JP6543872B2 - Control device, control method and program - Google Patents

Description

  The present invention relates to a control device, a control method, and a program.

In a system in which an inverter drives a motor, control signals for controlling switching elements that constitute the inverter that drives the motor are generated. For example, in an air conditioning system having an air conditioner (hereinafter, referred to as an air conditioner), a control signal is generated to control switching elements constituting an inverter for driving a compressor motor in a compressor. Generally, various voltages (analog values) in the system are detected to control the inverter to operate the motor in an appropriate manner for the state of the system. And based on the detected voltage, it is necessary to generate a control signal which controls a switching element which constitutes an inverter. At that time, an A / D conversion circuit that converts a voltage that is an analog value into a digital value may be used.
According to Patent Document 1, as a related technology, an output voltage value of an A / D conversion circuit that inputs a voltage that is an analog value of a voltage source and converts it into a digital signal is a state between an overcharge state and an overdischarge state. Techniques have been described for detecting in-range faults that are within the normal voltage range, but are digital values different from the actual analog voltage of the voltage source.

JP, 2013-234851, A

  Incidentally, in an air conditioning system in which an inverter drives a motor, an A / D conversion circuit converts various voltages (analog values) in the system into digital values. Then, the control signal for controlling the switching elements constituting the inverter is determined based on the digital value after conversion by the A / D conversion circuit, whereby the motor operates properly. In such an air conditioning system, when an abnormality occurs in the A / D conversion circuit, the A / D conversion circuit converts various voltages (analog values) different from actual values in the air conditioning system into digital values. Therefore, the control signal that controls the switching element that constitutes the inverter may become an inappropriate control signal. As a result, the inverter improperly drives the motor, and the system may be in an abnormal state.

  Then, this invention aims at providing the control apparatus which can solve said subject, a control method, and a program.

According to the first aspect of the present invention, the control device is a control device used in an outdoor unit provided with a motor, which has a maximum voltage of three voltages corresponding to the three-phase alternating current flowing to the motor. A first A / D converter for generating a digital value from an analog value; a second A / D converter for generating a digital value from an analog value of the minimum voltage of the three voltages corresponding to the three-phase alternating current; The average value of the digital value generated by the first A / D conversion unit and the digital value generated by the second A / D conversion unit is calculated, and the calculated average value and the predetermined period of the current flowing through the motor are determined in advance . A determination unit that determines that at least one of the first A / D conversion unit and the second A / D conversion unit is not operating normally when the difference from the reference value based on the average value is outside a predetermined range And.

According to a second aspect of the present invention, the control apparatus of the first aspect, at least one of the determination unit is the first A / D conversion unit and the first 2A / D conversion unit is not operating normally And a control unit that performs control to stop the operation of the outdoor unit when it is determined that the operation is not performed.

According to a third aspect of the present invention includes the control device of the first or second aspect, the voltage detecting unit for detecting the voltage corresponding to the previous SL three-phase alternating current, the.

According to a fourth aspect of the present invention, the control method is a control method by a control device used in an outdoor unit including a motor, and the first A / D conversion unit converts the three-phase alternating current flowing in the motor The digital value is generated from the analog value of the maximum voltage of the corresponding three voltages, and the second A / D conversion unit is configured to generate the digital value from the analog value of the minimum voltage of the three voltages corresponding to the three-phase alternating current The determination unit calculates an average value obtained by adding the digital value generated by the first A / D conversion unit and the digital value generated by the second A / D conversion unit for a fixed period, and averaging them. The first A / D conversion unit and the second A / D conversion when the difference between the calculated average value and a reference value based on an average value of current flowing through the motor in a predetermined period is outside a predetermined range. At least one of the parts is positive It determines that not working at all times.

According to a fifth aspect of the present invention, a program causes a computer of a control device used in an outdoor unit provided with a motor to be an analog of the maximum voltage of the three voltages corresponding to the three-phase alternating current flowing through the motor. First generating means for generating a digital value from values, second generating means for generating a digital value from an analog value of the minimum voltage of the three voltages corresponding to the three-phase alternating current, generated by the first generating means the calculated digital value and the average value of the generated said digital value and a predetermined period obtained by adding an average of the second generation means, the calculated average value, the average value of a certain period of the current flowing in the motor previously determined in If the difference between the reference value based is out of the predetermined range, at least one of a determination unit and not operating normally among the first generation means and the second generating means, and then To function.

  According to the control device according to the embodiment of the present invention, in the air conditioning system in which the inverter drives the motor, at least one of the one or more A / D conversion circuits is not operating normally, that is, it is abnormal. The abnormality can be detected, and the air conditioning system can be safely shut down.

It is a 1st figure which shows the structure of the outdoor unit used for an air-conditioning system provided with the control apparatus by 1st embodiment of this invention. FIG. 5 shows a control signal for controlling an inverter according to the first embodiment of the present invention. It is a figure which shows the voltage which the voltage detection part by 1st embodiment of this invention detects. It is a figure which shows the target value of the output voltage of the motor which the drive waveform generation part by 1st embodiment of this invention has. It is a figure which shows the processing flow which the outdoor unit by 1st embodiment of this invention produces | generates the alternating voltage which drives a motor. It is a figure which shows the processing flow which the outdoor unit by 1st embodiment of this invention detects abnormality of an A / D-conversion circuit. It is a 2nd figure showing composition of an outdoor unit used for an air-conditioning system provided with a control device by a first embodiment of the present invention. It is a 1st figure which shows the structure of the outdoor unit used for an air-conditioning system provided with the control apparatus by 2nd embodiment of this invention. It is a figure which shows the processing flow which the outdoor unit by 2nd embodiment of this invention detects abnormality of an A / D-conversion circuit. It is a figure which shows the voltage which the voltage detection part by 2nd embodiment of this invention detects. It is a 2nd figure showing composition of an outdoor unit used for an air-conditioning system provided with a control device by a second embodiment of the present invention. It is a 1st figure which shows the structure of the outdoor unit used for an air-conditioning system provided with the control apparatus by 3rd embodiment of this invention. It is a 2nd figure showing composition of an outdoor unit used for an air-conditioning system provided with a control device by a third embodiment of the present invention.

First Embodiment
Hereinafter, embodiments will be described in detail with reference to the drawings.
First, the structure of the outdoor unit used for the air conditioning system provided with the control device according to the first embodiment of the present invention will be described.
As shown in FIG. 1, the outdoor unit 1 (target device) according to the present embodiment includes an AC power supply 10, an AC (Alternative Current) -DC (Direct Current) converter 20, an inverter 30, a motor 40, and a control device. And 50.

The AC power supply 10 generates an AC voltage and outputs it to the AC-DC converter 20.
The AC-DC converter 20 includes a reactor 201, a rectifier diode stack 202, and a capacitor 203.
The rectifying diode stack 202 included in the AC-DC converter 20 rectifies the AC voltage input from the AC power supply 10.
The reactor 201 and the capacitor 203 form a smoothing filter that suppresses harmonics of the AC power supply 10, and reduces the ripple of the voltage rectified by the rectifying diode stack 202.
Then, the AC-DC converter 20 outputs the rectified DC voltage to the inverter 30.

The inverter 30 converts the DC voltage input from the AC-DC converter 20 into an AC voltage for driving the motor 40. The inverter 30 is configured of, for example, six switching elements. Each of switching elements 301 to 306 receives a control voltage from control device 50, turns on (conductive state) when the input control voltage is in the Hi state, and turns off (not connected) when the input control voltage is in the Lo state. Switch to the on state). Then, the inverter 30 generates the U-phase voltage, the V-phase voltage, and the W-phase voltage for driving the motor 40. The control voltage is, for example, a PWM (Pulse Width Modulation) signal as shown in FIG. The control voltage is a voltage having a sufficiently short cycle as compared with one cycle of the voltage at which the inverter 30 drives the motor 40. The control voltage changes the pulse width for each cycle of the control signal so that the amplitude of the AC voltage output from the inverter 30 to the motor 40 becomes appropriate at each timing.
Each of the switching elements 301 to 306 is, for example, an IGBT (Insulated Gate Bipolar Transistor) or a power MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

  The motor 40 operates in accordance with the AC voltage output from the inverter 30. The motor 40 is, for example, a compressor motor for a compressor of an air conditioner.

  The control device 50 includes a detection unit 501, a voltage detection unit 502, two A / D (Analog to Digital) conversion circuits 503 and 504 (A / D conversion unit), a drive signal generation unit 505, and a transistor circuit 506. And an A / D conversion determination unit 507 (determination unit).

  Detection unit 501 detects the current or voltage in outdoor unit 1. For example, the detection unit 501 is a resistor and detects a motor current which is a three-phase alternating current flowing in the motor 40. For example, when the switching elements 301, 304, and 306 are in the on state and the switching elements 302, 303, and 305 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 changes from the switching element 301 to the U phase. The signal is input to the motor 40 via the corresponding wiring, and is output from the motor 40 to the two switching elements 304 and 306 via the respective wirings corresponding to the V phase and the W phase. Therefore, when the switching elements 301, 304, and 306 are in the on state and the switching elements 302, 303, and 305 are in the off state, the detection unit 501 inputs to the motor 40 from the switching element 301 via the wiring corresponding to the U phase. Current can be detected.

  Also, for example, when the switching elements 301, 303, and 306 are in the on state and the switching elements 302, 304, and 305 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 is the two switching elements 301. , 303 are input to the motor 40 via the respective wires corresponding to the U phase and the V phase, and are output from the motor 40 to the switching element 306 via the wire corresponding to the W phase. Therefore, when the switching elements 301, 303, and 306 are in the on state and the switching elements 302, 304, and 305 are in the off state, the detection unit 501 outputs the signal from the motor 40 to the switching element 306 via the wiring corresponding to the W phase. Current can be detected.

  Further, for example, when the switching elements 302, 303, and 306 are in the on state and the switching elements 301, 304, and 305 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 is V The signal is input to the motor 40 via the wiring corresponding to the phase, and is output from the motor 40 to the two switching elements 302 and 306 via the wiring corresponding to each of the U phase and the W phase. Therefore, when the switching elements 302, 303, and 306 are in the on state and the switching elements 301, 304, and 305 are in the off state, the detection unit 501 inputs to the motor 40 from the switching element 303 via the wiring corresponding to the V phase. Current can be detected.

  Further, for example, when the switching elements 302, 303, and 305 are in the on state and the switching elements 301, 304, and 306 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 is the two switching elements 303. , 305 are input to the motor 40 via the respective wires corresponding to the V phase and the W phase, and are output from the motor 40 to the switching element 302 via the wire corresponding to the U phase. Therefore, when the switching elements 302, 303, and 305 are in the on state and the switching elements 301, 304, and 306 are in the off state, the detection unit 501 outputs the signal from the motor 40 to the switching element 302 via the wiring corresponding to the U phase. Current can be detected.

  Also, for example, when the switching elements 302, 304, and 305 are in the on state and the switching elements 301, 303, and 306 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 The signal is input to the motor 40 via the wiring corresponding to the phase, and is output from the motor 40 to the two switching elements 302 and 304 via the wirings corresponding to the U phase and the V phase, respectively. Therefore, when the switching elements 302, 304, and 305 are in the on state and the switching elements 301, 303, and 306 are in the off state, the detection unit 501 inputs to the motor 40 from the switching element 305 via the wiring corresponding to the W phase. Current can be detected.

  Further, for example, when the switching elements 301, 304, and 305 are in the on state and the switching elements 302, 303, and 306 are in the off state, the current corresponding to the control voltage for controlling the switching elements 301 to 306 is the two switching elements 301. , 305 are input to the motor 40 via the respective wires corresponding to the U phase and the W phase, and are output from the motor 40 to the switching element 304 via the wire corresponding to the V phase. Therefore, when the switching elements 301, 304, and 305 are in the on state and the switching elements 302, 303, and 306 are in the off state, the detection unit 501 outputs to the switching element 304 from the motor 40 via the wiring corresponding to the V phase. Current can be detected.

  Note that when the switching elements 301, 303, 305 are in the on state and the switching elements 302, 304, 306 are in the off state, or the switching elements 302, 304, 306 are in the on state, and the switching elements 301, 303, 305 are in the off state The motor current in this case is the return current of the motor (the current at which the motor winding coil tries to flow the current when it simultaneously becomes Hi state or Lo state simultaneously) is connected to each of the switching elements 301 to 306 Flow through the diode. In addition, it is previously determined that the average value of two cycles of the motor current is 0, and the current detected by the detection unit 501 is a pseudo sine wave whose amplitude swings to the positive side and the negative side around 0 amperes.

  The voltage detection unit 502 detects a voltage corresponding to the current detected by the detection unit 501. For example, the voltage detection unit 502 converts a voltage corresponding to the current detected by the detection unit 501 into an AC voltage in which the center of the amplitude matches the reference voltage (for example, 2.5 volts) as shown in FIG. It outputs at timings such as b1, a1, b2, a2, b3, a3,. In FIG. 3, the horizontal axis indicates the phase. The vertical axis shows the amplitude. The AC voltages corresponding to each of the U-phase, V-phase, and W-phase shown in FIG. 3 have an amplitude of 1.5 volts and are out of phase with each other by 120 degrees.

Each of the two A / D conversion circuits 503 and 504 acquires the voltage output from the voltage detection unit 502 at each predetermined timing.
When the AC voltage corresponding to each of the U phase, the V phase, and the W phase is in the phase relationship shown in FIG. 4, the voltage A corresponding to the U phase, which is the highest voltage at 0 degree to 60 degrees, It is a voltage that is input to the motor 40 via the wiring corresponding to the U phase and is output from the motor 40 to the two switching elements 304 and 306 via the respective wiring corresponding to each of the V phase and the W phase. . In addition, voltage B corresponding to the W phase, which is the lowest voltage at 0 ° to 120 °, is transmitted from the two switching elements 301 and 303 to the motor 40 via the respective wires corresponding to the U phase and the V phase. It is a voltage that is input and output from the motor 40 to the switching element 306 via the wiring corresponding to the W phase. The voltage A corresponding to the V phase, which is the highest voltage at 60 degrees to 180 degrees, is input from the switching element 303 to the motor 40 via the wiring corresponding to the V phase, and the motor 40 outputs U phase and W phase The voltage is output to the two switching elements 302 and 306 via the corresponding wiring. The voltage B corresponding to the U phase, which is the lowest voltage at 120 degrees to 240 degrees, is supplied to the motor 40 from the two switching elements 304 and 306 via the respective wires corresponding to the V phase and the W phase. It is a voltage that is input and output from the motor 40 to the switching element 302 via the wiring corresponding to the U phase. The voltage A corresponding to the W phase, which is the highest voltage at 180 degrees to 300 degrees, is input from the switching element 305 to the motor 40 via the wiring corresponding to the W phase, and the motor 40 outputs U phase and V phase The voltage is output to the two switching elements 302 and 304 via the corresponding wires. The voltage B corresponding to the V phase, which is the lowest voltage at 240 degrees to 360 degrees, has a current corresponding to the control voltage for controlling the switching elements 301 to 306 from the two switching elements 301 and 305 to the U phase and W phase. It is a voltage that is input to the motor 40 via the respective wires corresponding to each of the phases, and is output to the switching element 304 from the motor 40 via the wires corresponding to the V phase.

  Therefore, the A / D conversion circuit 503 turns on and off the switching elements 301, 304 and 306 at 0 degrees to 60 degrees at predetermined timings (for example, a1 in FIG. 4). The voltage A in FIG. 3 is acquired from the voltage detection unit 502 at each adjacent time interval of a2, a3,. Also, the A / D conversion circuit 503 is illustrated from the voltage detection unit 502 at each predetermined timing when the switching elements 302, 303, and 306 are on and the switching elements 301, 304, and 305 are off at 60 degrees to 180 degrees. Acquire the voltage A at 3. Also, the A / D conversion circuit 503 is illustrated from the voltage detection unit 502 every predetermined timing when the switching elements 302, 304, and 305 are in the on state and the switching elements 301, 303, and 306 are in the off state at 180 degrees to 300 degrees. Acquire the voltage A at 3. By doing this, the A / D conversion circuit 503 receives the voltage A shown in FIG. 4, that is, the input from the inverter 30 to the motor 40 via the wiring corresponding to each of the U phase, V phase and W phase. The voltage A corresponding to the maximum voltage among the voltages of V can be acquired at predetermined timings.

In addition, for example, the A / D conversion circuit 504 changes the switching elements 301, 303, and 306 in the ON state and the switching elements 302, 304, and 305 in the OFF state at 0 degrees to 120 degrees (for example, FIG. The voltage B in FIG. 3 is acquired from the voltage detection unit 502 at each adjacent time interval of b1, b2, b3,. Also, the A / D conversion circuit 504 is illustrated from the voltage detection unit 502 at each predetermined timing when the switching elements 302, 303, and 305 are on and the switching elements 301, 304, and 306 are off at 120 degrees to 240 degrees. The voltage B at 3 is obtained. Also, the A / D conversion circuit 504 is illustrated from the voltage detection unit 502 at each predetermined timing when the switching elements 301, 304, and 305 are on and the switching elements 302, 303, and 306 are off at 240 degrees to 360 degrees. The voltage B at 3 is obtained. By doing this, the A / D conversion circuit 504 generates the waveform B shown in FIG. 4, that is, each voltage output from the motor 40 via the wiring corresponding to each of the U phase, V phase and W phase. The voltage B corresponding to the minimum voltage can be acquired at predetermined timings.

The A / D conversion circuit 503 converts the acquired voltage A (analog value) into a digital value. Then, the A / D conversion circuit 503 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.
Also, the A / D conversion circuit 504 converts the acquired voltage B (analog value) into a digital value. Then, the A / D conversion circuit 504 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.

The drive signal generation unit 505 generates a control signal for controlling the switching elements 301 to 306 constituting the inverter 30. The drive signal generation unit 505 generates, for example, a PWM signal that controls the switching elements 301 to 306. At this time, the drive signal generation unit 505 feeds back a voltage A indicated by the digital value input from the A / D conversion circuit 503 and a voltage B indicated by the digital value input from the A / D conversion circuit 504 to generate a PWM signal. You may
The drive signal generation unit 505 outputs the generated control signal to the inverter 30 via the transistor circuit 506. In addition, the drive signal generation unit 505 outputs the generated control signal to the A / D conversion determination unit 507.

  The transistor circuit 506 converts the control signal input from the drive signal generation unit 505 into a signal capable of driving the inverter 30 and outputs the signal to the inverter 30. The transistor circuit 506 is, for example, a buffer circuit, and outputs a control signal suitable for each timing as shown in FIG. 2 to the inverter 30.

  In the outdoor unit 1, the detection unit 501 detects a motor current flowing to the motor 40. The two A / D conversion circuits 503 and 504 convert a voltage corresponding to the motor current detected by the detection unit 501 from an analog value to a digital value. The A / D conversion determination unit 507 calculates an average value of values obtained by adding a digital value after conversion by each of the two A / D conversion circuits 503 and 504 for a fixed period and multiplying by a half. Then, the A / D conversion determination unit 507 determines that the difference between the reference voltage (for example, 2.5 V) determined based on the average value 0 of the motor current for a predetermined period determined in advance and the calculated average value is within a predetermined range ( For example, when the voltage is outside 1.5 V to 3.5 V), it is determined that at least one of the two A / D conversion circuits 503 and 504 is not operating normally.

Next, processing performed by the outdoor unit 1 according to the present embodiment will be described.
Here, the processing will be described by taking the outdoor unit 1 shown in FIG. 1 as an example.

First, a process in a normal state in which the outdoor unit 1 rectifies a single-phase AC voltage output from the AC power supply 10 to generate a DC voltage and generates an AC voltage for driving the motor 40 from the generated DC voltage will be described.
A process flow of a normal state in which the outdoor unit 1 according to the present embodiment shown in FIG. 5 generates an AC voltage for driving the motor 40 will be described below.
The AC power supply 10 included in the outdoor unit 1 outputs, to the AC-DC converter 20, a single-phase AC voltage 180 degrees out of phase.

  The rectifier diode stack 202 included in the AC-DC converter 20 inputs a single-phase AC voltage from the AC power supply 10 (step S1). The rectifying diode stack 202 full-wave rectifies the input single-phase AC voltage (step S2).

  The reactor 201 and the capacitor 203 constitute a smoothing filter, and smoothes the rectified voltage (step S3). Then, reactor 201 and capacitor 203 output the smoothed DC voltage to inverter 30.

When the DC voltage is input, the inverter 30 generates an AC voltage for driving the motor 40 from the input DC voltage (step S4). The inverter 30 outputs the generated AC voltage to the motor 40.
When the AC voltage is input from the inverter 30, the motor 40 operates according to the input AC voltage (step S5).

Next, a process of detecting an abnormality in the two A / D conversion circuits 503 and 504 which the outdoor unit 1 performs in parallel with the process in the normal state will be described.
A process flow for detecting an abnormality in the two A / D conversion circuits 503 and 504 performed in parallel with the process in the normal state by the outdoor unit 1 according to the present embodiment shown in FIG. 6 will be described below.

  Following the process of step S5 performed by the outdoor unit 1, the A / D conversion determination unit 507 determines whether the motor 40 is in operation (step S6). Specifically, for example, the A / D conversion determination unit 507 acquires, from the drive signal generation unit 505, information as to whether or not the drive signal generation unit 505 outputs a control signal to the transistor circuit 506. When the A / D conversion determination unit 507 acquires information indicating that the control signal is output from the drive signal generation unit 505 to the transistor circuit 506, the A / D conversion determination unit 507 determines that the motor 40 is in operation. When the A / D conversion determination unit 507 acquires information indicating that the control signal is not output from the drive signal generation unit 505 to the transistor circuit 506, the A / D conversion determination unit 507 determines that the motor 40 is not in operation.

When the A / D conversion determination unit 507 determines that the motor 40 is not in operation (NO in step S6), the processing of the outdoor unit 1 is ended.
When the A / D conversion determination unit 507 determines that the motor 40 is operating (YES in step S6), the detection unit 501 detects each of the two A / D conversion circuits 503 and 504 in the normal state. An instruction signal for acquiring voltages respectively corresponding to the upper side and the lower side of the motor current being output is output. The voltage corresponding to the upper side of the motor current corresponds to the maximum voltage among the voltages input from the inverter 30 to the motor 40 via the wiring corresponding to each of the U phase, V phase, and W phase. Voltage (voltage A shown in FIG. 4). Further, the voltage corresponding to the lower side of the motor current is the voltage corresponding to the maximum voltage among the voltages output from the motor 40 via the wiring corresponding to each of the U phase, V phase and W phase (The voltage B shown in FIG. 4).

In the normal state, the detection unit 501 detects a motor current flowing to the motor 40. Further, the voltage detection unit 502 detects a voltage corresponding to the motor current detected by the detection unit 501.
When each of the two A / D conversion circuits 503 and 504 receives an instruction signal from the A / D conversion determination unit 507, the two A / D conversion circuits 503 and 504 acquire timing information of a control signal output from the drive signal generation unit 505 to the transistor circuit 506. Then, each of the two A / D conversion circuits 503 and 504 sets the upper side and the lower side of the motor current output from the voltage detection unit 502 based on the timing information of the control signal output from the drive signal generation unit 505 to the transistor circuit 506. The voltage corresponding to each side is acquired at each predetermined timing (step S7). More specifically, each of the two A / D conversion circuits 503 and 504 has the U phase at each timing as shown in FIG. 2 according to the timing information of the control signal output from the drive signal generation unit 505 to the transistor circuit 506. It can be determined whether each of the V phase and the W phase is in the on state or in the off state. Therefore, for example, when the voltages corresponding to each of the U phase, the V phase, and the W phase are in the phase relationship shown in FIG. 4, the A / D conversion circuit 503 switches the switching elements 301, 304, 306 at 0 degrees to 60 degrees. The voltage detection unit 502 outputs an output at each predetermined timing (for example, every adjacent time interval of a1, a2, a3,... In FIG. 4) in which the switching elements 302, 303, and 305 are in the on state. Voltage A to be obtained. Further, the A / D conversion circuit 503 receives the voltage from the voltage detection unit 502 at each predetermined timing when the switching elements 302, 303, and 306 are on and the switching elements 301, 304, and 305 are off at 60 degrees to 180 degrees. Get A In the A / D conversion circuit 503, the voltage detection unit 502 outputs an output at each predetermined timing when the switching elements 302, 304, and 305 turn on and the switching elements 301, 303, and 306 turn off at 180 degrees to 300 degrees. Voltage A to be obtained. By doing this, the A / D conversion circuit 503 receives the voltage A shown in FIG. 4, that is, the input from the inverter 30 to the motor 40 via the wiring corresponding to each of the U phase, V phase and W phase. The voltage A corresponding to the maximum voltage among the voltages of V can be acquired at predetermined timings.

  In addition, for example, the A / D conversion circuit 504 changes the switching elements 301, 303, and 306 in the ON state and the switching elements 302, 304, and 305 in the OFF state at 0 degrees to 120 degrees (for example, FIG. 4). The voltage B is acquired from the voltage detection unit 502 at adjacent time intervals of b1, b2, b3,. Further, the A / D conversion circuit 504 receives a voltage from the voltage detection unit 502 at each predetermined timing when the switching elements 302, 303, and 305 are turned on and the switching elements 301, 304, and 306 are turned off at 120 degrees to 240 degrees. Get B. Further, the A / D conversion circuit 504 receives a voltage from the voltage detection unit 502 at predetermined timings at which the switching elements 301, 304, and 305 are on and the switching elements 302, 303, and 306 are off at 240 degrees to 360 degrees. Get B. By doing this, the A / D conversion circuit 504 generates the waveform B shown in FIG. 4, that is, each voltage output from the motor 40 via the wiring corresponding to each of the U phase, V phase and W phase. The voltage B corresponding to the maximum voltage can be acquired at predetermined timings.

The A / D conversion circuit 503 converts the acquired voltage A (analog value) into a digital value. Then, the A / D conversion circuit 503 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.
Also, the A / D conversion circuit 504 converts the acquired voltage B (analog value) into a digital value. Then, the A / D conversion circuit 504 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.

The A / D conversion determination unit 507 receives a digital value corresponding to the voltage A (voltage corresponding to the upper side of the motor current) from the A / D conversion circuit 503. The A / D conversion determination unit 507 also receives a digital value corresponding to the voltage B (voltage corresponding to the lower side of the motor current) from the A / D conversion circuit 504. Then, the A / D conversion determination unit 507 calculates an average value of values obtained by adding a digital value corresponding to the input voltage A and a digital value corresponding to the voltage B for a fixed period and multiplying by a half (Step S8). ). The fixed period here is, for example, a period of two cycles with 360 degrees shown in FIG. 3 as one cycle. When the A / D conversion determination unit 507 calculates the average value of the values obtained by adding the input voltages A and B for a fixed period and dividing them by a half, the reference voltage (in the case of the voltage shown in FIG. It becomes predetermined beforehand that it becomes a bolt.
The A / D conversion determination unit 507 determines whether or not the difference between the calculated average value and the reference value determined based on the average value of the motor current determined in advance for a predetermined period is within a predetermined range (step S9).

When the difference between the calculated average value and the reference value determined based on the average value of the constant period of the motor current determined in advance is out of the predetermined range (step S9, NO), the A / D conversion determination unit 507 It is determined that at least one of the A / D conversion circuits 503 and 504 is not operating normally. For example, the A / D conversion determination unit 507 adds a digital value input from each of the two A / D conversion circuits 503 and 504 in a period corresponding to two cycles of the motor current for a fixed period and halves it. Calculate the average of the values. When the difference between the calculated average value and the reference voltage 2.5 volts used by the voltage detection unit 502 is 1 volt or more, the A / D conversion determination unit 507 operates normally. It determines that it does not do.
Then, the A / D conversion determination unit 507 (control unit) stops (abnormally stops) the operation of the outdoor unit 1 which is a device equipped with the control device 50 (step S10).

  In addition, when the difference between the calculated average value and the reference value determined based on the average value of the motor current for a predetermined period determined in advance is within the predetermined range (step S9, YES), the A / D conversion determination unit 507 ), It is determined that the state is normal, and the process returns to step S6.

  The process flow of the outdoor unit 1 provided with the control device 50 according to the first embodiment of the present invention has been described above. In the processing of the outdoor unit 1 described above, the detection unit 501 detects a motor current flowing to the motor 40. The voltage detection unit 502 detects a voltage corresponding to the current detected by the detection unit 501. Each of the two A / D conversion circuits 503 and 504 converts the voltage detected by the voltage detection unit 502 from an analog value to a digital value. The A / D conversion determination unit 507 calculates an average value of values obtained by adding a digital value after conversion by each of the two A / D conversion circuits 503 and 504 for a fixed period and multiplying by a half. Then, the A / D conversion determination unit 507 sets the difference between the calculated average value and a reference voltage (for example, 2.5 V) determined based on an average value 0 of a predetermined period of the motor current determined in advance to a predetermined range ( For example, when the voltage is outside 1.5 V to 3.5 V), it is determined that the two A / D conversion circuits 503 and 504 are not operating normally. Then, the A / D conversion determination unit 507 stops the operation of the outdoor unit 1 which is a device in which the control device 50 is mounted.

  In this way, in the outdoor unit 1 in which the inverter 30 drives the motor 40, if at least one of the two A / D conversion circuits 503 and 504 is not operating normally, that is, an abnormality is detected. It is possible to safely stop the outdoor unit 1 equipped with the control device 50. Furthermore, the air conditioning system including the outdoor unit 1 can be protected.

  The A / D conversion circuit according to the first embodiment of the present invention is not limited to a plurality of A / D conversion circuits. The A / D conversion circuit operates at high speed, and one A / D conversion circuit can acquire voltage A which is a voltage corresponding to the upper side of the motor current and voltage B which is a voltage corresponding to the lower side of the motor current. As long as it is possible to distinguish and process each of the voltage and the voltage B, as shown in FIG. 7, one A / D conversion circuit 503 converts a voltage based on the motor current detected by the detection unit 501 from an analog value to a digital value. May be there. Then, the A / D conversion determination unit 507 may determine the abnormal operation of the A / D conversion circuit 503 based on the digital value output from the A / D conversion circuit 503.

Second Embodiment
Next, the structure of the outdoor unit used for the air conditioning system provided with the control device according to the second embodiment of the present invention will be described.
As shown in FIG. 8, the outdoor unit 1 according to the second embodiment of the present invention has an AC power supply 10, an AC-DC converter 20, an inverter 30, and a motor, as in the outdoor unit 1 according to the first embodiment. 40 and a control device 50.
However, the control device 50 according to the second embodiment further includes a detection unit 508 in addition to the control device 50 according to the first embodiment.

  The detection unit 501 is connected between the switching element 302 and the negative voltage side terminal of the AC power supply 10. Therefore, the current corresponding to the U phase in the inverter 30 flows from the switching element 302 to the negative voltage side terminal of the AC power supply 10 via the detection unit 501 independently of the current corresponding to the V phase and the W phase.

  The detection unit 508 is connected between the switching element 304 and the negative voltage side terminal of the AC power supply 10. Therefore, the current corresponding to the V phase in the inverter 30 flows from the switching element 304 to the negative voltage side terminal of the AC power supply 10 via the detection unit 508 independently of the current corresponding to the U phase and the W phase.

  The switching element 306 is directly connected to the negative voltage side terminal of the AC power supply 10. Therefore, the current corresponding to the W phase in the inverter 30 flows from the switching element 306 directly to the negative voltage side terminal of the AC power supply 10 independently of the current corresponding to the U phase and the V phase.

  With the above configuration, the detection unit 501 can independently detect the current corresponding to the U phase. Also, the detection unit 508 can independently detect the current corresponding to the V phase.

Next, a process of detecting an abnormality in the two A / D conversion circuits 503 and 504 which the outdoor unit 1 performs in parallel with the process in the normal state will be described. The outdoor unit 1 rectifies a single-phase AC voltage output from the AC power supply 10 to generate a DC voltage, and generates an AC voltage for driving the motor 40 from the generated DC voltage. It can be considered the same as the processing according to the embodiment of.
A process flow for detecting an abnormality of the two A / D conversion circuits 503 and 504 performed in parallel with the process in the normal state by the outdoor unit 1 according to this embodiment shown in FIG. 9 will be described below.

  Subsequent to the process of step S5 performed by the outdoor unit 1, the A / D conversion determination unit 507 determines whether the motor 40 is in operation (step S21). Specifically, for example, the A / D conversion determination unit 507 acquires, from the drive signal generation unit 505, information as to whether or not the drive signal generation unit 505 outputs a control signal to the transistor circuit 506. When the A / D conversion determination unit 507 acquires information indicating that the control signal is output from the drive signal generation unit 505 to the transistor circuit 506, the A / D conversion determination unit 507 determines that the motor 40 is in operation. When the A / D conversion determination unit 507 acquires information indicating that the control signal is not output from the drive signal generation unit 505 to the transistor circuit 506, the A / D conversion determination unit 507 determines that the motor 40 is not in operation.

When the A / D conversion determination unit 507 determines that the motor 40 is not in operation (NO in step S21), the processing of the outdoor unit 1 is ended.
When A / D conversion determination unit 507 determines that motor 40 is operating (YES in step S21), A / D conversion circuit 503 detects the motor current detected by detection unit 501 in the normal state. An instruction signal for acquiring a voltage corresponding to the U phase is output, and an instruction signal for acquiring a voltage corresponding to the V phase of the motor current detected by the detection unit 508 in the normal state is output to the A / D conversion circuit 504 . The voltage corresponding to the U phase of the motor current is, for example, the voltage U shown in FIG. The voltage corresponding to the V phase of the motor current is, for example, the voltage V shown in FIG. The voltage corresponding to the W phase of the motor current is, for example, the voltage W shown in FIG.

When each of the two A / D conversion circuits 503 and 504 receives an instruction signal from the A / D conversion determination unit 507, the two A / D conversion circuits 503 and 504 acquire timing information of a control signal output from the drive signal generation unit 505 to the transistor circuit 506.
The A / D conversion circuit 503 sets the voltage C corresponding to the U phase of the motor current output from the voltage detection unit 502 to a predetermined timing based on the timing information of the control signal output from the drive signal generation unit 505 to the transistor circuit 506. It acquires each (step S22). Further, A / D conversion circuit 504 determines voltage D corresponding to the V phase of the motor current output from voltage detection unit 502 based on the timing information of the control signal output from drive signal generation unit 505 to transistor circuit 506. It acquires at every timing of (step S23).

The A / D conversion circuit 503 converts the acquired voltage C (analog value) into a digital value. Then, the A / D conversion circuit 503 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.
Also, the A / D conversion circuit 504 converts the acquired voltage D (analog value) into a digital value. Then, the A / D conversion circuit 504 outputs the digital value to the drive signal generation unit 505 and the A / D conversion determination unit 507.

It is determined in advance that the average value of the motor current of each of the voltages C and D acquired by each of the two A / D conversion circuits 503 and 504 in one cycle is zero. Therefore, the A / D conversion determination unit 507 calculates an average value by adding a digital value corresponding to the voltage C input from the A / D conversion circuit 503 for a fixed period (for example, 2 cycles of the motor current) (step S24) ).
The A / D conversion determination unit 507 calculates the average value calculated by the A / D conversion circuit 503 and a reference value (for example, 2.5 volts) determined based on an average value of a predetermined period of the motor current determined in advance. It is determined whether the difference is within a predetermined range (for example, 1.5 volts to 3.5 volts) (step S25).

The A / D conversion determination unit 507 calculates the average value calculated by the A / D conversion circuit 503 and a reference value (for example, 2.5 volts) determined based on an average value of a predetermined period of the motor current determined in advance. If the difference is outside the predetermined range (for example, 1.5 volts to 3.5 volts) (NO in step S25), it is determined that the A / D conversion circuit 503 is not operating normally.
Then, the A / D conversion determination unit 507 (control unit) stops (abnormally stops) the operation of the outdoor unit 1 which is a device equipped with the control device 50 (step S26).

  In addition, the A / D conversion determination unit 507 determines that the difference between the average value calculated by the A / D conversion circuit 503 and the reference value determined based on the average value of motor current for a predetermined period is within a predetermined range. If there is (YES in step S25), the digital value corresponding to the voltage D input from the A / D conversion circuit 504 is added for a fixed period (for example, one cycle of the motor current) to calculate an average value (step S27).

  The A / D conversion determination unit 507 sets the difference between the average value calculated by the A / D conversion circuit 504 and the reference value determined based on the average value of motor current determined in advance within a predetermined period to a predetermined range (for example, 1 It is determined whether the voltage is within 5 volts to 3.5 volts) (step S28).

The A / D conversion determination unit 507 sets the difference between the average value calculated by the A / D conversion circuit 504 and the reference value determined based on the average value of the motor current for a predetermined period to a predetermined range (for example, 1). If the voltage is outside the range of 5 volts to 3.5 volts (NO in step S28), it is determined that the A / D conversion circuit 504 is not operating normally.
Then, the A / D conversion determination unit 507 (control unit) stops (abnormally stops) the operation of the outdoor unit 1 which is a device equipped with the control device 50 (step S26).

  Further, A / D conversion determination unit 507 sets the difference between the average value calculated by A / D conversion circuit 504 and the reference value determined based on the average value of motor current for a predetermined period to a predetermined range (for example, If the voltage is within 1.5 to 3.5 volts (YES in step S28), it is determined that the state is normal, and the process returns to step S21.

  The process flow of the outdoor unit 1 including the control device 50 according to the second embodiment of the present invention has been described above. In the processing of the outdoor unit 1 described above, the detection unit 501 detects a motor current flowing to the motor 40. The voltage detection unit 502 detects a voltage corresponding to the current detected by the detection unit 501. The A / D conversion circuit 503 converts a voltage C corresponding to the U-phase motor current detected by the voltage detection unit 502 from an analog value to a digital value. The A / D conversion circuit 504 converts a voltage D corresponding to the V-phase motor current detected by the voltage detection unit 502 from an analog value to a digital value. The A / D conversion determination unit 507 calculates an average value of digital values corresponding to the voltage C converted by the A / D conversion circuit 503. Then, the A / D conversion determination unit 507 sets the difference between the calculated average value and a reference voltage (for example, 2.5 V) determined based on an average value 0 of a predetermined period of the motor current determined in advance to a predetermined range ( For example, when the voltage is outside 1.5 V to 3.5 V), it is determined that the A / D conversion circuit 503 is not operating normally. Further, the A / D conversion determination unit 507 calculates an average value of digital values corresponding to the voltage D converted by the A / D conversion circuit 504. Then, the A / D conversion determination unit 507 sets the difference between the calculated average value and a reference voltage (for example, 2.5 V) determined based on an average value 0 of a predetermined period of the motor current determined in advance to a predetermined range ( For example, when the voltage is outside 1.5 V to 3.5 V), it is determined that the A / D conversion circuit 504 is not operating normally. Then, the A / D conversion determination unit 507 stops the operation of the outdoor unit 1 which is a device in which the control device 50 is mounted.

  In this way, in the outdoor unit 1 in which the inverter 30 drives the motor 40, if the A / D conversion circuit 503 or the A / D conversion circuit 504 is not operating normally, that is, an abnormality is detected. It is possible to safely stop the outdoor unit 1 equipped with the control device 50. Furthermore, the air conditioning system including the outdoor unit 1 can be protected.

The A / D conversion circuit according to the second embodiment of the present invention is not limited to a plurality of A / D conversion circuits. The A / D conversion circuit operates at high speed, and the voltage C corresponding to the U phase and the voltage D corresponding to the V phase can be acquired by one A / D conversion circuit, and the voltage corresponding to the U phase and the voltage corresponding to the V phase As long as C and D can be distinguished and processed, as shown in FIG. 11, the voltage C corresponding to the U phase of the motor current detected by one A / D conversion circuit 503 and the voltage D corresponding to the V phase are analog The value may be converted to a digital value. Then, the A / D conversion determination unit 507 may determine the abnormal operation of the A / D conversion circuit 503 based on the digital value output from the A / D conversion circuit 503.
Further, the A / D conversion circuit according to the second embodiment of the present invention converts the voltage E corresponding to the W phase from the analog value instead of the voltage C corresponding to the U phase described above or the voltage D corresponding to the V phase. It may be converted to a digital value. In this case, the abnormal operation of the A / D conversion circuit may be determined based on the deviation from zero of the average value in one cycle of the motor current of the voltage E acquired by the A / D conversion circuit.

Third Embodiment
Next, the structure of the outdoor unit used for the air conditioning system provided with the control device according to the third embodiment of the present invention will be described.
As shown in FIG. 12, the outdoor unit 1 according to the third embodiment of the present invention has an AC power supply 10, an AC-DC converter 20, an inverter 30, and a motor as in the outdoor unit 1 according to the first embodiment. 40 and a control device 50.
However, in addition to the control device 50 according to the first embodiment, the control device 50 according to the third embodiment further includes a sensor 509, two multiplexers 510 and 511, and a sensor voltage conversion unit 512.

  Sensor 509 detects a current or voltage other than the motor current of motor 40 in outdoor unit 1. The sensor 509 detects, for example, motor current of a motor other than the motor 40 provided in the outdoor unit 1. Further, the sensor 509 detects, for example, an output voltage of an inverter that drives a motor other than the motor 40 included in the outdoor unit 1.

  The multiplexer 510 connects the voltage detection unit 502 or the sensor 509 to the A / D conversion circuit 503, and either the AC voltage detected by the voltage detection unit 502 or the current or voltage in the outdoor unit 1 detected by the sensor 509. Is output to the A / D conversion circuit 503.

  The multiplexer 511 connects the voltage detection unit 502 or the sensor 509 to the A / D conversion circuit 504, and either the voltage detected by the voltage detection unit 502 or the current or voltage in the outdoor unit 1 detected by the sensor 509 It is output to the A / D conversion circuit 504.

The sensor voltage conversion unit 512 converts the current or voltage in the outdoor unit 1 detected by the sensor 509 into a corresponding voltage. Then, the sensor voltage conversion unit 512 outputs the converted voltage to the A / D conversion circuit 503 via the multiplexer 510. Also, the sensor voltage conversion unit 512 outputs the converted voltage to the A / D conversion circuit 504 via the multiplexer 511.
Here, when the average value of the voltage acquired by the pair of A / D conversion circuits 503 and 504 in a predetermined period is determined in advance, the A / D conversion circuit 503 is obtained by the same method as the first embodiment or the second embodiment. An abnormality of the A / D conversion circuit 504 can be detected. Then, the A / D conversion determination unit 507 can stop the operation of the outdoor unit 1 which is a device equipped with the control device 50.

  In this way, in the outdoor unit 1 in which the inverter 30 drives the motor 40, when the A / D conversion circuit 503 or the A / D conversion circuit 504 is not operating normally, that is, when it is abnormal, the abnormal normal operation It can detect that it is not, and can stop the outdoor unit 1 provided with the control device 50 safely. Furthermore, the air conditioning system including the outdoor unit 1 can be protected.

  The A / D conversion circuit according to the third embodiment of the present invention is not limited to a plurality of A / D conversion circuits. As in the first embodiment and the second embodiment, as long as the A / D conversion circuit operates at high speed, voltages can be appropriately acquired by one A / D conversion circuit, and each voltage can be distinguished and processed. As shown in FIG. 13, one A / D conversion circuit 503 may convert a voltage from an analog value to a digital value. Then, the A / D conversion determination unit 507 may determine an abnormality of the A / D conversion circuit 503 based on the digital value output from the A / D conversion circuit 503.

  Further, the voltage detection unit 502 according to the embodiment of the present invention may detect the motor current based on the current detected by a current sensor such as a current transformer disposed instead of the detection unit 501.

  Moreover, although the process flow of the outdoor unit 1 by embodiment of this invention demonstrated the process about the three-phase alternating current voltage corresponding to a three-phase alternating current motor to an example, it is not limited to it. For example, the process flow of the outdoor unit 1 may be a process for a two-phase AC voltage or an AC voltage of four or more phases. However, when the outdoor unit 1 performs processing for two-phase AC voltage or four or more AC voltages, the phase difference between the voltages is different from the phase difference 120 degrees between the three-phase AC voltages. Also, the number of detection units, the number of A / D conversion circuits, and the like may be different.

  In the process flow according to the embodiment of the present invention, the order of the processes may be reversed as long as appropriate processes are performed.

  In addition, although embodiment of this invention was described, the control apparatus 50 with which the above-mentioned outdoor unit 1 is equipped has a computer system inside. The process of the process described above is stored in the form of a program in a computer readable recording medium, and the process is performed by the computer reading and executing the program. Here, the computer readable recording medium refers to a magnetic disk, a magneto-optical disk, a CD-ROM, a DVD-ROM, a semiconductor memory or the like. Alternatively, the computer program may be distributed to a computer through a communication line, and the computer that has received the distribution may execute the program.

  Further, the program may be for realizing a part of the functions described above. Furthermore, it may be a so-called difference file (difference program) that can realize the above-described functions in combination with a program already recorded in the computer system.

  While several embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. In addition, various omissions, replacements and changes can be made without departing from the scope of the invention.

Reference Signs List 1 outdoor unit 10 AC power supply 20 AC-DC converter 30 inverter 40 motor 50 control device 201 reactor 202 rectifier diode stack 203 · · · Capacitors 301, 302, 303, 304, 305, 306 · · · Switching element 501, 508 · · · Detection unit 502 · · · Voltage detection unit 503 · · · A / D conversion circuit 505 · · · · Signal generation unit 506 ... transistor circuit 507 ... A / D conversion determination unit 509 ... sensor 510, 511 ... multiplexer 512 ... sensor voltage conversion unit

Claims (5)

A control device used in an outdoor unit including a motor,
A first A / D conversion unit that generates a digital value from an analog value of the maximum voltage of three voltages corresponding to the three-phase alternating current flowing to the motor;
A second A / D conversion unit that generates a digital value from an analog value of the minimum voltage of the three voltages corresponding to the three-phase alternating current;
The digital value generated by the first A / D conversion unit and the digital value generated by the second A / D conversion unit are added for a fixed period to calculate an averaged value, and the calculated average value is determined in advance. At least one of the first A / D conversion unit and the second A / D conversion unit is normal when the difference between the current flowing through the motor and the reference value based on the average value of the constant period is out of the predetermined range. A determination unit that determines that it is not operating;
Control device comprising: When the determination unit determines that at least one of the first 1 A / D conversion unit and the first 2A / D conversion unit is not operating normally, the control unit performs control to stop the operation of the outdoor unit ,
The control device according to claim 1, comprising: Voltage detection unit for detecting the voltage corresponding to the previous SL three-phase alternating current,
Equipped with
The control device according to claim 1 or 2. A control method by a control device used in an outdoor unit including a motor, the control method comprising:
The first A / D conversion unit generates a digital value from an analog value of the maximum voltage of three voltages corresponding to the three-phase alternating current flowing to the motor,
The second A / D conversion unit generates a digital value from an analog value of the minimum voltage of the three voltages corresponding to the three-phase alternating current ,
The determination unit calculates an average value obtained by adding the digital value generated by the first A / D conversion unit and the digital value generated by the second A / D conversion unit for a fixed period , and calculating the average value. And at least one of the first A / D conversion unit and the second A / D conversion unit, when the difference between the current and the reference value based on the average value of the constant period of the current flowing through the motor is predetermined. one is judged as not operating normally, the control method. A computer of a control device used in an outdoor unit including a motor ;
First generation means for generating a digital value from an analog value of the maximum voltage of three voltages corresponding to the three-phase alternating current flowing to the motor;
Second generation means for generating a digital value from an analog value of a minimum voltage of the three voltages corresponding to the three-phase alternating current ;
The digital value generated by the first generation unit and the digital value generated by the second generation unit are added for a fixed period to calculate an average value, and the calculated average value flows in the motor determined in advance. A determination unit that determines that at least one of the first generation unit and the second generation unit is not operating normally when the difference between the current and the reference value based on the average value of the constant period is outside a predetermined range. ,
A program to function as

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