discharge tester 53 is connected to the coil device 4, and the recorder 54 is connected to the sensor 5 and the partial discharge tester 53. The partial discharge tester 53 is a device that measures a voltage value (discharge start voltage value) that starts discharge by applying a voltage. The partial discharge tester 53 outputs AC power having the same frequency as the inverter 3. Recorder 54 has been measured value M _{i (here,} the pressure value) measured by the sensor 5 is a recorder for recording the measured discharge start voltage value Vrms2_i and by the partial discharge tester 53. Human instead of the recorder 54 may record by hand measurements _{M i} and the discharge starting voltage value Vrms2_i. The discharge start voltage value measured by the partial discharge tester 53 is, for example, an effective value. If necessary, the measured value M _i measured by the sensor 5 as the recorder, and human-recording, partial discharge tester 53 may be configured. For example, an A / D converter may be provided between the sensor 5 and the recorder, and the A / D converter may convert the measured value into a digital signal and output it to the recorder. A human can read the measured value by providing a display for displaying the measured value.

Then, a measured value _{M i} and the discharge starting voltage value Vrms2_i is measured. The initial value of the variable i is set to 0. Here, the pressure value is used as the measured value M _i. Specifically, by operating the pump, the pressure in the chamber 52 is set to a pressure value P _i, sensor 5 measures the pressure values P _i, recorder 54 the pressure value P _i as a measurement value M _i Send to. Subsequently, the partial discharge tester 53 measures the discharge start voltage value Vrms2_i and transmits the discharge start voltage value Vrms2_i to the recorder 54. The recorder 54 records in association with the the discharge starting voltage value Vrms2_i measured pressure value measured by the sensor 5 _{P i} (measured value _{M i)} and the partial discharge tester 53. Variable i is increased by 1 from 0 to N, the measurement and recording of measured values _{M i} and the discharge starting voltage value Vrms2_i are performed sequentially.

The pressure value _Pi (i = 0 to N) includes the lowest atmospheric pressure and the highest atmospheric pressure assumed in the environment (use environment) in which the coil device 4 is used. For example, as the variable i is increased, the pressure value P _i is to increase, the pressure value P ₀ is less than the lowest atmospheric pressure envisioned in the environment of use, the pressure value P _N, the coil unit 4 use environment It is above the highest atmospheric pressure assumed in. Even if the pressure value _Pi (i = 0 to N) is set, for example, by evenly dividing the minimum atmospheric pressure and the maximum atmospheric pressure assumed in the usage environment of the coil device 4 by N. good.

Subsequently, the discharge start voltage value Vrms2_i is converted into the voltage value Vdis_i at the input voltage of the inverter 3 (step S3). The discharge start voltage value Vrms2_i is the voltage value of the AC voltage (output voltage of the inverter 3) applied to the coil device 4, and the relational expression (1) is established between the input voltage and the output voltage of the inverter 3. .. Therefore, in the relational expression (1), the discharge start voltage value Vrms2_i is substituted for the voltage value Vac, and the voltage value Vdis_i is substituted for the output voltage value Vdc. Is converted to the voltage value Vdis_i.

Subsequently, the target voltage value Vt_i to be output by the power supply 2 is calculated (step S4). The target voltage value Vt_i is calculated by multiplying the voltage value Vdis_i by the magnification α. The magnification α is a value greater than 0 and less than 1. That is, when the voltage value of the output voltage is the voltage value Vdis_i, the coil device 4 starts discharging, so that the target voltage value Vt_i needs to be set to a value smaller than the voltage value Vdis_i. The magnification α is set so that the possibility of discharge in the coil device 4 can be sufficiently reduced when the output voltage value Vdc is set to the target voltage value Vt_i in consideration of the measurement error and the manufacturing variation of the coil device 4. Will be done. The magnification α may be constant regardless of the value of the variable i, or may be changed for each value of the variable i. For example, in order to secure a certain margin, the smaller the target voltage value Vt_i, the smaller the magnification α may be set.

The target voltage value Vt_i may be calculated by subtracting the value β from the voltage value Vdis_i instead of multiplying the voltage value Vdis_i by the magnification α. The value β is a positive number smaller than the voltage value Vdis_i.

Then, N pieces of the set of the measured values _{M i} and the target voltage value Vt_i is set in the table 13a stored in the storage unit 13 (step S5). As described above, the table 13a is set.

When a plurality of coil devices 4 are designed to be the same as each other, even if the above procedure is performed for one coil device 4 to set the table 13a and the other coil devices 4 are set to the same table 13a. good. The above procedure may be performed for each coil device 4, and different tables 13a may be set for each of the plurality of coil devices 4.

When the output voltage value Vdc is set to the target voltage value Vt_i, the drive voltage of the coil device 4 (that is, the output voltage of the inverter 3) is represented by the equation (3) from the equation (1).

The target voltage value Vt_i is obtained by multiplying the voltage value Vdis_i by the magnification α, as shown in the equation (4).

By substituting the equation (4) into the equation (3), the drive voltage of the coil device 4 is expressed by the equation (5).

Further, by substituting the equation (2) into the equation (5), the drive voltage of the coil device 4 is represented by the equation (6).

Discharge starting voltage value Vrms2_i is a driving voltage to start discharge when the coil unit 4 is used at atmospheric pressure of the pressure values P _i, the magnification α is a positive value less than 1. Therefore, the drive voltage (voltage value Vac) of the coil device 4 represented by the equation (6) is a value smaller than the discharge start voltage value Vrms2_i, that is, a drive voltage that does not cause discharge. That is, when the coil unit 4 is used at atmospheric pressure of the pressure values P _i, if the output voltage value Vdc is set to the target voltage value Vt_i, the drive voltage of the coil unit 4 is represented by the formula (6) .. Therefore, since the drive voltage of the coil device 4 is smaller than the discharge start voltage value Vrms2_i, no discharge occurs.

Next, the output voltage setting method performed by the control device 10 will be described. FIG. 11 is a flowchart showing a series of processes of the output voltage setting method performed by the control device shown in FIG. The series of processes shown in FIG. 11 is started at predetermined time intervals. The predetermined time is set to be sufficiently shorter than the time during which the atmospheric condition changes to the extent that it affects the discharge start voltage value. For example, when the coil device 4 is a motor and the coil device 4 is mounted on a vehicle and the vehicle climbs or descends a mountain, the predetermined time may be set short. When the coil system 1 is a non-contact power feeding device, the installation location of the coil system 1 is basically the same, so that the predetermined time may be set longer. The predetermined time is set to, for example, about 30 minutes or 1 hour.

First, the acquisition unit 11 acquires the measured value M from the sensor 5 (step S11). Then, the acquisition unit 11 outputs the measured value M to the calculation unit 14.

Subsequently, when the calculation unit 14 receives the measured value M from the acquisition unit 11, it determines whether or not the detection unit 12 has detected an abnormality in the sensor 5 or the control device 10 (step S12). For example, when the calculation unit 14 receives the abnormality information from the detection unit 12, the calculation unit 14 detects that an abnormality has occurred in the sensor 5 or the control device 10. In step S12, when the calculation unit 14 determines that the detection unit 12 has not detected an abnormality (step S12; NO), the calculation unit 14 calculates the output voltage value Vdc according to the measured value M (step S13). Specifically, the calculation unit 14 refers to the table 13a stored in the storage unit 13 and acquires the target voltage value Vt corresponding to the measured value M. Then, when the power supply 2 can continuously change the output power value, the calculation unit 14 calculates the target voltage value Vt as the output voltage value Vdc. When the power supply 2 can change the output power value discretely, the calculation unit 14 calculates the maximum output voltage value that is equal to or less than the target voltage value Vt among the output voltage values that the power supply 2 can output as the output voltage value Vdc. do. Then, the calculation unit 14 outputs the output voltage value Vdc to the output unit 15.

On the other hand, in step S12, when the calculation unit 14 determines that the detection unit 12 has detected an abnormality (step S12; YES), the calculation unit 14 calculates the predetermined voltage value Vlim1 as the output voltage value Vdc (step S12). S14). Then, the calculation unit 14 outputs the output voltage value Vdc to the output unit 15.

Subsequently, when the output unit 15 receives the output voltage value Vdc from the calculation unit 14, it generates an output command C for causing the power supply 2 to output the output voltage of the output voltage value Vdc, and outputs the output command C to the power supply 2. (Step S15). As described above, a series of processes of the output voltage setting method performed by the control device 10 is completed.

Then, when the power supply 2 receives the output command C from the control device 10, it outputs an output voltage having the output voltage value Vdc specified by the output command C. The inverter 3 converts the output voltage output from the power supply 2 into a drive voltage, and supplies the drive voltage to the coil device 4. The voltage value of the drive voltage thus obtained is a voltage value at which no discharge occurs between the coil conductors of the coil device 4 in the state of the atmosphere around the coil of the coil device 4. Therefore, the coil device 4 is driven so that no discharge occurs between adjacent conductors of the coil.

Next, the operation and effect of the coil system 1 and the control device 10 will be described with reference to FIG. FIG. 12 is a diagram showing an example of the relationship between the atmospheric pressure and the output voltage value. For example, atmospheric pressure fluctuates with altitude and weather. Specifically, the higher the altitude, the lower the atmospheric pressure. The closer the cyclone is, the lower the atmospheric pressure is, and the closer the high pressure is, the higher the atmospheric pressure is. In the comparative example, a limit value is set for the voltage applied to the coil so that discharge does not occur between the conductors of the coil even if the altitude and the weather of the place where the coil device 4 is used changes. Therefore, in the comparative example, as shown by the thick broken line in FIG. 12, the output voltage is limited to a constant voltage value Vlim1 regardless of the atmospheric pressure.

However, due to changes in altitude and weather, even if the output voltage up to the voltage value Vlim2, which is higher than the voltage value Vlim1, is output from the power supply 2, discharge may not occur between the conductors of the coil (section of FIG. 12). 2). Similarly, even if an output voltage up to a voltage value of Vlim3, which is higher than the voltage value of Vlim2, is output from the power supply 2, discharge may not occur between the conductors of the coil (section 3 in FIG. 12). In the coil system 1 and the control device 10, the output voltage is changed according to the atmospheric pressure. For example, in section 2, an output voltage having a voltage value larger than the voltage value Vlim1 and having a voltage value equal to or lower than the voltage value Vlim2 is output. In the section 3, an output voltage having a voltage value larger than the voltage value Vlim1 and having a voltage value equal to or lower than the voltage value Vlim3 is output. That is, the output voltage value Vdc is set higher than the voltage value Vlim1 according to the change in atmospheric pressure.

Therefore, when the power supply 2 supplies a constant power Pdc, the output current value can be lowered, so that the power loss in the coil can be reduced. When the power supply 2 outputs a constant output current, the power Pdc output from the power supply 2 can be increased. The wider the range of use of the coil device 4, the more remarkable the above effect appears.

As described above, in the coil system 1 and the control device 10, the output voltage value Vdc that does not cause a discharge between the conductors of the coil of the coil device 4 is based on the measured value M for estimating the state of the atmosphere around the coil. Is calculated, and an output command C for outputting the output voltage of the output voltage value Vdc is output to the power supply 2. Therefore, the output voltage of the output voltage value Vdc according to the atmospheric condition is output from the power supply 2. For example, when the atmospheric pressure is high, even if the output voltage value Vdc is increased to some extent, no discharge occurs between the conductors of the coil. By outputting the output voltage of the output voltage value Vdc according to the atmospheric condition in this way, it is possible to increase the power Pdc as compared with the case where the output voltage value Vdc is fixed. Alternatively, when the power supply 2 outputs a constant power Pdc, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency.

The output voltage value Vdc is smaller than the voltage value Vdis. Therefore, it is possible to improve the power efficiency or increase the output without causing a discharge between the conductors of the coil. In other words, even if the atmospheric condition changes, no discharge occurs between the adjacent conductors of the coil, and the output voltage value Vdc cannot be lowered unnecessarily. Therefore, it is possible to at least either improve power efficiency or increase output.

The output voltage value Vdc is, for example, a value obtained by multiplying the voltage value Vdis by the magnification α. The output voltage value Vdc may be a value obtained by subtracting a positive value β smaller than the voltage value Vdis from the voltage value Vdis. In these cases, an output voltage value Vdc smaller than the voltage value Vdis can be obtained by a simple calculation.

If an abnormality is detected in the sensor 5 or the control device 10, the output voltage value Vdc according to the atmospheric condition may not be calculated accurately. On the other hand, when an abnormality is detected, the voltage value Vlim1 that does not cause a discharge between the conductors over the range of the atmospheric condition around the coil in which the coil is used is calculated as the output voltage value Vdc. Therefore, even if an abnormality is detected, the possibility of generating an electric discharge between the conductors of the coil can be reduced.

In the above embodiment, atmospheric pressure is used as the atmospheric condition. In this case, the output voltage of the output voltage value Vdc corresponding to the atmospheric pressure around the coil device 4 is output from the power supply 2. Therefore, it is possible to increase the power Pdc as compared with the case where the output voltage value Vdc is fixed. Alternatively, when the power supply 2 outputs a constant power Pdc, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency. Since the output voltage value Vdc is lower than the voltage value Vdis at which discharge occurs between adjacent conductors of the coil at atmospheric pressure around the coil of the coil device 4, the possibility of discharge occurring in the coil device 4 is reduced. When the atmospheric pressure changes and the discharge does not occur even at a higher voltage, the output voltage value Vdc can be increased, so that at least one of improving the power efficiency and increasing the output becomes possible.

In the coil system 1, the state of the atmosphere (atmospheric pressure) around the coil of the coil device 4 is measured by the sensor 5, and the output voltage value Vdc that does not cause discharge between the conductors of the coil is calculated based on the measured value M. ..

Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments.

For example, in the above embodiment, a sensor that directly measures the atmospheric state (pressure) is used as the sensor 5, but a sensor that indirectly measures the atmospheric condition may be used. For example, since it is known that there is a correlation between atmospheric pressure and altitude, an altitude sensor that measures the altitude of the coil device 4 may be used as the sensor 5. In this case, since the altitude is used as the measured value M, the set of the altitude and the target voltage value Vt is stored in the table 13a. Since the relationship between the atmospheric pressure and the altitude varies, the target voltage value Vt may be calculated by multiplying the voltage value Vdis_i by the magnification γ. The magnification γ is a value larger than 0 and less than 1, and a value smaller than the magnification α. In this case as well, the same effect as that of the above embodiment is achieved.

The voltage limit value at which no discharge occurs between the conductors of the coil may depend on the atmospheric conditions other than atmospheric pressure. For example, the voltage limit may depend on humidity. Therefore, a sensor (humidity sensor) that measures humidity may be used as the sensor 5. Alternatively, as the sensor 5, a humidity sensor may be used in addition to the pressure sensor. In this case, the control device 10 may receive the pressure value and the humidity as the measured values M, and may change the output voltage value Vdc according to the pressure value and the humidity of the atmosphere around the coil of the coil device 4. As the chamber 52, a chamber in which the pressure and humidity can be changed is used, and a set of various pressure values and humidity and a discharge start voltage value Vrms2 is recorded. A combination of pressure value, humidity, and target voltage value Vt is set in the table 13a.

For example, when the coil device 4 is used as a non-contact power transmission device, the coil device 4 may be installed on the ground outdoors. In such a case, the humidity around the coil may fluctuate. As mentioned above, the voltage value Vdis_i can be affected by humidity. On the other hand, the state of the atmosphere around the coil device 4 estimated by the measured value M may include humidity, and the sensor 5 may include a humidity sensor. According to this configuration, the output voltage of the output voltage value Vdc corresponding to the humidity around the coil device 4 is output from the power supply 2. Also in this case, it is possible to increase the power Pdc as compared with the case where the output voltage value Vdc is fixed. Alternatively, when the power supply 2 outputs a constant power Pdc, the output current can be reduced, so that the loss in the coil can be reduced. As a result, it is possible to improve power efficiency.

The calculation unit 14 may calculate the output voltage value Vdc without referring to the table 13a. For example, when the power supply 2 can output only the output voltages of two voltage values, the voltage value Vdca and the voltage value Vdcb, the threshold value Mth may be used instead of the table 13a. The voltage value Vdca is larger than the voltage value Vdcb. The threshold value Mth is a value that satisfies the following first condition and second condition. The first condition is that when the value for estimating the atmospheric state is equal to or greater than the threshold value Mth, if the output voltage value Vdc is set to the voltage value Vdca, a discharge occurs between adjacent conductors of the coils of the coil device 4. The condition is that there is no such thing. The second condition is that when the value for estimating the atmospheric state is less than the threshold value Mth, if the output voltage value Vdc is set to the voltage value Vdcb, a discharge occurs between the adjacent conductors of the coils of the coil device 4. The condition is that there is no such thing. In this case, when the measured value M is equal to or greater than the threshold value Mth, the calculation unit 14 calculates the voltage value Vdca as the output voltage value Vdc. When the measured value M is less than the threshold value Mth, the calculation unit 14 calculates the voltage value Vdcb as the output voltage value Vdc.

The threshold value Mth is determined as follows and stored in the storage unit 13 before the operation of the coil device 4 is started. For example, among the pairs of the measured values _{M i} and the target voltage value Vt_i set in the table 13a, the assembled including the target voltage value Vt_i is equal to or higher than the voltage value Vdca are extracted. Then, the minimum measured value M _i of the measured values M _i included in the extracted set is set to the threshold Mth. When atmospheric pressure is used as the measured value M, the target voltage value Vt_i is equal to or higher than the voltage value Vdca at atmospheric pressure equal to or higher than the threshold value Mth. Therefore, even if the output voltage value Vdc of the power supply 2 is set to the voltage value Vdca, no discharge occurs between the adjacent conductors of the coil.

If the set including the target voltage value Vt_i below the voltage value Vdcb present, at atmospheric pressure of less than the measured value M _i included in the set, even if the output voltage value Vdc of the power supply 2 is set to a voltage value Vdcb, Discharge can occur between adjacent conductors of the coil. In such a case, by modifying or replacing the power supply 2, the voltage value Vdcb is further lowered so that the set including the target voltage value Vt_i less than the voltage value Vdcb does not exist. As a result, when the atmospheric pressure is less than the threshold value Mth, the target voltage value Vt_i becomes the voltage value Vdcb or more, so that no discharge occurs between the adjacent conductors of the coil. In this embodiment, the storage unit 13 does not have to store the table 13a because the table 13a is only used to determine the threshold Mth.

In the above embodiment, the table 13a is set by the test, but the setting method of the table 13a is not limited to this. For example, the table 13a may be set by a simulation using a circuit model and a model for predicting the discharge start voltage value. The circuit model is a simulation model that predicts the voltage of each part of the coil device 4 when the inverter 3 operates at the output voltage of the power supply 2. The model that predicts the discharge start voltage value predicts the discharge start voltage value according to the atmospheric conditions, the material and shape of the coil conductor, the material and shape of the insulator, and the positional relationship between the coil conductor and the insulator. It is a simulation model to be used.

The control device 10 does not have to include the detection unit 12 when the abnormality is not detected. The control device 10 does not have to include the storage unit 13. In this case, the calculation unit 14 may refer to the table 13a stored in the storage unit outside the control device 10.

The inverter 3 may be replaced with a commutator that mechanically inverts the voltage. In this case, a DC motor may be adopted as the coil device 4. The motor winding corresponds to the coil.

The coil system 1 does not have to include the inverter 3. In this case, an AC output power supply with a variable voltage is used as the power supply 2, and the power supply 2 is directly connected to the coil device 4.

The coil system 1 does not have to include the sensor 5. In this case, the control device 10 acquires the measured value M from the sensor outside the coil system 1.

1 Coil system 2 Power supply 3 Inverter 4 Coil device 5 Sensor 10 Control device 11 Acquisition unit 12 Detection unit 13 Storage unit 13a Table 14 Calculation unit 15 Output unit

Claims (9)

1. A control device that controls the power supply for supplying electric power to the coil.
   An acquisition unit that acquires measured values for estimating the state of the atmosphere around the coil, and
   Based on the measured value, a calculation unit that calculates an output voltage value that does not cause a discharge between the conductors of the coil, and a calculation unit.
   An output unit that outputs a command to output the output voltage of the output voltage value to the power supply, and
   A control device comprising.
2. The control device according to claim 1, wherein the output voltage value is smaller than the minimum output voltage value that causes a discharge between the conductors in the atmospheric condition around the coil estimated from the measured value.
3. The control device according to claim 2, wherein the output voltage value is a value obtained by multiplying the minimum output voltage value by a magnification.
4. The control device according to claim 2, wherein the output voltage value is a value obtained by subtracting a positive value smaller than the minimum output voltage value from the minimum output voltage value.
5. It also has a detector to detect abnormalities.
   When an abnormality is detected by the detection unit, the calculation unit calculates a voltage value that does not cause a discharge between the conductors in the range of the atmospheric condition around the coil in which the coil is used as the output voltage value. , The control device according to any one of claims 1 to 4.
6. The control device according to any one of claims 1 to 5, wherein the atmospheric state includes atmospheric pressure.
7. The control device according to any one of claims 1 to 6.
   The power supply controlled by the control device and
   A coil device including a coil that receives power from the power source, and
   Coil system with.
8. The coil system according to claim 7, further comprising a sensor that outputs the measured value.
9. The atmospheric conditions include humidity and
   The coil system according to claim 8, wherein the sensor includes a humidity sensor.

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