JP2013182701A - Electrical power system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical power system capable of reducing the number of electromagnetic coils rather than that of switches.SOLUTION: Two switches 3a, 3b in three switches 3a to 3c are opened/closed by a first electromagnetic coil 5a, and an other switch 3c is opened/closed by a second electromagnetic coil 5b. Only one switch (a negative side main switch 3b) in two switches 3a, 3b becomes ON-state by applying a relatively low voltage to the first electromagnetic coil 5a, and both of two switches (a positive side main switch 3a and the negative main switch 3b) become ON-state by applying a high voltage being higher than the low voltage to it.

Description

  The present invention relates to a power supply system having an electromagnetic coil and a plurality of switches.

  Conventionally, as shown in FIG. 16, a power supply system 9 for electrically connecting or disconnecting an electronic device 92 to or from a DC power supply 91 is known (see Patent Document 1 below).

  The positive terminal of the DC power source 91 and the electronic device 92 are connected by the positive side wiring 99a, and the negative terminal of the DC power source 91 and the electronic device 92 are connected by the negative side wiring 99b. The positive side wiring 99a is provided with a positive side main switch 93a, and the negative side wiring 99b is provided with a negative side main switch 93b. A series body 95 in which a precharge resistor 94 and a precharge switch 93c are connected in series is connected in parallel to the positive main switch 93a. The individual switches 93a to 93c are opened and closed by switching between energization and deenergization of the electromagnetic coil 96.

The electronic device 92 is connected with a smoothing capacitor 98 for smoothing the DC voltage. When the electronic device 92 is activated, when the positive main switch 93a and the negative main switch 93b are turned on in a state where no electric charge is stored in the smoothing capacitor 98, an inrush current flows through the smoothing capacitor 98. 93b may be welded. Therefore, when operating the electronic device 92, first, the precharge switch 93c and the negative main switch 93b are turned on, and a current is gradually passed through the smoothing capacitor 98 via the precharge resistor 94. As a result, the inrush current flows through the smoothing capacitor 98 to prevent the main switches 93a and 93b from being welded.
Then, after the electric charge is sufficiently stored in the smoothing capacitor 98, the positive side main switch 93a is turned on and the precharge switch 93c is turned off. In this way, since the two main switches 93 a and 93 b are turned on, power is supplied from the DC power supply 91 to the electronic device 92.

  As described above, the power supply system 9 supplies power to the electronic device 92 and the state in which the smoothing capacitor 98 is charged (precharge state) by changing the combination of the switches 93 to be turned on among the plurality of switches 93a to 93c. It is configured to switch between states (power supply states).

JP 2005-222871 A

  However, since the conventional power supply system 9 opens and closes the positive main switch 93a, the negative main switch 93b, and the precharge switch 93c by separate electromagnetic coils 96, the same number as the switches 93a to 93c. The electromagnetic coil 96 was required. For this reason, the number of electromagnetic coils 96 is increased, resulting in a problem that the manufacturing cost of the power supply system 9 is increased and it is difficult to reduce the weight.

  The present invention has been made in view of such a background, and an object of the present invention is to provide a power supply system capable of reducing the number of electromagnetic coils than the number of switches.

According to a first aspect of the present invention, a positive main switch provided between a positive terminal of a DC power supply and a high potential side terminal of an electronic device,
A negative main switch provided between the negative terminal of the DC power source and the low potential side terminal of the electronic device;
A pre-charge resistor for flowing a current gradually through a smoothing capacitor connected in parallel to the electronic device at the time of starting the electronic device;
A precharge switch connected in series to the precharge resistor;
A first electromagnetic coil and a second electromagnetic coil for opening and closing three switches, the positive main switch, the negative main switch, and the precharge switch;
A control circuit unit that is connected to the first electromagnetic coil and the second electromagnetic coil and controls an opening / closing operation of the switch;
A series body in which the precharge resistor and the precharge switch are connected in series is connected in parallel to the positive main switch or the negative main switch,
The control circuit section includes a power cut-off state in which the three switches are turned off, and a main unit that is not connected in parallel to the series body among the two main switches of the positive main switch and the negative main switch. A precharge state in which charges are stored in the smoothing capacitor by turning on the switch and the precharge switch, and power is supplied to the electronic device by turning on the two main switches after the precharge state. Switch between power supply status,
Of the three switches, two of the switches are opened and closed by the first electromagnetic coil, and the other one of the switches is opened and closed by the second electromagnetic coil.
By applying a relatively low low voltage to the first electromagnetic coil, only one of the two switches is turned on, and by applying a high voltage higher than the low voltage, the two electromagnetic switches The power supply system is configured to turn on both of the switches (claim 1).

The second aspect of the present invention is provided between the positive terminal of the DC power source and the high potential side terminal of the electronic device, or between the negative terminal of the DC power source and the low potential side terminal of the electronic device. Main switch
A pre-charge resistor for flowing a current gradually through a smoothing capacitor connected in parallel to the electronic device at the time of starting the electronic device;
A precharge switch connected in series to the precharge resistor;
An electromagnetic coil for opening and closing two switches, the main switch and the precharge switch;
A control circuit unit connected to the electromagnetic coil for controlling the opening and closing operations of the two switches,
A series body in which the precharge resistor and the precharge switch are connected in series is connected in parallel to the main switch,
The control circuit unit includes a power cutoff state in which the two switches are turned off, a precharge state in which charges are stored in the smoothing capacitor by turning on only the precharge switch, and after the precharge state, By switching on both of the two switches, the power supply state for supplying power to the electronic device is switched,
By applying a relatively low low voltage to the electromagnetic coil, only the precharge switch is turned on to be in the precharge state, and then a high voltage higher than the low voltage is applied, whereby the main switch and the The power supply system is configured to turn on both the precharge switches to enter the power supply state (claim 9).

In the power supply system according to the first aspect, by applying a low voltage to the first electromagnetic coil, only one of the two switches is turned on, and by applying a high voltage, both the two switches are turned on. Both are configured to turn on.
In this way, by changing the voltage applied to the first electromagnetic coil, it is possible to turn on only one of the two switches or turn on both switches. Moreover, the said power supply system has opened and closed another 1 switch with the 2nd electromagnetic coil. Therefore, three switches can be opened and closed using these two electromagnetic coils, and the power cut-off state, the precharge state, and the power supply state can be easily switched.
Thus, with the above configuration, the three states can be switched while the number of electromagnetic coils is smaller than the number of switches. Therefore, the manufacturing cost of the power supply system can be reduced.

In the power supply system according to the second aspect, only the precharge switch is turned on by applying a low voltage to the electromagnetic coil, and both the main switch and the precharge switch are turned on by applying a high voltage. It is configured.
In this way, it is possible to turn on only the precharge switch or turn on both switches by changing the voltage applied to the electromagnetic coil. Therefore, it is possible to easily switch between the power cut-off state, the precharge state, and the power supply state by opening and closing two switches using the single electromagnetic coil.
Thus, with the above configuration, the three states can be switched while the number of electromagnetic coils is smaller than the number of switches. Therefore, the manufacturing cost of the power supply system can be reduced.

  As described above, a power supply system that can reduce the number of electromagnetic coils than the number of switches can be provided.

The circuit diagram of the power supply system in the electric power interruption state in Example 1. FIG. 1 is a circuit diagram of a power supply system in a precharge state in Embodiment 1. FIG. 1 is a circuit diagram of a power supply system in a power supply state in Embodiment 1. FIG. Sectional drawing of the relay which opens and closes the positive side main switch and the negative side main switch in Example 1. FIG. Sectional drawing of a relay in the state which applied the low voltage to the 1st electromagnetic coil in Example 1. FIG. Sectional drawing of a relay in the state which applied the high voltage to the 1st electromagnetic coil in Example 1. FIG. Sectional drawing of the relay which opens and closes the precharge switch in Example 1. FIG. FIG. 2 is a block diagram of a control circuit unit in the first embodiment. The flowchart at the time of performing welding confirmation of the power supply system in Example 1. FIG. 3 is a flowchart when the power supply system of the power supply system according to the first embodiment is connected. The circuit diagram of the power supply system in Example 2. FIG. 9 is a flowchart when performing welding confirmation of the power supply system in the second embodiment. 9 is a flowchart when a power supply is connected in the power supply system according to the second embodiment. The circuit diagram of the power supply system in Example 3. FIG. 10 is a flowchart of a power supply system in Embodiment 3. The circuit diagram of the power supply system in a prior art example.

In the power supply system, it is preferable that the power supply state is a state in which, after the precharge state, the two main switches are turned on and the precharge switch is turned off.
In this case, since the precharge switch is turned off in the power supply state, an overcurrent instantaneously flows in the power supply state, thereby preventing a problem that the precharge switch is welded.

Further, the two main switches are opened and closed by the first electromagnetic coil, the precharge switch is opened and closed by the second electromagnetic coil, and the low voltage is applied to the first electromagnetic coil. Of these, only the main switch that is not connected in parallel to the series body can be turned on.
In this case, the two main switches can be opened and closed by one electromagnetic coil (first electromagnetic coil). The electromagnetic coil that opens and closes the precharge switch is energized only for a relatively short time when it enters the precharge state, whereas the electromagnetic coil that opens and closes the main switch is energized for a relatively long time when the electronic device is operated. For this reason, the electromagnetic coil that opens and closes the main switch is required to have high reliability, tends to be large and expensive. Accordingly, by opening and closing the two main switches with one electromagnetic coil as described above, the number of electromagnetic coils for the main switch, which is easy to increase in size, can be reduced to one, and the effect of reducing the electromagnetic coils is increased. be able to.

In addition, the control circuit unit applies the low voltage to the first electromagnetic coil and energizes the second electromagnetic coil to turn on the main switch and the precharge switch that are not connected in parallel to the series body. Then, after the electric charge is stored in the smoothing capacitor, the two main switches are turned on by raising the voltage applied to the first electromagnetic coil to the high voltage. (2) By stopping the energization to the two electromagnetic coils, it is possible to turn off only the precharge switch and set the power supply state.
If the charge is stored in the smoothing capacitor, the precharge switch is turned off, and then the two main switches are turned on. After the precharge switch is turned off, the two main switches are turned on. Since no voltage is applied to the smoothing capacitor, charges stored in the smoothing capacitor are easily discharged. However, as described above, after accumulating electric charge in the smoothing capacitor, if the two main switches are turned on and then the precharge switch is turned off, the voltage is applied to the smoothing capacitor while these switches are switched. Therefore, it is possible to prevent the smoothing capacitor from being discharged.

The control circuit unit turns on only the precharge switch before entering the precharge state, and determines whether or not a main switch that is not connected in parallel to the series body is welded. Only a main switch that is not connected in parallel to the series body by applying a low voltage to the first electromagnetic coil, and whether the main switch connected in parallel to the series body or the precharge switch is welded. And a second welding judgment means for judging whether or not.
In this case, it is possible to determine whether any of the three switches is welded before operating the electronic device. If it is determined that any of the switches is welded, for example, the electronic device can be controlled not to operate to ensure safety. Therefore, the safety of the electronic device can be further increased.
For example, it is possible to determine whether or not the switch is welded by providing a voltmeter in the smoothing capacitor and checking whether or not the voltage of the smoothing capacitor has increased.

The main switch not connected in parallel to the series body and the precharge switch are opened and closed by the first electromagnetic coil, and the main switch connected in parallel to the series body is opened and closed by the second electromagnetic coil, By applying the low voltage to one electromagnetic coil, only the main switch that is not connected in parallel to the series body among the two switches can be turned on (Claim 6).
In this case, it is possible to easily switch between the power cutoff state, the precharge state, and the power supply state using two electromagnetic coils of the first electromagnetic coil and the second electromagnetic coil.

In addition, the control circuit unit applies a high voltage to the first electromagnetic coil to turn on the main switch and the precharge switch that are not connected in parallel to the series body, thereby bringing the precharge state into the smoothing state. After the electric charge is stored in the capacitor, by energizing the second electromagnetic coil, the main switch connected in parallel to the series body is turned on, and then the voltage applied to the first electromagnetic coil is lowered to the low voltage. Thus, only the precharge switch can be turned off and the power supply state can be established (claim 7).
If the charge is stored in the smoothing capacitor, the precharge switch is turned off, and then the two main switches are turned on. After the precharge switch is turned off, the two main switches are turned on. Since no voltage is applied to the smoothing capacitor, charges stored in the smoothing capacitor are easily discharged. However, as described above, after accumulating electric charge in the smoothing capacitor, if the two main switches are turned on and then the precharge switch is turned off, the voltage is applied to the smoothing capacitor while these switches are switched. Therefore, it is possible to prevent the smoothing capacitor from being discharged.

Further, the control circuit unit turns on only the main switch that is not connected in parallel with the series body before the precharge state, and the main switch or the precharge switch that is connected in parallel with the series body is welded. Only the first welding judgment means for judging whether or not the main switch connected in parallel to the series body is turned on, and it is judged whether or not the main switch not connected in parallel to the series body is welded. And a second welding determination means (claim 8).
In this case, it is possible to determine whether any of the three switches is welded before operating the electronic device. If it is determined that any of the switches is welded, for example, the electronic device can be controlled not to operate to ensure safety. Therefore, the safety of the electronic device can be further increased.

Example 1
Examples of the power supply system will be described with reference to FIGS. As shown in FIG. 1, the power supply system 1 of this example includes a positive main switch 3a, a negative main switch 3b, a precharge resistor 4, a precharge switch 3c, a first electromagnetic coil 5a, and a second electromagnetic coil. A coil 5b and a control circuit unit 6 are provided.
The positive main switch 3 a is provided between the positive terminal of the DC power supply 10 and the high potential side terminal 111 of the electronic device 11. The negative main switch 3 b is provided between the negative terminal of the DC power supply 10 and the low potential terminal 112 of the electronic device 11. The precharge resistor 4 is provided to allow a current to flow gradually through the smoothing capacitor 12 connected in parallel to the electronic device 11 when the electronic device 11 is activated.

  The precharge switch 3 c is connected in series to the precharge resistor 4. The first electromagnetic coil 5a and the second electromagnetic coil 5b open and close three switches 3 including a positive main switch 3a, a negative main switch 3b, and a precharge switch 3c. The control circuit unit 6 is connected to the first electromagnetic coil 5a and the second electromagnetic coil 5b, and controls the opening / closing operations of the switches 3a to 3c.

  A series body 13 in which the precharge resistor 4 and the precharge switch 3c are connected in series is connected in parallel to the positive main switch 3a. The control circuit unit 6 switches between a power cutoff state (see FIG. 1), a precharge state (see FIG. 2), and a power supply state (see FIG. 3).

  As shown in FIG. 1, the three switches 3 a to 3 c are turned off in the power cutoff state. Further, as shown in FIG. 2, in the precharge state, the main switch (negative main switch 3b) that is not connected in parallel to the series body 13 and the precharge switch 3c are turned on. As a result, the current I is gradually passed through the precharge switch 3c, and charges are stored in the smoothing capacitor 12.

  After the electric charge is sufficiently stored in the smoothing capacitor 12, the power supply state is switched as shown in FIG. In the power supply state, the two main switches 3a and 3b are turned on, and the precharge switch 3c is turned off. In this state, power is supplied to the electronic device 11.

  As shown in FIG. 1, among the three switches 3a to 3c, two switches (the positive main switch 3a and the negative main switch 3b) are opened and closed by the first electromagnetic coil 5a, and the other switch ( The precharge switch 3c) is opened and closed by the second electromagnetic coil 5b.

  Then, by applying a relatively low low voltage to the first electromagnetic coil 5a, only one of the two switches 3a and 3b (the negative main switch 3b) is turned on, and the low voltage is applied to the first electromagnetic coil 5a. By applying a high voltage higher than the voltage, the two switches (positive main switch 3a and negative main switch 3b) are both turned on.

  The electronic device 11 of this example is a power conversion device mounted on a vehicle such as an electric vehicle or a hybrid vehicle.

  As shown in FIG. 1, in this example, the positive terminal of the DC power source 10 and the high potential side terminal 11 of the electronic device 11 are connected by the positive side wiring 2a. A positive main switch 3a is provided on the positive wiring 2a. In this example, the negative terminal of the DC power supply 10 and the low potential side terminal 112 of the electronic device 11 are connected by the negative wiring 2b. A negative main switch 3b is provided on the negative wiring 2b. A current sensor 69 is provided on the positive side wiring 2a. In this example, the positive main switch 3a, the negative main switch 3b, and the first electromagnetic coil 5a are combined into one relay (first relay 14).

  As shown in FIG. 4, the first relay 14 includes a first electromagnetic coil 5a, a positive main switch 3a, a negative main switch 3b, a yoke 71, and two plungers 7 (a positive plunger 7a and a negative side). Plunger 7b) and two fixed cores 74 (a positive fixed core 74a and a negative fixed core 74b). The yoke 71, the plunger 7 and the fixed core 74 are each made of a soft magnetic material. The negative side plunger 7b and the negative side fixed core 74b are arranged inside the first electromagnetic coil 5a, and the positive side plunger 7a and the positive side fixed core 74a are arranged outside the first electromagnetic coil 5a.

  The positive main switch 3a and the negative main switch 3b are respectively a fixed contact 31, a movable contact 32, a metal fixed contact support 33 that supports the fixed contact 31, and a metal movable that supports the movable contact 32. And a contact support portion 34. A contact-side spring member 73 is attached to the movable contact support portion 34. The contact-side spring member 73 presses the movable contact support portion 34 toward the fixed contact support portion 33 side.

  A plunger-side spring member 72 is provided between the plunger 7 and the fixed core 74. The plunger side spring member 72 presses the plunger 7 toward the movable contact support portion 34 side. The spring constant of the plunger side spring member 72 is larger than the spring constant of the contact side spring member 73.

  As shown in FIG. 5, when the first electromagnetic coil 5a is energized, a magnetic flux Φ is generated, and the magnetic flux Φ is divided into two magnetic circuits, the first magnetic circuit C1 and the second magnetic circuit C2. The first magnetic circuit C1 is a magnetic circuit in which the magnetic flux Φ flows through the negative plunger 7b, the yoke 71, and the negative fixed core 74b. The second magnetic circuit C2 is a magnetic circuit in which the magnetic flux Φ flows through the negative plunger 7b, the yoke 71, the positive plunger 7a, the positive fixed core 74a, and the negative fixed core 74b.

  Thus, since the first magnetic circuit C1 has a short flow length of the magnetic flux Φ, the amount of leakage magnetic flux is small, and a large amount of magnetic flux Φ flows through the first magnetic circuit C1. Therefore, even if a relatively low voltage (low voltage) is applied to the first electromagnetic coil 5a, a strong magnetic force can be generated in the negative plunger 7b, and the negative plunger 7b can be attracted to the negative fixed core 74b.

  On the other hand, since the second magnetic circuit C1 has a long flow length of the magnetic flux Φ, the amount of leakage magnetic flux increases, and the amount of magnetic flux flowing through the second magnetic circuit C2 tends to decrease. Therefore, if the voltage applied to the first electromagnetic coil 5a is low, a strong magnetic force is hardly generated in the positive plunger 7a, and the positive plunger 7a cannot be attracted to the positive fixed core 74a.

  When the negative side plunger 7b is attracted to the negative side fixed core 74a, the movable contact support part 34 is pressed toward the fixed contact support part 33 by the pressing force of the contact side spring member 73. Thereby, the negative side main switch 3b is turned on.

  In this way, by applying a low voltage to the first electromagnetic coil 5a, only the negative plunger 7b can be attracted and only the negative main switch 3b can be turned on.

  Further, as shown in FIG. 6, when the voltage applied to the first electromagnetic coil 5a is changed to a high voltage higher than the low voltage, the amount of the magnetic flux Φ flowing through the second magnetic circuit C2 increases, and the positive side plunger 7a becomes positive. It is sucked into the side fixed core 74a. Therefore, the positive side main switch 3a is turned on. Thereby, both the positive main switch 3a and the negative main switch 3b are turned on.

  When the energization to the first electromagnetic coil 5a is stopped, the magnetic flux Φ decreases as shown in FIG. Therefore, the magnetic force is reduced, and the plungers 7a and 7b are pressed toward the movable contact support portion 34 by the pressing force of the plunger-side spring member 72. Then, the insulating member 70 attached to the plunger 7 abuts on the movable contact support portion 34 and separates the movable contact support portion 34 from the fixed contact support portion 33 against the pressing force of the contact side spring member 73. As a result, the two main switches 3a and 3b are turned off.

Further, as shown in FIG. 7, the present example includes a relay (second relay 15) different from the first relay 14. The precharge switch 3c and the second electromagnetic coil 5b described above are provided in the second relay 15. The second relay 15 is provided with a plunger 7c, a fixed core 74c, and a yoke 71. The plunger 7c, the fixed core 74c, and the yoke 71 are each made of a soft magnetic material. When the second electromagnetic coil 5b is energized, a magnetic force is generated, and the plunger 7c is attracted to the fixed core 74c. Further, when energization to the second electromagnetic coil 5b is stopped, the magnetic force is reduced, and the plunger 7c is pressed toward the movable contact support portion 34 by the pressing force of the plunger-side spring member 72c. Therefore, the precharge switch 3c is turned off.
Thus, the precharge switch 3c is opened and closed by switching between energization and de-energization of the second electromagnetic coil 5b.

  On the other hand, as shown in FIG. 8, the control circuit unit 6 of this example is composed of an ECU (Engine Control Unit). The control circuit unit 6 includes a CPU 60, a ROM 61, a RAM 62, an I / O 63, and a line 64 that connects them. The ROM 61 stores a program 61p. The CPU 60 reads and executes the program 61p to control opening and closing of the switches 3a to 3c.

  Further, the control circuit unit 6 includes a first welding determination unit 65 and a second welding determination unit 66 that determine whether or not the switches 3a to 3c are welded before the electronic device 11 is operated. These first welding determination means 65 and second welding determination means 66 are realized by the CPU 60 executing the program 61p.

  FIG. 9 shows a flowchart for determining whether or not the switches 3a to 3c are welded before the electronic device 11 is operated. As shown in the figure, first, the second electromagnetic coil 5b is energized to turn on only the precharge switch 3c among the three switches 3a to 3c (step S1).

  After performing Step S1, the process proceeds to Step S2, and it is determined whether or not the current sensor 69 (see FIG. 1) provided on the positive wiring 2a detects a current. If the negative side main switch 3b is welded, a current flows through the smoothing capacitor 12 when the precharge switch 3c is turned on, and the current sensor 69 detects the current. If the negative main switch 3b is not welded, no current flows through the smoothing capacitor 12, and the current sensor 69 does not detect the current.

  When it is determined that the current is detected (Yes) in step S2, the process moves to step S7, and it is determined that the negative side main switch 3b is welded. Then, the electronic device 11 is controlled not to operate. That is, control is performed so as not to shift to the precharge state (see FIG. 2) and the power supply state (see FIG. 3).

  If it is determined in step S2 that no current is detected (No), it is determined that the negative main switch 3b is not welded, and steps S3 and S4 are performed.

  In step S3, the precharge switch 3c is turned off. In step S4, a low voltage is applied to the first electromagnetic coil 5a, and only the negative main switch 3b is turned on. Thereafter, the process proceeds to step S5, and it is determined whether or not the current sensor 69 has detected a current.

  If the precharge switch 3c or the positive main switch 3a is welded, a current flows through the smoothing capacitor 12 when the negative main switch 3b is turned on, and the current sensor 69 (see FIG. 1) detects the current. To do. If the precharge switch 3c or the positive main switch 3a is not welded, no current flows through the smoothing capacitor 12 when the negative main switch 3b is turned on, and the current sensor 69 does not detect the current.

If it is determined in step S5 that the current has been detected (Yes), the process proceeds to step S8, where it is determined that the positive main switch 3a or the precharge switch 3c is welded. Then, the electronic device 11 is controlled not to operate.
If it is determined in step S5 that no current is detected (No), the process proceeds to step S6 and it is determined that all the switches 3a to 3c are not welded. And the process (step S9-step S12: refer FIG. 10) which operates the electronic device 11 is performed.

  In this example, it is determined whether or not the switch 3 is welded by determining whether or not the current sensor 69 has detected a current. For example, a voltage sensor is provided in the smoothing capacitor 12. Whether or not the switch 3 is welded may be determined by determining whether or not the voltage of the smoothing capacitor 12 has increased. In addition, by providing a voltage sensor for measuring the voltage between the positive terminal of the smoothing capacitor 12 and the negative terminal of the DC power supply 10, in step S5, by determining whether or not this voltage has increased, It may be determined whether or not the switches 3a and 3c are welded.

  As shown in FIG. 10, when the electronic device 11 is operated, the second electromagnetic coil 5b (see FIG. 1) is first energized to turn on the precharge switch 3c (step S9). Then, it moves to step S10 and applies a low voltage to the 1st electromagnetic coil 5a, and turns ON the negative side main switch 3b. As a result, the precharge switch 3c and the negative main switch 3b are turned on (see FIG. 2).

  Thereafter, the process proceeds to step S11. Here, after waiting for a predetermined time, the smoothing capacitor 12 is charged. Then, after fully charging the smoothing capacitor 12, a high voltage is applied to the first electromagnetic coil 3a, and both the positive main switch 3a and the negative main switch 3b are turned on.

  Thereafter, the process proceeds to step S12, the energization to the second electromagnetic coil 3b is stopped, and the precharge switch 3c is turned off. As a result, a power supply state (see FIG. 3) in which only the positive main switch 3a and the negative main switch 3b are turned on is obtained.

The effect of this example will be described. As shown in FIG. 2, the power supply system 1 of this example turns on only one of the two switches 3a and 3b by applying a low voltage to the first electromagnetic coil 5a, and as shown in FIG. By applying a high voltage to the first electromagnetic coil 5a, the two switches 3a and 3b are both turned on.
In this way, by changing the voltage applied to the first electromagnetic coil 5a, only one switch 3b of the two switches 3a and 3b can be turned on, or both switches 3a and 3b can be turned on. It becomes possible. In the power supply system 1 of the present example, the other switch 3c is opened and closed by the second electromagnetic coil 5b. Therefore, the three switches 3a to 3c can be opened and closed by using these two electromagnetic coils 5a and 5b, and the power cutoff state (see FIG. 1), the precharge state (see FIG. 2), and the power supply state (see FIG. 3) can be easily switched.
Thus, in this example, the above three states can be switched while the number of electromagnetic coils 5 (two) is smaller than the number of switches 3 (three). Therefore, the manufacturing cost of the power supply system 1 can be reduced.

  In this example, one switch (first relay 14) is constituted by the two switches 3a and 3b and the first electromagnetic coil 5a. In this way, the volume of the entire relay can be reduced as compared with the case where the two switches 3a and 3b are separate relays. Therefore, the volume of the power supply system 1 can be reduced.

In this example, the two main switches 3a and 3b are opened and closed by the first electromagnetic coil 5a, and the precharge switch 3c is opened and closed by the second electromagnetic coil 5b.
In this way, the two main switches 3a and 3b can be opened and closed by one electromagnetic coil (first electromagnetic coil 5a). The electromagnetic coil that opens and closes the precharge switch 3c is energized only for a relatively short time when it is in the precharge state, whereas the electromagnetic coil that opens and closes the main switches 3a and 3b has a relatively long time for operating the electronic device 11. Energized. For this reason, the electromagnetic coil 5 that opens and closes the main switches 3a and 3b is required to have high reliability, and is likely to be large and expensive. Therefore, by opening and closing the two main switches 3a and 3b with one electromagnetic coil 5 as in this example, the number of the electromagnetic coils 5 for the main switches 3a and 3b, which can be easily increased in size, can be reduced to one. The reduction effect of the electromagnetic coil 5 can be increased.

  Further, as in this example, when two main switches 3a and 3b are turned on using one electromagnetic coil 5, compared to the case where two main switches are turned on using two electromagnetic coils. The power consumption of the electromagnetic coil 5 in the power supply state (see FIG. 3) can be reduced.

Further, in this example, as shown in FIG. 10, the power supply system 1 is set in the precharge state (steps S9 and S10), waits for a predetermined time (step S11), stores charges in the smoothing capacitor 12, and then stores two mains. The switches 3a and 3b are turned on. After that, by stopping energization to the second electromagnetic coil 5b (step S12), only the precharge switch 3c is turned off to be in the power supply state.
If the charge is stored in the smoothing capacitor 12, the precharge switch 3c is turned off, and then the two main switches 3a and 3b are turned on. After the precharge switch 3c is turned off, the two main switches 3a are turned off. , 3b until the voltage is applied to the smoothing capacitor 12, the electric charge stored in the smoothing capacitor 12 is easily discharged. However, as described above, after the electric charge is stored in the smoothing capacitor 12, if the two main switches 3a and 3b are turned on and then the precharge switch 3c is turned off, the switches 3 are switched. Since a voltage is applied to the smoothing capacitor 12 in the meantime, the electric charge of the smoothing capacitor 12 can be prevented from being discharged.

Further, as shown in FIGS. 8 and 9, the control circuit unit 6 of the present example includes a first welding determination unit 65 and a second welding for determining whether or not the switch 3 is welded before the electronic device 11 is operated. Judgment means 66 is provided. The first welding determination means 65 turns on only the precharge switch 3c and checks whether or not the current sensor 69 detects a current, whereby a main switch (negative side main switch) that is not connected in parallel to the series body 13 is checked. It is determined whether or not 3b) is welded. The second welding determination means 66 applies a low voltage to the first electromagnetic coil 5a and turns on only the main switch (negative main switch 3b) that is not connected in parallel to the series body 13, and the current sensor 69 detects the current. It is determined whether the main switch (positive side main switch 3a) or the precharge switch 3c connected in parallel to the series body 13 is welded.
If it does in this way, before operating electronic equipment 11, it can be checked whether any of three switches 3a-3c is welded. Therefore, when any one of the switches 3 is welded, the electronic device 11 can be controlled not to operate in order to ensure safety. Thereby, the safety | security of the electronic device 11 can be improved more.

  In this example, as shown in FIG. 1, the series body 10 is connected in parallel to the positive main switch 3a, but the series body 10 may be connected in parallel to the negative main switch 3b.

In this example, the precharge switch 3c is turned off in the power supply state (see FIG. 3), but the precharge switch 3c may be kept on in the power supply state. In this case, the three switches 3a to 3c are turned on in the power supply state, but since the resistance value of the precharge resistor 4 is relatively large, almost the current flows through the main switches 3a and 3b. Not much current flows. Therefore, there is no big problem in practical use.
As in this example, when the precharge switch 3c is turned off in the power supply state, the precharge switch 3c is welded even when a large current flows for some reason when power is supplied to the electronic device 11. Can be prevented.

  Further, in this example, the first electromagnetic coil 5a is configured using one copper wire, but the first electromagnetic coil 5a may be configured using a plurality of copper wires. That is, the first electromagnetic coil 5a may be divided into a plurality of parts. Each part may be connected to the control circuit unit 6. Moreover, you may comprise the 2nd electromagnetic coil 5b in this way.

  As described above, according to this example, it is possible to provide a power supply system that can reduce the number of electromagnetic coils than the number of switches.

(Example 2)
In this example, the combination of the switches 3 that are opened and closed by the first electromagnetic coil 5a is changed. As shown in FIG. 11, in this example, the main switch (negative main switch 3 b) and the precharge switch 3 c that are not connected in parallel to the series body 13 are opened and closed by the first electromagnetic coil 5 a and connected in parallel to the series body 13. The main switch (positive main switch 3a) is opened and closed by the second electromagnetic coil 5b. When a low voltage is applied to the first electromagnetic coil 5a, only the negative main switch 3b is turned on. When a high voltage is applied, both the precharge switch 3c and the negative main switch 3b Both are configured to be on.

In this example, as in the first embodiment, before the electronic device 11 is operated, it is confirmed whether or not the switches 3a to 3c are welded. FIG. 12 shows a flowchart for confirming welding.
In order to confirm the presence or absence of welding, first, a low voltage is applied to the first electromagnetic coil 3a, and only the negative-side main switch 3b is turned on (step S13). Thereafter, the process proceeds to step S14 to determine whether or not the current sensor 69 has detected a current. If the precharge switch 3c or the positive main switch 3a is welded, a current flows through the smoothing capacitor 12 when the negative main switch 3b is turned on, and the current sensor 69 detects the current. Further, if the precharge switch 3c or the positive main switch 3a is not welded, no current flows and the current sensor 69 does not detect the current.

  If it is determined in step S14 that the current sensor 69 has detected a current (Yes), the process proceeds to step S19, where it is determined that the precharge switch 3c or the main main switch 3a is welded. Then, the electronic device 11 is controlled not to operate.

  In Step S14, when it is determined that the current sensor 69 does not detect current (No), it is determined that the precharge switch 3c or the main main switch 3a is not welded, and Steps S15 and S16 are executed. In step S15, the negative main switch 3b is turned off. In step S16, the positive main switch 3a is turned on by energizing the second electromagnetic coil 5b. Thereafter, the process proceeds to step S17.

  If the negative main switch 3b is welded, a current flows through the smoothing capacitor 12 when the positive main switch 3a is turned on, and the current sensor 69 detects the current. If the negative main switch 3b is not welded, no current flows, and the current sensor 69 does not detect the current.

  In step S17, when it is determined that the current sensor 69 has detected a current (Yes), the process proceeds to step S20, and it is determined that the negative main switch 3b is welded. Then, the electronic device 11 is controlled not to operate.

  In Step S17, when current sensor 69 judges that current is not detected (No), it moves to Step S18 and judges that all switches 3a-3c are not welded. And the process (steps S21-S23: refer FIG. 13) which operates the electronic device 11 is performed.

  The steps S13 to S20 are performed by the first welding determination unit 65 and the second welding determination unit 66 of the control circuit unit 6 as in the first embodiment.

  As shown in FIG. 13, when the electronic device 11 is operated, first, a high voltage is applied to the first electromagnetic coil 5a, and both the precharge switch 3c and the negative main switch 3b are turned on (step S21). As a result, a precharge state in which charges are gradually stored in the smoothing capacitor 12 via the precharge resistor 4 is established.

Step S22 is performed after step S21. Here, the charge is sufficiently stored in the smoothing capacitor 12 after waiting for a predetermined time. Thereafter, the main main switch 3a is turned on.
Thereafter, the process proceeds to step S23, the voltage applied to the first electromagnetic coil 5a is lowered to a low voltage, and the precharge switch 3c is turned off. As a result, only the positive main switch 3a and the negative main switch 3b are turned on.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described. In this example, as shown in FIG. 11, the negative main switch 3b and the precharge switch 3c are opened and closed by the first electromagnetic coil 5a, and the positive main switch 3a is opened and closed by the second electromagnetic coil 5b. And it is comprised so that only the negative side main switch 3b may be turned ON among two switches 3b and 3c by applying a low voltage to the 1st electromagnetic coil 5a.
If it does in this way, switching between an electric power interruption state, a precharge state, and an electric power supply state can be easily performed using two electromagnetic coils, the 1st electromagnetic coil 5a and the 2nd electromagnetic coil 5b.

Further, in this example, as shown in FIG. 13, a high voltage is applied to the first electromagnetic coil 5a to be in a precharge state (step S21), and after waiting for a predetermined time (step S22), electric charges are stored in the smoothing capacitor 12, The main main switch 3a is turned on. Thereafter, the voltage applied to the first electromagnetic coil 5a is lowered to a low voltage (step S23), so that only the precharge switch 3c is turned off to enter the power supply state.
If the charge is stored in the smoothing capacitor 12, the precharge switch 3c is turned off, and then the two main switches 3a and 3b are turned on. After the precharge switch 3c is turned off, the two main switches 3a are turned off. , 3b until the voltage is applied to the smoothing capacitor 12, the electric charge stored in the smoothing capacitor 12 is easily discharged. However, as described above, after accumulating charges in the smoothing capacitor 12, if the two main switches 3a and 3b are turned on and then the precharge switch 3c is turned off, these switches are being switched. Since a voltage is applied to the smoothing capacitor 12, it is possible to prevent the electric charge of the smoothing capacitor 12 from being discharged.

In this example, as shown in FIG. 12, before operating the electronic device 11, the first welding determination means 65 for determining whether or not the precharge switch 3c or the positive main switch 3a is welded, and the negative main Second welding determination means 66 for determining whether or not the switch 3b is welded.
If it does in this way, before operating electronic equipment 11, it can be judged whether any of three switches 3a-3c are welded. Therefore, when it is determined that any one of the switches 3 is welded, the electronic device 11 can be controlled not to operate in order to ensure safety. Thereby, the safety | security of the electronic device 11 can be improved.
In addition, the same effects as those of the first embodiment are obtained.

  In this example, as shown in FIG. 11, the series body 13 is connected in parallel to the positive switch 3a, but the series body 13 may be connected in parallel to the negative switch 3b. In this case, the precharge switch 3c and the positive switch 3a are opened and closed by the first electromagnetic coil 3a, and the negative switch 3b is opened and closed by the second electromagnetic coil 3b.

(Example 3)
In this example, the number of switches 3 and electromagnetic coils 5 is changed. As shown in FIG. 14, the power supply system 1 of this example includes two switches 3 including a main switch 3d and a precharge switch 3c, and one electromagnetic coil 5. In addition, the power supply system 1 of this example includes a precharge resistor 4 and a control circuit unit 6. The main switch 3 d is provided between the positive terminal of the DC power supply 10 and the high potential side terminal 111 of the electronic device 11. The precharge switch 3 c is connected in series to the precharge resistor 4. The electromagnetic coil 5 opens and closes two switches 3 including a main switch 3d and a precharge switch 3c.

As shown in FIG. 14, a serial body 13 in which the precharge resistor 4 and the precharge switch 3c are connected in series is connected in parallel to the main switch 3d.
The control circuit unit 6 includes a power cutoff state in which the two switches 3c and 3d are turned off, a precharge state in which charges are stored in the smoothing capacitor 12 by turning on only the precharge switch 3c, and a precharge state. By switching on both of the two switches 3c and 3d, the power supply state for supplying power to the electronic device 11 is switched.

  When a relatively low voltage is applied to the electromagnetic coil 5, only the precharge switch 3c is turned on. When a voltage higher than the low voltage is applied, both the main switch 3d and the precharge switch 3c are turned on. It is configured.

As shown in FIG. 15, when operating the electronic device 11, first, by applying a relatively low voltage to the electromagnetic coil 5, only the precharge switch 3 c is turned on. As a result, a precharge state in which electric charges are gradually stored in the smoothing capacitor 12 via the precharge resistor 4 is established (step S24). Thereafter, the process proceeds to step S25. Here, the charge is sufficiently stored in the smoothing capacitor 12 by waiting for a predetermined time. Thereafter, by applying the high voltage, both the main switch 3d and the precharge switch 3c are turned on to enter the power supply state.
In addition, the same configuration as that of the first embodiment is provided.

The effect of this example will be described. The power supply system 1 of this example is configured to turn on only the precharge switch 3c by applying a low voltage to the electromagnetic coil 5, and to turn on both the main switch 3d and the precharge switch 3c by applying a high voltage. Has been.
In this way, it is possible to turn on only the precharge switch 3c or turn on both switches 3c and 3d by changing the voltage applied to the electromagnetic coil 5. Therefore, it is possible to easily switch between the power cutoff state, the precharge state, and the power supply state by opening and closing the two switches 3c and 3d using the single electromagnetic coil 5.
As described above, in this example, the three states can be switched while the number of the electromagnetic coils 5 is smaller than the number of the switches 3c and 3d. Therefore, the manufacturing cost of the power supply system 1 can be reduced.

  In this example, since both the main switch 3d and the precharge switch 3c are turned on in the power supply state, a current continues to flow through the precharge resistor 4 in the power supply state. However, if a resistor having a large resistance value is used for the precharge resistor 4, most of the current flows through the main switch 3 d, and the current hardly flows through the precharge resistor 4. Therefore, it is realizable also with the circuit of this example.

  In this example, the main switch 3d is provided between the positive terminal of the DC power source 10 and the high potential side terminal 111 of the electronic device 11. However, the negative terminal of the DC power source 10 and the low potential side terminal of the electronic device 11 are provided. 112 may be provided.

  In addition, the same effects as those of the first embodiment are obtained.

DESCRIPTION OF SYMBOLS 1 Power supply system 10 DC power supply 11 Electronic device 12 Smoothing capacitor 13 Serial body 2a Positive side wiring 2b Negative side wiring 3a Positive side main switch 3b Negative side main switch 3c Precharge switch 4 Precharge resistance 5a First electromagnetic coil 5b Second electromagnetic Coil 6 Control circuit section

Claims (9)

A positive main switch (3a) provided between the positive terminal of the DC power source (10) and the high potential side terminal (111) of the electronic device (11);
A negative main switch (3b) provided between the negative terminal of the DC power source and the low potential side terminal (112) of the electronic device;
A precharge resistor (4) for gradually passing a current through a smoothing capacitor (12) connected in parallel to the electronic device when the electronic device is activated;
A precharge switch (3c) connected in series to the precharge resistor;
A first electromagnetic coil (5a) and a second electromagnetic coil (5b) for opening and closing three switches (3) of the positive main switch, the negative main switch, and the precharge switch;
A control circuit unit (6) connected to the first electromagnetic coil and the second electromagnetic coil for controlling the opening / closing operation of the switch;
A series body (13) in which the precharge resistor and the precharge switch are connected in series is connected in parallel to the positive main switch or the negative main switch,
The control circuit section is in parallel with the series body of the two main switches (3a, 3b) of the power cut-off state in which the three switches are turned off and the positive main switch and the negative main switch. A precharge state in which electric charge is stored in the smoothing capacitor by turning on the unconnected main switch and the precharge switch, and the electronic device by turning on the two main switches after the precharge state Switch between the power supply state to supply power to
Of the three switches, two of the switches are opened and closed by the first electromagnetic coil, and the other one of the switches is opened and closed by the second electromagnetic coil.
By applying a relatively low low voltage to the first electromagnetic coil, only one of the two switches is turned on, and by applying a high voltage higher than the low voltage, the two electromagnetic switches A power supply system configured to turn on both switches.   The power supply system according to claim 1, wherein the power supply state is a state in which the two main switches are turned on and the precharge switch is turned off after the precharge state. .   3. The power supply system according to claim 2, wherein the two main switches are opened and closed by the first electromagnetic coil, the precharge switch is opened and closed by the second electromagnetic coil, and the low voltage is applied to the first electromagnetic coil. Thus, only the main switch that is not connected in parallel to the series body among the two main switches is turned on.   4. The power switch system according to claim 3, wherein the control circuit unit applies the low voltage to the first electromagnetic coil and energizes the second electromagnetic coil, so that the main switch is not connected in parallel to the series body. And the precharge switch are turned on to be in the precharge state, and after the electric charge is stored in the smoothing capacitor, the voltage applied to the first electromagnetic coil is increased to the high voltage, whereby the two main switches Is turned on, and then the energization of the second electromagnetic coil is stopped, so that only the precharge switch is turned off and the power supply state is set.   5. The power supply system according to claim 4, wherein the control circuit unit turns on only the precharge switch before entering the precharge state, and whether a main switch not connected in parallel to the series body is welded. First welding judgment means (65) for judging whether or not, a main switch that applies a low voltage to the first electromagnetic coil and turns on only the main switch that is not connected in parallel to the series body, and is connected in parallel to the series body Or a second welding judgment means (66) for judging whether or not the precharge switch is welded.   3. The power supply system according to claim 2, wherein a main switch not connected in parallel to the series body and the precharge switch are opened and closed by the first electromagnetic coil, and a main switch connected in parallel to the series body is connected to the second body. By opening and closing by an electromagnetic coil and applying the low voltage to the first electromagnetic coil, only the main switch that is not connected in parallel to the series body is turned on among the two switches. Power system.   The power supply system according to claim 6, wherein the control circuit unit turns on a main switch and the precharge switch that are not connected in parallel to the series body by applying a high voltage to the first electromagnetic coil. After the charge is stored in the smoothing capacitor in the precharged state, the second electromagnetic coil is energized to turn on the main switch connected in parallel to the series body, and then applied to the first electromagnetic coil A power supply system characterized in that only the precharge switch is turned off and the power is supplied by lowering the voltage to the low voltage.   8. The power supply system according to claim 7, wherein the control circuit unit turns on only a main switch that is not connected in parallel to the series body and is connected in parallel to the series body before entering the precharge state. Only the first welding judgment means for judging whether or not the main switch or the precharge switch is welded and the main switch connected in parallel to the series body are turned on, and the main switch not connected in parallel to the series body is welded And a second welding determination means for determining whether or not the power supply system. Provided between the positive terminal of the DC power source (10) and the high potential side terminal (111) of the electronic device (11), or between the negative terminal of the DC power source and the low potential side terminal (112) of the electronic device. Main switch (3d),
A precharge resistor (4) for gradually passing a current through a smoothing capacitor (12) connected in parallel to the electronic device when the electronic device is activated;
A precharge switch (3c) connected in series to the precharge resistor;
An electromagnetic coil (5) for opening and closing two switches, the main switch and the precharge switch;
A control circuit unit (6) connected to the electromagnetic coil and controlling the opening / closing operation of the two switches;
A series body (13) in which the precharge resistor and the precharge switch are connected in series is connected in parallel to the main switch,
The control circuit unit includes a power cutoff state in which the two switches are turned off, a precharge state in which charges are stored in the smoothing capacitor by turning on only the precharge switch, and after the precharge state, By switching on both of the two switches, the power supply state for supplying power to the electronic device is switched,
By applying a relatively low low voltage to the electromagnetic coil, only the precharge switch is turned on to be in the precharge state, and then a high voltage higher than the low voltage is applied, whereby the main switch and the A power supply system configured to turn on both precharge switches to enter the power supply state.

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