WO2021019640A1 - Power feed system - Google Patents

Power feed system Download PDF

Info

Publication number
WO2021019640A1
WO2021019640A1 PCT/JP2019/029645 JP2019029645W WO2021019640A1 WO 2021019640 A1 WO2021019640 A1 WO 2021019640A1 JP 2019029645 W JP2019029645 W JP 2019029645W WO 2021019640 A1 WO2021019640 A1 WO 2021019640A1
Authority
WO
WIPO (PCT)
Prior art keywords
ground fault
relays
pair
devices
power supply
Prior art date
Application number
PCT/JP2019/029645
Other languages
French (fr)
Japanese (ja)
Inventor
鴻飛 呂
彰久 前北
Original Assignee
三菱電機株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱電機株式会社 filed Critical 三菱電機株式会社
Priority to PCT/JP2019/029645 priority Critical patent/WO2021019640A1/en
Priority to JP2021536482A priority patent/JP7112038B2/en
Publication of WO2021019640A1 publication Critical patent/WO2021019640A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/16—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to fault current to earth, frame or mass

Definitions

  • the present invention relates to a power supply system that supplies electric power from a power source to a plurality of devices.
  • DC power supply systems are attracting attention from the viewpoint of increasing awareness of business continuity (BCP: Business Continuity Planning) in the event of a disaster and energy saving.
  • BCP Business Continuity Planning
  • an earth leakage breaker compatible with DC voltage has not been developed. Therefore, there is a power supply system in which the positive and negative electrodes of the power supply are connected to the ground via a high resistance element so that the ground fault current becomes a predetermined current or less when a ground fault occurs on the load side or the like. ..
  • the DC power supply if a ground fault occurs at one location on the load side, etc., the DC power supply is grounded via the high resistance element, so the ground fault current can be kept below the safe current by the high resistance element. It becomes.
  • Patent Document 1 An example of a DC power supply system that detects a ground fault current flowing through a DC line has been proposed (see, for example, Patent Document 1).
  • the power feeding system disclosed in Patent Document 1 two capacitors are connected in series between the positive and negative outputs of a DC voltage, and the connection points of the two capacitors are connected to the ground via a resistance element.
  • a bridge circuit is composed of these two capacitors and two resistance elements provided on the power supply side. When a ground fault occurs, the ground fault is detected by utilizing the fact that the bridge circuit is in an unbalanced state.
  • a discrimination device for detecting a ground fault that occurs in a plurality of lines branched from a main circuit including a power supply has been proposed (see, for example, Patent Document 2).
  • a relay for detecting a ground fault accident is provided in the main circuit for each of a plurality of lines, and a ground fault accident occurs intermittently in the DC control power supply circuit provided in the main circuit. It identifies the ground fault line.
  • each line is equipped with a current transformer that detects a momentary change in the current flowing through the line due to the charging and discharging of the ground capacitance existing in the line due to a ground fault accident.
  • the ground fault line is identified by the difference in the detected current change.
  • Patent Document 2 proposes a ground fault detection circuit for finding a branch circuit in which a DC ground fault has occurred, but since each branch circuit requires a current transformer, the manufacturing cost becomes high. ..
  • the present invention has been made to solve the above problems, and provides a power supply system that can easily identify the location where a ground fault occurs.
  • the power supply system corresponds to a plurality of devices connected in parallel via a DC power supply and a positive voltage line and a negative voltage line, a controller communication connected to the plurality of devices, and each of the plurality of devices.
  • the positive voltage line and the negative voltage line are provided with a plurality of pairs of relays for switching connection and disconnection with the DC power supply, and each device is provided between the positive voltage line and the negative voltage line.
  • a detection device including a voltage detector that detects a potential difference caused by a current flowing when a ground fault occurs, a communication circuit that transmits the value of the potential difference detected by the voltage detector to the controller, and the communication.
  • the controller includes a relay control circuit that is connected to the controller via a circuit and controls the pair of relays corresponding to the device, and the controller detects the occurrence of the ground fault by the plurality of detection devices.
  • a relay control means that controls at least one pair of relays in the connected state and controls the other pair of relays in the disconnected state, and the plurality of pairs of relays by the relay control means. When the state of the relay is switched, it has a specific means for identifying the location where the ground fault occurs based on the plurality of potential differences received from the plurality of voltage detectors.
  • a plurality of pairs of relays are provided corresponding to a plurality of branch circuits, and among the plurality of pairs of relays, one pair of relays is connected and the other pair of relays is disconnected.
  • the presence or absence of detection of potential difference is determined by a plurality of voltage detectors. Therefore, it is possible to determine which pair of relays is in the connected state when the ground fault has occurred, and the location where the ground fault has occurred can be easily identified as compared with the conventional case.
  • FIG. It is a figure which shows one configuration example of the power distribution system of the air-conditioning system which concerns on Embodiment 1.
  • FIG. It is a figure which shows one configuration example of the refrigerant circuit which each air conditioner shown in FIG. 1 has.
  • FIG. It is a figure which shows the case where the ground fault occurs in the transmission line on the negative electrode side in the air conditioning system shown in FIG.
  • the power supply system of the present embodiment is a system having a plurality of devices that receive power from a DC power source.
  • the device for receiving power is an air conditioner
  • the power supply system is not limited to the air conditioner system.
  • FIG. 1 is a diagram showing a configuration example of a power distribution system of the air conditioning system according to the first embodiment.
  • the air conditioning system 100 includes a plurality of air conditioners 9 to 11 connected in parallel to the DC power supply 1, a system controller 12 for detecting the occurrence of a ground fault, and a plurality of air conditioners 9 to 11. It has a plurality of pairs of relays 3 to 5 for switching connection and disconnection with the DC power supply 1.
  • Each device of the air conditioners 9 to 11 is a device that harmonizes the air in the room which is the space to be air-conditioned.
  • the transmission line of the positive electrode line 7 is connected to the positive electrode side of the DC power supply 1, and the transmission line of the negative electrode line 8 is connected to the negative electrode side.
  • the positive electrode line 7 is branched into a plurality of positive electrode branch lines 7a to 7c.
  • the negative electrode line 8 is branched into a plurality of negative electrode branch lines 8a to 8c.
  • the positive electrode branch line 7a and the negative electrode branch line 8a are connected to the air conditioner 9.
  • the positive electrode branch line 7b and the negative electrode branch line 8b are connected to the air conditioner 10.
  • the positive electrode branch line 7c and the negative electrode branch line 8c are connected to the air conditioner 11.
  • a branch circuit is configured for each of the air conditioners 9 to 11.
  • Resistor elements R1 and R2 are connected in series between the positive electrode line 7 and the negative electrode line 8.
  • the connection point between the resistance element R1 and the resistance element R2 is grounded to the ground, and the potential between the resistance element R1 and the resistance element R2 becomes the ground potential.
  • the resistance values of the resistance elements R1 and R2 are the same, for example, 40 k ⁇ to 50 k ⁇ .
  • the pair of relays 3 is composed of a relay 3-1 provided on the positive electrode branch line 7a and a relay 3-2 provided on the negative electrode branch line 8a.
  • the pair of relays 3 switches the connection and disconnection of the air conditioner 9 to the DC power supply 1.
  • the pair of relays 4 is composed of a relay 4-1 provided on the positive electrode branch line 7b and a relay 4-2 provided on the negative electrode branch line 8b.
  • the pair of relays 4 switches the connection and disconnection of the air conditioner 10 to the DC power supply 1.
  • the pair of relays 5 is composed of a relay 5-1 provided in the positive electrode branch line 7c and a relay 5-2 provided in the negative electrode branch line 8c.
  • the pair of relays 5 switches the connection and disconnection of the air conditioner 11 with the DC power supply 1.
  • the air conditioner 9 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 3.
  • the air conditioner 10 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 4.
  • the air conditioner 11 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 5.
  • FIG. 1 shows a case where the pair of relays 3 are provided inside the air conditioner 9, the installation location of the pair of relays 3 is not limited to the inside of the air conditioner 9.
  • the pair of relays 3 may be provided outside the air conditioner 9.
  • the installation location of the pair of relays 4 and 5 is the same as that of the pair of relays 3. That is, the pair of relays 4 may be provided outside the air conditioner 10, and the pair of relays 5 may be provided outside the air conditioner 11.
  • the air conditioner 9 has a detection device 15a for detecting a ground fault and a control circuit 13a.
  • the detection device 15a includes a first resistance element R3, a second resistance element R4, a third resistance element R5, and a voltage detector 2a.
  • the first resistance element R3 and the second resistance element R4 are connected in series between the positive electrode branch line 7a and the negative electrode branch line 8a.
  • the third resistance element R5 is provided between the connection point of the first resistance element R3 and the second resistance element R4 and the ground.
  • the voltage detector 2a is connected in parallel to the third resistance element R5.
  • the voltage detector 2a detects the potential difference Vda caused by the current flowing through the third resistance element R5.
  • the voltage detector 2a outputs the current direction information indicating the direction of the current flowing through the third resistance element R5 and the detected potential difference Vda to the control circuit 13a.
  • a remote controller 14a for the user of the air conditioner 9 to instruct the air conditioner 9 of setting information such as a set temperature and an air volume is connected to the control circuit 13a via a transmission line 24.
  • the air conditioner 10 has a detection device 15b for detecting a ground fault and a control circuit 13b.
  • the detection device 15b includes a first resistance element R6, a second resistance element R7, a third resistance element R8, and a voltage detector 2b.
  • the first resistance element R6 and the second resistance element R7 are connected in series between the positive electrode branch line 7b and the negative electrode branch line 8b.
  • the third resistance element R8 is provided between the connection point of the first resistance element R6 and the second resistance element R7 and the ground.
  • the voltage detector 2b is connected in parallel to the third resistance element R8. The voltage detector 2b detects the potential difference Vdb caused by the current flowing through the third resistance element R8.
  • the voltage detector 2b outputs the current direction information indicating the direction of the current flowing through the third resistance element R8 and the detected potential difference Vdb to the control circuit 13b.
  • a remote controller 14b for the user of the air conditioner 10 to instruct the air conditioner 10 of setting information is connected to the control circuit 13b via a transmission line 24.
  • the air conditioner 11 has a detection device 15c for detecting a ground fault and a control circuit 13c.
  • the detection device 15c includes a first resistance element R9, a second resistance element R10, a third resistance element R11, and a voltage detector 2c.
  • the first resistance element R9 and the second resistance element R10 are connected in series between the positive electrode branch line 7c and the negative electrode branch line 8c.
  • the third resistance element R11 is provided between the connection point of the first resistance element R9 and the second resistance element R10 and the ground.
  • the voltage detector 2c is connected in parallel to the third resistance element R11. The voltage detector 2c detects the potential difference Vdc caused by the current flowing through the third resistance element R11.
  • the voltage detector 2c outputs the current direction information indicating the direction of the current flowing through the third resistance element R11 and the detected potential difference Vdc to the control circuit 13c.
  • a remote controller 14c for the user of the air conditioner 11 to instruct the air conditioner 11 of setting information is connected to the control circuit 13c via a transmission line 24.
  • the resistance value of each element of the resistance elements R1 and R2 is 40 k ⁇
  • the resistance value of each element of the first resistance elements R3, R6 and R9 and the second resistance elements R4, R7 and R10 is 100 k ⁇ .
  • the resistance value of each of the third resistance elements R5, R8 and R11 is set so that the potential difference caused by a minute current can be detected.
  • the resistance value of each of the third resistance elements R5, R8, and R11 is, for example, 1 k ⁇ .
  • the control circuits 13a to 13c are connected to the system controller 12 via the transmission line 23.
  • the transmission line 23 may be provided with a repeater (not shown) that relays the transmission of signals.
  • a power supply unit 6 for supplying electric power to a communication device such as a repeater (not shown) for signal transmission may be provided.
  • FIG. 2 is a diagram showing a configuration example of a refrigerant circuit included in each air conditioner shown in FIG. Since the refrigerant circuits included in the air conditioners 9 to 11 have the same configuration, the refrigerant circuit provided in the air conditioner 9 will be described.
  • the air conditioner 9 includes a compressor 51 that compresses and discharges the refrigerant, a four-way valve 52 that switches the flow path of the refrigerant, and a heat source side heat exchanger 53 that exchanges heat with the outside air. It has an expansion device 54 that expands the refrigerant, and a load side heat exchanger 55 that exchanges heat with the air in the room.
  • the compressor 51, the heat source side heat exchanger 53, the expansion device 54, and the load side heat exchanger 55 are connected by a refrigerant pipe 56 to form a refrigerant circuit 50 in which the refrigerant circulates.
  • the compressor 51 is, for example, an inverter type compressor whose capacity can be changed.
  • the expansion device 54 is, for example, an electronic expansion valve.
  • the heat source side heat exchanger 53 and the load side heat exchanger 55 are, for example, fin-and-tube heat exchangers.
  • the compressor 51, the four-way valve 52 and the expansion device 54 are communicated with the control circuit 13a.
  • a converter circuit and an inverter circuit connected to the positive electrode branch line 7a and the negative electrode branch line 8a are provided.
  • the converter circuit (not shown) and the inverter circuit (not shown) lower the DC voltage supplied from the DC power supply 1 to a value suitable for the power supply voltage of each refrigerant device of the compressor 51, the expansion device 54, and the four-way valve 52. And supply power to these refrigerant devices.
  • the air conditioner 9 may be provided with a blower that supplies outside air to the heat source side heat exchanger and a blower that supplies indoor air to the load side heat exchanger. Further, although not shown in FIG. 2, various sensors such as a temperature sensor for detecting the indoor temperature and a pressure sensor for detecting the pressure of the refrigerant discharged from the compressor 51 may be provided in the air conditioner 9. ..
  • FIG. 3 is a block diagram showing a configuration example of the control circuit shown in FIG. Since the control circuits 13a to 13c have the same configuration, the configuration of the control circuit 13a will be described here.
  • the control circuit 13a includes a microcomputer 31a, a communication circuit 32a, a relay control circuit 33a, and a converter circuit 34a.
  • the communication circuit 32a is communicatively connected to the system controller 12 via the transmission line 23, and relays information transmitted and received between the microcomputer 31a and the system controller 12.
  • the converter circuit 34a is a DC (direct current) / DC (direct current) converter circuit that supplies an operating voltage to the relay control circuit 33a. Although not shown in FIG. 3, the converter circuit 34a is connected to the positive electrode branch line 7a and the negative electrode branch line 8a.
  • the converter circuit 34a supplies an operating voltage not only to the relay control circuit 33a but also to the microcomputer 31a and the communication circuit 32a.
  • the microcomputer 31a transmits the ground fault information including the potential difference Vda and the current direction information input from the voltage detector 2a to the system controller 12 via the communication circuit 32a.
  • the microcomputer 31a receives the control signal regarding the connection state and the disconnection state of the pair of relays 3 from the system controller 12 via the communication circuit 32a, the microcomputer 31a operates the relay control circuit 33a according to the control signal.
  • the microcomputer 31a has a refrigerant circuit shown in FIG. 2 based on the setting information input via the remote controller 14a and the values of various sensors (not shown) provided in the air conditioner 9 shown in FIG. Control 50 refrigeration cycles. Specifically, the microcomputer 31a controls the four-way valve 52 according to the operation mode included in the setting information. The microcomputer 31a controls the operating frequency of the compressor 51 and the opening degree of the expansion device 54 based on the setting information and the values of various sensors not shown in the figure.
  • ground fault information is transmitted from the voltage detector 2a to the system controller 12 via the microcomputer 31a, and a control signal is operated from the system controller 12 via the microcomputer 31a to operate the relay control circuit 33a.
  • the ground fault information output from the voltage detector 2a may be transmitted to the system controller 12 via the communication circuit 32a without going through the microcomputer 31a.
  • the control signal transmitted from the system controller 12 may be input to the relay control circuit 33a via the communication circuit 32a without passing through the microcomputer 31a.
  • the relay control circuit 33a may cause the pair of relays 3 to connect or disconnect the line according to the input control signal.
  • the control circuit 13b includes a microcomputer 31b, a communication circuit 32b, a relay control circuit 33b, and a converter circuit 34b.
  • the control circuit 13c includes a microcomputer 31b, a communication circuit 32b, a relay control circuit 33b, and a converter circuit 34b.
  • the microcomputers 31b and 31c have the same configuration as the microcomputer 31a.
  • the communication circuits 32b and 32c have the same configuration as the communication circuit 32a.
  • the relay control circuits 33b and 33c have the same configuration as the relay control circuit 33a.
  • the converter circuits 34b and 34c have the same configuration as the converter circuit 34a. Therefore, detailed description of the control circuits 13b and 13c will be omitted.
  • FIG. 4 is a block diagram showing a configuration example of the system controller shown in FIG.
  • the system controller 12 has a memory 22 for storing a program and a CPU (Central Processing Unit) 21 for executing processing according to the program stored in the memory 22.
  • the CPU 21 executes the program, the determination means 41, the identification means 42, and the relay control means 43 shown in FIG. 4 are configured.
  • the determination means 41 determines whether or not a ground fault has occurred based on the potential differences Vda to Vdc detected by the voltage detectors 2a to 2c. Specifically, the determination means 41 compares the determined threshold value Vth with the potential differences Vda to Vdc, and determines that a ground fault has occurred when the potential difference detected by each of the potential differences Vda to Vdc becomes larger than the threshold value Vth. To do.
  • the threshold value Vth is stored in the memory 22 shown in FIG.
  • the determination means 41 may determine that a ground fault has occurred when at least one potential difference becomes larger than the threshold value Vth even when all of the potential differences Vda to Vdc become larger than the threshold value Vth. In this case, ground fault detection will be faster.
  • the relay control means 43 controls at least one pair of relays among the pair of relays 3 to 5 in a connected state, and controls the remaining pair of relays. Control to disconnect state.
  • the identification means 42 identifies the location where the ground fault occurs based on the potential differences Vda to Vdc received from the voltage detectors 2a to 2c. The detailed operation of the relay control means 43 and the specific means 42 will be described later.
  • the system controller 12 may be provided in the microcomputers 31a to 31c.
  • the determination means 41 may be provided in each of the microcomputers 31a to 31c.
  • a ground fault may occur in the power supply system and inside each of the air conditioners 9 to 11.
  • the power supply system has a configuration including a DC power supply 1 and a transmission line from the DC power supply 1 to a pair of relays 3 to 5.
  • the transmission line is composed of a positive electrode line 7 and a negative electrode line 8, a positive electrode branch line 7a to 7c, and a negative electrode branch line 8a to 8c.
  • FIG. 5 is a flowchart showing an example of the operation procedure of the air conditioning system shown in FIG. As an initial state, it is assumed that all of the pair of relays 3 to 5 are in the connected state.
  • step S101 the determination means 41 determines whether or not each of the potential differences Vda to Vdc detected by the voltage detectors 2a to 2c is larger than the threshold value Vth. As a result of the determination, when all of the potential differences Vda to Vdc are equal to or less than the threshold value Vth, the determination means 41 determines that no ground fault has occurred, and returns to step S101 (step S101: No). On the other hand, as a result of the determination in step S101, if at least one potential difference among the potential differences Vda to Vdc is larger than the threshold value Vth, it is determined that a ground fault has occurred (step S101: Yes).
  • a bridge circuit is composed of high resistance resistance elements R1 and R2 connected to the DC power supply 1 side and a series resistance provided in the detection device of each branch circuit. Specifically, a bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R3 and the second resistance element R4 of the detection device 15a. A bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R6 and the second resistance element R7 of the detection device 15b. A bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R9 and the second resistance element R10 of the detection device 15c. Due to the equilibrium state of these bridge circuits, the voltage across the third resistance elements R5, R8 and R11 becomes zero. If the potential difference between both ends of the third resistance elements R5, R8 and R11 is zero, it can be determined that no ground fault has occurred.
  • the bridge circuit formed by the resistance elements R1 and R2 and the series resistance of each branch circuit becomes unbalanced. As a result, a potential difference is generated at both ends of the third resistance elements R5, R8 and R11. Then, it can be determined that a ground fault has occurred by detecting that a potential difference has occurred by the voltage detectors 2a to 2c. Due to the resistance at the location where the ground fault occurs, the bridge circuits composed of the resistance elements R1 and R2, the first resistance elements R3, R6 and R9 of the air conditioner, and the second resistance elements R4, R7 and R10 are all the same. Since it is in a balanced state, the same ground fault current flows through each branch circuit. Therefore, the system controller 12 can detect the occurrence of the ground fault in step S101, but cannot specify the location where the ground fault has occurred.
  • step S101 when the determination means 41 determines that a ground fault has occurred, it transmits ground fault information indicating that the ground fault has occurred to the microcomputers 31b and 31c.
  • the microcomputer 31b receives the ground fault information from the system controller 12, the microcomputer 31b stops the operation of the air conditioner 10 when the air conditioner 10 is operating.
  • the microcomputer 31c receives the ground fault information from the system controller 12, the microcomputer 31c stops the operation of the air conditioner 11 when the air conditioner 11 is operating.
  • the microcomputers 31b and 31c transmit stop information to the effect that the operation of the air conditioner has been stopped to the system controller 12.
  • the relay control means 43 controls to switch the pair of relays 4 and 5 to the disconnected state (step S102). Specifically, the relay control means 43 transmits a disconnection control signal to switch the pair of relays to the disconnection state to the relay control circuits 33b and 33c.
  • the identifying means 42 determines whether or not the potential difference Vda detected by the voltage detector 2a is larger than the threshold value Vth (step S103). As a result of the determination, when the potential difference Vda is larger than the threshold value Vth (step S103: Yes), the relay control means 43 transitions to the first specific mode (step S104).
  • the relay control means 43 controls to switch the pair of relays 3 to the disconnected state and the pair of relays 4 to the connected state (step S105). Specifically, the relay control means 43 transmits a disconnection control signal to the relay control circuit 33a, and transmits a connection control signal to switch the pair of relays 4 to the connection state to the relay control circuit 33b.
  • the identifying means 42 determines whether or not the potential difference Vdb detected by the voltage detector 2b is larger than the threshold value Vth (step S106). As a result of the determination, when the potential difference Vdb is larger than the threshold value Vth (step S106: Yes), the specific means 42 determines that a ground fault has occurred in the power supply system (step S107). On the other hand, as a result of the determination in step S106, when the potential difference Vdb is equal to or less than the threshold value Vth (step S106: No), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 9 (step S108).
  • steps S107 and S108 The reason for the determination result in steps S107 and S108 will be described.
  • the locations where the ground fault occurs are the positive electrode side of the transmission line, the negative electrode side of the transmission line, and the air conditioner 9. It can be inferred to be one of the inside of.
  • the pair of relays 3 on the air conditioner 9 side are disconnected, and the pair of relays 4 on the air conditioner 10 side are connected.
  • the voltage detector 2b of the air conditioner 10 detects the potential difference, it can be determined that it is impossible for the ground fault to occur inside the air conditioner 9 among the candidates estimated as the location where the ground fault occurs. .. Therefore, it can be determined that the location where the ground fault occurs is the positive electrode side or the negative electrode side of the transmission line.
  • the transmission line can be excluded from the candidates for the location where the ground fault occurs, and it can be determined that the ground fault has occurred inside the air conditioner 9.
  • step S109 when the potential difference Vda detected by the voltage detector 2a of the air conditioner 9 is equal to or less than the threshold value Vth, the relay control means 43 transitions to the second specific mode (step S109). At this time, since no ground fault has occurred in the air conditioner 9 and the power supply system, the air conditioner 9 may be operated by connecting the pair of relays 3. Therefore, the air conditioner 9 can be operated in the process of identifying the ground fault location.
  • the relay control means 43 controls to switch the pair of relays 4 to the connected state (step S110). Specifically, the relay control means 43 transmits a connection control signal to the relay control circuit 33b.
  • the identifying means 42 determines whether or not the potential difference Vdb detected by the voltage detector 2b is larger than the threshold value Vth (step S111). As a result of the determination, when the potential difference Vdb is larger than the threshold value Vth (step S111: Yes), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 10 (step S112).
  • step S111 when the potential difference Vdb is equal to or less than the threshold value Vth (step S111: No), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 11 (step S113).
  • step S113 the determination result in step S113 is that there are three branch circuits of the air conditioners 9 to 11 in the first embodiment. That is, since the specifying means 42 has determined that no ground fault has occurred in any of the power supply system and the air conditioners 9 and 10 according to the procedures from step S103 to step S111, the remaining equipment of the air conditioner 11 It can be determined that a ground fault has occurred inside.
  • the relay control means 43 connects a pair of relays corresponding to each of the two or more other air conditioners except the air conditioner 9 in order, and the specific means 42 connects the voltage detector with a potential difference. It can be determined that a ground fault has occurred inside the air conditioner in which the above occurred.
  • step S102 shown in FIG. 5 the case where the pair of relays 3 corresponding to the air conditioner 9 are connected and determined is described.
  • the air conditioner to be determined first is not limited to the air conditioner 9, but the air conditioner. It may be 10 or 11.
  • FIG. 6 is a diagram showing a case where a ground fault occurs in the transmission line on the positive electrode side in the air conditioning system shown in FIG.
  • FIG. 7 is a diagram showing a case where a ground fault occurs in the transmission line on the negative electrode side in the air conditioning system shown in FIG.
  • the ground fault resistance R20 shown in FIGS. 6 and 7 is a virtual resistance at a location where a ground fault has occurred.
  • the ground fault current which is the current generated by the ground fault, is indicated by the broken line arrow.
  • the direction of the current flowing through the third resistance element R5 is the direction of the broken arrow arrow.
  • the direction of the current flowing through the third resistance element R5 is the negative direction.
  • the potential difference between both ends of the third resistance element R5 is set to a negative value. If the voltage detector 2a transmits the information of the potential difference Vda including the positive and negative information to the system controller 12 via the communication circuit 32a, the specific means 42 can determine that the ground fault occurrence location is on the positive electrode side of the transmission line.
  • the third resistance is shown by the broken arrow.
  • the direction of the current flowing through the element R5 is a positive direction.
  • the potential difference between both ends of the third resistance element R5 is set to a positive value. If the voltage detector 2a transmits the information of the potential difference Vda including the positive and negative information to the system controller 12 via the communication circuit 32a, the identifying means 42 can determine that the ground fault occurrence location is on the negative electrode side of the transmission line.
  • the identifying means 42 can identify which side of the positive electrode side and the negative electrode side of the transmission line the ground fault has occurred, depending on the direction of the current flowing through the third resistance element R5.
  • a ground fault occurs in the positive electrode line 7
  • the specific means 42 can determine that a ground fault has occurred on the positive electrode side.
  • a ground fault occurs in the negative electrode line 8 is described with reference to FIG. 7, even if a ground fault occurs in the branch lines of the negative electrode branch lines 8a to 8c shown in FIG.
  • the specific means 42 can determine that a ground fault has occurred on the negative electrode side. Further, the specifying means 42 can determine whether the ground fault has occurred on the positive electrode side or the negative electrode side inside the air conditioners 9 to 11 in the same manner as the method described with reference to FIGS. 6 and 7. ..
  • the air conditioning system 100 of the first embodiment is provided corresponding to the air conditioners 9 to 11, the system controller 12, and the air conditioners 9 to 11, which are a plurality of devices connected in parallel to the DC power supply 1, and is DC. It has a pair of relays 3 to 5 for switching connection and disconnection with the power supply 1.
  • Each device of the air conditioners 9 to 11 includes a detection device including a voltage detector that detects a potential difference caused by a current flowing when a ground fault occurs, a communication circuit that transmits the detected potential difference value to a controller, and an air conditioner. It has a relay control circuit that controls a pair of relays corresponding to the machine.
  • the system controller 12 has a relay control means 43 and a specific means 42.
  • the relay control means 43 controls at least one pair of relays 3 among the pair of relays 3 to 5 in a connected state, and the other pair.
  • the relays 4 and 5 of the above are controlled to be disconnected.
  • the identification means 42 identifies the location where the ground fault occurs based on the plurality of potential differences Vda to Vdc received from the plurality of voltage detectors 2a to 2c. ..
  • a plurality of pairs of relays are provided corresponding to a plurality of branch circuits, one pair of relays is connected and the other pair of relays is disconnected from the plurality of pairs of relays.
  • the presence or absence of detection of the potential difference is determined by a plurality of voltage detectors. Therefore, it is possible to determine which pair of relays is in the connected state when the ground fault has occurred, and to identify the location where the ground fault has occurred.
  • a plurality of pairs of relays and a plurality of detection devices are provided corresponding to the plurality of branch circuits, and the ground fault can be easily detected and the ground fault location can be specified. Since the configuration is simpler than the conventional one, the manufacturing cost can be suppressed.
  • the system controller 12 may output information indicating the detection of the ground fault and the location of the ground fault to the remote controllers 14a to 14c via the control circuits 13a to 13c.
  • the user of the air conditioning system 100 can request the worker of the maintenance company of the air conditioning system 100 for repair.
  • the location where the ground fault occurs is the positive electrode including the positive electrode line 7 based on the current direction information. It may be determined which of the side transmission line and the negative electrode side transmission line including the negative electrode line 8 is.
  • the system controller 12 may output the information of the transmission line in which the ground fault has occurred to the remote controllers 14a to 14c via the control circuits 13a to 13c. From the information output by the remote controllers 14a to 14c, the operator who repairs the air conditioning system 100 knows which of the positive electrode side transmission line and the negative electrode side transmission line should be inspected. As a result, the operator can repair the air conditioning system 100 faster.
  • the power supply target device of the power supply system is an air conditioner
  • the power supply target device is not limited to the air conditioner.
  • an elevator can be considered.
  • the air conditioning system described in the first embodiment can be applied to a power supply system that supplies electric power to a plurality of elevators provided in one building.

Landscapes

  • Emergency Protection Circuit Devices (AREA)
  • Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)

Abstract

This power feed system has: a plurality of devices connected in parallel with a DC power supply; a controller communicably connected to the plurality of devices; and a plurality of pairs of relays respectively provided corresponding to the plurality of devices and switching between connection to and disconnection from the DC power supply. The devices each have: a detection device including a voltage detector for detecting a voltage difference caused by the current flowing when a ground fault has occurred; a communication circuit for transmitting the value of the detected voltage difference to the controller; and a relay control circuit for controlling the pair of relays corresponding to the device. The controller has: a relay control means which, when the occurrence of the ground fault is detected, controls at least one pair of relays among the plurality of pairs of relays to a connection state and the other pairs of relays to a disconnection state; and an identification means for identifying, on the basis of the voltage differences received from the voltage detectors, the location where the ground fault has occurred.

Description

給電システムPower supply system
　本発明は、複数の機器に電源から電力を供給する給電システムに関する。 The present invention relates to a power supply system that supplies electric power from a power source to a plurality of devices.
　現在、災害時の事業継続性（ＢＣＰ：Ｂｕｓｉｎｅｓｓ　Ｃｏｎｔｉｎｕｉｔｙ　Ｐｌａｎｎｉｎｇ）の意識の高まりおよび省エネの観点から直流給電システムが注目されている。しかし、直流電圧対応の漏電遮断器が開発されていない。そのため、負荷側等で地絡が発生した場合に地絡電流が所定電流以下となるように、電源の正極と負極のそれぞれの極が高抵抗素子を介してグランドに接続された給電システムがある。この給電システムでは、負荷側等で地絡が１箇所で発生すると、直流電源が高抵抗素子を介して接地されているため、高抵抗素子により地絡電流を安全な電流以下にすることが可能となる。しかし、さらに別の箇所に地絡が発生すると、地絡発生箇所の間が短絡し、大電流が流れて電源設備の配線用遮断器の動作または負荷側のヒューズ溶断が発生するおそれがある。配線用遮断器の動作またはヒューズ溶断が発生すると、負荷が停止し、重大な影響を与える可能性がある。したがって、地絡が１箇所、発生した時点で、地絡を検出するとともに地絡箇所を特定し、修復する必要がある。 Currently, DC power supply systems are attracting attention from the viewpoint of increasing awareness of business continuity (BCP: Business Continuity Planning) in the event of a disaster and energy saving. However, an earth leakage breaker compatible with DC voltage has not been developed. Therefore, there is a power supply system in which the positive and negative electrodes of the power supply are connected to the ground via a high resistance element so that the ground fault current becomes a predetermined current or less when a ground fault occurs on the load side or the like. .. In this power supply system, if a ground fault occurs at one location on the load side, etc., the DC power supply is grounded via the high resistance element, so the ground fault current can be kept below the safe current by the high resistance element. It becomes. However, if a ground fault occurs at another location, a short circuit may occur between the locations where the ground fault occurs, a large current may flow, and the circuit breaker for wiring of the power supply equipment may operate or the fuse on the load side may be blown. If the molded case circuit breaker operates or the fuse blows, the load may stop and have a serious effect. Therefore, when a ground fault occurs at one location, it is necessary to detect the ground fault, identify the ground fault location, and repair it.
　直流回線に流れる地絡電流を検出する直流給電システムの一例が提案されている（例えば、特許文献１参照）。特許文献１に開示された給電システムでは、直流電圧の正負の出力間に２つのコンデンサが直列に接続され、２つのコンデンサの接続点が抵抗素子を介してグランドに接続されている。この２つのコンデンサと電源側に設けられた２つの抵抗素子とでブリッジ回路が構成される。地絡が発生すると、ブリッジ回路が不平衡状態になることを利用し、地絡が検出される。 An example of a DC power supply system that detects a ground fault current flowing through a DC line has been proposed (see, for example, Patent Document 1). In the power feeding system disclosed in Patent Document 1, two capacitors are connected in series between the positive and negative outputs of a DC voltage, and the connection points of the two capacitors are connected to the ground via a resistance element. A bridge circuit is composed of these two capacitors and two resistance elements provided on the power supply side. When a ground fault occurs, the ground fault is detected by utilizing the fact that the bridge circuit is in an unbalanced state.
　また、電源を含む主回路から分岐した複数の回線に発生する地絡事故を検出する判別装置が提案されている（例えば、特許文献２参照）。特許文献２に開示された判別装置は、複数の回線毎に地絡事故を検出する継電器が主回路に設けられ、主回路に設けられた直流制御電源回路に間欠的に地絡事故が発生した地絡回線を判別するものである。この判別装置は、地絡事故に起因する、回線に存在する対地静電容量の充放電によって回線に流れる瞬間的な電流の変化を検出する変流器が各回線に設けられ、変流器が検出する電流の変化の違いで地絡回線を判別する。 Further, a discrimination device for detecting a ground fault that occurs in a plurality of lines branched from a main circuit including a power supply has been proposed (see, for example, Patent Document 2). In the discrimination device disclosed in Patent Document 2, a relay for detecting a ground fault accident is provided in the main circuit for each of a plurality of lines, and a ground fault accident occurs intermittently in the DC control power supply circuit provided in the main circuit. It identifies the ground fault line. In this discrimination device, each line is equipped with a current transformer that detects a momentary change in the current flowing through the line due to the charging and discharging of the ground capacitance existing in the line due to a ground fault accident. The ground fault line is identified by the difference in the detected current change.
特開２０１４－１５８３６４号公報Japanese Unexamined Patent Publication No. 2014-158364 特開２００８－１１３５４６号公報Japanese Unexamined Patent Publication No. 2008-11546
　しかし、特許文献１に開示された給電システムでは、複数の分岐回路の場合に、不平衡状態が生じた地絡電流を検出できるが、地絡発生箇所が持つ抵抗は各分岐回線に対して全て不平衡状態になる。そのため、各分岐回路に同じ地絡電流が流れ、地絡発生箇所を特定できない。また、特許文献２には、直流地絡事故が発生した分岐回路を見つけ出す地絡検出回路が提案されているが、各分岐回路に変流器が必要となるため、製造コストが高くなってしまう。 However, in the power supply system disclosed in Patent Document 1, in the case of a plurality of branch circuits, the ground fault current in which the unbalanced state occurs can be detected, but the resistance of the ground fault occurrence location is all for each branch line. It becomes unbalanced. Therefore, the same ground fault current flows in each branch circuit, and the location where the ground fault occurs cannot be specified. Further, Patent Document 2 proposes a ground fault detection circuit for finding a branch circuit in which a DC ground fault has occurred, but since each branch circuit requires a current transformer, the manufacturing cost becomes high. ..
　本発明は、上記のような課題を解決するためになされたもので、簡便で地絡の発生箇所を特定できる給電システムを提供するものである。 The present invention has been made to solve the above problems, and provides a power supply system that can easily identify the location where a ground fault occurs.
　本発明に係る給電システムは、直流電源と正極回線および負極回線を介して並列に接続される複数の機器と、前記複数の機器と通信接続されるコントローラと、それぞれが前記複数の機器に対応して前記正極回線および前記負極回線に設けられ、前記直流電源との接続および切断を切り替える複数の一対のリレーと、を有し、前記各機器は、前記正極回線および前記負極回線との間に設けられ、地絡が発生したときに流れる電流によって生じる電位差を検出する電圧検出器を含む検出装置と、前記電圧検出器によって検出される前記電位差の値を前記コントローラに送信する通信回路と、前記通信回路を介して前記コントローラと接続され、前記機器に対応する前記一対のリレーを制御するリレー制御回路と、を有し、前記コントローラは、複数の前記検出装置によって前記地絡の発生が検出されると、前記複数の一対のリレーのうち、少なくとも１つの一対のリレーを接続状態に制御し、他の一対のリレーを切断状態に制御するリレー制御手段と、前記リレー制御手段によって前記複数の一対のリレーの状態が切り替わると、複数の前記電圧検出器から受信する複数の前記電位差に基づいて前記地絡の発生箇所を特定する特定手段と、を有するものである。 The power supply system according to the present invention corresponds to a plurality of devices connected in parallel via a DC power supply and a positive voltage line and a negative voltage line, a controller communication connected to the plurality of devices, and each of the plurality of devices. The positive voltage line and the negative voltage line are provided with a plurality of pairs of relays for switching connection and disconnection with the DC power supply, and each device is provided between the positive voltage line and the negative voltage line. A detection device including a voltage detector that detects a potential difference caused by a current flowing when a ground fault occurs, a communication circuit that transmits the value of the potential difference detected by the voltage detector to the controller, and the communication. The controller includes a relay control circuit that is connected to the controller via a circuit and controls the pair of relays corresponding to the device, and the controller detects the occurrence of the ground fault by the plurality of detection devices. A relay control means that controls at least one pair of relays in the connected state and controls the other pair of relays in the disconnected state, and the plurality of pairs of relays by the relay control means. When the state of the relay is switched, it has a specific means for identifying the location where the ground fault occurs based on the plurality of potential differences received from the plurality of voltage detectors.
　本発明によれば、複数の分岐回路に対応して複数の一対のリレーが設けられ、複数の一対のリレーのうち、１つの一対のリレーが接続状態、他の一対のリレーが切断状態で、複数の電圧検出器で電位差の検出の有無が判定される。そのため、どの一対のリレーが接続状態のときに地絡が発生したかが判定され、従来に比べて、簡便に地絡の発生箇所を特定できる。 According to the present invention, a plurality of pairs of relays are provided corresponding to a plurality of branch circuits, and among the plurality of pairs of relays, one pair of relays is connected and the other pair of relays is disconnected. The presence or absence of detection of potential difference is determined by a plurality of voltage detectors. Therefore, it is possible to determine which pair of relays is in the connected state when the ground fault has occurred, and the location where the ground fault has occurred can be easily identified as compared with the conventional case.
実施の形態１に係る空調システムの配電系統の一構成例を示す図である。It is a figure which shows one configuration example of the power distribution system of the air-conditioning system which concerns on Embodiment 1. FIG. 図１に示した各空調機が有する冷媒回路の一構成例を示す図である。It is a figure which shows one configuration example of the refrigerant circuit which each air conditioner shown in FIG. 1 has. 図１に示した制御回路の一構成例を示すブロック図である。It is a block diagram which shows one structural example of the control circuit shown in FIG. 図１に示したシステムコントローラの一構成例を示すブロック図である。It is a block diagram which shows one configuration example of the system controller shown in FIG. 図１に示した空調システムの動作手順の一例を示すフローチャートである。It is a flowchart which shows an example of the operation procedure of the air-conditioning system shown in FIG. 図１に示した空調システムにおいて、正極側の送電線に地絡が発生した場合を示す図である。It is a figure which shows the case where the ground fault occurs in the transmission line on the positive electrode side in the air conditioning system shown in FIG. 図１に示した空調システムにおいて、負極側の送電線に地絡が発生した場合を示す図である。It is a figure which shows the case where the ground fault occurs in the transmission line on the negative electrode side in the air conditioning system shown in FIG.
　本実施の形態の給電システムは、直流電源から電力の供給を受ける複数の機器を有するシステムである。本実施の形態では、電力の供給を受ける機器が空調機である空調システムの場合で説明するが、給電システムは空調システムに限らない。 The power supply system of the present embodiment is a system having a plurality of devices that receive power from a DC power source. In the present embodiment, the case where the device for receiving power is an air conditioner is described, but the power supply system is not limited to the air conditioner system.
実施の形態１．
　本実施の形態１の空調システムの構成を説明する。図１は、実施の形態１に係る空調システムの配電系統の一構成例を示す図である。図１に示すように、空調システム１００は、直流電源１に並列に接続される複数の空調機９～１１と、地絡の発生を検出するシステムコントローラ１２と、複数の空調機９～１１の直流電源１との接続および切断を切り替える複数の一対のリレー３～５とを有する。空調機９～１１の各機器は、空調対象空間である室内の空気調和を行う装置である。 Embodiment 1.
The configuration of the air conditioning system according to the first embodiment will be described. FIG. 1 is a diagram showing a configuration example of a power distribution system of the air conditioning system according to the first embodiment. As shown in FIG. 1, the air conditioning system 100 includes a plurality of air conditioners 9 to 11 connected in parallel to the DC power supply 1, a system controller 12 for detecting the occurrence of a ground fault, and a plurality of air conditioners 9 to 11. It has a plurality of pairs of relays 3 to 5 for switching connection and disconnection with the DC power supply 1. Each device of the air conditioners 9 to 11 is a device that harmonizes the air in the room which is the space to be air-conditioned.
　直流電源１の正極側には正極回線７の送電線が接続され、負極側には負極回線８の送電線が接続されている。正極回線７は複数の正極分岐回線７ａ～７ｃに分岐している。負極回線８は複数の負極分岐回線８ａ～８ｃに分岐している。正極分岐回線７ａおよび負極分岐回線８ａは空調機９に接続されている。正極分岐回線７ｂおよび負極分岐回線８ｂは空調機１０に接続されている。正極分岐回線７ｃおよび負極分岐回線８ｃは空調機１１に接続されている。空調機９～１１毎に分岐回路が構成される。 The transmission line of the positive electrode line 7 is connected to the positive electrode side of the DC power supply 1, and the transmission line of the negative electrode line 8 is connected to the negative electrode side. The positive electrode line 7 is branched into a plurality of positive electrode branch lines 7a to 7c. The negative electrode line 8 is branched into a plurality of negative electrode branch lines 8a to 8c. The positive electrode branch line 7a and the negative electrode branch line 8a are connected to the air conditioner 9. The positive electrode branch line 7b and the negative electrode branch line 8b are connected to the air conditioner 10. The positive electrode branch line 7c and the negative electrode branch line 8c are connected to the air conditioner 11. A branch circuit is configured for each of the air conditioners 9 to 11.
　正極回線７と負極回線８との間に抵抗素子Ｒ１およびＲ２が直列に接続されている。抵抗素子Ｒ１と抵抗素子Ｒ２との接続点がグランドに接地されており、抵抗素子Ｒ１と抵抗素子Ｒ２との間の電位が接地電位となる。抵抗素子Ｒ１およびＲ２の各抵抗素子の抵抗値は同じ値であり、例えば、４０ｋΩ～５０ｋΩである。 Resistor elements R1 and R2 are connected in series between the positive electrode line 7 and the negative electrode line 8. The connection point between the resistance element R1 and the resistance element R2 is grounded to the ground, and the potential between the resistance element R1 and the resistance element R2 becomes the ground potential. The resistance values of the resistance elements R1 and R2 are the same, for example, 40 kΩ to 50 kΩ.
　一対のリレー３は、正極分岐回線７ａに設けられたリレー３－１および負極分岐回線８ａに設けられたリレー３－２で構成される。一対のリレー３は、空調機９の直流電源１への接続および切断を切り替える。一対のリレー４は、正極分岐回線７ｂに設けられたリレー４－１および負極分岐回線８ｂに設けられたリレー４－２で構成される。一対のリレー４は、空調機１０の直流電源１への接続および切断を切り替える。一対のリレー５は、正極分岐回線７ｃに設けられたリレー５－１および負極分岐回線８ｃに設けられたリレー５－２で構成される。一対のリレー５は、空調機１１の直流電源１との接続および切断を切り替える。 The pair of relays 3 is composed of a relay 3-1 provided on the positive electrode branch line 7a and a relay 3-2 provided on the negative electrode branch line 8a. The pair of relays 3 switches the connection and disconnection of the air conditioner 9 to the DC power supply 1. The pair of relays 4 is composed of a relay 4-1 provided on the positive electrode branch line 7b and a relay 4-2 provided on the negative electrode branch line 8b. The pair of relays 4 switches the connection and disconnection of the air conditioner 10 to the DC power supply 1. The pair of relays 5 is composed of a relay 5-1 provided in the positive electrode branch line 7c and a relay 5-2 provided in the negative electrode branch line 8c. The pair of relays 5 switches the connection and disconnection of the air conditioner 11 with the DC power supply 1.
　空調機９は、正極回線７および負極回線８と、一対のリレー３を含む分岐回線とを介して、直流電源１から電力が供給される。空調機１０は、正極回線７および負極回線８と、一対のリレー４を含む分岐回線とを介して、直流電源１から電力が供給される。空調機１１は、正極回線７および負極回線８と、一対のリレー５を含む分岐回線とを介して、直流電源１から電力が供給される。なお、図１では、一対のリレー３が空調機９の内部に設けられている場合を示しているが、一対のリレー３の設置場所は空調機９の内部に限らない。一対のリレー３は空調機９の外部に設けられていてもよい。一対のリレー４および５の設置場所についても、一対のリレー３と同様である。つまり、一対のリレー４は空調機１０の外部に設けられていてもよく、一対のリレー５は空調機１１の外部に設けられていてもよい。 The air conditioner 9 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 3. The air conditioner 10 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 4. The air conditioner 11 is supplied with electric power from the DC power supply 1 via the positive electrode line 7 and the negative electrode line 8 and a branch line including a pair of relays 5. Although FIG. 1 shows a case where the pair of relays 3 are provided inside the air conditioner 9, the installation location of the pair of relays 3 is not limited to the inside of the air conditioner 9. The pair of relays 3 may be provided outside the air conditioner 9. The installation location of the pair of relays 4 and 5 is the same as that of the pair of relays 3. That is, the pair of relays 4 may be provided outside the air conditioner 10, and the pair of relays 5 may be provided outside the air conditioner 11.
　図１に示すように、空調機９は、地絡を検出する検出装置１５ａと、制御回路１３ａとを有する。検出装置１５ａは、第１抵抗素子Ｒ３、第２抵抗素子Ｒ４および第３抵抗素子Ｒ５と、電圧検出器２ａとを有する。第１抵抗素子Ｒ３および第２抵抗素子Ｒ４は、正極分岐回線７ａと負極分岐回線８ａとの間に直列に接続されている。第３抵抗素子Ｒ５は、第１抵抗素子Ｒ３および第２抵抗素子Ｒ４の接続点とグランドとの間に設けられている。電圧検出器２ａは、第３抵抗素子Ｒ５に並列に接続されている。電圧検出器２ａは、第３抵抗素子Ｒ５に流れる電流によって生じる電位差Ｖｄａを検出する。電圧検出器２ａは、第３抵抗素子Ｒ５に流れる電流の方向を示す電流方向情報と、検出する電位差Ｖｄａとを制御回路１３ａに出力する。空調機９のユーザが設定温度および風量などの設定情報を空調機９に指示するためのリモートコントローラ１４ａが伝送線２４を介して制御回路１３ａと接続されている。 As shown in FIG. 1, the air conditioner 9 has a detection device 15a for detecting a ground fault and a control circuit 13a. The detection device 15a includes a first resistance element R3, a second resistance element R4, a third resistance element R5, and a voltage detector 2a. The first resistance element R3 and the second resistance element R4 are connected in series between the positive electrode branch line 7a and the negative electrode branch line 8a. The third resistance element R5 is provided between the connection point of the first resistance element R3 and the second resistance element R4 and the ground. The voltage detector 2a is connected in parallel to the third resistance element R5. The voltage detector 2a detects the potential difference Vda caused by the current flowing through the third resistance element R5. The voltage detector 2a outputs the current direction information indicating the direction of the current flowing through the third resistance element R5 and the detected potential difference Vda to the control circuit 13a. A remote controller 14a for the user of the air conditioner 9 to instruct the air conditioner 9 of setting information such as a set temperature and an air volume is connected to the control circuit 13a via a transmission line 24.
　空調機１０は、地絡を検出する検出装置１５ｂと、制御回路１３ｂとを有する。検出装置１５ｂは、第１抵抗素子Ｒ６、第２抵抗素子Ｒ７および第３抵抗素子Ｒ８と、電圧検出器２ｂとを有する。第１抵抗素子Ｒ６および第２抵抗素子Ｒ７は、正極分岐回線７ｂと負極分岐回線８ｂとの間に直列に接続されている。第３抵抗素子Ｒ８は、第１抵抗素子Ｒ６および第２抵抗素子Ｒ７の接続点とグランドとの間に設けられている。電圧検出器２ｂは、第３抵抗素子Ｒ８に並列に接続されている。電圧検出器２ｂは、第３抵抗素子Ｒ８に流れる電流によって生じる電位差Ｖｄｂを検出する。電圧検出器２ｂは、第３抵抗素子Ｒ８に流れる電流の方向を示す電流方向情報と、検出する電位差Ｖｄｂとを制御回路１３ｂに出力する。空調機１０のユーザが設定情報を空調機１０に指示するためのリモートコントローラ１４ｂが伝送線２４を介して制御回路１３ｂと接続されている。 The air conditioner 10 has a detection device 15b for detecting a ground fault and a control circuit 13b. The detection device 15b includes a first resistance element R6, a second resistance element R7, a third resistance element R8, and a voltage detector 2b. The first resistance element R6 and the second resistance element R7 are connected in series between the positive electrode branch line 7b and the negative electrode branch line 8b. The third resistance element R8 is provided between the connection point of the first resistance element R6 and the second resistance element R7 and the ground. The voltage detector 2b is connected in parallel to the third resistance element R8. The voltage detector 2b detects the potential difference Vdb caused by the current flowing through the third resistance element R8. The voltage detector 2b outputs the current direction information indicating the direction of the current flowing through the third resistance element R8 and the detected potential difference Vdb to the control circuit 13b. A remote controller 14b for the user of the air conditioner 10 to instruct the air conditioner 10 of setting information is connected to the control circuit 13b via a transmission line 24.
　空調機１１は、地絡を検出する検出装置１５ｃと、制御回路１３ｃとを有する。検出装置１５ｃは、第１抵抗素子Ｒ９、第２抵抗素子Ｒ１０および第３抵抗素子Ｒ１１と、電圧検出器２ｃとを有する。第１抵抗素子Ｒ９および第２抵抗素子Ｒ１０は、正極分岐回線７ｃと負極分岐回線８ｃとの間に直列に接続されている。第３抵抗素子Ｒ１１は、第１抵抗素子Ｒ９および第２抵抗素子Ｒ１０の接続点とグランドとの間に設けられている。電圧検出器２ｃは、第３抵抗素子Ｒ１１に並列に接続されている。電圧検出器２ｃは、第３抵抗素子Ｒ１１に流れる電流によって生じる電位差Ｖｄｃを検出する。電圧検出器２ｃは、第３抵抗素子Ｒ１１に流れる電流の方向を示す電流方向情報と、検出する電位差Ｖｄｃとを制御回路１３ｃに出力する。空調機１１のユーザが設定情報を空調機１１に指示するためのリモートコントローラ１４ｃが伝送線２４を介して制御回路１３ｃと接続されている。 The air conditioner 11 has a detection device 15c for detecting a ground fault and a control circuit 13c. The detection device 15c includes a first resistance element R9, a second resistance element R10, a third resistance element R11, and a voltage detector 2c. The first resistance element R9 and the second resistance element R10 are connected in series between the positive electrode branch line 7c and the negative electrode branch line 8c. The third resistance element R11 is provided between the connection point of the first resistance element R9 and the second resistance element R10 and the ground. The voltage detector 2c is connected in parallel to the third resistance element R11. The voltage detector 2c detects the potential difference Vdc caused by the current flowing through the third resistance element R11. The voltage detector 2c outputs the current direction information indicating the direction of the current flowing through the third resistance element R11 and the detected potential difference Vdc to the control circuit 13c. A remote controller 14c for the user of the air conditioner 11 to instruct the air conditioner 11 of setting information is connected to the control circuit 13c via a transmission line 24.
　地絡検出のために、検出装置１５ａは、（第１抵抗素子Ｒ３の抵抗値）＝（第２抵抗素子Ｒ４の抵抗値）＞＞（抵抗素子Ｒ１の抵抗値）＝（抵抗素子Ｒ２の抵抗値）の関係を満たす。検出装置１５ｂも、検出装置１５ａと同様に、（第１抵抗素子Ｒ６の抵抗値）＝（第２抵抗素子Ｒ７の抵抗値）＞＞（抵抗素子Ｒ１の抵抗値）＝（抵抗素子Ｒ２の抵抗値）の関係を満たす。検出装置１５ｃも、検出装置１５ａと同様に、（第１抵抗素子Ｒ９の抵抗値）＝（第２抵抗素子Ｒ１０の抵抗値）＞＞（抵抗素子Ｒ１の抵抗値）＝（抵抗素子Ｒ２の抵抗値）の関係を満たす。例えば、抵抗素子Ｒ１およびＲ２の各素子の抵抗値が４０ｋΩである場合、第１抵抗素子Ｒ３、Ｒ６およびＲ９と第２抵抗素子Ｒ４、Ｒ７およびＲ１０との各素子の抵抗値は１００ｋΩである。 For ground fault detection, the detection device 15a uses (resistance value of first resistance element R3) = (resistance value of second resistance element R4) >> (resistance value of resistance element R1) = (resistance of resistance element R2). Value) is satisfied. Similarly to the detection device 15a, the detection device 15b also has (resistance value of the first resistance element R6) = (resistance value of the second resistance element R7) >> (resistance value of the resistance element R1) = (resistance of the resistance element R2). Value) is satisfied. Similarly to the detection device 15a, the detection device 15c also has (resistance value of the first resistance element R9) = (resistance value of the second resistance element R10) >> (resistance value of the resistance element R1) = (resistance of the resistance element R2). Value) is satisfied. For example, when the resistance value of each element of the resistance elements R1 and R2 is 40 kΩ, the resistance value of each element of the first resistance elements R3, R6 and R9 and the second resistance elements R4, R7 and R10 is 100 kΩ.
　第３抵抗素子Ｒ５、Ｒ８およびＲ１１の各素子の抵抗値は、微小電流によって生じる電位差を検出できるように設定する。第３抵抗素子Ｒ５、Ｒ８およびＲ１１の各素子の抵抗値は、例えば、１ｋΩである。制御回路１３ａ～１３ｃは伝送線２３を介してシステムコントローラ１２と接続される。伝送線２３には、信号の伝送を中継する中継器（不図示）が設けられていてもよい。図１に示すように、信号伝送のための中継器（不図示）等の通信機器に電力を供給する給電ユニット６が設けられていてもよい。 The resistance value of each of the third resistance elements R5, R8 and R11 is set so that the potential difference caused by a minute current can be detected. The resistance value of each of the third resistance elements R5, R8, and R11 is, for example, 1 kΩ. The control circuits 13a to 13c are connected to the system controller 12 via the transmission line 23. The transmission line 23 may be provided with a repeater (not shown) that relays the transmission of signals. As shown in FIG. 1, a power supply unit 6 for supplying electric power to a communication device such as a repeater (not shown) for signal transmission may be provided.
　ここで、空調機９～１１に設けられる冷媒回路の構成を説明する。図２は、図１に示した各空調機が有する冷媒回路の一構成例を示す図である。空調機９～１１が有する冷媒回路は同一の構成であるため、空調機９に設けられる冷媒回路について説明する。 Here, the configuration of the refrigerant circuit provided in the air conditioners 9 to 11 will be described. FIG. 2 is a diagram showing a configuration example of a refrigerant circuit included in each air conditioner shown in FIG. Since the refrigerant circuits included in the air conditioners 9 to 11 have the same configuration, the refrigerant circuit provided in the air conditioner 9 will be described.
　図２に示すように、空調機９は、冷媒を圧縮して吐出する圧縮機５１と、冷媒の流路を切り替える四方弁５２と、冷媒が外気と熱交換する熱源側熱交換器５３と、冷媒を膨張させる膨張装置５４と、冷媒が室内の空気と熱交換する負荷側熱交換器５５とを有する。圧縮機５１、熱源側熱交換器５３、膨張装置５４および負荷側熱交換器５５が冷媒配管５６で接続され、冷媒が循環する冷媒回路５０が構成される。圧縮機５１は、例えば、容量を変えることができるインバータ式圧縮機である。膨張装置５４は、例えば、電子膨張弁である。熱源側熱交換器５３および負荷側熱交換器５５は、例えば、フィンアンドチューブ式熱交換器である。 As shown in FIG. 2, the air conditioner 9 includes a compressor 51 that compresses and discharges the refrigerant, a four-way valve 52 that switches the flow path of the refrigerant, and a heat source side heat exchanger 53 that exchanges heat with the outside air. It has an expansion device 54 that expands the refrigerant, and a load side heat exchanger 55 that exchanges heat with the air in the room. The compressor 51, the heat source side heat exchanger 53, the expansion device 54, and the load side heat exchanger 55 are connected by a refrigerant pipe 56 to form a refrigerant circuit 50 in which the refrigerant circulates. The compressor 51 is, for example, an inverter type compressor whose capacity can be changed. The expansion device 54 is, for example, an electronic expansion valve. The heat source side heat exchanger 53 and the load side heat exchanger 55 are, for example, fin-and-tube heat exchangers.
　圧縮機５１、四方弁５２および膨張装置５４は制御回路１３ａと通信接続される。図２に示していないが、正極分岐回線７ａおよび負極分岐回線８ａと接続されるコンバータ回路とインバータ回路が設けられている。コンバータ回路（不図示）とインバータ回路（不図示）は、直流電源１から供給される直流電圧を、圧縮機５１、膨張装置５４および四方弁５２の各冷媒機器の電源電圧に適した値まで降圧し、これらの冷媒機器に電力を供給する。 The compressor 51, the four-way valve 52 and the expansion device 54 are communicated with the control circuit 13a. Although not shown in FIG. 2, a converter circuit and an inverter circuit connected to the positive electrode branch line 7a and the negative electrode branch line 8a are provided. The converter circuit (not shown) and the inverter circuit (not shown) lower the DC voltage supplied from the DC power supply 1 to a value suitable for the power supply voltage of each refrigerant device of the compressor 51, the expansion device 54, and the four-way valve 52. And supply power to these refrigerant devices.
　なお、熱源側熱交換器に外気を供給する送風機、および負荷側熱交換器に室内の空気を供給する送風機が空調機９に設けられていてもよい。また、図２に示していないが、室内の温度を検出する温度センサ、および圧縮機５１から吐出される冷媒の圧力を検出する圧力センサなどの各種センサが空調機９に設けられていてもよい。 The air conditioner 9 may be provided with a blower that supplies outside air to the heat source side heat exchanger and a blower that supplies indoor air to the load side heat exchanger. Further, although not shown in FIG. 2, various sensors such as a temperature sensor for detecting the indoor temperature and a pressure sensor for detecting the pressure of the refrigerant discharged from the compressor 51 may be provided in the air conditioner 9. ..
　図１に示した制御回路１３ａ～１３ｃの構成を説明する。図３は、図１に示した制御回路の一構成例を示すブロック図である。制御回路１３ａ～１３ｃは同一の構成であるため、ここでは、制御回路１３ａの構成を説明する。 The configuration of the control circuits 13a to 13c shown in FIG. 1 will be described. FIG. 3 is a block diagram showing a configuration example of the control circuit shown in FIG. Since the control circuits 13a to 13c have the same configuration, the configuration of the control circuit 13a will be described here.
　制御回路１３ａは、マイクロコンピュータ３１ａと、通信回路３２ａと、リレー制御回路３３ａと、コンバータ回路３４ａとを有する。通信回路３２ａは、伝送線２３を介してシステムコントローラ１２と通信接続され、マイクロコンピュータ３１ａとシステムコントローラ１２との間で送受信される情報を中継する。コンバータ回路３４ａは、リレー制御回路３３ａに動作電圧を供給するＤＣ（直流）／ＤＣ（直流）コンバータ回路である。図３に示していないが、コンバータ回路３４ａは正極分岐回線７ａおよび負極分岐回線８ａと接続されている。コンバータ回路３４ａが、リレー制御回路３３ａだけでなく、マイクロコンピュータ３１ａおよび通信回路３２ａにも動作電圧を供給する。また、一対のリレー３を切断した場合には、伝送線２３を介して、他の空調機１０および１１のコンバータ回路の伝送電源を受電してリレー制御回路３３ａに一対のリレー３に駆動電源を供給する構成である。 The control circuit 13a includes a microcomputer 31a, a communication circuit 32a, a relay control circuit 33a, and a converter circuit 34a. The communication circuit 32a is communicatively connected to the system controller 12 via the transmission line 23, and relays information transmitted and received between the microcomputer 31a and the system controller 12. The converter circuit 34a is a DC (direct current) / DC (direct current) converter circuit that supplies an operating voltage to the relay control circuit 33a. Although not shown in FIG. 3, the converter circuit 34a is connected to the positive electrode branch line 7a and the negative electrode branch line 8a. The converter circuit 34a supplies an operating voltage not only to the relay control circuit 33a but also to the microcomputer 31a and the communication circuit 32a. When the pair of relays 3 is disconnected, the transmission power of the converter circuits of the other air conditioners 10 and 11 is received via the transmission line 23, and the relay control circuit 33a supplies the drive power to the pair of relays 3. It is a configuration to supply.
　マイクロコンピュータ３１ａは、電圧検出器２ａから入力される電位差Ｖｄａおよび電流方向情報を含む地絡情報を、通信回路３２ａを介してシステムコントローラ１２に送信する。マイクロコンピュータ３１ａは、一対のリレー３の接続状態および切断状態に関する制御信号を、通信回路３２ａを介してシステムコントローラ１２から受信すると、制御信号にしたがってリレー制御回路３３ａを動作させる。 The microcomputer 31a transmits the ground fault information including the potential difference Vda and the current direction information input from the voltage detector 2a to the system controller 12 via the communication circuit 32a. When the microcomputer 31a receives the control signal regarding the connection state and the disconnection state of the pair of relays 3 from the system controller 12 via the communication circuit 32a, the microcomputer 31a operates the relay control circuit 33a according to the control signal.
　また、マイクロコンピュータ３１ａは、リモートコントローラ１４ａを介して入力される設定情報および図２に示した空調機９に設けられた各種センサ（不図示）の値に基づいて、図２に示した冷媒回路５０の冷凍サイクルを制御する。具体的には、マイクロコンピュータ３１ａは、設定情報に含まれる運転モードにしたがって四方弁５２を制御する。マイクロコンピュータ３１ａは、設定情報および図に示さない各種センサの値に基づいて、圧縮機５１の運転周波数および膨張装置５４の開度を制御する。 Further, the microcomputer 31a has a refrigerant circuit shown in FIG. 2 based on the setting information input via the remote controller 14a and the values of various sensors (not shown) provided in the air conditioner 9 shown in FIG. Control 50 refrigeration cycles. Specifically, the microcomputer 31a controls the four-way valve 52 according to the operation mode included in the setting information. The microcomputer 31a controls the operating frequency of the compressor 51 and the opening degree of the expansion device 54 based on the setting information and the values of various sensors not shown in the figure.
　図３を参照して、地絡情報が電圧検出器２ａからマイクロコンピュータ３１ａを介してシステムコントローラ１２に送信され、制御信号がシステムコントローラ１２からマイクロコンピュータ３１ａを介してリレー制御回路３３ａを動作させる場合で説明したが、この場合に限らない。例えば、電圧検出器２ａから出力される地絡情報が、マイクロコンピュータ３１ａを経由せずに、通信回路３２ａを介してシステムコントローラ１２に送信されてもよい。また、システムコントローラ１２から送信される制御信号が、マイクロコンピュータ３１ａを経由せずに、通信回路３２ａを介してリレー制御回路３３ａに入力されてもよい。この場合、リレー制御回路３３ａは、入力される制御信号にしたがって、一対のリレー３に回線の接続または切断を実行させればよい。 With reference to FIG. 3, when ground fault information is transmitted from the voltage detector 2a to the system controller 12 via the microcomputer 31a, and a control signal is operated from the system controller 12 via the microcomputer 31a to operate the relay control circuit 33a. Although explained in, it is not limited to this case. For example, the ground fault information output from the voltage detector 2a may be transmitted to the system controller 12 via the communication circuit 32a without going through the microcomputer 31a. Further, the control signal transmitted from the system controller 12 may be input to the relay control circuit 33a via the communication circuit 32a without passing through the microcomputer 31a. In this case, the relay control circuit 33a may cause the pair of relays 3 to connect or disconnect the line according to the input control signal.
　図に示していないが、制御回路１３ｂは、マイクロコンピュータ３１ｂ、通信回路３２ｂ、リレー制御回路３３ｂおよびコンバータ回路３４ｂを有する。制御回路１３ｃは、マイクロコンピュータ３１ｂ、通信回路３２ｂ、リレー制御回路３３ｂおよびコンバータ回路３４ｂを有する。マイクロコンピュータ３１ｂおよび３１ｃはマイクロコンピュータ３１ａと同様な構成である。通信回路３２ｂおよび３２ｃは通信回路３２ａと同様な構成である。リレー制御回路３３ｂおよび３３ｃはリレー制御回路３３ａと同様な構成である。コンバータ回路３４ｂおよび３４ｃはコンバータ回路３４ａと同様な構成である。そのため、制御回路１３ｂおよび１３ｃについての詳細な説明を省略する。 Although not shown in the figure, the control circuit 13b includes a microcomputer 31b, a communication circuit 32b, a relay control circuit 33b, and a converter circuit 34b. The control circuit 13c includes a microcomputer 31b, a communication circuit 32b, a relay control circuit 33b, and a converter circuit 34b. The microcomputers 31b and 31c have the same configuration as the microcomputer 31a. The communication circuits 32b and 32c have the same configuration as the communication circuit 32a. The relay control circuits 33b and 33c have the same configuration as the relay control circuit 33a. The converter circuits 34b and 34c have the same configuration as the converter circuit 34a. Therefore, detailed description of the control circuits 13b and 13c will be omitted.
　図４は、図１に示したシステムコントローラの一構成例を示すブロック図である。図１に示すように、システムコントローラ１２は、プログラムを記憶するメモリ２２と、メモリ２２が記憶するプログラムにしたがって処理を実行するＣＰＵ（Ｃｅｎｔｒａｌ　Ｐｒｏｃｅｓｓｉｎｇ　Ｕｎｉｔ）２１とを有する。ＣＰＵ２１がプログラムを実行することで、図４に示す判定手段４１、特定手段４２およびリレー制御手段４３が構成される。 FIG. 4 is a block diagram showing a configuration example of the system controller shown in FIG. As shown in FIG. 1, the system controller 12 has a memory 22 for storing a program and a CPU (Central Processing Unit) 21 for executing processing according to the program stored in the memory 22. When the CPU 21 executes the program, the determination means 41, the identification means 42, and the relay control means 43 shown in FIG. 4 are configured.
　判定手段４１は、電圧検出器２ａ～２ｃで検出される電位差Ｖｄａ～Ｖｄｃに基づいて、地絡が発生したか否かを判定する。具体的には、判定手段４１は、決められた閾値Ｖｔｈと電位差Ｖｄａ～Ｖｄｃとを比較し、電位差Ｖｄａ～Ｖｄｃのそれぞれが検出する電位差が閾値Ｖｔｈよりも大きくなると、地絡が発生したと判定する。閾値Ｖｔｈは図１に示したメモリ２２に記憶されている。なお、判定手段４１は、電位差Ｖｄａ～Ｖｄｃの全てが閾値Ｖｔｈよりも大きくなる場合でも、少なくとも１つの電位差が閾値Ｖｔｈよりも大きくなった時点で、地絡が発生したと判定してもよい。この場合、地絡検出がより早くなる。 The determination means 41 determines whether or not a ground fault has occurred based on the potential differences Vda to Vdc detected by the voltage detectors 2a to 2c. Specifically, the determination means 41 compares the determined threshold value Vth with the potential differences Vda to Vdc, and determines that a ground fault has occurred when the potential difference detected by each of the potential differences Vda to Vdc becomes larger than the threshold value Vth. To do. The threshold value Vth is stored in the memory 22 shown in FIG. The determination means 41 may determine that a ground fault has occurred when at least one potential difference becomes larger than the threshold value Vth even when all of the potential differences Vda to Vdc become larger than the threshold value Vth. In this case, ground fault detection will be faster.
　空調システム１００が正常な状態では、電位差Ｖｄａ～Ｖｄｃの全てが０Ｖになる。地絡が発生していない状態では、例えば、直流電源１および空調機９に注目すると、抵抗素子Ｒ１、抵抗素子Ｒ２、第１抵抗素子Ｒ３および第２抵抗素子Ｒ４で構成するブリッジ回路が平衡状態になっている。平衡状態では、（抵抗素子Ｒ１の抵抗値×第２抵抗素子Ｒ４の抵抗値＝抵抗素子Ｒ２の抵抗値×第１抵抗素子Ｒ３の抵抗値）の関係が成り立ち、第３抵抗素子Ｒ５には電流が流れない。一方、空調システム１００において、どこかで地絡が発生すると、第３抵抗素子Ｒ５、Ｒ８およびＲ１１に電流が流れ、電圧検出器２ａ～２ｃで電位差が検出される。しかし、空調システム１００のどこで地絡が発生したかはわからない。 When the air conditioning system 100 is in a normal state, all of the potential differences Vda to Vdc become 0V. In a state where no ground fault has occurred, for example, focusing on the DC power supply 1 and the air conditioner 9, the bridge circuit composed of the resistance element R1, the resistance element R2, the first resistance element R3, and the second resistance element R4 is in a balanced state. It has become. In the balanced state, the relationship (resistance value of resistance element R1 x resistance value of second resistance element R4 = resistance value of resistance element R2 x resistance value of first resistance element R3) is established, and a current is applied to the third resistance element R5. Does not flow. On the other hand, in the air conditioning system 100, when a ground fault occurs somewhere, a current flows through the third resistance elements R5, R8 and R11, and the voltage detectors 2a to 2c detect the potential difference. However, it is unknown where in the air conditioning system 100 the ground fault occurred.
　リレー制御手段４３は、検出装置１５ａ～１５ｃによって地絡の発生が検出されると、一対のリレー３～５のうち、少なくとも１つの一対のリレーを接続状態に制御し、残りの一対のリレーを切断状態に制御する。特定手段４２は、リレー制御手段４３によって一対のリレー３～５の状態が切り替わると、電圧検出器２ａ～２ｃから受信する電位差Ｖｄａ～Ｖｄｃに基づいて地絡の発生箇所を特定する。リレー制御手段４３および特定手段４２の詳細な動作については後で説明する。 When the occurrence of a ground fault is detected by the detection devices 15a to 15c, the relay control means 43 controls at least one pair of relays among the pair of relays 3 to 5 in a connected state, and controls the remaining pair of relays. Control to disconnect state. When the state of the pair of relays 3 to 5 is switched by the relay control means 43, the identification means 42 identifies the location where the ground fault occurs based on the potential differences Vda to Vdc received from the voltage detectors 2a to 2c. The detailed operation of the relay control means 43 and the specific means 42 will be described later.
　なお、システムコントローラ１２が備える機能の一部がマイクロコンピュータ３１ａ～３１ｃに設けられていてもよい。例えば、判定手段４１がシステムコントローラ１２に設けられている場合で説明したが、判定手段４１がマイクロコンピュータ３１ａ～３１ｃのそれぞれに設けられていてもよい。 Note that some of the functions provided by the system controller 12 may be provided in the microcomputers 31a to 31c. For example, although the case where the determination means 41 is provided in the system controller 12 has been described, the determination means 41 may be provided in each of the microcomputers 31a to 31c.
　上述した空調システム１００において、地絡は、電源系統と、空調機９～１１の各空調機の内部とに起こり得る。電源系統は、直流電源１と、直流電源１から一対のリレー３～５までの送電線とを含む構成である。送電線は、正極回線７および負極回線８と、正極分岐回線７ａ～７ｃおよび負極分岐回線８ａ～８ｃとで構成される。 In the above-mentioned air conditioning system 100, a ground fault may occur in the power supply system and inside each of the air conditioners 9 to 11. The power supply system has a configuration including a DC power supply 1 and a transmission line from the DC power supply 1 to a pair of relays 3 to 5. The transmission line is composed of a positive electrode line 7 and a negative electrode line 8, a positive electrode branch line 7a to 7c, and a negative electrode branch line 8a to 8c.
　次に、本実施の形態１の空調システム１００による地絡検出の手順を説明する。図５は、図１に示した空調システムの動作手順の一例を示すフローチャートである。初期状態として、一対のリレー３～５の全てが接続状態であるものとする。 Next, the procedure for detecting a ground fault by the air conditioning system 100 of the first embodiment will be described. FIG. 5 is a flowchart showing an example of the operation procedure of the air conditioning system shown in FIG. As an initial state, it is assumed that all of the pair of relays 3 to 5 are in the connected state.
　ステップＳ１０１において、判定手段４１は、電圧検出器２ａ～２ｃによって検出される電位差Ｖｄａ～Ｖｄｃの各電位差が閾値Ｖｔｈよりも大きいか否かを判定する。判定の結果、電位差Ｖｄａ～Ｖｄｃの全てが閾値Ｖｔｈ以下である場合、判定手段４１は、地絡が発生していないと判定し、ステップＳ１０１に戻る（ステップＳ１０１：Ｎｏ）。一方、ステップＳ１０１の判定の結果、電位差Ｖｄａ～Ｖｄｃの各電位差のうち、少なくとも１つの電位差が閾値Ｖｔｈより大きい場合、地絡が発生したと判定する（ステップＳ１０１：Ｙｅｓ）。 In step S101, the determination means 41 determines whether or not each of the potential differences Vda to Vdc detected by the voltage detectors 2a to 2c is larger than the threshold value Vth. As a result of the determination, when all of the potential differences Vda to Vdc are equal to or less than the threshold value Vth, the determination means 41 determines that no ground fault has occurred, and returns to step S101 (step S101: No). On the other hand, as a result of the determination in step S101, if at least one potential difference among the potential differences Vda to Vdc is larger than the threshold value Vth, it is determined that a ground fault has occurred (step S101: Yes).
　直流電源１側に接続された高抵抗の抵抗素子Ｒ１およびＲ２と、各分岐回路の検出装置に設けられた直列抵抗とで、ブリッジ回路が構成される。具体的には、直流電源１の抵抗素子Ｒ１およびＲ２と、検出装置１５ａの第１抵抗素子Ｒ３および第２抵抗素子Ｒ４とで、ブリッジ回路が構成される。直流電源１の抵抗素子Ｒ１およびＲ２と、検出装置１５ｂの第１抵抗素子Ｒ６および第２抵抗素子Ｒ７とで、ブリッジ回路が構成される。直流電源１の抵抗素子Ｒ１およびＲ２と、検出装置１５ｃの第１抵抗素子Ｒ９および第２抵抗素子Ｒ１０とで、ブリッジ回路が構成される。これらのブリッジ回路の平衡状態によって、第３抵抗素子Ｒ５、Ｒ８およびＲ１１の両端は電圧がゼロになる。第３抵抗素子Ｒ５、Ｒ８およびＲ１１の両端の電位差がゼロであれば、地絡が発生していないと判断できる。 A bridge circuit is composed of high resistance resistance elements R1 and R2 connected to the DC power supply 1 side and a series resistance provided in the detection device of each branch circuit. Specifically, a bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R3 and the second resistance element R4 of the detection device 15a. A bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R6 and the second resistance element R7 of the detection device 15b. A bridge circuit is formed by the resistance elements R1 and R2 of the DC power supply 1 and the first resistance element R9 and the second resistance element R10 of the detection device 15c. Due to the equilibrium state of these bridge circuits, the voltage across the third resistance elements R5, R8 and R11 becomes zero. If the potential difference between both ends of the third resistance elements R5, R8 and R11 is zero, it can be determined that no ground fault has occurred.
　一方、直流電源１の正極回線７または負極回線８に地絡が発生すると、抵抗素子Ｒ１およびＲ２と各分岐回路の直列抵抗とで形成されたブリッジ回路が不平衡状態になる。その結果、第３抵抗素子Ｒ５、Ｒ８およびＲ１１の両端に電位差が発生する。そして、電圧検出器２ａ～２ｃによって電位差が生じたことが検出されることで、地絡が発生したと判断できる。地絡の発生箇所の抵抗によって抵抗素子Ｒ１およびＲ２と、空調機の第１抵抗素子Ｒ３、Ｒ６およびＲ９と、第２抵抗素子Ｒ４、Ｒ７およびＲ１０とによって構成される各ブリッジ回路は全て同じ不平衡状態になるため、各分岐回路は同じ地絡電流が流れる。そのため、システムコントローラ１２は、ステップＳ１０１において地絡の発生を検出できるが、地絡の発生箇所を特定できない。 On the other hand, when a ground fault occurs in the positive electrode line 7 or the negative electrode line 8 of the DC power supply 1, the bridge circuit formed by the resistance elements R1 and R2 and the series resistance of each branch circuit becomes unbalanced. As a result, a potential difference is generated at both ends of the third resistance elements R5, R8 and R11. Then, it can be determined that a ground fault has occurred by detecting that a potential difference has occurred by the voltage detectors 2a to 2c. Due to the resistance at the location where the ground fault occurs, the bridge circuits composed of the resistance elements R1 and R2, the first resistance elements R3, R6 and R9 of the air conditioner, and the second resistance elements R4, R7 and R10 are all the same. Since it is in a balanced state, the same ground fault current flows through each branch circuit. Therefore, the system controller 12 can detect the occurrence of the ground fault in step S101, but cannot specify the location where the ground fault has occurred.
　続いて、空調システム１００による地絡発生箇所の特定方法を説明する。ステップＳ１０１において、判定手段４１は、地絡が発生したと判定すると、地絡が発生したことを示す地絡情報をマイクロコンピュータ３１ｂおよび３１ｃに送信する。マイクロコンピュータ３１ｂは、地絡情報をシステムコントローラ１２から受信すると、空調機１０が運転している場合、空調機１０の運転を停止する。マイクロコンピュータ３１ｃは、地絡情報をシステムコントローラ１２から受信すると、空調機１１が運転している場合、空調機１１の運転を停止する。マイクロコンピュータ３１ｂおよび３１ｃは空調機の運転を停止した旨の停止情報をシステムコントローラ１２に送信する。 Next, a method of identifying the location where the ground fault occurs by the air conditioning system 100 will be described. In step S101, when the determination means 41 determines that a ground fault has occurred, it transmits ground fault information indicating that the ground fault has occurred to the microcomputers 31b and 31c. When the microcomputer 31b receives the ground fault information from the system controller 12, the microcomputer 31b stops the operation of the air conditioner 10 when the air conditioner 10 is operating. When the microcomputer 31c receives the ground fault information from the system controller 12, the microcomputer 31c stops the operation of the air conditioner 11 when the air conditioner 11 is operating. The microcomputers 31b and 31c transmit stop information to the effect that the operation of the air conditioner has been stopped to the system controller 12.
　システムコントローラ１２がマイクロコンピュータ３１ｂおよび３１ｃから停止情報を受信すると、リレー制御手段４３は、一対のリレー４および５を切断状態に切り替える制御を行う（ステップＳ１０２）。具体的には、リレー制御手段４３は、一対のリレーを切断状態に切り替える旨の切断制御信号をリレー制御回路３３ｂおよび３３ｃに送信する。ステップＳ１０２の後、特定手段４２は、電圧検出器２ａが検出する電位差Ｖｄａが閾値Ｖｔｈより大きいか否かを判定する（ステップＳ１０３）。判定の結果、電位差Ｖｄａが閾値Ｖｔｈより大きい場合（ステップＳ１０３：Ｙｅｓ）、リレー制御手段４３は第１特定モードに遷移する（ステップＳ１０４）。第１特定モードにおいて、リレー制御手段４３は、一対のリレー３を切断状態に切り替え、一対のリレー４を接続状態に切り替える制御を行う（ステップＳ１０５）。具体的には、リレー制御手段４３は、切断制御信号をリレー制御回路３３ａに送信し、一対のリレー４を接続状態に切り替える旨の接続制御信号をリレー制御回路３３ｂに送信する。 When the system controller 12 receives the stop information from the microcomputers 31b and 31c, the relay control means 43 controls to switch the pair of relays 4 and 5 to the disconnected state (step S102). Specifically, the relay control means 43 transmits a disconnection control signal to switch the pair of relays to the disconnection state to the relay control circuits 33b and 33c. After step S102, the identifying means 42 determines whether or not the potential difference Vda detected by the voltage detector 2a is larger than the threshold value Vth (step S103). As a result of the determination, when the potential difference Vda is larger than the threshold value Vth (step S103: Yes), the relay control means 43 transitions to the first specific mode (step S104). In the first specific mode, the relay control means 43 controls to switch the pair of relays 3 to the disconnected state and the pair of relays 4 to the connected state (step S105). Specifically, the relay control means 43 transmits a disconnection control signal to the relay control circuit 33a, and transmits a connection control signal to switch the pair of relays 4 to the connection state to the relay control circuit 33b.
　ステップＳ１０５の後、特定手段４２は、電圧検出器２ｂが検出する電位差Ｖｄｂが閾値Ｖｔｈより大きいか否かを判定する（ステップＳ１０６）。判定の結果、電位差Ｖｄｂが閾値Ｖｔｈより大きい場合（ステップＳ１０６：Ｙｅｓ）、特定手段４２は、電源系統に地絡が発生したと判定する（ステップＳ１０７）。一方、ステップＳ１０６の判定の結果、電位差Ｖｄｂが閾値Ｖｔｈ以下である場合（ステップＳ１０６：Ｎｏ）、特定手段４２は、空調機９の内部に地絡が発生したと判定する（ステップＳ１０８）。 After step S105, the identifying means 42 determines whether or not the potential difference Vdb detected by the voltage detector 2b is larger than the threshold value Vth (step S106). As a result of the determination, when the potential difference Vdb is larger than the threshold value Vth (step S106: Yes), the specific means 42 determines that a ground fault has occurred in the power supply system (step S107). On the other hand, as a result of the determination in step S106, when the potential difference Vdb is equal to or less than the threshold value Vth (step S106: No), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 9 (step S108).
　ステップＳ１０７およびＳ１０８の判定結果の理由を説明する。空調機１０および１１の運転が停止した状態で、空調機９の電圧検出器２ａに電位差が生じると、地絡の発生箇所は、送電線の正極側、送電線の負極側、および空調機９の内部のいずれかと推測できる。そして、第１特定モードでは、ステップＳ１０５で説明したように、空調機９側の一対のリレー３を切断状態にし、空調機１０側の一対のリレー４を接続状態にする。この状態で、空調機１０の電圧検出器２ｂが電位差を検出した場合、地絡発生箇所として推測した候補のうち、空調機９の内部で地絡が発生することは不可能であると判断できる。そのため、地絡発生箇所は送電線の正極側または負極側と判断できる。一方、空調機１０の電圧検出器２ｂが電位差を検出しなかった場合、地絡発生箇所の候補から送電線を排除でき、空調機９の内部に地絡が発生したと判断できる。 The reason for the determination result in steps S107 and S108 will be described. When a potential difference occurs in the voltage detector 2a of the air conditioner 9 while the operations of the air conditioners 10 and 11 are stopped, the locations where the ground fault occurs are the positive electrode side of the transmission line, the negative electrode side of the transmission line, and the air conditioner 9. It can be inferred to be one of the inside of. Then, in the first specific mode, as described in step S105, the pair of relays 3 on the air conditioner 9 side are disconnected, and the pair of relays 4 on the air conditioner 10 side are connected. In this state, when the voltage detector 2b of the air conditioner 10 detects the potential difference, it can be determined that it is impossible for the ground fault to occur inside the air conditioner 9 among the candidates estimated as the location where the ground fault occurs. .. Therefore, it can be determined that the location where the ground fault occurs is the positive electrode side or the negative electrode side of the transmission line. On the other hand, when the voltage detector 2b of the air conditioner 10 does not detect the potential difference, the transmission line can be excluded from the candidates for the location where the ground fault occurs, and it can be determined that the ground fault has occurred inside the air conditioner 9.
　図５に示したフローチャートの説明に戻る。ステップＳ１０３の判定の結果、空調機９の電圧検出器２ａが検出する電位差Ｖｄａが閾値Ｖｔｈ以下である場合、リレー制御手段４３は第２特定モードに遷移する（ステップＳ１０９）。このとき、空調機９および電源系統に地絡が発生していないので、一対のリレー３を接続状態にし、空調機９が運転してもよい。そのため、地絡箇所を特定する過程に空調機９を稼働させることができる。 Return to the explanation of the flowchart shown in FIG. As a result of the determination in step S103, when the potential difference Vda detected by the voltage detector 2a of the air conditioner 9 is equal to or less than the threshold value Vth, the relay control means 43 transitions to the second specific mode (step S109). At this time, since no ground fault has occurred in the air conditioner 9 and the power supply system, the air conditioner 9 may be operated by connecting the pair of relays 3. Therefore, the air conditioner 9 can be operated in the process of identifying the ground fault location.
　第２特定モードにおいて、リレー制御手段４３は、一対のリレー４を接続状態に切り替える制御を行う（ステップＳ１１０）。具体的には、リレー制御手段４３は、接続制御信号をリレー制御回路３３ｂに送信する。ステップＳ１１０の後、特定手段４２は、電圧検出器２ｂが検出する電位差Ｖｄｂが閾値Ｖｔｈより大きいか否かを判定する（ステップＳ１１１）。判定の結果、電位差Ｖｄｂが閾値Ｖｔｈより大きい場合（ステップＳ１１１：Ｙｅｓ）、特定手段４２は、空調機１０の内部に地絡が発生したと判定する（ステップＳ１１２）。一方、ステップＳ１１１の判定の結果、電位差Ｖｄｂが閾値Ｖｔｈ以下である場合（ステップＳ１１１：Ｎｏ）、特定手段４２は、空調機１１の内部に地絡が発生したと判定する（ステップＳ１１３）。ステップＳ１１３の判定結果は、本実施の形態１では分岐回路が空調機９～１１の３つの場合だからである。つまり、特定手段４２は、ステップＳ１０３からステップＳ１１１の手順にしたがって、電源系統、空調機９および１０のいずれにも地絡が発生していないと判断したので、残りの機器である空調機１１の内部に地絡が発生していると判断できる。 In the second specific mode, the relay control means 43 controls to switch the pair of relays 4 to the connected state (step S110). Specifically, the relay control means 43 transmits a connection control signal to the relay control circuit 33b. After step S110, the identifying means 42 determines whether or not the potential difference Vdb detected by the voltage detector 2b is larger than the threshold value Vth (step S111). As a result of the determination, when the potential difference Vdb is larger than the threshold value Vth (step S111: Yes), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 10 (step S112). On the other hand, as a result of the determination in step S111, when the potential difference Vdb is equal to or less than the threshold value Vth (step S111: No), the specifying means 42 determines that a ground fault has occurred inside the air conditioner 11 (step S113). This is because the determination result in step S113 is that there are three branch circuits of the air conditioners 9 to 11 in the first embodiment. That is, since the specifying means 42 has determined that no ground fault has occurred in any of the power supply system and the air conditioners 9 and 10 according to the procedures from step S103 to step S111, the remaining equipment of the air conditioner 11 It can be determined that a ground fault has occurred inside.
　なお、本実施の形態１では、分岐回路の数が３つの場合で説明したが、分岐回路の数が３つよりも多くてもよい。この場合、第２特定モードでリレー制御手段４３が空調機９を除く、２以上の他の空調機のそれぞれに対応する一対のリレーを順に接続状態にし、特定手段４２は、電圧検出器に電位差が生じた空調機の内部に地絡が発生したと判定することができる。 In the first embodiment, the case where the number of branch circuits is three has been described, but the number of branch circuits may be larger than three. In this case, in the second specific mode, the relay control means 43 connects a pair of relays corresponding to each of the two or more other air conditioners except the air conditioner 9 in order, and the specific means 42 connects the voltage detector with a potential difference. It can be determined that a ground fault has occurred inside the air conditioner in which the above occurred.
　また、図５に示すステップＳ１０２において、空調機９に対応する一対のリレー３を接続状態にして判定する場合で説明したが、最初の判定対象の空調機は空調機９に限らず、空調機１０または１１であってもよい。 Further, in step S102 shown in FIG. 5, the case where the pair of relays 3 corresponding to the air conditioner 9 are connected and determined is described. However, the air conditioner to be determined first is not limited to the air conditioner 9, but the air conditioner. It may be 10 or 11.
　次に、地絡が発生した場合に、送電線の正極側と負極側のどちら側で地絡が発生しているかを判定する方法を、図６および図７を参照して説明する。図６は、図１に示した空調システムにおいて、正極側の送電線に地絡が発生した場合を示す図である。図７は、図１に示した空調システムにおいて、負極側の送電線に地絡が発生した場合を示す図である。図６および図７に示す地絡抵抗Ｒ２０は地絡が発生した箇所の仮想抵抗である。図６および図７では、地絡によって発生した電流である地絡電流を破線矢印で示す。 Next, when a ground fault occurs, a method of determining whether the ground fault has occurred on the positive electrode side or the negative electrode side of the transmission line will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing a case where a ground fault occurs in the transmission line on the positive electrode side in the air conditioning system shown in FIG. FIG. 7 is a diagram showing a case where a ground fault occurs in the transmission line on the negative electrode side in the air conditioning system shown in FIG. The ground fault resistance R20 shown in FIGS. 6 and 7 is a virtual resistance at a location where a ground fault has occurred. In FIGS. 6 and 7, the ground fault current, which is the current generated by the ground fault, is indicated by the broken line arrow.
　図６に示すように、正極側の送電線である正極回線７に地絡が発生した場合、第３抵抗素子Ｒ５に流れる電流の方向は、破線矢印の方向になる。図６において、右方向を正方向、左方向を負方向と定義すれば、第３抵抗素子Ｒ５に流れる電流の方向は負の方向である。この場合、第３抵抗素子Ｒ５の両端の電位差を負の値とする。電圧検出器２ａが正負の情報を含む電位差Ｖｄａの情報を、通信回路３２ａを介してシステムコントローラ１２に送信すれば、特定手段４２は地絡発生箇所が送電線の正極側であると判定できる。 As shown in FIG. 6, when a ground fault occurs in the positive electrode line 7 which is the transmission line on the positive electrode side, the direction of the current flowing through the third resistance element R5 is the direction of the broken arrow arrow. In FIG. 6, if the right direction is defined as the positive direction and the left direction is defined as the negative direction, the direction of the current flowing through the third resistance element R5 is the negative direction. In this case, the potential difference between both ends of the third resistance element R5 is set to a negative value. If the voltage detector 2a transmits the information of the potential difference Vda including the positive and negative information to the system controller 12 via the communication circuit 32a, the specific means 42 can determine that the ground fault occurrence location is on the positive electrode side of the transmission line.
　一方、負極側の送電線である負極回線８に地絡が発生した場合、図７において、右方向を正方向、左方向を負方向と定義すれば、破線矢印に示すように、第３抵抗素子Ｒ５に流れる電流の方向は正の方向である。この場合、第３抵抗素子Ｒ５の両端の電位差を正の値とする。電圧検出器２ａが正負の情報を含む電位差Ｖｄａの情報を、通信回路３２ａを介してシステムコントローラ１２に送信すれば、特定手段４２は地絡発生箇所が送電線の負極側であると判定できる。 On the other hand, when a ground fault occurs in the negative electrode line 8 which is the transmission line on the negative electrode side, if the right direction is defined as the positive direction and the left direction is defined as the negative direction in FIG. 7, the third resistance is shown by the broken arrow. The direction of the current flowing through the element R5 is a positive direction. In this case, the potential difference between both ends of the third resistance element R5 is set to a positive value. If the voltage detector 2a transmits the information of the potential difference Vda including the positive and negative information to the system controller 12 via the communication circuit 32a, the identifying means 42 can determine that the ground fault occurrence location is on the negative electrode side of the transmission line.
　このようにして、特定手段４２は、第３抵抗素子Ｒ５に流れる電流の方向によって、送電線の正極側および負極側のうち、どちら側に地絡が発生したかを特定できる。図６を参照して、正極回線７に地絡が発生した場合で説明したが、図１に示した正極分岐回線７ａ～７ｃの分岐回線に地絡が発生しても、正極回線７と同様に、特定手段４２は正極側に地絡が発生したと判定できる。図７を参照して、負極回線８に地絡が発生した場合で説明したが、図１に示した負極分岐回線８ａ～８ｃの分岐回線に地絡が発生しても、負極回線８と同様に、特定手段４２は負極側に地絡が発生したと判定できる。さらに、特定手段４２は、空調機９～１１の内部の正極側および負極側のどちらに地絡が発生したかについても、図６および図７を参照して説明した方法と同様にして判断できる。 In this way, the identifying means 42 can identify which side of the positive electrode side and the negative electrode side of the transmission line the ground fault has occurred, depending on the direction of the current flowing through the third resistance element R5. Although the case where a ground fault occurs in the positive electrode line 7 has been described with reference to FIG. 6, even if a ground fault occurs in the branch lines of the positive electrode branch lines 7a to 7c shown in FIG. 1, it is the same as that of the positive electrode line 7. In addition, the specific means 42 can determine that a ground fault has occurred on the positive electrode side. Although the case where a ground fault occurs in the negative electrode line 8 is described with reference to FIG. 7, even if a ground fault occurs in the branch lines of the negative electrode branch lines 8a to 8c shown in FIG. 1, it is the same as that of the negative electrode line 8. In addition, the specific means 42 can determine that a ground fault has occurred on the negative electrode side. Further, the specifying means 42 can determine whether the ground fault has occurred on the positive electrode side or the negative electrode side inside the air conditioners 9 to 11 in the same manner as the method described with reference to FIGS. 6 and 7. ..
　本実施の形態１の空調システム１００は、直流電源１に並列に接続される複数の機器となる空調機９～１１と、システムコントローラ１２と、空調機９～１１に対応して設けられ、直流電源１との接続および切断を切り替える一対のリレー３～５とを有する。空調機９～１１の各機器は、地絡が発生したときに流れる電流によって生じる電位差を検出する電圧検出器を含む検出装置と、検出される電位差の値をコントローラに送信する通信回路と、空調機に対応する一対のリレーを制御するリレー制御回路とを有する。システムコントローラ１２は、リレー制御手段４３および特定手段４２を有する。リレー制御手段４３は、複数の検出装置１５ａ～１５ｃによって地絡の発生が検出されると、一対のリレー３～５のうち、少なくとも１つの一対のリレー３を接続状態に制御し、他の一対のリレー４および５を切断状態に制御する。特定手段４２は、リレー制御手段４３によって一対のリレー３～５の状態が切り替わると、複数の電圧検出器２ａ～２ｃから受信する複数の電位差Ｖｄａ～Ｖｄｃに基づいて地絡の発生箇所を特定する。 The air conditioning system 100 of the first embodiment is provided corresponding to the air conditioners 9 to 11, the system controller 12, and the air conditioners 9 to 11, which are a plurality of devices connected in parallel to the DC power supply 1, and is DC. It has a pair of relays 3 to 5 for switching connection and disconnection with the power supply 1. Each device of the air conditioners 9 to 11 includes a detection device including a voltage detector that detects a potential difference caused by a current flowing when a ground fault occurs, a communication circuit that transmits the detected potential difference value to a controller, and an air conditioner. It has a relay control circuit that controls a pair of relays corresponding to the machine. The system controller 12 has a relay control means 43 and a specific means 42. When the occurrence of a ground fault is detected by the plurality of detection devices 15a to 15c, the relay control means 43 controls at least one pair of relays 3 among the pair of relays 3 to 5 in a connected state, and the other pair. The relays 4 and 5 of the above are controlled to be disconnected. When the state of the pair of relays 3 to 5 is switched by the relay control means 43, the identification means 42 identifies the location where the ground fault occurs based on the plurality of potential differences Vda to Vdc received from the plurality of voltage detectors 2a to 2c. ..
　本実施の形態１によれば、複数の分岐回路に対応して複数の一対のリレーが設けられ、複数の一対のリレーのうち、１つの一対のリレーが接続状態、他の一対のリレーが切断状態において、複数の電圧検出器で電位差の検出の有無が判定される。そのため、どの一対のリレーが接続状態のときに地絡が発生したかが判定され、地絡の発生箇所を特定できる。本実施の形態１では、複数の分岐回路に対応して、複数の一対のリレーおよび複数の検出装置が設けられ、簡便に地絡の検出および地絡箇所の特定をすることができる。従来に比べて、簡便な構成なので、製造コストを抑制できる。 According to the first embodiment, a plurality of pairs of relays are provided corresponding to a plurality of branch circuits, one pair of relays is connected and the other pair of relays is disconnected from the plurality of pairs of relays. In the state, the presence or absence of detection of the potential difference is determined by a plurality of voltage detectors. Therefore, it is possible to determine which pair of relays is in the connected state when the ground fault has occurred, and to identify the location where the ground fault has occurred. In the first embodiment, a plurality of pairs of relays and a plurality of detection devices are provided corresponding to the plurality of branch circuits, and the ground fault can be easily detected and the ground fault location can be specified. Since the configuration is simpler than the conventional one, the manufacturing cost can be suppressed.
　本実施の形態１において、システムコントローラ１２は、地絡の検出および地絡箇所を示す情報を、制御回路１３ａ～１３ｃを介してリモートコントローラ１４ａ～１４ｃに出力させてもよい。この場合、空調システム１００のユーザは、空調システム１００のメンテナンス業者の作業者に修理を依頼することができる。 In the first embodiment, the system controller 12 may output information indicating the detection of the ground fault and the location of the ground fault to the remote controllers 14a to 14c via the control circuits 13a to 13c. In this case, the user of the air conditioning system 100 can request the worker of the maintenance company of the air conditioning system 100 for repair.
　また、本実施の形態１において、特定手段４２が、電流方向情報を電流検出器から通信回路を介して受信すると、電流方向情報に基づいて、地絡の発生した箇所が正極回線７を含む正極側の送電線または負極回線８を含む負極側の送電線のうち、いずれの送電線であるかを判定してもよい。この場合、システムコントローラ１２が地絡の発生した送電線の情報を、制御回路１３ａ～１３ｃを介してリモートコントローラ１４ａ～１４ｃに出力させてもよい。空調システム１００を修理する作業者は、リモートコントローラ１４ａ～１４ｃが出力する情報から、正極側の送電線および負極側の送電線うち、いずれの送電線を点検すればよいかわかる。その結果、作業者は、より早く空調システム１００を修理することができる。 Further, in the first embodiment, when the specific means 42 receives the current direction information from the current detector via the communication circuit, the location where the ground fault occurs is the positive electrode including the positive electrode line 7 based on the current direction information. It may be determined which of the side transmission line and the negative electrode side transmission line including the negative electrode line 8 is. In this case, the system controller 12 may output the information of the transmission line in which the ground fault has occurred to the remote controllers 14a to 14c via the control circuits 13a to 13c. From the information output by the remote controllers 14a to 14c, the operator who repairs the air conditioning system 100 knows which of the positive electrode side transmission line and the negative electrode side transmission line should be inspected. As a result, the operator can repair the air conditioning system 100 faster.
　なお、本実施の形態１では、給電システムの電力供給対象の機器が空調機の場合で説明したが、電力供給対象の機器は空調機に限らない。電力供給対象の機器として、例えば、エレベータが考えられる。本実施の形態１で説明した空調システムを、１つのビルに設けられた複数のエレベータに電力を供給する給電システムに適用することができる。 In the first embodiment, the case where the power supply target device of the power supply system is an air conditioner has been described, but the power supply target device is not limited to the air conditioner. As a device to be supplied with electric power, for example, an elevator can be considered. The air conditioning system described in the first embodiment can be applied to a power supply system that supplies electric power to a plurality of elevators provided in one building.
　１　直流電源、２ａ～２ｃ　電圧検出器、３～５　一対のリレー、３－１、３－２　リレー、４－１、４－２　リレー、５－１、５－２　リレー、６　給電ユニット、７　正極回線、７ａ～７ｃ　正極分岐回線、８　負極回線、８ａ～８ｃ　負極分岐回線、９～１１　空調機、１２　システムコントローラ、１３ａ～１３ｃ　制御回路、１４ａ～１４ｃ　リモートコントローラ、１５ａ～１５ｃ　検出装置、２１　ＣＰＵ、２２　メモリ、２３、２４　伝送線、３１ａ～３１ｃ　マイクロコンピュータ、３２ａ～３２ｃ　通信回路、３３ａ～３３ｃ　リレー制御回路、３４ａ～３４ｃ　コンバータ回路、４１　判定手段、４２　特定手段、４３　リレー制御手段、５０　冷媒回路、５１　圧縮機、５２　四方弁、５３　熱源側熱交換器、５４　膨張装置、５５　負荷側熱交換器、５６　冷媒配管、１００　空調システム、Ｒ１、Ｒ２　抵抗素子、Ｒ３　第１抵抗素子、Ｒ４　第２抵抗素子、Ｒ５　第３抵抗素子、Ｒ６　第１抵抗素子、Ｒ７　第２抵抗素子、Ｒ８　第３抵抗素子、Ｒ９　第１抵抗素子、Ｒ１０　第２抵抗素子、Ｒ１１　第３抵抗素子、Ｒ２０　地絡抵抗。 1 DC power supply, 2a to 2c voltage detector, 3 to 5 pair of relays, 3-1 and 3-2 relays, 4-1 and 4-2 relays, 5-1 and 5-2 relays, 6 power supply units, 7 Positive line, 7a-7c positive branch line, 8 negative line, 8a-8c negative branch line, 9-11 air conditioner, 12 system controller, 13a-13c control circuit, 14a-14c remote controller, 15a-15c detection device, 21 CPU, 22 memory, 23, 24 transmission line, 31a to 31c microcomputer, 32a to 32c communication circuit, 33a to 33c relay control circuit, 34a to 34c converter circuit, 41 determination means, 42 specific means, 43 relay control means, 50 Refrigerator circuit, 51 compressor, 52 four-way valve, 53 heat source side heat exchanger, 54 expansion device, 55 load side heat exchanger, 56 refrigerant piping, 100 air conditioning system, R1, R2 resistance element, R3 first resistance element, R4 2nd resistance element, R5 3rd resistance element, R6 1st resistance element, R7 2nd resistance element, R8 3rd resistance element, R9 1st resistance element, R10 2nd resistance element, R11 3rd resistance element, R20 ground fault resistance.

Claims (6)

  1. 　直流電源と正極回線および負極回線を介して並列に接続される複数の機器と、
    　前記複数の機器と通信接続されるコントローラと、
    　それぞれが前記複数の機器に対応して前記正極回線および前記負極回線に設けられ、前記直流電源との接続および切断を切り替える複数の一対のリレーと、
    　を有し、
    　前記各機器は、
    　前記正極回線および前記負極回線との間に設けられ、地絡が発生したときに流れる電流によって生じる電位差を検出する電圧検出器を含む検出装置と、
    　前記電圧検出器によって検出される前記電位差の値を前記コントローラに送信する通信回路と、
    　前記通信回路を介して前記コントローラと接続され、前記機器に対応する前記一対のリレーを制御するリレー制御回路と、を有し、
    　前記コントローラは、
    　複数の前記検出装置によって前記地絡の発生が検出されると、前記複数の一対のリレーのうち、少なくとも１つの一対のリレーを接続状態に制御し、他の一対のリレーを切断状態に制御するリレー制御手段と、
    　前記リレー制御手段によって前記複数の一対のリレーの状態が切り替わると、複数の前記電圧検出器から受信する複数の前記電位差に基づいて前記地絡の発生箇所を特定する特定手段と、を有する、
    　給電システム。     Multiple devices connected in parallel via a DC power supply and positive and negative lines,
    A controller that is connected to the plurality of devices by communication,
    A pair of relays, each of which is provided on the positive electrode line and the negative electrode line corresponding to the plurality of devices and switches connection and disconnection with the DC power supply.
    Have,
    Each of the above devices
    A detection device provided between the positive electrode line and the negative electrode line and including a voltage detector for detecting a potential difference caused by a current flowing when a ground fault occurs.
    A communication circuit that transmits the value of the potential difference detected by the voltage detector to the controller, and
    It has a relay control circuit that is connected to the controller via the communication circuit and controls the pair of relays corresponding to the device.
    The controller
    When the occurrence of the ground fault is detected by the plurality of detection devices, at least one pair of relays among the plurality of pairs of relays is controlled to be connected, and the other pair of relays is controlled to be disconnected. Relay control means and
    When the state of the pair of relays is switched by the relay control means, the relay control means includes a specific means for identifying a location where the ground fault occurs based on the plurality of potential differences received from the plurality of voltage detectors.
    Power supply system.
  2. 　前記コントローラは、前記複数の電圧検出器で検出される前記複数の電位差に基づいて前記地絡が発生したか否かを判定する判定手段をさらに有し、
    　前記リレー制御手段は、
    　前記判定手段によって前記地絡が発生したと判定された場合、前記複数の機器のうち、いずれか１つの機器である第１の機器に対応する前記一対のリレーを接続状態に制御し、前記複数の機器のうち、前記第１の機器を除く他の機器に対応する前記一対のリレーを切断状態に制御し、
    　前記特定手段は、
    　前記第１の機器に属する前記電圧検出器が検出する前記電位差が決められた閾値よりも大きい場合、前記直流電源を含む電源系統、または前記第１の機器を、前記地絡の発生箇所と判定する、
    　請求項１に記載の給電システム。     The controller further includes a determination means for determining whether or not the ground fault has occurred based on the plurality of potential differences detected by the plurality of voltage detectors.
    The relay control means
    When it is determined by the determination means that the ground fault has occurred, the pair of relays corresponding to the first device, which is any one of the plurality of devices, is controlled to be in a connected state, and the plurality of devices are connected. The pair of relays corresponding to other devices other than the first device are controlled to be disconnected.
    The specific means
    When the potential difference detected by the voltage detector belonging to the first device is larger than a determined threshold value, the power system including the DC power supply or the first device is determined to be the location where the ground fault occurs. To do
    The power supply system according to claim 1.
  3. 　前記他の機器が２以上の機器を含み、
    　前記リレー制御手段は、
    　前記第１の機器に属する前記電圧検出器が検出する前記電位差が前記閾値よりも大きい場合、前記他の機器のうち、いずれか１つの機器である第２の機器に対応する前記一対のリレーを接続状態に切り替え、前記第１の機器に対応する前記一対のリレーを切断状態に切り替える第１特定モードを実行し、
    　前記特定手段は、
    　前記リレー制御手段が前記第１特定モードを実行すると、前記第２の機器に属する前記電圧検出器によって検出される前記電位差が前記閾値よりも大きい場合、前記電源系統に前記地絡が発生したと判定し、前記第２の機器に属する前記電圧検出器によって検出される前記電位差が前記閾値以下である場合、前記第１の機器に前記地絡が発生したと判定する、
    　請求項２に記載の給電システム。     The other device includes two or more devices
    The relay control means
    When the potential difference detected by the voltage detector belonging to the first device is larger than the threshold value, the pair of relays corresponding to the second device, which is any one of the other devices, is used. The first specific mode of switching to the connected state and switching the pair of relays corresponding to the first device to the disconnected state is executed.
    The specific means
    When the relay control means executes the first specific mode, if the potential difference detected by the voltage detector belonging to the second device is larger than the threshold value, the ground fault has occurred in the power supply system. When the potential difference detected by the voltage detector belonging to the second device is equal to or less than the threshold value, it is determined that the ground fault has occurred in the first device.
    The power supply system according to claim 2.
  4. 　前記他の機器が２以上の機器を含み、
    　前記リレー制御手段は、
    　前記第１の機器に属する前記電圧検出器が検出する前記電位差が前記閾値以下である場合、前記他の機器のうち、いずれか１つの機器である第２の機器に対応する前記一対のリレーを接続状態に制御し、前記他の機器のうち、前記第２の機器を除く残りの機器に対応する前記一対のリレーを切断状態に制御する第２特定モードを前記他の機器毎に実行し、
    　前記特定手段は、
    　前記各他の機器に対応して前記第２特定モードが実行される度に、前記他の機器に属する前記電圧検出器が検出する前記電位差と前記閾値とを比較し、前記電位差が前記閾値よりも大きい前記他の機器に前記地絡が発生したと判定する、
    　請求項２に記載の給電システム。     The other device includes two or more devices
    The relay control means
    When the potential difference detected by the voltage detector belonging to the first device is equal to or less than the threshold value, the pair of relays corresponding to the second device, which is any one of the other devices, is used. A second specific mode for controlling the connection state and controlling the pair of relays corresponding to the remaining devices other than the second device among the other devices to the disconnected state is executed for each of the other devices.
    The specific means
    Each time the second specific mode is executed corresponding to each of the other devices, the potential difference detected by the voltage detector belonging to the other device is compared with the threshold value, and the potential difference is greater than the threshold value. It is determined that the ground fault has occurred in the other device, which is also large.
    The power supply system according to claim 2.
  5. 　前記検出装置は、
    　前記正極回線および前記負極回線との間に直列に接続された第１抵抗素子および第２抵抗素子と、
    　前記第１抵抗素子および前記第２抵抗素子の接続点とグランドとの間に設けられた第３抵抗素子と、
    　前記第３抵抗素子に並列に接続され、前記第３抵抗素子に流れる電流によって生じる前記電位差を検出する前記電圧検出器と、を有する、
    　請求項１～４のいずれか１項に記載の給電システム。     The detection device
    A first resistance element and a second resistance element connected in series between the positive electrode line and the negative electrode line,
    A third resistance element provided between the connection point of the first resistance element and the second resistance element and the ground, and
    It has the voltage detector which is connected in parallel to the third resistance element and detects the potential difference caused by the current flowing through the third resistance element.
    The power supply system according to any one of claims 1 to 4.
  6. 　前記特定手段は、
    　前記第３抵抗素子に流れる電流の方向を示す電流方向情報を前記電圧検出器から前記通信回路を介して受信すると、前記電流方向情報に基づいて、前記地絡の発生した箇所が前記正極回線および前記負極回線のうち、いずれの回線であるかを判定する、
    　請求項５に記載の給電システム。     The specific means
    When current direction information indicating the direction of the current flowing through the third resistance element is received from the voltage detector via the communication circuit, the location where the ground fault occurs becomes the positive electrode line and the positive electrode line based on the current direction information. Which of the negative electrode lines is used?
    The power supply system according to claim 5.
PCT/JP2019/029645 2019-07-29 2019-07-29 Power feed system WO2021019640A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/JP2019/029645 WO2021019640A1 (en) 2019-07-29 2019-07-29 Power feed system
JP2021536482A JP7112038B2 (en) 2019-07-29 2019-07-29 power supply system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2019/029645 WO2021019640A1 (en) 2019-07-29 2019-07-29 Power feed system

Publications (1)

Publication Number Publication Date
WO2021019640A1 true WO2021019640A1 (en) 2021-02-04

Family

ID=74229801

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/029645 WO2021019640A1 (en) 2019-07-29 2019-07-29 Power feed system

Country Status (2)

Country Link
JP (1) JP7112038B2 (en)
WO (1) WO2021019640A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7182332B1 (en) 2022-08-12 2022-12-02 寛 須藤 Support device for golf ball collecting device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003223841A (en) * 2001-11-22 2003-08-08 Toyota Motor Corp Ground-fault detector
JP2005168156A (en) * 2003-12-02 2005-06-23 Mitsubishi Heavy Ind Ltd Ground fault countermeasure device and power generating system
JP2011019312A (en) * 2009-07-07 2011-01-27 Hitachi Ltd Power conversion device
JP2019030099A (en) * 2017-07-28 2019-02-21 住友電気工業株式会社 Dc power supply system and earth determination method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003223841A (en) * 2001-11-22 2003-08-08 Toyota Motor Corp Ground-fault detector
JP2005168156A (en) * 2003-12-02 2005-06-23 Mitsubishi Heavy Ind Ltd Ground fault countermeasure device and power generating system
JP2011019312A (en) * 2009-07-07 2011-01-27 Hitachi Ltd Power conversion device
JP2019030099A (en) * 2017-07-28 2019-02-21 住友電気工業株式会社 Dc power supply system and earth determination method

Also Published As

Publication number Publication date
JP7112038B2 (en) 2022-08-03
JPWO2021019640A1 (en) 2021-11-04

Similar Documents

Publication Publication Date Title
JP2667950B2 (en) Air conditioner and its address setting method
EP2570745A2 (en) Air conditioner
EP1691139B1 (en) Checking Air Conditioning System Installation
US20040120084A1 (en) Power supply with multiple transformer current sharing
CN111174391A (en) Emergency power supply protection device for indoor unit of multi-split system
KR19990043509A (en) Multi-inverter air conditioning equipment and test method with installation check
WO2021019640A1 (en) Power feed system
CN105423484A (en) Detection method and detection circuit for insufficiency of air conditioning refrigerant
KR101075229B1 (en) Apparatus for diagnosing communication error of a multi air conditioner system and method thereof
JPH10300292A (en) Freezer
JP6530920B2 (en) Air conditioner, indoor unit of air conditioner, and communication method of air conditioner
EP4086539A1 (en) Air-conditioning system
JPH1114123A (en) Air conditioner
CN111365827A (en) Air conditioner, control method of air conditioner, and computer-readable storage medium
JPH07305879A (en) Detecting method of erroneous wiring of multi-type air conditioner
KR100896283B1 (en) Air Conditioner And Control Method For The Same
JPH09145129A (en) Multi-room air conditioning control system
US11619412B2 (en) Environment control system, and air conditioner or air conditioning system
JPH06281301A (en) Air conditioner
KR101203517B1 (en) Air conditioning system and method for detecting short state of refregerant pipes of the same
JPH10300174A (en) Piping error or wiring error detecting device for multiple room air conditioning system
CN220707656U (en) Air conditioner
KR101903640B1 (en) Air conditioner
KR20140100651A (en) Apparatus and method for air conditioner
JPH0755279A (en) Air conditioner

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19939342

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2021536482

Country of ref document: JP

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19939342

Country of ref document: EP

Kind code of ref document: A1