KR100323931B1 - Motor control unit and air conditioner using this control unit - Google Patents

Abstract

The present invention relates to an electric motor control device and an air conditioner using the control device, comprising: a converter for converting an AC voltage supplied from an AC power source into a DC voltage; and a refrigeration cycle by converting the DC voltage converted from the converter device into a PWM voltage. A short circuit energization of a forced energizing circuit and a forced circuit, comprising an inverter device for supplying a compressor drive motor to a compressor, a reactor connected in series to the power supply side of the converter device, and a switching element for forcibly short-circuiting the reactor and AC power. It is possible to easily reduce the leakage current by providing a control control pattern for setting any one of a short-circuit energization mode for controlling a power factor or a DC voltage and a non-short-energization mode for prohibiting short-circuit current. .

Description

Electric motor controller and air conditioner using this controller

The present invention relates to a control device of a motor for a refrigeration cycle drive device that performs speed control of a compressor drive motor on the basis of a difference between a room temperature and a set temperature, and in particular, a power supply device that improves the power factor of a power input from an AC power source. It relates to a control device of the electric motor for a refrigeration cycle driving device provided and an air conditioner using the same.

In general, a control device of a motor for a refrigeration cycle drive device converts an AC voltage supplied from an AC power source into a DC voltage, and connects to an AC power source when supplying the DC voltage to a compressor driving motor that forms a refrigeration cycle by pulse width modulation. There is a control device for an electric motor for a refrigeration cycle drive device that installs a reactor in a path, forcibly short-circuits the reactor and AC power, and uses the energy accumulation effect to improve it.

The control device of a conventional refrigeration cycle drive motor, in which a reactor is installed in a connection path to an AC power source, has a wide range of reactor and AC power supply from a low to maximum value in order to improve the power factor. Since the short-circuit current is applied, the converted DC voltage tends to increase too much in the range where the AC input current is small. When the voltage rise is suppressed and the duty of the pulse width modulation is reduced, the number of chopping increases and the loss is reduced. At the same time as this increases, the leak current also increases.

In general, in a capacitor input type DC power supply circuit as a converter device, the input current does not flow outside the section in which the input voltage exceeds the voltage at both ends of the capacitor, and since there is no element limiting the current in this section, the peak value of the input current. It becomes a large, narrow current-carrying pulse current, and increases the harmonics which leak to the power supply side. To prevent this, it is common to connect a reactor to the input circuit. Thereby, power factor can be reduced and power harmonics can be reduced.

However, in order to reduce power supply harmonics by increasing the power factor, a reactor having a large inductance is required.

On the other hand, when a reactor having a large inductance is used, the current phase flowing from the power supply is delayed, and the voltage drop of the DC output is increased, thereby limiting the maximum output power.

In addition, a DC power supply device that achieves the same waveform improvement as that used with a reactor having a large inductance by forcibly short-circuiting an AC power supply for a predetermined period using a reactor having a small inductance has also been proposed.

However, this DC power supply device does not take into account the variation of the DC output or the rotational speed based on the load (torque) change of the motor driven through the inverter device, but when the reactor and AC power are shorted to improve the power factor. The DC output tends to rise too much at a time, and if the duty of the pulse width modulation carried out in the inverter device is reduced in order to suppress this, there is a problem that the number of chopping is large, the loss is large, and the leakage current from the motor is large.

A first object of the present invention is to provide an electric motor control device capable of simply reducing the leakage current and an air conditioner using the control device.

A second object of the present invention is to provide an electric motor control device capable of reducing an excessive rise in direct current output in response to load (torque) fluctuations of an electric motor, and a refrigeration cycle device using the electric motor control device.

A third object of the present invention is to provide an electric motor control device capable of compensating for the lack of the variable speed capability of the inverter device by the converter device when the DC voltage of the converter device is converted into alternating current by the inverter device and supplied to the motor. It is to provide a refrigeration cycle apparatus and an air conditioner used.

1 is a circuit diagram partially showing the overall configuration showing a first embodiment of the present invention;

FIG. 2 is a block diagram showing a detailed configuration of main elements of the embodiment shown in FIG. 1; FIG.

3 is a diagram showing a relationship between an AC input current and a DC voltage section for explaining the operation of the embodiment shown in FIG. 1;

4 is a waveform diagram showing waveforms of voltage, current, and short-circuit energizing pulses for explaining the operation of the embodiment shown in FIG. 1;

5 is a waveform diagram showing waveforms of voltage and current for explaining the operation of the embodiment shown in FIG. 1;

6 is a waveform diagram showing waveforms of voltage and current for explaining the operation of the embodiment shown in FIG. 1;

7 is a waveform diagram showing waveforms of a voltage and a short-circuit energizing pulse for explaining the operation of the embodiment shown in FIG. 1;

8 is a waveform diagram showing waveforms of a voltage and a forced energizing pulse for explaining the operation of the embodiment shown in FIG. 1;

9 is a view showing an operation range of a forced energizing circuit for explaining the operation of the embodiment shown in FIG. 1;

10 is a waveform diagram showing energized pulses for suppressing electronic sounds of a reactor;

11 is a block diagram showing the configuration of a second embodiment of an electric motor control apparatus according to the present invention;

12 is a circuit diagram showing a detailed configuration example of a converter device constituting the motor control device shown in FIG. 11;

13 is an explanatory diagram for illustrating a schematic operation of the electric motor control device shown in FIG. 11;

14 is a diagram showing the relationship between the rotational speed and the counter electromotive voltage of a DC brushless motor for explaining the operation of the electric motor control device shown in FIG. 11;

FIG. 15 is a diagram showing the relationship between the command rotation speed of an AC motor, the duty of a pulse width modulation waveform, a DC voltage, and a forced energization time to explain the operation of the motor control apparatus shown in FIG. 11;

FIG. 16 is a circuit diagram showing another detailed configuration example of a converter device constituting the motor control device shown in FIG. 11;

17 is a block diagram showing the construction of a third embodiment of an electric motor controller according to the present invention;

18 is a block diagram showing a configuration of an embodiment of an air conditioner according to the present invention;

Fig. 19 is a waveform diagram in the case of using a noise-carrying pulse in the motor control apparatus according to the present invention.

* Explanation of symbols for the main parts of the drawings

103, 300: indoor control unit 113: AC input current detector

114, 231: zero cross detector 115, 214: forced energization circuit

116, 233: energization control circuit 117: double voltage rectifier circuit

118, 221: inverter main circuit 119: compressor driven motor

121: DC voltage detector (overvoltage detector) 122: rotor position detector

130, 400: outdoor control unit 133, 225: speed deviation detection means

134: duty ratio command means 135, 223: inverter control circuit

136: data memory 137: power supply mode switching means

138: energization state determination means 142: energization control pattern setting means

L, 211: Reactor CD: Smoothing capacitor

202a: compressor drive motor 210: converter device

212: rectifier circuit 213: smoothing capacitor

220: inverter device 222: position detector

230: voltage compensation unit 232: power supply section determination means

234: DC voltage detector 240: operation mode switching means

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on the most suitable embodiments. FIG. 1 is a circuit diagram partially showing the overall configuration of an electric motor control device for a refrigeration cycle drive device as a first embodiment of the present invention. Fig. 1 shows a control device of an air conditioner as a control device of an electric motor for a refrigeration cycle drive device. The air conditioner includes an indoor unit and an outdoor unit, and is configured to connect the indoor unit to the AC power source 101. In the indoor unit, the operating power is supplied from the AC power supply 101 to the indoor control unit 103 in which the microcomputer is built in through the noise filter 102.

The indoor control unit 103 includes a receiving unit 105 for receiving a command from the remote control device 104, a temperature sensor 106 for detecting an indoor temperature, an indicator 107 for displaying an operation state, and an indoor heat exchanger (not shown). An indoor fan 108 for circulating wind and a louver 109 for changing the direction of blown air are connected.

On the other hand, in the outdoor unit, the AC power supply 101 supplies the operating power to the compressor driving motor 119 and the outdoor controller 130 through the noise filter 111 (the outdoor controller 130 for simplicity of the drawing). Omit the feeder for). In this case, the reactor is connected to one power supply path on the load side of the noise filter 111, and the current transformer 112 is connected to the other supply path. The current transformer 112 is connected to an AC input current detector 113 that detects an AC input current based on the output voltage. Further, a zero cross detector 114 for detecting a zero cross point of the AC voltage is connected between the power supply side of the reactor L and the load side of the current transformer 112. The forced current supply circuit 115 is connected between the AC power supply line on the load side of the reactor L and the AC power supply line on the load side of the current transformer 112. The forced energizing circuit 115 includes a full-wave rectifier circuit in which diodes D3 to D6 are bridged, and an AC input terminal thereof is connected between AC power lines through a fuse F.

The base drive power supply DS is connected in parallel with the zero cross detector 114. The base drive power supply DS rectifies and smoothes an AC power supply voltage to apply a DC voltage to the light receiving element of the photocoupler PC. The transistor Q is connected between the DC output terminals of the full-wave rectifying circuit constituting the forced energization circuit 115, and one end of the base drive power supply DS is one end of the light receiving element of the photocoupler PC. The other end of the light receiving element is connected to the base of the transistor Q, and the other end of the base drive power supply DS is connected to the emitter of the transistor Q. In addition, a light emitting element of the photocoupler PC is connected to the outdoor controller 130. The base control power supply DS, the photocoupler PC, and the transistor Q constitute the energization control circuit 116 for controlling the forced energization circuit 115.

It also has a series connection circuit of diodes DH and DL and a parallel connection circuit of capacitors CH and CL and an AC power supply line on the load side of reactor L at an interconnection point of diodes DH and DL. This is connected, and the double voltage rectification circuit 117 which connects the AC power supply line of the load side of the current transformer 112 to the interconnection point of capacitors CH and CL is provided.

In addition, a diode D1 for preventing the reverse charging of the capacitor CH and a diode D2 for preventing the reverse charging of the capacitor CL are respectively connected in parallel. A smoothing capacitor CD is connected between both ends of the double voltage rectifying circuit 117, that is, the output terminal of the DC voltage, and is known by the double voltage rectifying circuit 117 and the smoothing capacitor CD. A converter device is constructed.

Inverter main circuit 118 is connected to this converter device to convert a DC voltage into a PWM (pulse width modulation) voltage and to apply it to compressor drive motor 119 by controlling the switching element group on and off. An inverter device known as an inverter control circuit to be described later included in the main circuit 118 and the outdoor control unit 130 is configured. In this case, a DC voltage detector 121 for detecting the DC voltage output from the converter device and a rotor position detector 122 for detecting the rotor position of the compressor driving motor 119 are provided in the outdoor controller 130, respectively. Connected. The outdoor control unit 130 includes a four-way valve 123 for changing the circulation direction of the refrigerant according to each operation mode of cooling and heating, a temperature sensor 124 for detecting the temperature of the outdoor heat exchanger, and an outdoor heat exchanger (not shown). An outdoor fan 125 for sending out is connected. The outdoor controller 130 also includes a microcomputer and is configured to transmit and receive control information to and from the indoor controller 103.

2 is a block diagram showing the detailed configuration of the indoor control unit 103 and the outdoor control unit 130, the control system of the indoor fan 108, the louver 109 in the indoor unit and the four-way valve 123 in the outdoor unit And since the control system of the outdoor fan 125 is known, the illustration of the control system for the power supply control circuit 116 and the PWM modulation system for the inverter main circuit 118 that is deeply related to the present invention is omitted. will be.

In FIG. 2, the indoor control unit 103 includes a communication control unit 141 and an energization control pattern setting unit 142. On the other hand, the outdoor controller 130 is the communication control unit 131, the rotation speed command unit 132, the rotation speed deviation detection unit 133, the duty ratio command unit 134, the inverter control circuit 135, the data memory 136 ), Energization mode switching means 137 and energization state determination means 138 are provided. The communication control unit 131 of the outdoor control unit 130 transmits and receives control information to and from the communication control unit 141 of the indoor control unit 103, and the rotation speed command unit 132 of the communication control unit 131 The rotational speed command is discriminated from the received signal. Then, the determined rotation speed command is transmitted to the rotation speed deviation detecting means 133 and the duty ratio command means 134.

The rotational speed deviation detecting means 133 calculates the actual rotational speed from the rotor position signal of the compressor drive motor 119 detected by the rotor position detector 122 and further, the command rotational speed of the rotational speed command unit 132. Are compared and the deviation signal is transmitted to the duty ratio command means 134. The duty ratio command means 134 transmits a PWM signal to the inverter control circuit 135 by referring to a table or the like of the data memory 136 described later when the rotation speed command from the rotation speed command unit 132 is transmitted. The duty ratio of the PWM signal is corrected to correct the speed deviation of the speed deviation detection means 133.

The data memory 136 sets the threshold value for switching the energization mode, the set current value I ₁ of the AC input current, and the allowable maximum value as the "AC input current set value" SA, and the DC voltage to the forced energization circuit 115. First, the relationship between the short-circuit energization time and the duty ratio in the energization mode is "short-circuit energization time / duty ratio: table" TA, and the relationship between the short-circuit energization time and the duty ratio in the high power factor priority energization mode is Time / Duty Ratio: Table ”TB, and the relationship between the command rotation speed for the compressor drive motor 119 and the PWM duty ratio for the inverter main circuit 118 is expressed as the“ PWM duty ratio / command rotation speed: table ”TR. The value of correcting the detection value of the AC input current detector 113 due to the difference in the power supply mode of the short circuit current supply circuit 115 is the "AC input current correction value" CA, and the power supply time is corrected according to the power supply frequency, or the power supply mode Interval or energized at switching It is respectively storing a correction value for correcting a liver "converter switching time correction table," TS.

The energization mode switching unit 137 is connected to the output signal of the zero cross detector 114, the current detection value of the AC input current detector 113, and the overvoltage detector 121 according to the energization control pattern received through the communication control unit 131. By this, a short circuit energization signal is generated based on the presence or absence of overvoltage detection and the stored data of the data memory 136 and transmitted to the energization control circuit 116. Further, the energization state determination means 138 determines whether the short-circuit energization circuit 115 operates normally in accordance with the current detection value by the AC input current detector 113 and the duty ratio command output from the duty ratio command means 134. , The determination signal is transmitted to the communication control unit 131 and transmitted to the indoor control unit 103. In addition, although the current information of the AC input current detector 113 is not shown, the current control pattern setting means 142 through the communication control unit 131 of the outdoor control unit 130 and the communication control unit 141 of the indoor control unit 103. It is meant to be delivered to.

The general control operation of the air conditioner will first be described with respect to the operation of the present embodiment configured as described above, and then the short-circuit energizing operation will be described with reference to FIGS. 3 to 9.

First, the AC voltage of the AC power source 101 is supplied to the indoor control unit 103 through the noise filter 102, and is supplied to the double voltage rectifier circuit 117 and the outdoor control unit 130 through the noise filter 111. do. The double voltage rectifier circuit 117 charges the capacitor CH through the diode DH in a positive half cycle of the AC power supply voltage, and the capacitor CL through the diode DL in a negative half cycle of the AC power supply voltage. To charge. Therefore, the voltage of the sum of the voltage of the capacitor CH and the voltage of the capacitor CL is applied to the smoothing capacitor CD, and a DC voltage twice the AC power supply voltage is generated at both ends of the smoothing capacitor CD. Voltage is supplied to the inverter main circuit 118. The diodes D1 and D2 have a function of preventing the capacitors CH and CL from being charged in the reverse direction at the beginning of the operation start.

In this state, commands such as start of operation, cooling, heating operation mode, indoor set temperature, wind speed of the indoor fan, and wind direction are transmitted from the remote control device 104 to the receiver 105. Accordingly, the indoor control unit 103 displays an operation state and the like on the display unit 107, performs drive control of the indoor fan 108 and the louver 109, and drives the compressor in accordance with the deviation between the set temperature and the room temperature. The rotation speed for driving the motor 119 is calculated and the rotation speed command is transmitted to the outdoor controller 130 together with the operation mode.

The outdoor controller 130 sets the four-way valve 123 in the excited or non-excited state according to the operation mode (cooling and heating), and detects the actual rotation detected by the rotor position detector 122. The switching element group of the inverter main circuit 118 is turned on and off so that the number corresponds to the rotational speed command. In addition, the outdoor controller 130 drives the outdoor fan 125 and controls the four-way valve 123 according to the detected temperature of the temperature sensor 124 in the heating operation mode to perform defrosting operation or the like.

Next, a short circuit energization operation is demonstrated. When charging the capacitors CH and CL, a current flows through the reactor L in a period in which the instantaneous value of the power supply voltage exceeds the voltage across the capacitor. In this case, the zero cross detector 114 detects the zero cross point of the alternating voltage, and when the conduction mode switching means 137 elapses a constant delay time from the zero cross point or the zero cross point, When the signal is transmitted to the photocoupler PH for a predetermined time, and the transistor Q is turned on, the reactor is forced through the forced current circuit 115 regardless of the charging voltage of the capacitors CH and CL. (L) and the AC current are short-circuited to flow the current. In this way, an operation of forcibly flowing a current from the AC power supply to the reactor L is called short-circuit energization. When the short circuit current is stopped, the current flowing through the reactor flows toward the capacitors CH and CL. Therefore, by changing the time of short-circuit energization, it is possible to improve the power factor by keeping the output of the converter device, i.e., the DC voltage, in the range most suitable for PWM control or by changing the current waveform. It is also possible to operate without a short circuit energizing operation, and when the duty ratio of the PWM control reaches 100% to maintain the command rotation speed, the DC voltage is increased by short circuit energization to compensate for the shortage of the rotation speed. You can also control it.

Hereinafter, a mode in which no short-circuit energizing operation is performed is referred to as a non-short-circuit energizing mode (Mo), and a energizing mode for maintaining a DC voltage below a predetermined value while maintaining a power factor of about 92% by a short-circuit energizing operation. First, the energization mode (M ₁ ), the energization mode that maintains the power factor around 98% by the short-circuit energization operation, maintains the command rotation speed by increasing and decreasing the DC voltage by the high power factor priority energization mode (M ₂ ) and the short-circuit energization operation. The energization mode to be referred to as the rotation speed priority energization mode (M ₃ ), the DC voltage priority energization mode (M ₁ ), the high power factor priority energization mode (M ₂ ), the rotation speed priority energization mode (M ₃ ) collectively short circuit. It is called energized mode. In addition, adjusting the power factor to 92% or 98% can be adjusted by changing the length of the short-circuit energizing time.

In the present embodiment, whether the AC input current exceeds a predetermined value determined by the low compressor rotation speed range, whether the duty ratio reaches a preset set duty ratio (100%), or whether the AC input current reaches the maximum value of the allowable range. A plurality of control patterns for changing the energization mode are prepared according to whether or not, and the control patterns are automatically set so as not to increase the leakage current or set manually by the remote control device 104. Therefore, a representative control pattern is shown in FIG. 3 to facilitate understanding.

In Fig. 3, the control pattern ① is not short-circuit energized in the non-short energization mode M ₀ until the AC input current reaches the set current value I ₁ , and in all ranges in which the AC input current exceeds I ₁ . The case of operating in DC voltage priority energization mode M ₁ is shown. Control pattern ② is to arrive at non-short-circuit conduction mode (M ₀₎ paragraph without energized after the AC input current is greater than I ₁ the duty ratio of 100% duty ratio set in the PWM signal to the up to the AC input current reaches I ₁ to a direct current voltage first power application mode (M _1), though operation and a duty ratio of 100% of the PWM signal it is though to the number of revolutions in the case lower than the actual revolution speed the rotational speed command of the compressor driving motor 119 is first energized mode (M ₃ Indicates a case where a short circuit is energized. Also in this case, the rotation speed priority energizing mode M ₃ is implemented on the premise that the AC input current I ₃ when the duty ratio of the PWM signal is 100% is smaller than the allowable maximum current. The control pattern ③ does not short-circuit energize in the non-short energization mode (M ₀ ) until the duty ratio of the PWM signal reaches 100% and the actual rotational speed of the compressor driving motor 119 rotates the command even though the duty ratio of the PWM signal is 100%. It is an example of short-circuit energizing in the rotation speed priority energization mode M ₃ when it is lower than the number. The rotation speed priority energizing mode M ₃ may be used when the duty ratio of the PWM signal reaches a range of 70% to 100% of the duty ratio when the set duty ratio (100%). It is implemented on the premise that the AC input current I ₂ is less than 20 A in the case of the general assumption of the allowable maximum current. Control pattern ④ is a full range of high power factor first energization mode (M ₂₎ in which is not energized to a non-short-energized mode (M ₀₎ short-circuited until the AC input current reaches I _1, AC input current exceeds I ₁ The case of driving is shown. The control pattern 5 shows a case of operating in the DC voltage priority energization mode M ₁ regardless of the AC input current.

The power supply control pattern setting means 142 constituting the indoor control unit 103 shown in FIG. 2 is a model code of an air conditioner stored in a storage unit connected to the indoor control unit 103 or the setting contents of the remote control unit 104. According to this, any one of control patterns ①, ②, ③, and ④ for short-circuit energization is automatically set, and the set control pattern signal is output. When the control pattern for short-circuit energization is not set by the model code, the control pattern for forced energization is automatically set based on the operation mode of cooling and heating or the current information detected by the AC input current detector 113.

In addition, in the air conditioner having a forced energization circuit, a control pattern? For driving in the DC voltage priority energization mode M ₁ is adopted regardless of the AC input current. That is, when the waveform diagram of voltage and current is shown in Fig. 4A and the short-circuit energizing pulse FP is shown in Fig. 4B, respectively, in the non-short energization mode M ₀ , the AC voltage ( In the DC voltage-priority conduction mode (M ₁ ), the reactor (L) is short-circuited by the time (T) at the zero cross point of the AC voltage due to the flow of the alternating current (I ₁₁ ), which is out of phase with respect to V), to reduce the power factor. By energizing the current to flow alternating current I ₁₂ , the waveform can be improved and the power factor can be improved. In this case, in the DC voltage priority energization mode M ₁ , the short-circuit energization time T is changed in accordance with the AC input current to maintain the voltage most suitable for PWM control.

By the way, when the short-circuit energization control is performed in the α section until the AC input current reaches a small range, for example, the current I ₁ shown in FIG. 3, the DC voltage tends to rise too much due to the small load of the motor. have. Therefore, such control of suppressing the voltage rise and narrowing the energization time becomes difficult, and in some cases, as shown in FIG. 5, the current I ₂₁ and the double voltage due to short-circuit energization in the half cycle period of the AC voltage V are shown. The current I ₂₂ flowing through the rectifier circuit 117 may shift in the time axis direction, resulting in two peaks. In this way, the current flows divided into two acids, leading to deterioration of the power factor. Therefore, in order to ensure a predetermined power factor even in the current section α shown in FIG. 3, waveform diagrams of voltage and current are shown in FIG. 6A, and forced energizing pulses FP are shown in FIG. 6B, respectively. in the delayed time T ₀ degree hour at zero-cross point of the AC voltage T ₁ time as occurs the need to shaping the current waveform as shown in Fig. I by ₃₁ to forcibly energized as described.

Therefore, in the present embodiment, all of the control patterns ① to ④ automatically determined by the energization control pattern setting means 142 are always non-short energized in the range of the current section α below the set power supply value I ₁ shown in FIG. It operates in the mode (M ₀ ) to prevent the rise of the DC voltage. Specifically, the duty ratio of the PWM signal is set after exceeding the current (I ₁ ) stored as the "AC input current set value" SA, which must increase the power factor and suppress the current value during heating operation with a relatively high air conditioning load. Operate in DC voltage priority energization mode (M ₁ ) within the range until the duty ratio reaches 100%, and set the control pattern ② to operate in rotation priority energization mode (M ₃ ) when the duty ratio becomes higher than the set duty ratio. In the cooling operation with relatively low air conditioning load, the control pattern ① for operating in the DC voltage-priority conduction mode M ₁ is set in the range exceeding the current I ₁ , which should widen the duty ratio.

Further, the energization control pattern setting means 142 performs the AC input current to the allowable maximum value stored as the "AC input current set value" SA during operation in the rotation speed priority energization mode M ₃ of the pattern ① or the pattern ②. When it reaches | attains, it has a function which sets and changes a short circuit energization time so that the current value may fall within an allowable range.

The energization control pattern signal is transmitted to the outdoor controller 130 as a serial signal together with the operation mode command for cooling and heating and the rotation speed command of the compressor driving motor. The outdoor control unit 130 receives the signal from the communication control unit 131, converts the signal into a parallel signal, and transmits the signal to the rotational speed command unit 132 and the energization mode switching unit 137. The rotation speed command part 132 extracts a rotation speed command from this signal, and transmits it to the rotation speed deviation detection means 133 and the duty ratio command means 134.

The duty ratio command means 134 refers to the " PWM duty ratio / command rotation speed: table " TR of the data memory 136 to generate a PWM signal having a duty ratio corresponding to the rotation speed command to the inverter control circuit 135. Tell. The rotation speed deviation detecting means 133 calculates the actual rotation speed from the rotor position signal detected by the rotor position detector 122, and compares the deviation signal with the duty ratio command means 134 in comparison with the rotation speed command. To tell. In addition, the duty ratio command means 134 corrects the duty ratio of the PWM signal so that the speed deviation becomes zero in accordance with the rotation deviation signal output from the speed deviation detection means 133. The inverter control circuit 135 controls the switching element group constituting the inverter main circuit 118 on and off in accordance with this PWM signal.

On the other hand, the energization mode switching means 137 receives a signal from the communication control unit 131 and determines the set control pattern. In this case, if the control pattern is the control pattern 1 in FIG. 3 including the DC voltage-priority conduction mode M ₁ , the short-circuit energization signal is generated by referring to the "short conduction time / duty ratio: table" TA and conduction control circuit 116 Tell). At this time, the short-circuit energization time corresponding to the duty ratio output from the duty ratio command means is read from the "short-circuit energization time / duty ratio: table" TA, and the short-circuit energization is performed based on the zero-cross point detected by the zero-cross detector 114. Output the signal. In this way, the AC input current is operated in the non-short conduction mode (M ₀ ) in the range smaller than the set current value (I ₁ ), and in the DC input priority operation mode (M ₁ ) in the range in which the AC input current exceeds I ₁ . Is driven. For the control pattern ② is short-energization time / duty ratio: is operating in a non-short-circuit power application mode, a range between the table (TA) with reference to the AC input current (I ₁₎ a, in excess of the AC input current (I ₁₎ It operates in DC voltage priority energization mode (M ₁ ) until the duty ratio of the PWM signal reaches 100% .In the state where the duty ratio is 100%, the rotation speed priority energization mode (M is referred to by referring to the "Converter switching time correction value table" TS. Drive ₃ ). The energization mode switching means 137 refers to the "converter switching time correction value table" TS when the overvoltage is detected by the overvoltage detector 121 during the operation in the DC voltage priority energization mode M ₁ . Correction is performed to shorten this time.

Next, the energization mode switching means 137 determines the energization control pattern from the output signal of the communication control unit 131, and if it is the control pattern ③, the non-short energization mode until the duty ratio of the PWM signal reaches the set duty ratio. When the set duty ratio is exceeded, the engine is operated in the rotation speed priority energizing mode M ₁ with reference to the table TS.

Next, the energization mode switching means 137, a result of determining a control pattern of the power application from the output signal of the communication control unit 131, a high power factor first energization mode, the control pattern of FIG. 3, including the (M ₂₎ ④ is "short-energized A short-circuit energizing signal is generated with reference to the time / duty ratio: table " TB, and transmitted to the energization control circuit 116. FIG. At this time, the short-circuit energization time corresponding to the detected value of the AC input current detector 113 is read out from the "short-circuit energization time / duty ratio: table" TB, and the zero-crossing point detected by the zero-cross detector 114 is referred to. Output short-circuit energized signal. Thus by operating at a high power factor is first energized mode (M ₂₎ in the range of the ac input current is in a range between I ₁ is operating in a non-short-energized mode (M _0), the AC input current is greater than the I _1.

As described above, since the control patterns 1 to 4 all operate in a non-short energization mode which prohibits short-circuit energization in a range where the AC input current is small, it is possible to suppress an excessive rise of the DC voltage, thereby reducing the number of chopping of the inverter main circuit. Since there is no need to increase, the occurrence of leakage current can be reduced. Therefore, in the air conditioner or the refrigerating device using HFC (hydrofluorocarbon) refrigerant which is likely to increase the leakage current from the compressor casing, by adopting the control of the present embodiment, the reliability and safety of the air conditioner or the refrigerating device using the HFC refrigerant can be improved. Can be improved.

As a specific component of the HFC refrigerant, R410A obtained by mixing approximately 50 wt% of R32 (difluoromethane) and R125 (pentafluoroethane) may be used.

Therefore, when switching from the non-short energization mode (M ₀ ) to the high power factor priority energization mode (M ₂ ) during operation in the control pattern (4), or during operation in the control pattern (1) or ( ₂ ), the non-short energization mode (M _0). ) when a transition from a first DC voltage energization mode (M _1), and changes the AC input current waveform. The change in this current waveform results in an error in the current detection value. The correction value for correcting this error is stored in the data memory 136 as "AC input current correction value" CA. Therefore, when the electrification mode is switched, the energization mode switching means 137 corrects the current detection value of the AC input current detector 113 and reads the corresponding short circuit energization time from the tables TA and TB to short circuit energization signals. Create

In the control patterns ①, ②, and ④, the DC voltage suddenly rises when the transition from the non-short energization mode M ₀ to the DC voltage priority conduction mode M ₁ or the high power factor priority conduction mode M ₂ occurs. Therefore, the rotation state of the compressor drive electric motor 119 changes, and a "beat sound" is generated. The energization mode switching means 137 is provided with the function which prevents this "beat sound." As a method of preventing the "playing sound", the width of the short-circuit energizing pulse FP output for each zero cross point of the AC voltage V is T ₁ , T ₁ , T ₂ (> T ₁ ). , T ₂ , T ₃ (> T ₂ ), T ₃ ,.. As shown in FIG. 8, the output interval of the short-circuit energizing pulse FP immediately after switching the energization mode may be widened as shown in FIG. 8. Thereafter, the energizing interval may be gradually narrowed to generate each of the zero cross points of the AC voltage.

Also, as in the control patterns ①, ②, and ④, when a transition is made from the non-short energization mode M ₀ to the DC voltage priority energization mode M ₁ or the high power factor priority energization mode M ₂ , electronic noise is likely to be generated from the reactor. As a method of preventing this, when the short-circuit energizing pulse FS is used for a plurality of times after the short-circuit energizing pulse FP, a noise effect is obtained as shown in FIG.

Therefore, there is also a need to confirm the operation state of whether or not the forced energizing circuit 115 is normally operated. Therefore, in this embodiment, the energization state determination means 138 is provided. In this case, the AC input current and duty ratio in the DC voltage priority energization mode (M ₁ ), high power factor priority energization mode (M ₂ ), and rotation speed priority energization mode (M ₃ ) are determined in the non-short energization mode (M ₀ ). Larger compared to AC input current and duty ratio. Therefore, as shown in FIG. 9, the threshold value I _r is set for the AC input current I, the threshold value D _r is also set for the duty ratio, and the AC input current I is I> I. _{When r} and duty ratio D becomes D > D _r , it is determined that the forced energization circuit is normally operated, and the information is returned to the indoor control unit 103 as control information to display the indicator of the indoor control unit 103 ( 107). In this case, since the threshold values I _r and D _r change depending on the rating or the like, an optimal value is selected by simulation or experiment.

In this way, even if the short-circuit energization mode is set, if the contents of the normally operated forced energization circuit are not displayed on the indicator 107 of the indoor control unit 103, it can be determined that the forced energization circuit is abnormal. Even in the case where abnormality is determined, it is possible to continue in the non-short energization mode by prohibiting short circuit energization of the forced energization circuit.

In addition, as a simple method for determining whether the device is operated in the short-circuit energizing mode, it may be determined by, for example, whether the increase of the duty ratio exceeds a predetermined value or whether the increase of the AC input current exceeds the predetermined value.

Therefore, the forced current supply circuit 115 shown in FIG. 1 has a structure in which the diodes D3 to D6 are bridged, the AC terminals are connected to an AC power supply line, and the transistor Q is connected between the DC terminals. For this reason, if the transistor Q is short-circuited, the function of the converter device itself will be lost and the drive of the compressor drive motor 119 will be impossible. In the present embodiment, since the fuse F is connected to the forced current path, when the transistor Q is short-circuited, the fuse F is immediately melted to cut off the forced current circuit 115. Thus, it can be vanished on the function of the forced energizing circuit 115 to continue to drive the compressor drive motor 119 is energized by the non-short-circuit mode (M _0).

In the above embodiment, the energized mode switching means outputs a forced energized pulse based on the data in the data memory, but the memory means and the energized mode switching means are provided in a short-circuit energized custom LSI or IC to output and control short-circuit energized pulses. In this case, time delay caused by software processing is eliminated, and high precision processing is possible.

In the above embodiment, the data memory is used, but these functions are calculated by the microcomputer from the AC input current, the compressor rotation speed, or the duty ratio of the PWM signal to calculate the short-circuit conduction time (or the amount of correction of the short-circuit conduction time), and the zero-cross detector. It is also possible to input a zero-cross signal from the microcomputer and generate a short-circuit energizing pulse using a timer in the microcomputer. In this case, there is an advantage in that it is completed even without using a dedicated IC. In this case, it is not necessary to use a DC voltage detector to determine the load of the compressor.

In the above embodiment, the transition from the non-short energization mode M ₀ to the DC voltage priority energization mode M ₁ and the high power factor priority energization mode M ₂ provided that the AC input current reached I ₁ . Instead, when the compressor driving motor is operated so that an AC input current exceeds a predetermined value and a logical product condition is established that the duty ratio of the PWM voltage exceeds a predetermined value, DC voltage priority is given from the non-short energization mode (M ₀ ). By configuring the power supply mode (M ₁ ) and the high power factor priority power supply mode (M ₂ ), it is possible to ensure reliable operation without being affected by noise.

As apparent from the above description, according to the present invention shown in the first embodiment, a converter device for converting an AC voltage supplied from an AC power source into a DC voltage, and a DC voltage converted from the converter device to a PWM voltage to be refrigerated A forced energizing circuit comprising an inverter device supplied to a compressor driving motor forming a cycle, a reactor connected in series to the power supply side of the converter device, and a switching element for forcibly short-circuiting the reactor and AC power, Non-short energized mode when the AC input current is less than a predetermined value because a short-circuit energized mode for controlling the power factor or DC voltage and short-circuit energized mode forbidting short-circuit energization by short-circuit energization is provided. Of electric motor caused by DC rise by driving It is effective in preventing leakage current increase and power factor deterioration in advance.

Next, a second embodiment of the present invention will be described.

11 is a block diagram showing a configuration of a second embodiment of a power conversion device according to the present invention. In Fig. 11, a converter device 210 for converting an AC voltage of a commercial AC power supply 201 into a DC voltage, and a DC motor of the converter device 210 is converted into an AC voltage having a variable voltage variable frequency to convert an AC motor ( Inverter device 220 to be supplied to 202, voltage compensator 230 for controlling to compensate for the shortage of the output voltage of converter device 210, and the converter according to the rotation speed command of the motor speed determining means 203. Operation mode switching means 240 for outputting an operation mode command for selecting an operation mode of the device 210 and the inverter device 220 is provided.

In particular, the converter device 210 includes a reactor 211, a rectifier circuit 212, a smoothing capacitor 213, and a forced energization circuit 214. Here, one end of the reactor 211 is connected to one end of the AC power supply 201, and one input end of the rectifier circuit 212 is connected to the other end of the reactor 211. The other end of the rectifier circuit 212 is connected to the other end of the AC power supply 201. In addition, a forced current supply circuit 214 is connected between the other end of the reactor 211 and the other end of the AC power supply 201. In addition, a smoothing capacitor 213 is connected between the positive and negative output terminals of the rectifier circuit 212.

In addition, the inverter device 220 is constituted by the inverter main circuit 221, the position detector 222, the inverter control circuit 223, the rotation speed detection means 224, and the rotation speed deviation detection means 225. Here, the inverter main circuit 221 is composed of a three-phase bridge connected to the switching element, the input terminal is connected to the output terminal of the converter device 210, that is, the output terminal of the DC voltage of the rectifier circuit 212, the output terminal The electric motor 202 is connected. The position detector 222 detects the position of the rotor of the electric motor 202, and the rotation speed detection means 224 detects the actual rotation speed of the electric motor 202 from the position detection signal. The position detection signal of the position detector 222 is also transmitted to the inverter control circuit 223. The rotation speed deviation detecting means 225 calculates the difference between the commanded speed of the motor output from the motor speed determining means 203 and the actual speed detected by the speed detecting means 224, that is, the speed deviation. To the inverter control circuit 223. The inverter control circuit 223 controls the inverter main circuit 221 so that the speed deviation output by the speed deviation detection means 225 is zero based on the output signal of the position detector 222 or the motor speed The inverter main circuit 221 is controlled in accordance with the reference rotational speed of the determination means 203.

In addition, the voltage compensator 230 is configured by a zero cross detector 231, an energization section determining unit 232, and an energization control circuit 233. In this case, the zero cross detector 231 detects the zero cross point of the AC voltage of the AC power supply 201 and transmits the timing signal to the energization control circuit 233, and the energization section determining means 232 detects the rotation speed deviation. The short circuit energizing section which makes the rotation speed deviation detected by the means 225 zero is determined. The energization control circuit 233 turns on the forced energization circuit 214 for the time determined by the energization section determination means 232 for each detection timing of the zero cross point.

In addition, the operation mode switching means 240 determines whether the variation range of the duty ratio of the pulse width modulation signal detected by the inverter control circuit 223 is greater than or equal to a predetermined value to the low load (low speed) region and the high load (high speed) region. The first and second operation mode commands are transmitted to the inverter control circuit 223 and the voltage compensator 230 according to each load region.

In addition, the motor is a non-commutator motor having a permanent magnet rotor and inputs an induced voltage generated when the motor is driven as a signal to detect the position and rotation speed of the rotor from this signal.

12 is a circuit diagram showing a detailed configuration of the converter device 210 described above. This converter device 210 is proposed in Japanese Patent Application Laid-Open No. 8-74675 filed in Japan by the same applicant as the present application, the outline of which will be described below.

The rectifier circuit 212 is composed of full-wave rectifier circuits by diodes DH, DL, D3, and D4. The mutual junction of diode DH and DL is connected to the one end of AC power supply 201 via reactor 211. As shown in FIG. The mutual junction of the diodes D3 and D4 is connected to the other end of the AC power supply 201. In addition, a series connection circuit of the intermediate capacitors CH and CL is connected between the DC output terminals of the rectifier circuit 212, that is, at both ends of the series connection circuits of the diodes D3 and D4, and the intermediate capacitor CH is connected to the junction of the diodes D3 and D4. And the mutual junction of CL are connected. In addition, a smoothing capacitor (CD) is connected to the series connection circuit of the intermediate capacitor CH and CL.

The forced energization circuit 214 further includes a full-wave rectified diode bridge of diodes D5-D8,

It consists of a transistor Q for controlling the current and a base driving circuit G for supplying a driving current to the base of the transistor. In addition, an IGBT is used as the transistor Q.

The operation of the second embodiment configured as described above will be described in detail with reference to the operation description of FIG. 13 expressed by a switch, an adder / subtracter, etc. for easy understanding.

First, the command rotation speed for the electric motor 202 is "N _s ", and the actual rotation speed is "N _a ". The subtractor 251 subtracts the actual rotation speed N _a from the command rotation speed N _s and outputs a rotation speed deviation ΔN. On the other hand, the operation mode switching means 240 is to change the variation range of the duty (D _a ) of the pulse width modulated signal output from the inverter control circuit 223 by the switching duty (D ₁ ) two areas, that is, D _a ≤ D _It is assumed that the first and second operating mode commands are outputted by dividing into _a low load area of _{1 and} a high load area of D _a > D ₁ .

Next, the duty of the pulse width modulation signal (D _a) is when in the low load region, the operation mode switching means 240 is a subtractor 252 to keep the switch (253, 254) as a first operation mode command toward SW1 The operation of the electrolytic voltage compensator 230 is turned off to the inverter control circuit 223 by the rotational speed difference ΔN output from the inverter. At this time, the inverter control circuit 223 uses the duty and frequency of the pulse width modulation signal so that the rotation speed deviation ΔN becomes zero (the duty and frequency are proportional to each other in the normal variable speed region. PWM duty variable speed feedback control is implemented.

Next, when in the high load region of the electric motor 202, the driving mode switching means 240 switches the switches 253 and 254 to the SW2 side as the second driving mode command. Thus the rotation speed command to the inverter control circuit (223) (N _s) has been reported as it, is also possible that the voltage compensation operation of the voltage compensator 230. In this case, the inverter control circuit 223 changes the duty (D _s ) of the pulse width modulation waveform in proportion to the command rotation speed (N _s ), and the duty is 100% over the set rotation speed (N _m ) in the high load region. Has a data table 256. Therefore, as the command rotation speed N _s increases, the duty increases, and the inverter main circuit 221 is controlled to maintain the duty at 100% above the rotation speed N _m . On the other hand, since the DC voltage transmitted to the inverter main circuit 221 drops as the duty increases, the voltage compensating unit compensates for the drop, that is, sets the rotational deviation ΔN output from the subtractor 251 to zero. The control unit 230 controls the short-circuit energization time T of the forced energization circuit to increase in proportion to the increase in the rotation speed deviation ΔN, and raises the DC voltage to execute the PAM forced energization variable speed feedback control.

Next, when the command speed N _s of the electric motor 202 reaches the speed N _m , the duty is 100% constant in the data table 256. As a result, the inverter control circuit 223 continues the control of changing the frequency only in accordance with the command rotation speed N _s while maintaining the duty at 100%, while the voltage compensator 230 sets the rotation speed deviation ΔN to zero. By changing the short-circuit energization time of the forced energization circuit, PAM forced energization variable speed feedback control is executed.

As mentioned above, although the outline operation | movement of 2nd Embodiment was demonstrated using FIG. 13, the detailed operation of 2nd Embodiment shown in FIG. 11 and FIG. 12 is demonstrated below with reference to FIG. 14 and FIG. First, FIG. 12 which shows the detailed circuit as an operation | movement of the converter apparatus 210 is demonstrated.

During the positive half cycle of the alternating current power source 201, charging current flows to the intermediate capacitor CH through the reactor 211 and the diode DH. At this time, the diode D4 forms its discharge circuit so that the intermediate capacitor CL is not charged in the reverse direction. In addition, during the negative half cycle of the AC power supply 201, a charging current is caused to flow through the reactor 211 and the diode DL to the intermediate capacitor CL. At this time, the diode D4 forms its discharge circuit so that the intermediate capacitor CH is not charged in the reverse direction.

As long as the intermediate capacitors CH and CL are charged so that there is a voltage in the same direction between the respective terminals, that is, a voltage in the upper direction of the drawing, the diodes D3 and D4 do not function substantially, and then the diode DH. The intermediate capacitor CH is charged through the capacitor, and the intermediate capacitor CL is charged through the diode DL.

In this way, the sum of the terminal voltages of the capacitors CL and CH connected in series is applied to both ends of the smoothing capacitor CD to charge the smoothing capacitor CD. That is, the smoothing capacitor CD is charged by the discharge of the electric charge charged in the intermediate capacitor CL and CH. The voltage across the smoothing capacitor CD is supplied to the inverter device 220 as the output of the converter device 210. The forced energization circuit 214 transmits the transistor from the base driving circuit G by the output of the energization control circuit 233 whenever the zero cross point of the AC voltage transmitted from the AC power supply 201 to the rectifier circuit 212 passes. The base current is supplied to (Q) for a predetermined time. Each time the transistor Q is turned on, the reactor 211 and the alternating current are forcibly short-circuited to obtain an energy accumulation effect by short circuit energization. In general, as the short-circuit conduction section of the forced short-circuit current is widened, a large current flows. At that time, when the transistor Q ₁ is turned off, the energy of the reactor 211 flows into the smoothing capacitor CD to reduce the DC output voltage. Increase

Thus, the rotational frequency and weights (逆起) of the DC brushless motor (brushless motor) voltage (V _f) are in the relationship shown in Fig. An inverter device for driving the unit 220 performs speed control by applying a voltage obtained by adding a voltage (V _T) of the load torque in the counter-electromotive voltage (V _f) to control the duty of the PWM. That is, the voltage applied to the DC brushless motor (V _M ) is represented by the following equation (1).

[Equation 1]

V _M = k (V _f + V _T )

only,

k: proportional constant

V _f : Speed EMF Constant

V _T : Torque Voltage

to be.

The inverter device controlled the (V _f + V _T ) by varying the duty of the pulse width modulation waveform (PWM) as the DC input voltage was constant. Alternatively, in a system in which the DC voltage is variable, the voltage control is all performed at the converter side, and the inverter device only plays a role of transferring current. Of these, the former corresponds to the PWM mode and the latter corresponds to the PAM mode.

The second embodiment shown in FIG. 11 is provided with both of these two operation modes. The voltage corresponding to V _f is shared by the inverter device 220, and the voltage corresponding to V _T is shared by the converter device 210. It is composed.

Therefore, the motor rotation speed determining means 203 calculates the command rotation speed N _s for the electric motor 202 and transmits it to the inverter device 220 according to the load condition.

In the inverter device 220, the position detector 222 detects the position of the rotor of the electric motor 202, and transmits the position detection signal to the inverter control circuit 223 and the rotation speed detection means 224. The rotation speed detection means 224 detects the actual rotation speed N _a of the electric motor 202 based on this position detection signal, and transmits the detection signal to the rotation speed deviation detection means 225. The rotation speed deviation detecting unit 225 subtracts the actual rotation speed N _a from the command rotation speed N _s , detects the rotation speed deviation ΔN, and transmits the result to the inverter control circuit 223. ) Controls the switching elements constituting the inverter main circuit 221 on and off based on the position detection signal of the position detector 222.

When the inverter control circuit 223 controls the inverter main circuit 221, the PWM modulation control is executed in accordance with the operation mode command of the operation mode switching means 240. That is, the operation mode switching means 240 is in, PWM duty (D) to the variation range as a boundary of a predetermined value (D ₁₎ low-load region, divided into the high load region, and a low load region, as shown in Figure 15 in conveys the command rotational speed of the PWM mode (1) for changing the duty (D _a) of the PWM waveform variation (ΔN) to zero to the inverter control circuit 223. In addition, in the high load region, the operation mode switching means 240 receives the instruction of the PWM mode 2 by the above-described data table which changes the duty and frequency of the PWM waveform in accordance with the command rotation speed N _s . And a PAM mode command for controlling the voltage of the converter device 210 so that the rotational speed deviation? N is zero, to the energization section determining means 232. When the command rotation speed N _s is equal to or greater than the set number N _m according to the data table, the inverter control circuit 223 sends a command to change the frequency only while maintaining the duty of the PWM waveform at 100%. Subsequently, a PAM mode command for increasing and controlling the DC voltage of the converter device 210 is transmitted to the energization section determining means 232 so that the rotation speed deviation ΔN becomes zero.

As a result, the inverter control circuit 223 as shown in (a) of FIG. 15, be In rotation command to the low load region (N _s) and the actual rotating speed (N _a) the deviation (ΔN) of the to-zero Control of the PWM mode 1 which varies the duty is performed. In the high load region, control of the PWM mode 2 that controls the duty of the PWM in accordance with the command rotation speed N _s is performed. In addition, the data table incorporated in the inverter control circuit 223 is determined so that the duty of the PWM becomes 100% when the rotational speed command N _s becomes N _m .

In general, in the control of the electric motor by the inverter device, the duty of the PWM is increased so that the output voltage of the converter device 210 gradually decreases as indicated by the dotted line V ₀ in FIG. 15B. At this time, since a difference is generated between the command rotation speed N _s and the actual rotation speed N _a , the energization section determination means 232 determines the short circuit energization section such that the rotation speed deviation ΔN becomes zero. In addition, when the PAM mode command is transmitted, the energization control circuit 233 controls the short circuit energization time based on the zero cross point. FIG. 15C shows the result of the change in the short-circuit energization time of the forced energization circuit 214 when the rotational speed N _s of the motor increases. In addition, as shown in FIG. 13, this short-circuit energization time is made to increase linearly as rotation speed variation changes. In addition, with this increase in the energization time, the output voltage of the converter device 210 is kept substantially constant until the PWM duty reaches 100%.

In addition, the inverter control circuit 223 changes only the frequency while maintaining the duty of the PWM at 100% when the command rotation speed N _s exceeds the set rotation speed N _m . On the other hand, in the voltage compensator 230, the time of the forced short circuit energization by the forced energization circuit 214 is controlled so that the rotation speed deviation (DELTA) N becomes zero. As a result, as shown in FIG.15 (c), a short circuit energization time becomes long as the rotation speed N increases, and the output voltage of the converter device 210 rises as shown in FIG.15 (b). .

In this manner, according to the second embodiment, since the short-circuit energization by the forced energization circuit is deactivated in the low load region, the output voltage of the converter device under low load can be prevented from rising and the leakage current can be reduced. have.

In addition, since the load fluctuation is discriminated from the duty of the PWM, it is not necessary to use an AC input current detector that directly detects the load fluctuation, thereby making it simple. In addition, even if there is a fluctuation in the voltage, frequency of the AC power supply, or torque fluctuation of the motor, the rotation speed of the motor can be matched with the command rotation speed.

Further, according to the second embodiment, when the direct current output of the converter device is converted into alternating current by the inverter device and supplied to the motor, the lack of the variable speed capability of the inverter device can be compensated by the converter device.

Therefore, the IGBT constituting the forced energization circuit 214 may be destroyed by the temperature rise when the short circuit energization time in the high load region becomes long. Therefore, if the temperature sensor for detecting the temperature of the IGBT is provided and configured to stop the operation of the voltage compensator 230 when the detected temperature reaches a predetermined value, the destruction of the IGBT can be prevented.

In order to prevent hunting of the control, the energization section determining means 232 constituting the voltage compensator 230 may have a hysteresis characteristic when the duty of the PWM increases and decreases so as to determine the short energization section.

In addition, in this second embodiment, since the leakage current can be suppressed, reliability and safety can be improved by employing the motor controller in a refrigeration cycle apparatus using a single or mixed refrigerant composed of HFC as the refrigerant used in the refrigeration cycle. Can be. As the HFC refrigerant, for example, R410A obtained by mixing approximately 50% by weight of R32 and R125 can be used.

16 is a circuit diagram illustrating another configuration example of the converter device 210. In the figure, the same code | symbol is attached | subjected to the same element as FIG. 12, and the description is abbreviate | omitted. This apparatus is a device in which a transistor Q is connected in parallel to a series connection circuit of diodes DH and DL constituting a full-wave rectifier circuit, and an energization control circuit 233 is connected to the base driving circuit G. It has a simple configuration in which the diodes D5 to D8 shown in the drawings are removed.

In this FIG. 16, a charging current flows through the reactor 211 and the diode DH to the intermediate capacitor CH during a positive half cycle of the AC power supply 201. At this time, the diode D4 forms its discharge circuit so that the intermediate capacitor CL is not charged in the reverse direction. In addition, during the negative half cycle of the AC power supply 201, the charging current flows to the intermediate capacitor CL through the reactor 211 and the diode DL. At this time, the diode D4 forms its discharge circuit so that the intermediate capacitor CH is not charged in the reverse direction.

As long as the intermediate capacitors CH and CL are charged so that there is a voltage in the same direction between the respective terminals, i.e., the voltage in the upper direction of the figure, the diodes D3 and D4 do not function substantially, after which the diode DH The intermediate capacitor CH is charged through the intermediate capacitor CL, and the intermediate capacitor CL is charged through the diode DL.

In this way, the sum of the terminal voltages of the capacitors CL and CH connected in series is applied to both ends of the smoothing capacitor CD to charge the smoothing capacitor CD. That is, the smoothing capacitor CD is charged by the discharge of the electric charge charged in the intermediate capacitor CL and CH. The voltage across the smoothing capacitor CD is supplied to the inverter device 220 as the output of the converter device 210.

The forced energization circuit 214 transmits the transistor from the base driving circuit G by the output of the energization control circuit 233 whenever the zero cross point of the AC voltage transmitted from the AC power supply 201 to the rectification circuit 212 passes. Supply a base current to (Q). Whenever the transistor Q is turned on, current flows in the reactor 211 forcibly. In this case, as the short-circuit conduction section of the forced current is widened, a large current flows. At that time, when the transistor Q is turned off, the energy of the reactor 211 flows into the smoothing capacitor CD to reduce the DC output voltage. Increase

In this manner, the converter device 210 having the simplified structure shown in FIG. 16 can also perform the same operation as the above embodiment.

Fig. 17 is a block diagram showing the construction of the third embodiment of the present invention, in which the same elements as in Fig. 11 are denoted by the same reference numerals and the description thereof is omitted. In this third embodiment, a data table for providing a DC voltage detector 234 for detecting the output voltage of the converter device 210 in the voltage compensator 230 and linearizing the relationship between the detected value and the short-circuit energizing section. (235) is installed. This makes it very easy to determine the short-circuit energizing section in the energization section determining means 232.

Further, in the second and third embodiments described above, the reactor is forcedly energized by the energization section determined as a starting point when the zero cross detector 231 detects the zero cross point of the AC voltage. The effect is enhanced by forcibly energizing when the absolute value is close to the voltage across the flat capacitor. Therefore, the time point at which a predetermined moment has elapsed from the detection of the zero cross point may be used as the starting point of forced energization.

18 is a block diagram showing the configuration of an embodiment of an air conditioner to which the electric motor control device described above is applied. This embodiment uses the power converter shown in FIG. 11 or FIG. 16 as a device for converting alternating current into a direct current, and among the control elements other than the converter device 210 and the inverter device 220, the motor rotation speed determining means 203. To the indoor control unit, the voltage compensation unit 230 and the operation mode switching means 240 is assembled to the outdoor control unit.

The air conditioner is composed of an indoor unit and an outdoor unit, and is configured to connect the indoor unit to the AC power supply 201. In the indoor unit, the operating power is supplied from the AC power supply 201 to the indoor control unit 300 through the noise filter 261. The indoor controller 300 includes a receiver 264 for receiving a command from the remote controller 263, a temperature sensor 265 for detecting indoor temperature, an indicator 266 for displaying an operation state, and an indoor heat exchanger (not shown). An indoor fan 267 for circulating wind into the room and a louver 268 for changing the direction of blown air are connected. On the other hand, in the outdoor unit, the operating power is supplied from the AC power supply 201 to the converter device 210 and the outdoor control unit 400 via the noise filter 262. In this case, the outdoor control unit 400 includes a temperature sensor 271 for detecting the temperature of the outdoor heat exchanger, a four-way valve 272 for changing the circulation direction of the refrigerant according to the operation mode, and an outdoor air for sending air to an outdoor heat exchanger (not shown). The fan 273 is connected.

In addition, the indoor control unit 300 and the outdoor control unit 400 is configured to transmit and receive information with each other. The operation of the air conditioner configured as described above will be described below.

First, commands such as operation start, operation mode, indoor set temperature, indoor fan wind speed, and wind direction are sent from the remote control device 263 to the receiving unit 264. Accordingly, the indoor control unit 300 displays the operation state and the like on the display 266, executes the drive control of the indoor fan 267 and the louver 268, and is set by the motor speed determining means 203. The rotation speed of the compressor driving motor 202a is determined according to the deviation between the temperature and the indoor temperature, and the command rotation speed N _s is transmitted to the outdoor controller 400 together with the operation mode signal.

Next, the outdoor controller 400 sets the four-way valve 272 to the excited (or non-excited) state in accordance with the operation mode signal, and operates the converter device 210 and the inverter device 220 according to the command rotation speed N _s . In addition, the four-way valve 272 is controlled by a detection signal or the like of the temperature sensor 271 to perform defrosting operation or the like. In addition, in the outdoor controller 400, the operation mode switching means 240 determines whether it is a low load region or a high load region and outputs the first or second operation mode instruction as described above. In accordance with the operation mode command, the inverter device 220 executes pulse width modulation control, and the voltage compensator 230 forcibly energizes the converter device 210 to compensate for the voltage drop.

Therefore, the air conditioning load in the case of operating the air conditioner in the heating mode is very large compared with the air conditioning load in the case of the cooling mode operation. For this reason, since the rotation speed of the compressor drive motor 202a at the time of cooling operation is determined low, it is thought that the fall of the output voltage of the converter device 210 by pulse width modulation control is small. Therefore, during the cooling operation, even if forced energization by the voltage compensating unit 230 is omitted, there is no problem. Thereby, the process of a microcomputer etc. can be simplified.

Thus, according to the embodiment shown in FIG. 18, the air conditioner which can cope with the fluctuation | variation of the voltage, frequency of an AC power supply, the torque fluctuation of an electric motor, etc. can be provided.

In addition, when converting the DC voltage of the converter device into an alternating current by the inverter device and supplying it to an AC motor, an air conditioner capable of compensating for the lack of the variable capability of the inverter device by the converter device can be provided.

Further, as shown in FIG. 19, the short-circuit energization is performed once again after a predetermined time of the short-circuit energizing PD, and the electronic sound generated in the reactor can be suppressed.

As apparent from the above description, according to the present invention shown in the second and third embodiments, the short-circuit energization by the forced energization circuit is deactivated in the low load region, so that the output voltage of the converter device under low load rises. Can be prevented and the leakage current can be reduced.

In addition, since the load fluctuation is discriminated from the duty of the PWM, it is not necessary to use an AC input current detector that directly detects the load fluctuation, thereby enabling a simple configuration.

As can be seen from the above description, according to the present invention, since short-circuit energization by a forced energization circuit is deactivated in the low load region, an excessive increase in the output voltage of the converter device under low load can be prevented, and the leakage current can be prevented. Can be reduced.

In addition, since the load fluctuation is determined by the duty of the PWM, it is not necessary to use an AC input current detector that directly detects the load fluctuation, thereby making it simple.

In addition, a converter device for converting an AC voltage supplied from an AC power source into a DC voltage, an inverter device for converting the DC voltage converted from the converter device into a PWM voltage and supplying it to a compressor driving motor for forming a refrigeration cycle, A forced current circuit including a reactor connected in series to the power supply side, a switching element forcibly short-circuit energizing the reactor and AC power, and a short-circuit current mode for controlling the power factor or DC voltage by short-circuit energization of the forced current circuit; And a current mode switching means for switching to any of the non-short current modes to prohibit short-circuit current, so that the leakage current of the motor caused by the rise of the DC by operating in the non-short current mode when the AC input current It is effective in preventing increase in power factor deterioration.

Claims (22)

A converter device for converting an AC voltage supplied from an AC power source into a DC voltage; An inverter device for converting the DC voltage converted in the converter device into a PWM voltage and supplying the compressor drive motor to form a refrigeration cycle; A reactor connected in series with the power supply side of the converter device; A forced energization circuit including a switching element for forcibly short-circuit energizing the reactor and an AC power source; And An energization mode for switching the forced energization circuit to one of a short-circuit conduction mode for controlling a power factor or a DC voltage by short-circuit energizing for a predetermined short-circuit conduction time during a half cycle of an AC power supply, and a non-short conduction mode forbidding the short-circuit An electric motor control apparatus comprising a switching means. The method of claim 1, And an AC input current detector for detecting an AC input current, wherein said energization mode switching means sets a non-short energization mode when said AC input current is equal to or less than a predetermined current value. The method of claim 1, And wherein the energization mode switching means gradually lengthens the short circuit energization time when transitioning from the non-short energization mode to the short circuit energization mode. The method of claim 1, And said energization mode switching means shortens the short circuit energization time when it transitions from a short circuit energization mode to a non-short energization mode. The method of claim 1, In the energization mode switching means, the short-circuit energization mode includes a DC voltage-priority energization mode for suppressing the DC voltage output from the converter device to a predetermined voltage value or less by short-circuit energization of the forced energization circuit. Device. The method of claim 1, In the energization mode switching means, the short circuit energization mode includes a rotation speed priority energization mode for controlling the rotation speed of the compressor driving motor by increasing or decreasing the DC voltage output from the converter device by short circuit energization of the forced energization circuit. Electric motor controller. The method of claim 1, The short circuit energization mode in the energization mode switching means includes a high power factor priority energization mode for controlling the power factor of the converter device to a predetermined value or more by short circuit energization of the forced energization circuit. The method of claim 1, The energization mode switching means includes a high power factor priority energization mode for controlling the power factor of the converter device to a predetermined value or more by the short circuit energization of the forced energization circuit in the short circuit energization mode, and a compressor by short circuit energization of the forced energization circuit. A rotation speed priority energizing mode for controlling the rotation speed of the drive motor, An AC input current detector for detecting an AC input current input from an AC power source, Control the energization mode switching means, and set the control pattern to the non-short energization mode when the AC input current is less than a predetermined current value, and shift to the rotational priority energization mode when the duty ratio of the PWM voltage reaches a preset duty ratio. An electric motor control device comprising an energization control pattern setting means. The method of claim 7, wherein An AC input current detector for detecting an AC input current input from an AC power source, The energization control for controlling the energization mode switching means and setting a control pattern for transitioning to the non-short energization mode when the AC input current is less than a predetermined current value and to transition to the high power factor energization mode when the AC input current exceeds a predetermined current value. An apparatus for controlling an electric motor, comprising pattern setting means. The method of claim 1, And a storage means for storing an energization time correction value corresponding to the power source frequency of the AC power source, wherein the energization mode switching means corrects the short circuit energization time by the energization time correction value stored in the storage means in accordance with the power source frequency. An electric motor controller, characterized in that. The method of claim 2, A storage means for storing an input current correction value for correcting the current detection value by the AC input current detector by the difference in the current waveform due to the difference in the power supply mode is provided, and in the power supply mode switched by the power supply mode switching means. Therefore, the motor control apparatus, characterized in that for correcting the current detection value by the input current correction value. The method of claim 1, And a fuse which cuts off the forced energizing circuit when the short-circuit energizing current flowing in the forced energizing circuit exceeds a predetermined value. A converter device for converting an AC voltage supplied from an AC power source into a DC voltage; An inverter device for converting the DC voltage converted in the converter device into a PWM voltage and supplying the compressor drive motor to form a refrigeration cycle; A reactor connected in series with the power supply side of the converter device; A forced energization circuit including a switching element for forcibly short-circuit energizing the reactor and an AC power source; Energization mode switching means for setting a short-circuit energization mode for short-circuit energizing the forced energization circuit for a predetermined short-circuit energization time during a half cycle of an AC power source; An AC input current detector for detecting an AC input current input from an AC power source; And The operating state of the forced energization circuit is set when the energization mode switching means detects that the AC input current detected by the AC input current detector during the short circuit energization mode setting exceeds a predetermined value and the duty ratio of the PWM voltage exceeds a predetermined value. An electric motor control device comprising the energization state determination means for determining that it is normal. The method of claim 7, wherein An AC input current detector for detecting an AC input current input from an AC power source, An energized state that detects a change in the current value detected by the AC input current detector at the time when switching from the non-short energized mode to the high power factor priority energized mode, and determines that the operating state of the forced energizing circuit is normal based on this change. An electric motor control apparatus provided with the determination means. The method of claim 7, wherein An energization for detecting an increase in the duty ratio of the PWM voltage at the time when switching from the non-short energization mode to the high power factor priority energization mode, and determining that the operating state of the forced energization circuit is normal when this increase exceeds a predetermined value. And a state determination means. The method of claim 1, And a reactor noise energizing means for short-circuit energizing the switching element after the short-circuit energization of the switching element of the forced energization circuit by a time shorter than the short-circuit energization time. A converter device for converting an AC voltage supplied from an AC power source into a DC voltage; An inverter device for converting the DC voltage converted in the converter device into a PWM voltage and supplying the compressor drive motor to form a refrigeration cycle; A reactor connected in series with the power supply side of the converter device; A forced energization circuit including a switching element for forcibly short-circuit energizing the reactor and an AC power source; Means for detecting the actual rotation speed of the electric motor and means for detecting the rotation speed deviation between the command rotation speed and the actual rotation speed; And Operation mode switching means for outputting a first operation mode command in a low load region in which the duty ratio of the PWM voltage is less than or equal to a predetermined value, and a second operation mode command in a high load region in which the duty ratio of the PWM voltage exceeds a predetermined value; A voltage compensating unit for changing the short-circuit conduction time of the forced conduction circuit to deactivate the short-circuit energization of the forced conduction circuit in the load region, and to set the deviation of the rotational speed to zero in the high load region; The inverter device changes the duty of the PWM voltage of the inverter device so that the rotation speed deviation is zero when the driving mode switching means outputs the first driving mode command, and the driving mode switching means makes the second driving mode command. Outputs a large duty cycle of the PWM voltage according to an increase in the command rotation speed, and the voltage compensating unit includes a zero cross detector for detecting a zero cross point of the AC power supply, and the operation mode switching means includes a first operation mode. The point at which the forced energizing circuit is kept off when the command is output, and when the operation mode switching means outputs the second operation mode command, a predetermined time has elapsed from the zero cross point of the AC power supply or the zero cross point. A short-circuit energization operation is performed by turning the forced energization circuit ON for a predetermined time as a starting point, and setting the rotation speed deviation to zero. Electric motor control device, characterized in that to change the lock short circuit the power application time. The method of claim 17, And a hysteresis characteristic for switching between the first operation mode of the low load region and the second operation mode of the high load region in the operation mode switching means. The method of claim 18, The voltage compensator A direct current voltage detector for detecting an output voltage of the converter device; And a data table for linearizing the relationship between the output voltage of the converter device and the short-circuit energizing time, And the voltage compensator changes the short-circuit energizing time according to this data table. The method of claim 1, The energization mode switching means includes a high power factor priority energization mode for controlling the power factor of the converter device to a predetermined value or more by the short circuit energization of the forced energization circuit in the short circuit energization mode, and a short circuit energization of the forced energization circuit. A rotation speed priority energizing mode for controlling the rotation speed of the drive motor, And a plurality of control patterns comprising a plurality of combinations of the high power factor priority energization mode, the rotation speed priority energization mode, and the non-short energization mode, and a power supply control pattern setting means for setting one of the control patterns. Motor controller. The method of claim 20, Storage means for storing the short-circuit energization time with respect to an AC input current as said table data for every said electricity supply mode; An AC input current detector for detecting an AC input current; And Zero cross point detection means for detecting a zero cross point of an AC voltage, The energization mode switching means is zero of an alternating current voltage by the short-circuit energization time stored in the storage means corresponding to the detection value of the AC input current detector, respectively, according to the electrification mode selected according to the control pattern set by the energization control pattern setting means. And an on / off control of the switching element so as to energize the forced energizing circuit with a starting point after a predetermined time at a cross point or a zero cross point. An air conditioner capable of switching between a cooling operation for cooling a room and a heating operation for heating a room, wherein the energization control pattern setting means sets different control patterns according to whether the operation mode is a cooling operation or a heating operation. An air conditioner using the motor control unit of clause 21.