JPH04136648A - Demand control device of air-conditioner - Google Patents

Abstract

PURPOSE:To achieve demand control at the minimum and continue operation of an air conditioner even in the demand control for maintenance of air conditioned environment by limiting stepwise an operation current of a compressor in response to the level of the demand control utilizing inverter control of the compressor of the air-conditioner. CONSTITUTION:There is provided a microcomputer 7 in a demand control device 1 for controlling an inverter control circuit 6 that controls operation frequency of a compressor 4 such that it keeps an upper limit restricting stepwise an operation current of the compressor 4 by receiving an input from a current sensor 5. The current sensor 5 detects at all times a current flowing through the compressor 4 via the inverter control circuit 6 and outputs the detected value to the microcomputer 7. Further, the inverter control circuit 6 controls the operation frequency of the compressor 4 so as to ensure the operation frequency of the compressor 4 determined by the microcomputer 7. Thus, the operation frequency is determined under the current determined by the microcomputer 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a demand control device for an air conditioner to cope with peak cuts in power demand.

BACKGROUND OF THE INVENTION In recent years, the electric power situation has seen a significant increase in the demand for electric power during the extremely hot summer months, sometimes reaching the limit of electric power supply. This is due to various causes, but power consumption due to the use of air conditioners is said to be one of the major causes.

Therefore, the current electricity situation requires us to respond and cooperate with the electricity situation, including regional characteristics such as factories, buildings, and residences.

In view of these circumstances, air conditioners that can cope with peak cuts in electricity demand are installed in buildings, etc., and these air conditioners are sent to each other between the central control unit and the living room. It was controlled by so-called demand control, which controlled while receiving information, and this control simply started and stopped the air conditioner.

Problems to be Solved by the Invention In such a conventional configuration, demand control to suppress electricity demand simply stops the operation of the air conditioner. The problem was that all the air conditioners stopped all at once for demand control, suddenly creating an uncomfortable environment with no air conditioning at all.

The present invention solves the above-mentioned conventional problems by realizing the minimum necessary demand control commensurate with the amount of power consumption reduction and by allowing the air conditioner to continue operating even during demand control, thereby improving the air conditioning environment. It is an object of the present invention to provide a demand control device for an air conditioner that can maintain as much as possible.

Means for Solving the Problems In order to solve this problem, the present invention includes a current sensor that detects the operating current of the compressor, and a sensor that detects the operating current of the compressor in response to a demand operation command from the air conditioning monitoring and control system of the building. Determine a limit value, monitor the value of the current sensor in order to control this limit value, control an inverter control circuit connected to the compressor, and determine the operating frequency of the compressor by controlling the inverter control circuit. This is a demand control device for an air conditioner consisting of a microcomputer and a microcomputer.

Function: With this configuration, the microcomputer selects and determines the upper limit of the compressor's operating current, which is predetermined according to the level of the demand operation command from the building's air conditioning monitoring and control system. The current value detected by the current sensor that detects the operating current is constantly monitored. , and the microcomputer compares the current value detected by the current sensor with the upper limit value (hereinafter referred to as upper limit value) of the operating current of the compressor previously selected and determined according to the level of the demand operation command; If the value of the current sensor exceeds the upper limit, a command is issued to the inverter control circuit to lower the operating frequency of the compressor by one rank, thereby reducing the operating current of the compressor. Then, compare the upper limit value and the current sensor value again.

By repeating similar control, the operating current of the air conditioner is regulated in stages in response to the previous demand operation command, and the power consumption of the air conditioner in the building is controlled.

EXAMPLE An example of the present invention will be described below with reference to FIGS. 1 and 2. In FIG. 1, a demand control device 1 for an air conditioner is connected by a communication line to an air conditioning monitoring and control system 2 that receives commands from a building monitoring station. The demand operation command 3 is received from the demand operation command 3, and according to the contents of the demand operation command 3, the operating current of the compressor 4 is lower than the operating current when there is no demand operation command. The compressor 4 is set to a predetermined value corresponding to the contents of 3, and receives input from the current sensor 5 to maintain the upper limit value that regulates the operating current of the compressor 4 in stages. A microcomputer 7 is provided for controlling an inverter control circuit 6 that controls the operating frequency of the compressor 4.The current sensor 5 constantly detects the value of the current flowing through the compressor 4 via the inverter control circuit 6, and The inverter control circuit 6 is configured to control the operating frequency of the compressor 4 so that the operating frequency of the compressor 4 is determined by the microcomputer 7. Therefore, the operating frequency is the current value determined by the microcomputer 7 at that time.

The operation and principle of the above configuration will be explained based on FIG. 2.

First, when the air conditioner starts operating 10, the microcomputer 7 checks whether there is a demand command from the demand operation command 3 to 11, and if there is no demand command 12, the compressor 4 When there is no operation command 3, the compressor performs operation 13 within the normal control operating current range, and continues to operate as it is until the air conditioner is started or stopped normally or until demand operation command 3 is input. .

Next, the air conditioner starts operating 10, and the microcomputer 7 checks whether there is a demand operation command 3 or not. The upper limit value of the compressor operating current is determined 15. Next, if the value of the current sensor 5 is equal to or greater than the previously determined upper limit value of the compressor operating current, 16 is checked, and if it is 17 or more, the microcomputer 7 , issues a command to the inverter control circuit 6 to lower the compressor operating frequency by one rank to 18. Then, the microcomputer 7 executes the steps 16 → 17 → 18 → until the operating current of the compressor 4 becomes equal to or greater than the previously determined upper limit of the compressor operating current during demand control or less than 16 (19).
After repeating the control in step 16, when the compressor operating current becomes less than the upper limit value 19, the operating frequency of the compressor 4 is fixed at 20 as it is, and thereafter, if there is no change in the demand operation command, the operating frequency is The compressor operating frequency is always controlled so as to maintain the upper limit value of the compressor operating current determined in the above. At the same time, at this point, the microcomputer 7 is constantly checking 21, although there is no change in the demand operation command.
If there is no change (22), the same as above, but if there is a change (23), what are the changes? 24, and if the change content is demand operation command cancellation 25, the compressor performs operation 13 within the operating current range of normal control and stops the operation of the air conditioner, or demand operation command 3 is input. Continue to operate until the Also, what are the changes? 24, and if the content of the change is change 26 of the level of the demand operation command, the microcomputer 7 again determines the upper limit value 15 of the compressor operating current according to the level stage of the demand operation command, and the subsequent steps are as described above. The control is the same as the control after determining the upper limit value of the compressor operating current 15 according to the level of the demand operation command after the start of operation 10.

Effects of the Invention As is clear from the description of the above embodiments, the present invention utilizes inverter control of the compressor of an air conditioner to limit the operating current of the compressor in stages according to the level of demand control. Because of this, unlike conventional demant control, the air conditioner does not suddenly stop, so it is possible to achieve current restriction through the minimum necessary demand operation without significantly changing the indoor temperature environment. It has the following effects.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a demand control device for an air conditioner according to an embodiment of the present invention, and FIG. 2 is a flowchart of demand control for the air conditioner. 1...Demand control device, 2...Air conditioning monitoring control system, 3...Demand operation command,
4...Compressor, 5...Current sensor, 6
...Inverter control circuit, 7...Microcomputer. Name of agent: Patent attorney Akira Koeji and two others 40,000-10,000] Fubara

Claims (1)

[Claims] A current sensor that detects the operating current of the compressor; and a current sensor that determines the limit value of the compressor operating current in response to a demand operation command from the building's air conditioning monitoring and control system, and controls this limit value. An air conditioner demand control device consisting of an inverter control circuit connected to the compressor and a microcomputer that controls the inverter control circuit and determines the operating frequency of the compressor.