GR1009886B - Surveillance and voltage stabilizer for commercial-use refrigeration devices without use of an autotransformer - Google Patents

Abstract

The invention relates to an electronic device destined for the monitoring of voltage, frequency, temperature and current. Said electronic device ensures voltage stabilization and smooth load start for the protection and smooth operation of commercial refrigeration appliances (commercial refrigerators, freezers, mixers, etc.). The device in question has a delay start function (to protect the compressor) functioning in variable time (to protect the mains from overload). The advantage of the invention is that it protects the professional refrigeration appliance in multiple ways, using innovative technologies and algorithms.

Description

Voltage monitoring and stabilization device for commercial refrigeration devices without the use of a transformer.

Description

The invention refers to an electronic voltage, frequency, temperature and current monitoring device, voltage stabilization and smooth load start-up, for the protection and smooth operation of commercial refrigeration devices (Commercial refrigerators, soft drinks refrigerators, freezers, mixers, etc.). The device uses a microcomputer (Figure 1-A) to read and manage all system functions and a semiconductor switch (Figure 1-B) to stabilize the output voltage and protect the commercial refrigeration device and the device itself. The device also has a start delay function (to protect the compressor) with variable time (to protect the electrical network from overload) as well as the ability to change the compressor speed.

The devices currently used for the protection and smooth operation of commercial refrigeration devices are described below: Voltage stabilization devices are used in unstable electrical networks to correct the voltage level.

Voltage monitors (Cutter) are also used in unstable electrical networks, to isolate the load from the electrical network when the voltage values are out of bounds.

Softstarter devices are used to reduce the load starting current and the smooth mechanical start of electric motors.

Current control devices are used to control the current value.

The devices so far have the ability to perform one function, as a result of which the set of functions has a high cost of purchase (more than one device), installation (enough time to install the various devices), while their design is not oriented for cooling devices commercial use.

The present invention includes all the above functions as well as several others with low purchase and installation costs.

The set of functions of the invention are:

Voltage stabilization:

The device rectifies and stabilizes the voltage at the desired values using a Triac semiconductor switch (Figure 1-B) by varying its firing angle. The microcomputer (Figure 1-A) utilizing the measurements of the current voltage and the voltage and current crossing time from zero, varies the ignition angle, thus achieving a constant effective value of the output voltage.

Voltage and frequency monitoring (Cutter):

The device monitors the mains voltage and frequency and isolates the commercial refrigeration appliance from the mains when the voltage or frequency values are out of range. The use of the semiconductor switch (Figure 1-B) allows us to immediately interrupt and reconnect the output with great time precision, resulting in the protection of the commercial refrigeration device and the device itself

Current monitoring:

The device monitors the current intensity of the commercial refrigeration appliance and when it exceeds the limit, it isolates it from the mains. The current limit can either be fixed, or calculated and set by the device itself using usage statistics. Also, the device detects current zero-crossing, utilizing it in this function.

Temperature monitoring:

The device monitors the temperature in the environment in which it is located and isolates the commercial cooling device from the electrical network when the temperature value exceeds the upper limit or when the slope of the temperature rise curve is high.

Variable Start Delay:

• The start time delay allows the cooling circuit to balance the pressure of the cooling liquid, preventing starting under high pressures increasing the life of the compressor.

• With the variable time delay, the device protects the electrical network from overload and voltage drop in the case of several connected commercial refrigeration appliances on the same power line due to simultaneous start-up after a power failure. • The start delay is activated after a certain time of continuous operation of the commercial refrigeration appliance. With this function, the production process time of commercial refrigeration devices is reduced by not having this time delay in their production line.

Lightning protection:

The device using a surge absorbing component provides surge protection to the connected commercial refrigeration equipment from surges.

Reconnection lag:

The device, when reconnecting after an output interruption (due to a voltage lower than the certain lower limit), uses a sufficient voltage window to avoid the voltage falling below the lower limit due to a voltage drop in the power line.

Reversing:

The device has the ability to change the speed of the compressor thus controlling the cooling rate of the device.

Usage example

At the input of the device we connect electrical characteristics of the voltage if (Figure 1-A) as well as the temperature decides for its correction with a semiconductor switch (Figure 1-B). In the commercial refrigeration appliance (Fig. The size of the appliance is small, compared to commercial refrigeration appliances.

the mains voltage. They are recognized by the microcomputer. Based on these the microcomputer of the voltage using the output of the invention we connect a 2).

so it is easily placed inside

Claims (6)

1. Electronic voltage, frequency, temperature and current monitoring device, voltage stabilization and load smooth start for the protection and smooth operation of commercial refrigeration devices, the device uses a microcomputer (Figure 1-A) to read and manage all system functions, semiconductor switch (Figure 1-B) to protect the commercial refrigeration appliance and the appliance itself. 2. According to claim 1, the microcomputer (Figure 1-A) is used to measure voltage, current, temperature, frequency and voltage zero crossing, also used to manage the semiconductor switch. 3. According to claim 1, the device includes a circuit consisting of a semiconductor switch (Figure 1-B) for stabilizing the output voltage, protecting the commercial refrigeration device and the device itself. 4. According to claim 1, the device varies the compressor speed of the commercial refrigeration appliances using the semiconductor switch (Figure 1-B), thereby controlling the cooling rate of the appliance 5. Method of operation of an electronic device that includes a semiconductor switch (Figure 1-B), in combination with the microcomputer (Figure 1-A), the smooth start of the commercial refrigeration device (softstart) is achieved. 6. According to operation method 5, the device achieves a variable start-up delay to protect the power grid from overload and voltage drop in the case of many connected commercial refrigeration appliances on the same power line due to simultaneous start-up after a power failure.