JP2005265220A - Gas heat pump type air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air conditioner with power generation function having high power generation efficiency. <P>SOLUTION: This gas heat pump type air conditioner has a compressor 13 driven by a gas engine 11, a first blower 16 which is electric auxiliary machinery, an outdoor unit provided with a cooling water pump 21 and installed outdoors, and second blowers 33, 34 which are indoor units installed indoors. It has a synchronous motor 52 driven by the gas engine 11, a PWM converter 50 controlling the synchronous motor 52 by regeneration to obtain direct current electric power, a converter 40 for rectifying and smoothing two or three phase alternate current commercial power supply to obtain direct current electric power, and a PWM converter 70 which is a control means for supplying electric power obtained by the PWM converter 50 as power supply of the electric auxiliary machinery in the outdoor unit or the indoor unit while detecting direct current electric power obtained by the converter 40. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a gas heat pump type air conditioner that drives a compressor by a gas engine, and more particularly, to an invention related to a gas heat pump type air conditioner that generates power with the remaining power of the gas engine.

2. Description of the Related Art Conventionally, in a gas heat pump that drives a compressor by a gas engine, a gas heat pump type air conditioner that drives an AC generator with the surplus power of the gas engine to generate AC power is known.
For example, Patent Document 1 discloses a power generation apparatus including a generator that is driven by a gas engine that drives a compressor and outputs an AC output. Furthermore, the power generation device converts an AC power output from the generator into a DC power, an AC / DC converter, and converts the DC power converted by the AC / DC converter into an AC power having a specified frequency to generate an electric power. And a DC / AC converter to be supplied to the device.
Here, AC / DC conversion and DC / AC conversion are performed because the engine speed changes with the load fluctuation of the gas heat pump and the generated output frequency and output voltage change. This is because it is converted to the specified value. The reason for converting to the specified value of the commercial power supply is to enable linkage with the commercial power supply.

JP 2001-324240 A

However, the conventional gas heat pump type air conditioner has the following problems.
(1) In the invention described in Patent Document 1, it is necessary to provide the second converter with a synchronization function and a protection device that synchronizes with the electric system, voltage, frequency, and the like of the commercial power source in order to link the commercial power source with the system. There was a problem that the cost increased.
(2) In the invention described in Patent Document 1, there is a problem that the output load of the gas engine becomes large when the gas engine is started.

(3) In the invention described in Patent Document 1, the direct current voltage obtained by AC / DC conversion of the generated power is controlled so as to become a specified set voltage. The DC voltage level is generally set to a voltage value at which the amount of inflow from the AC commercial power supply becomes zero. Since the AC commercial power supply is 202 plus or minus 20V, the DC voltage set by the AC / DC converter must be set to a value higher than 222 × (√2) = 314V. Under this condition, it is normally set to 320V.
However, on average, it may be set to a value higher than 202 × (√2) = 286 V, and 320 V is a voltage value at which the AC commercial power inflow becomes zero in all cases. However, the difference of (320-286) V compared with the average value deteriorates the power generation efficiency.
The reason is that the copper loss of the motor = armature winding resistance × (armature current) ² and the iron loss of the motor = (induced voltage) ² / equivalent iron loss resistance. Because it rises. Further, the loss in the switching device and other parts also increases.
Thus, there has been a problem that the loss has increased on average due to the constant DC voltage control.

  Then, this invention solves this subject and it aims at providing the air conditioning apparatus with a power generation function with high power generation efficiency.

The gas heat pump type air conditioner of the present invention has the following configuration in order to solve the above problems.
(1) In a gas heat pump type air conditioner having an outdoor unit that is provided outdoors and a compressor that is driven by a gas engine and an electric auxiliary machine, and is driven by a gas engine And a PWM converter that regeneratively controls the synchronous motor to obtain DC power, and supplies the electric power obtained by the PWM converter as an electric auxiliary machine in the outdoor unit or a power source for the indoor unit.

(2) The gas heat pump type air conditioner described in (1) further includes a converter for rectifying a single-phase or three-phase AC commercial power supply, and the power consumption of the electric auxiliary machine in the outdoor unit or the indoor unit On the other hand, when the power obtained by the PWM converter is insufficient, the unexpected power is supplemented from the commercial power source through the converter, and when the power obtained by the PWM converter exceeds the power consumption, the DC voltage of the DC power is commercialized. It is characterized by controlling to the lowest voltage at which the inflow current from the power source becomes zero.
(3) In the gas heat pump type air conditioner described in (1), by controlling the PWM converter as a PWM inverter, the synchronous motor is powered by the electric power flowing from the single-phase or three-phase AC commercial power supply side. It has the power running operation control means to perform.

The gas heat pump type air conditioner of the present invention has the following operations and effects.
The gas engine driving the compressor has an extra capacity with respect to the required air conditioning capacity, and generates electricity by the extra capacity of the gas engine.
The gas engine rotationally drives the rotating shaft of a synchronous motor for power generation. The PWM converter regeneratively controls the synchronous motor to obtain DC power. By supplying this DC power as an electric auxiliary machine for the outdoor unit or a power source for the indoor unit, a power generation operation is performed. According to the present invention, by using a PWM converter that can optimally control a high-efficiency synchronous motor with a built-in permanent magnet, it is possible to realize further highly efficient power generation.
In addition, the AC power obtained by the PWM converter is supplied as an electric auxiliary machine in the outdoor unit of the gas heat pump or the power source of the indoor unit without being linked to the AC commercial power source, so that it is operated with the AC commercial power source. In addition to reducing the possibility of electrical influence on external electrical equipment, it is possible to eliminate a synchronization function and a protection device that synchronizes with the voltage, frequency, etc. for system linkage, thereby realizing cost reduction. In this case, the DC power obtained by the PWM converter can be converted into AC power by a load inverter or the like and supplied to an electric auxiliary machine or the like.

In addition, when the current detection means detects the inflow current from the AC commercial power supply, the direct current voltage of the DC power generated by the PWM converter is controlled so that the inflow current is reduced to zero. Since it is possible to obtain the minimum voltage required to drive the electric auxiliary machine in the outdoor unit or the indoor unit, the iron loss of the motor can be reduced, and the switching device and other parts can be used. Loss can also be reduced. Therefore, the above loss can be reduced as compared with the conventional DC voltage constant control.
Also, by controlling the PWM converter as a PWM inverter, it has power running operation control means for power running the synchronous motor with current flowing from the AC commercial power supply, so that the output load of the gas engine is reduced when the gas engine is started Can do. Here, since the synchronous motor has a high starting torque and is suitable for a starter motor that requires a high output torque at a low speed, the starting stability of the gas engine can be improved.

Next, an embodiment of a gas heat pump type air conditioner according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a gas heat pump type air conditioner of the present embodiment.
The gas heat pump type air conditioner includes an outdoor unit 10, an indoor unit 30, and a refrigerant circulation passage 1 that circulates between the outdoor unit 10 and the indoor unit 30.
The outdoor unit 10 includes a gas engine 11 for driving the compressors 13A and 13B, an accumulator 12 that completely separates the gaseous refrigerant and the liquid refrigerant, and outdoor heat that performs heat exchange of the refrigerant for air conditioning. And an exchanger 14. A synchronous motor 52 that is a generator is connected to the gas engine 11.
The indoor unit 30 includes an indoor heat exchanger 31 that performs heat exchange between indoor air and a refrigerant, and an expansion valve 32 that expands the refrigerant.
The compressor 13 sucks gaseous refrigerant and discharges high-pressure gaseous refrigerant.

Next, the operation when the room is cooled will be described. The gas engine 11 is driven by the fuel gas, and the compressors 13A and 13B are driven. The compressors 13A and 13B suck and compress the gaseous refrigerant of the accumulator 12 and discharge it as a high-temperature and high-pressure gas. The discharged gaseous refrigerant is separated from the refrigerant in the oil separator 19. The refrigerant from which the oil has been separated flows into the outdoor heat exchanger 14 through the four-way valve 17.
The high-temperature and high-pressure gaseous refrigerant is cooled and liquefied by the outdoor heat exchanger 14. The liquefied refrigerant is expanded in the expansion valve 32 via the filter dryer 22, the ball valve 23, and the strainer 31n, and becomes a low temperature.
The low-temperature refrigerant reaches the indoor heat exchanger 31 through the strainer 31m and cools the indoor air. Next, the refrigerant is returned to the accumulator 12 through the double pipe heat exchanger 18. The refrigerant is stored in the accumulator 12 in a state of being separated into a liquid refrigerant and a gaseous refrigerant.

Next, the operation when the room is heated will be described. The gas engine 11 is driven by the fuel gas, and the compressors 13A and 13B are driven. The compressors 13A and 13B suck and compress the gaseous refrigerant of the accumulator 12 and discharge it as a high-temperature and high-pressure gas. The discharged gaseous refrigerant is separated from the refrigerant in the oil separator 19. The refrigerant from which the oil has been separated flows into the indoor heat exchanger 31 through the four-way valve 17. The high-temperature and high-pressure refrigerant heats indoor air in the indoor heat exchanger 17.
Next, the refrigerant is expanded by the expansion valve 32 through the strainer 31, and reaches the outdoor heat exchanger 14 through the ball valve 23 and the filter dryer 22. And it returns to the accumulator 12 through the four-way valve 17 and the double heat exchanger 18.

The synchronous motor 52 connected to the gas engine 11 generates power when the gas engine 11 has sufficient power.
In the gas heat pump type air conditioner of the present embodiment, a first blower 16 for blowing air to the outdoor heat exchanger 14 and a cooling water pump 21 for cooling the gas engine 11 are provided as auxiliary machines in the outdoor unit. Moreover, the 2nd air blowers 33 and 34 which ventilate to the indoor heat exchanger 31 are provided as an indoor unit.
In addition to the auxiliary machine, there are other motors, solenoid valves, outdoor unit control boards, indoor unit control boards, and wind direction plate changing motors for the indoor unit 30.

Next, the configuration of the electrical system is shown in FIG. 2 as a system block diagram.
A synchronous motor 52 that is a generator is connected to the gas engine 11. From the synchronous motor 52, three AC electric wires 53 come out and are connected to the power generation PWM converter 50. A current transformer 51 for detecting a current value is attached to two of the three AC wires 53. Two DC electric wires 54 come out from the power generation PWM converter 50.
On the other hand, an AC commercial power supply 41 is input to the converter 40. The converter includes six diodes 42 and an electrolytic capacitor 44. A current sensor 43 is attached to the electric wire.
The DC electric wires 54 output from the power generation PWM converter 50 are connected to the two DC electric wires output from the converter 40 and connected to the load inverter 60. A load current sensor 55 is attached to the DC electric wire. An auxiliary machine 90 such as a motor is connected to the load inverter 60.
A current transformer 51, a current sensor 43, a DC voltage detector 45, and a load current sensor 55 are connected to the PWM converter control means 70 that is a microcomputer for controlling the power generation PWM converter 50.
A motor controller 80 is connected to the load inverter 60.

ここで、υａ 、υｂ 、υｃ は各相の電機子電圧である。ｉａ ，ｉｂ ，ｉｃ は、各相の電機子電流である。υｄ，υｑ は、電機子電圧のｄ，ｑ軸成分である。ｉｄ，ｉｑは、電機子電流のｄ，ｑ軸成分である。Ｒａは、電機子巻線抵抗である。Ｌｄ，Ｌｑ は、ｄ，ｑ軸インダクタンスである。ｐ は、微分演算子（ｐ＝d/dt）である。ω は、同期モータ５２の電機子角速度である。Ψａ は、永久磁石の電機子鎖交磁束である。 FIG. 3 shows a basic vector diagram as a dq diagram. The voltage equation is shown in Equation 1.

Here, υa, υb, and υc are armature voltages of the respective phases. ia, ib and ic are the armature currents of the respective phases. υd and υq are d- and q-axis components of the armature voltage. id and iq are d and q axis components of the armature current. Ra is an armature winding resistance. Ld and Lq are d and q axis inductances. p is a differential operator (p = d / dt). ω is the armature angular velocity of the synchronous motor 52. Ψa is the armature flux linkage of the permanent magnet.

Next, the control is shown in FIG. 4 as a current vector control system diagram. The DC voltage optimum control 64 is connected to the torque calculator 63 and the vector current control algorithm 65. The torque calculation unit 63 is connected to the vector current algorithm 66 and the estimation algorithm 66.
The power generation PWM converter 50 operates by either control of DC voltage optimum control that is the first operation mode or output limit control that is the second operation mode. In the DC voltage optimum control, all the electric power required by the load inverter 60 is supplied from the synchronous motor 52. On the other hand, in the output restriction control, necessary power is supplied in cooperation between the synchronous motor 52 and the commercial power supply 41.

First, the DC voltage optimum control that is the first operation mode will be described.
The direct current optimum control 64 receives a commercial current inflow value I0 (n), a direct current voltage measured value Vdc (n), and a direct current voltage command initial value Vdc (0). Here, the DC voltage needs to be equal to or higher than DC282V in order to set the voltage applied to the load to an effective value of AC200V.
There are three ways to achieve this. The first method is a method of always monitoring so that the inflow current from the commercial power supply becomes zero.
In the second method, when the power generation PWM converter 50 is started, the DC voltage is increased at about 1 V / second so that the inflow current from the commercial power supply becomes zero, and is controlled to be constant to that value. If there is an inflow current from, the voltage is similarly increased at about 1 V / second. However, in this case, DC 282V or more is required.
The third method is a method in which the DC voltage at the time of full load stop is detected by stopping the power generation PWM converter 50 at the time of start-up, and constant control is performed to a voltage obtained by adding 5 to 6 V to this value. That is, the voltage from the commercial power source is measured while the synchronous motor 52 is stopped, and 5 to 6 V is added to the value.
The third method is the most appropriate method because it does not require an extra sensor.
The DC voltage command value Vdc * is output from the DC voltage optimum control 64 by any one of the above methods.

Idc(n) は、負荷側の直流電流実測値であり、(n) は、処理時点のサンプル値を示す。
同期モータ５２の出力P(M)は、後述するように、例えば、夏場に空調用圧縮機の負荷が大きいときには、常時出力制限される可能性がある。すなわち、発電機からの取り出し電力に制限がかかっていない場合は、「同期モータからの取り出し電力＝負荷側モータ総必要電力となる。一方、発電機からの取り出し電力に制限がかかっている場合は、「同期モータからの取り出し電力＋商用電源からの電力＝負荷側モータ総必要電力」となる。 Next, the torque calculator 63 will be described. The DC voltage command value Vdc * is input from the DC voltage optimum control 64 to the torque calculator 63, and the load side DC current measured value Idc (n) is input. Further, the rotor angular speed ωm (n) of the synchronous motor 52 is input from the estimation algorithm 66. From these values, a take-out output P (M) from the synchronous motor 52 is calculated using Equation 2.

Idc (n) is a measured DC current value on the load side, and (n) indicates a sample value at the time of processing.
As will be described later, the output P (M) of the synchronous motor 52 may be constantly limited when the load of the air conditioning compressor is large in summer, for example. That is, if there is no limit on the power taken out from the generator, “the power taken out from the synchronous motor = the total required power on the load side motor. On the other hand, if there is a limit on the power taken out from the generator” , “Extracted power from the synchronous motor + Power from the commercial power source = Total required power on the load side motor”.

ここで、Ｔ*は、トルクである。Pn は、極対数である。Ψa は、誘導電圧であり、常数である。（Ld−Lq）は、固定値である。 Next, using Equation 3, an expression expressing iq as a function of id is obtained and output as Iq *.

Here, T * is torque. Pn is the number of pole pairs. Ψa is an induced voltage and is a constant. (Ld−Lq) is a fixed value.

ここで、Ie は、相電流実効値である。ａ，ｂは、同期モータ５２のモータ特性より決定される係数である。すなわち、同期モータ５２が過度に加熱することを防止するために、同期モータ５２からの出力電流を制限しているのである。 The output current from the synchronous motor 52 is always limited by the limit current Ia of the synchronous motor 52 as shown in Equation 4.

Here, Ie is a phase current effective value. a and b are coefficients determined from the motor characteristics of the synchronous motor 52. That is, the output current from the synchronous motor 52 is limited in order to prevent the synchronous motor 52 from being heated excessively.

The meaning of Equation 4 means that when the square root √ (id ² + iq ² ) of the obtained sum of squares of id and iq is larger than √3 (a · ω + b), Ia determined by √3 (a · ω + b) And id and iq are determined based on.
That is, if id and iq calculated based on the required power on the load side exceed the limit value of the synchronous motor 52 that is a generator, it is determined that there is no condition that satisfies Equation 5, Equation 2, and Equation 3. This is the same as when the output is limited.
However, it is obtained from the simultaneous equations of Equations 5 and 4.
Since the generator alone cannot cover the total power on the load side, the DC voltage is lowered and power is taken from the commercial power supply. Therefore, Vdc in Equation 5 is Vdc * = Vdc (n) as in the output limit control. Become.

ここで、Vdc* は、直流電圧指令値であり、Vdc(I0=0) である。また、Vdc(0) は、直流電圧指令初期値であり、本実施例では、２８２Ｖである。また、I0(n) は、商用電源流入電流実測値であり、(n) は、処理時点のサンプル値である。
Vdc* は、初期値を２８２Ｖとし、I0(n) の目標値との偏差を加算する形で、I0(n)＝０となるように、ＰＩ制御する。ただし、Vdc*＝２８２〜３２０Ｖとする。 Next, the vector current control algorithm 65 will be described. The vector current control algorithm 65 receives a DC voltage command value Vdc * from the DC voltage optimum control 64. Further, Iq * is input from the torque calculation unit 63. Further, the rotor angular speed ωm (n) of the synchronous motor 52 is input from the estimation algorithm 66.
The vector current control algorithm 65 obtains id based on Equation 5.

Here, Vdc * is a DC voltage command value and is Vdc (I0 = 0). Vdc (0) is a DC voltage command initial value, and is 282 V in this embodiment. Further, I0 (n) is a measured value of commercial power inflow current, and (n) is a sample value at the time of processing.
Vdc * is PI-controlled so that I0 (n) = 0 by setting the initial value to 282 V and adding a deviation from the target value of I0 (n). However, Vdc * = 282 to 320V.

Next, a specific procedure for direct current voltage optimum control will be described.
(A) Set Vdc (0) = 282V (initial value).
(A) Measure I0 (n) at 1 second intervals.
(C) If I0 (n) is greater than zero, increase Vdc by 1 volt.
(D) Repeat (a) and (c), and let Vdc when I0 (n) becomes zero be the DC voltage command value Vdc *. Vdc * = Vdc (I0 (n) = 0)
(E) The electric power P (M) * extracted from Equation 2 is calculated from the obtained Vdc * and the DC voltage measured value Idc (n) required by the load side.
(F) The torque T * is calculated from the angular velocity ω of the synchronous motor 52 and P (M) *.
T * = P (M) * / ω
(G) Substituting the obtained Vdc *, ω and other constants into Equations 5 and 3 to create simultaneous equations of id and iq, and from these, id and iq are obtained.

Here, in (e), Vdc * · Idc (n) is compared with P (M) Lim. When the comparison result is Vdc * · Idc (n)> P (M) Lim, the motor output is limited. In this case, Vdc * is an actually measured value (voltage value actually required on the load side).
Further, when id, iq obtained in (ki) is √ (id ² + iq ² )> √3 (a · ω + b), a current exceeding the limit current of the motor flows, and thus the current is limited. In this case, id and iq are obtained from the simultaneous equations of Equation 5 and √ (id ² + iq ² ) = √3 (a · ω + b).

The obtained id and iq are output as optimum current command values id * and iq *. Next, in PI control, id * and iq * are substituted into Equation 1 to obtain υd and υq, which are input to the 2-phase / 3-phase / rotation / stationary conversion 62.
In the two-phase / three-phase / rotation / static conversion 62, υd and υq are converted into υa, υb, and υc, and are input to the PWM converter 52 as three-phase currents ia, ib, and ic. That is, υa, υb, and υc are three-phase modulated waves, and act as gate signals for switching control of IGBTs (insulated gate / bipolar transistors: semiconductor switching elements) in the PWM converter by comparison with triangular carrier waves.
id (n) and iq (n) are fed back to id * and iq * by measuring ia and ic by the measuring instrument 51 and converted by the three-phase / 2-phase / stationary / rotation conversion 67. Control is performed so that the deviations of the outputs id (n) and iq (n) are zero with respect to id * and iq *.

The output restriction control that is the second operation mode will be described. In the output restriction control, the operation is performed in such a manner that the amount of power required by the synchronous motor 52 is insufficient from the commercial power supply for the required power.
FIG. 5 shows a graph of the engine output limit value. The horizontal axis indicates the external limit command value Vs, and the vertical axis indicates the percentage of the engine output P (E / G). Vs is a command value given from the GHP main controller to the PWM converter control means 70 which is a generator controller. The command value is given as an analog input of 0 to 5 V at intervals of 10 seconds or more. P (E / G) is not a ratio of the total engine power but a ratio given to the generator. In the 20 HP GHP, the engine output is about 15 kW, but the maximum power supplied to the generator is about 2 kW. That is, P (E / G) = 100% is 2 kW.
When the demand for air conditioning in summer is large and the load on the compressor is large, power generation is stopped to prioritize air conditioning.
The output P (M) of the synchronous motor 52 = P (E / G) · η (M). Here, η (M) is the motor efficiency.
The output limit value P (M) Lim of the synchronous motor 52 is limited to the smaller one of the limit by P (E / G) and (Vdc * · Idc (n)).

Next, the vector control algorithm 65 will be described.
In the case of Vdc * · Idc (n)> P (M) Lim, Vdc * = Vdc (n) in Equation 5. Also, in Equation 2 or Equation 3, P (M) * = P (M) Lim. Here, Vdc (n) is a measured value of the direct current. (N) is a sample value at the time of processing. Accordingly, the increase or decrease speed of the P (M) value is limited in consideration of engine torque fluctuation.
On the other hand, in the case of Vdc * · Idc (n) <P (M) Lim, Vdc * = Vdc (I0 = 0) in Equation 5. Further, in the formula 2 or 3, it is assumed that P (M) * = Vdc * · Idc (n).

The power generation PWM converter 50 compensates for the shortage of the synchronous motor 52, which is a generator, and supplies power to the load via the electrolytic capacitor 44 of direct current (the portion where the initial value is 282V). The electric wire to which the electrolytic capacitor 44 is attached serves as a DC intermediate bus.
When the motor output is limited, the load current is insufficient only with the current (charge) supplied from the power generation PWM converter 50 to the electrolytic capacitor 44, and the voltage of the electrolytic capacitor 44 is reduced. When the voltage of the electrolytic capacitor 44 decreases, current flows from the commercial power source, and the voltage is determined when the balance is maintained. This is used as Vdc.
However, even if the motor output is limited, if the motor output is reduced at once, the load on the engine may change and the voltage balance may also cause hunting, so the P (M) value will increase in consideration of the engine torque. Or the descending speed is limited. In practice, the generator output is reduced quite slowly.

A time chart of the gas heat pump type air conditioner having the above configuration will be described. First, start-up control will be described.
FIG. 6 shows a timing chart at the start. When there is a GHP operation command, commercial power is input and the cooling pump Wp is driven. Next, the gas valve is opened and the engine 11 is started. Here, by controlling the power generation PWM converter 50 as a PWM inverter, there is a PWM converter control means 70 for powering the synchronous motor 52 with a current flowing from the AC commercial power supply 41. Since the synchronous motor 52 is used as a starter, high power control is performed, and gate control is performed with a predetermined pattern from the PWM converter control means 70, whereby the power generation PWM converter 50 can be operated as a PWM inverter.
That is, by using the starter motor for starting the engine as the synchronous motor 52, the starter motor and the power supply unit for the starter motor can be reduced.
After 35 to 160 seconds have elapsed since the engine was started, the compressor 13 and the first blower 16 are driven. Thereafter, the four-way valve is controlled within 60 seconds. An operation command for the power generation converter PWM 50 is issued 5 seconds after the compressor is switched or 10 seconds after the four-way valve is switched.
As the output of the generator comes out, the input of the commercial power supply is reduced and is basically zero.
That is, as described above, the power generation PWM converter 50 operates by either the DC voltage optimum control that is the first operation mode or the output limit control that is the second operation mode. In the DC voltage optimum control, all the power required by the load inverter 60 is supplied from the synchronous motor 52. On the other hand, in the output restriction control, necessary power is supplied in cooperation between the synchronous motor 52 and the commercial power supply 41.

Next, normal stop time control will be described.
FIG. 7 shows a timing chart at the time of stopping. When there is a GHP stop command, an operation stop command for the power generation PWM converter 50 is immediately issued. As the generator is stopped, the commercial power supply increases to supply power to the cooling pump, compressor, and the like.
Next, the compressor is stopped and the gas valve is closed. As a result, the engine stops. After closing the gas valve, the fan is driven and stopped for a maximum of 180 seconds. Ten seconds later, the cooling water pump is stopped.

  As described above in detail, according to the gas heat pump type air conditioner of the present embodiment, the compressor 13 driven by the gas engine 11, the first blower 16, which is an electric auxiliary machine, the cooling water pump 21, and the like. A gas heat pump type air conditioner having an outdoor unit installed outside and a second blower 33, 34, etc., which is an indoor unit installed indoors, and a synchronous motor 52 driven by the gas engine 11 A PWM converter 50 that regeneratively controls the synchronous motor 52 to obtain DC power, a converter 40 that obtains DC power by rectifying and smoothing a two-phase or three-phase AC commercial power supply, and DC power obtained by the converter 40 And PWM converter control means 70, which is a control means for supplying the electric power obtained by the PWM converter 50 as an electric auxiliary machine in the outdoor unit or as a power source for the indoor unit. Since, risk is reduced to provide an electrical influence on an external electrical device that is running on the AC commercial power supply. Further, it is possible to eliminate a synchronization function and a protection device that synchronizes with the voltage, frequency, etc. for system linkage, and cost reduction can be realized.

Further, the gas heat pump type air conditioner of the present embodiment includes a current sensor 43 that is a current detection unit that detects a current flowing from the AC commercial power supply 41, and the inflow current when the current detection unit detects the inflow current. DC voltage control means for controlling the DC voltage of the DC power generated by the PWM converter so as to reduce the minimum required to drive the electric auxiliary machine or the indoor unit in the outdoor unit of the gas heat pump In particular, the iron loss of the motor can be reduced, and the loss in the switching device and other parts can also be reduced.
In this way, the loss that has been increased on average can be reduced by performing constant DC voltage control.

  Further, the gas heat pump type air conditioner according to the present embodiment controls the PWM converter as a PWM inverter, whereby the PWM converter control means 70 is a power running control means for power running the synchronous motor with a current flowing from the AC commercial power supply. Thus, the starter motor for starting the engine can also be used as the synchronous motor 52, and the power supply unit for the starter motor can be reduced. In particular, the synchronous motor 52 is suitable for a starter that requires a high starting torque, a low speed, and a high output torque. In the past, there was a case where an induction motor was also used as a starter, but the induction motor has a low starting torque, and when used as a starter, it requires a large starting current from a commercial power source, and the size of the inverter must be increased and the size must be increased. There was a problem, but according to the present embodiment, the problem can be solved.

As mentioned above, although one Example of the gas heart pump type air conditioning apparatus concerning this invention was described, this invention is not limited to this, A various change is possible in the range which does not deviate from the meaning.
For example, in the embodiment, a compressor and a blower are driven as auxiliary machines, but electromagnetic valves or the like that are other auxiliary machines may be driven.

It is a lineblock diagram of a gas heat pump type air harmony device. It is a system block diagram which shows the structure of an electric system. It is a basic vector diagram. It is a current vector control system diagram. It is a figure which shows the limit value of an engine output. It is a timing chart figure at the time of starting. It is a timing chart figure at the time of a stop.

Explanation of symbols

11 Gas Engine 13 Compressor 16 First Blower 21 Cooling Water Pumps 33, 34 Second Blower 40 Converter 41 Commercial AC Power Supply 50 Power Generation PWM Converter 52 Synchronous Motor 60 Load Inverter 70 PWM Converter

Claims (3)

In a gas heat pump type air conditioner having a compressor driven by a gas engine, an outdoor unit provided with an electric auxiliary machine, and an indoor unit installed indoors,
A synchronous motor driven by the gas engine;
A PWM converter that regeneratively controls the synchronous motor and obtains DC power;
A gas heat pump type air conditioner that supplies electric power obtained by the PWM converter as an electric auxiliary machine in the outdoor unit or a power source of the indoor unit. In the gas heat pump type air conditioner according to claim 1,
A converter for rectifying a single-phase or three-phase AC commercial power supply;
When the electric power obtained by the PWM converter is insufficient with respect to the electric power of the outdoor unit or the electric power of the indoor unit, the electric power obtained by the PWM converter is supplemented with the unexpected power from the commercial power source through the converter. When the electric power exceeds the power consumption, the direct current voltage of the direct current power is controlled to the lowest voltage at which the inflow current from the commercial power source becomes zero. In the gas heat pump type air conditioner according to claim 2,
A gas heat pump type air conditioner comprising power running operation control means for power running the synchronous motor with electric power flowing from the single-phase or three-phase AC commercial power supply side by controlling the PWM converter as a PWM inverter apparatus.

Images