CN112532221A - Switch circuit and photovoltaic air conditioning system - Google Patents

Switch circuit and photovoltaic air conditioning system Download PDF

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Publication number
CN112532221A
CN112532221A CN202011313689.5A CN202011313689A CN112532221A CN 112532221 A CN112532221 A CN 112532221A CN 202011313689 A CN202011313689 A CN 202011313689A CN 112532221 A CN112532221 A CN 112532221A
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CN
China
Prior art keywords
circuit
switch
semiconductor switch
sub
output end
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Pending
Application number
CN202011313689.5A
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Chinese (zh)
Inventor
杜斌
黄猛
冯上贤
孙一嘉
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Gree Electric Appliances Inc of Zhuhai
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Gree Electric Appliances Inc of Zhuhai
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Priority to CN202011313689.5A priority Critical patent/CN112532221A/en
Publication of CN112532221A publication Critical patent/CN112532221A/en
Pending legal-status Critical Current

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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
    • H03K17/567—Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/88—Electrical aspects, e.g. circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
    • F24F5/0046—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater using natural energy, e.g. solar energy, energy from the ground
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/327—Testing of circuit interrupters, switches or circuit-breakers
    • G01R31/3277—Testing of circuit interrupters, switches or circuit-breakers of low voltage devices, e.g. domestic or industrial devices, such as motor protections, relays, rotation switches
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
    • F24F5/0046—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater using natural energy, e.g. solar energy, energy from the ground
    • F24F2005/0064—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater using natural energy, e.g. solar energy, energy from the ground using solar energy
    • F24F2005/0067—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater using natural energy, e.g. solar energy, energy from the ground using solar energy with photovoltaic panels

Abstract

The invention relates to the technical field of switch control, in particular to a switch circuit and a photovoltaic air conditioning system, wherein a first input end of a switch detection sub-circuit of the switch circuit collects a first electrical parameter output by a semiconductor switch sub-circuit, and a second input end of the switch detection sub-circuit collects a second electrical parameter of an external circuit. The switch detection sub-circuit determines the working state of the semiconductor switch sub-circuit according to the first electrical parameter and the second electrical parameter, and controls the output end of the external circuit to stop outputting current if the working state is abnormal. The technical scheme that this application provided uses semiconductor switch to replace the relay, need not judge whether the relay adheres, has also avoided the relay to take place the adhesion under operating condition simultaneously, and unable detection leads to the problem of unable disconnection, has reduced the complexity of control, in case break down can the quick definite fault location, and then realizes quick corresponding maintenance processing, has improved the reliability of control.

Description

Switch circuit and photovoltaic air conditioning system
Technical Field
The invention relates to the technical field of switch control, in particular to a switch circuit and a photovoltaic air conditioning system.
Background
Relays are electronic control devices that are very widely used. However, in the process of long-time use, the strong electric contacts of the relay are easy to be stuck and cannot be reliably disconnected in time, so that a plurality of unstable and uncontrollable factors are brought. In order to avoid unstable factors caused by adhesion of strong electric contacts of the relay, an additional relay detection circuit needs to be arranged to detect the working state of the relay.
For example, currently, in photovoltaic air conditioning systems, the market uses relays as grid-side switches. Fig. 1 shows a relay detection circuit which is commonly used at present. The control logic of the method is that the relay RLY1 is controlled to be closed, the relay RLY2 is kept to be turned off, the absolute values of the voltage difference between the R, S, T side and the U, V, W side are respectively obtained through voltage sampling, then the absolute values are compared with a preset threshold, if the absolute values are larger than or equal to the preset threshold, the relay RLY2 is judged to be adhered, and otherwise, the relay RLY2 is not adhered; similarly, the relay RLY2 is controlled to be closed, the relay RLY1 is kept to be turned off, the absolute values of the voltage difference between the R, S, T side and the U, V, W side are respectively obtained through voltage sampling and then are compared with the preset threshold, if the absolute values are larger than or equal to the preset threshold, it is judged that the relay RLY1 is adhered, and otherwise, the relay RLY1 is not adhered.
By adopting the mode that the relay is combined with the fault detection circuit, when the relay has the adhesion fault, the specific relay can not be determined which path has the adhesion fault; moreover, the adhesion detection of the current relay is performed before power is supplied, but if the relay is adhered in a working state, the adhesion state cannot be detected, and the relay cannot be disconnected when the relay is required to be disconnected, so that great hidden danger is brought. Therefore, the manner in which the relay incorporates the relay fault detection circuit is less reliable.
Disclosure of Invention
In view of the above, the present invention provides a switching circuit and a photovoltaic air conditioning system, so as to overcome the problem of low reliability of the conventional relay combined with a relay fault detection circuit.
In order to achieve the purpose, the invention adopts the following technical scheme:
a switching circuit includes a semiconductor switching sub-circuit and a switching detection sub-circuit;
the semiconductor switch subcircuit is used for being connected with an external circuit; the input end of the semiconductor switch sub-circuit is used for being connected with the output end of the external circuit, and the output end of the semiconductor switch sub-circuit is used for being connected with the load end of the external circuit;
the signal end of the semiconductor switch sub-circuit is connected with the first input end of the switch detection sub-circuit; a first input end of the switch detection sub-circuit collects a first electrical parameter output by a signal end of the semiconductor switch sub-circuit; the second input end of the switch detection sub-circuit is used for being connected with the output end of the external circuit, and the second input end of the switch detection sub-circuit acquires a second electrical parameter of the output end of the external circuit;
the output end of the switch detection sub-circuit is used for being connected with the control end of the external circuit, the switch detection sub-circuit determines the working state of the switch detection sub-circuit according to the first electrical parameter and the second electrical parameter, and if the working state of the switch detection sub-circuit is abnormal, the control end of the external circuit controls the output end of the external circuit to stop current output.
Further, the switching circuit described above, the semiconductor switch sub-circuit comprising a first semiconductor switch, a second semiconductor switch and a diode;
the first end of the first semiconductor switch and the first end of the second semiconductor switch are connected to form a node; the second end of the first semiconductor switch and the second end of the second semiconductor switch are connected with the cathode end of the diode at the same time, and the anode end of the diode is connected with the node; the node is used as a signal end of the semiconductor switch sub-circuit;
and the third end of the first semiconductor switch is used as the input end of the semiconductor switch sub-circuit, and the third end of the second semiconductor switch is used as the output end of the semiconductor switch sub-circuit.
Further, in the above switching circuit, the first semiconductor switch and the second semiconductor switch each include an IGBT device.
Further, in the above switching circuit, the first semiconductor switch and the second semiconductor switch each include a P-channel semiconductor switch;
the first ends of the first semiconductor switch and the second semiconductor switch are both gate electrodes;
the second ends of the first semiconductor switch and the second semiconductor switch are both emitters;
and the third ends of the first semiconductor switch and the second semiconductor switch are collectors.
Further, the switch circuit described above, the switch detection sub-circuit includes a subtractor, a double-limit comparator and a signal converter;
a first input end of the subtractor is used as a first input end of the switch detection sub-circuit, and a second input end of the subtractor is used as a second input end of the switch detection sub-circuit;
the output end of the subtracter is connected with the first input end of the double-limit comparator, the second input end of the double-limit comparator is used for inputting a first threshold signal, and the third input end of the double-limit comparator is used for inputting a second threshold signal; the output end of the double-limit comparator is connected with the input end of the signal converter;
and the output end of the signal converter is used as the output end of the switch detection sub-circuit.
Further, in the switching circuit described above, the first input terminal of the subtractor includes a negative input terminal;
the second input of the subtractor comprises a positive input.
Further, in the above switching circuit, the second input terminal of the double-limit comparator includes a positive input terminal;
the third input of the double-limit comparator comprises a negative input.
Further, in the above switching circuit, the signal converter includes a DSP control board.
Further, the above switching circuit further comprises a switch indication sub-circuit;
the switch indication sub-circuit is connected with the semiconductor switch sub-circuit;
the switch indication sub-circuit is used for indicating the working state of the semiconductor switch sub-circuit.
Further, in the above-described switch circuit, the switch indication sub-circuit includes a light emitting diode.
The invention also provides a photovoltaic air conditioning system, which comprises a photovoltaic power generation circuit, a rectification inverter circuit, a rectification circuit, an air conditioning circuit and any one of the switch circuits;
the switching circuit comprises a semiconductor switching sub-circuit and a switching detection sub-circuit;
the output end of the photovoltaic power generation circuit is connected with the input end of the rectifying circuit, and the output end of the rectifying circuit is respectively connected with the input end of the rectifying and inverting circuit and the air conditioning circuit;
the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are respectively and correspondingly connected with one switch circuit, and the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are respectively connected with the input ends of the semiconductor switch sub-circuits in the corresponding switch circuits; the output ends of all the semiconductor switch sub-circuits are connected to a power grid;
the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are also connected with the second input end of the switch detection sub-circuit in the corresponding switch circuit;
the output ends of all the switch detection sub-circuits are connected with the control end of the rectification inverter circuit, and the output ends of all the switch detection sub-circuits are also connected with the control end of the rectification circuit.
The switch circuit and the photovoltaic air conditioning system comprise a semiconductor switch sub-circuit and a switch detection sub-circuit, wherein a first input end of the switch detection sub-circuit is used for collecting first electrical parameters output by a signal end of the semiconductor switch sub-circuit, and a second input end of the switch detection sub-circuit is used for collecting second electrical parameters of an output end of an external circuit. The switch detection sub-circuit determines the working state of the semiconductor switch sub-circuit according to the first electrical parameter and the second electrical parameter, and controls the output end of the external circuit to stop outputting current if the working state is abnormal. The technical scheme that this application provided uses semiconductor switch to replace the relay, need not judge whether the relay adheres, has also avoided the relay to take place the adhesion under operating condition simultaneously, and unable detection leads to the problem of unable disconnection, has reduced the complexity of control, in case break down can the quick definite fault location, and then realizes quick corresponding maintenance processing, has improved the reliability and the stability of control.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a prior art relay detection circuit for a photovoltaic air conditioning system;
FIG. 2 is a block diagram of a circuit provided by one embodiment of the switching circuit of the present invention;
FIG. 3 is a circuit diagram provided by one embodiment of the switching circuit of the present invention;
fig. 4 is a circuit diagram of a photovoltaic air conditioning system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.
Fig. 2 is a block diagram of a switching circuit according to an embodiment of the present invention.
As shown in fig. 2, the switching circuit of the present embodiment includes a semiconductor switch sub-circuit 11 and a switch detection sub-circuit 12. The semiconductor switch sub-circuit 11 is used for accessing the external circuit 2, the input end of the semiconductor switch sub-circuit 11 is used for being connected with the output end of the external circuit 2, and the output end of the semiconductor switch sub-circuit 11 is used for being connected with the load end of the external circuit 2. The signal terminal of the semiconductor switch sub-circuit 11 is connected to the first input terminal of the switch detection sub-circuit 12; a second input of the switch detection sub-circuit 12 is adapted to be connected to an output of the external circuit 2. The output terminal of the switch detection sub-circuit 12 is adapted to be connected to a control terminal of the external circuit 2.
Specifically, a first input terminal of the switch detection sub-circuit 12 is used for acquiring a first electrical parameter output by the signal terminal of the semiconductor switch sub-circuit 11, and a second input terminal of the switch detection sub-circuit 12 is used for acquiring a second electrical parameter of the output terminal of the external circuit 2. The switch detection sub-circuit 12 is configured to determine a working state of the switch detection sub-circuit 12 according to the first electrical parameter and the second electrical parameter, and if the working state of the switch detection sub-circuit 12 is abnormal, it may be determined that the semiconductor switch sub-circuit 11 has a fault, and the control terminal of the external circuit 2 may control the output terminal of the external circuit 2 to stop outputting current, so as to prevent components in the external circuit 2 from being damaged.
The technical scheme that this application provided uses semiconductor switch to replace the relay, need not judge whether the relay adheres, has also avoided the relay to take place the adhesion under operating condition simultaneously, and unable detection leads to the problem of unable disconnection, has reduced the complexity of control, in case break down can the quick definite fault location, and then realizes quick corresponding maintenance processing, has improved the reliability of control.
The present invention also provides an embodiment to explain the circuit structure of the switching circuit in detail, based on a general inventive concept.
Fig. 3 is a circuit diagram provided by an embodiment of the switching circuit of the present invention.
As shown in fig. 3, in the switch circuit of the present embodiment, the semiconductor switch sub-circuit 11 includes a first semiconductor switch T1, a second semiconductor switch T2, and a diode D. The first terminal of the first semiconductor switch T1 and the first terminal of the second semiconductor switch T2 are connected, the intersection point forms a node a, the second terminal of the first semiconductor switch T1 and the second terminal of the second semiconductor switch T2 are simultaneously connected to the cathode terminal of the diode D, the anode terminal of the diode D is connected to the node a, the node a is used as the signal terminal of the semiconductor switch sub-circuit 11, the third terminal of the first semiconductor switch T1 is used as the input terminal of the semiconductor switch sub-circuit 11, and the third terminal of the second semiconductor switch T2 is used as the output terminal of the semiconductor switch sub-circuit 11.
In addition, the first and second semiconductor switches T1 and T2 of the present embodiment may employ IGBT or MOSFET devices or the like. In a specific embodiment, the first semiconductor switch T1 and the second semiconductor switch T2 both employ IGBT devices. The IGBT device is smaller in size, so that the size of the PCB can be greatly saved. Meanwhile, the semiconductor switch is very low in cost and free of limitation of use times, and the IGBT device with low switching frequency and low conduction voltage drop is selected, so that the service life of the whole IGBT device is prolonged, and the loss of the IGBT device is reduced.
In a specific embodiment, the first and second semiconductor switches T1 and T2 are both P-channel semiconductor switches. First ends of the first semiconductor switch T1 and the second semiconductor switch T2 are gates, second ends of the first semiconductor switch T1 and the second semiconductor switch T2 are emitters, and third ends of the first semiconductor switch T1 and the second semiconductor switch T2 are collectors.
It should be noted that, in this embodiment, it is not limited that the first semiconductor switch T1 and the second semiconductor switch T2 only can be P-channel semiconductor switches, and the first semiconductor switch T1 and the second semiconductor switch T2 can also be N-channel semiconductor switches, based on the contents described in this embodiment and in fig. 3, a person skilled in the art can obtain a circuit diagram of the first semiconductor switch T1 and the second semiconductor switch T2 that use N-channel semiconductor switches without any creative effort, and details are not described here.
Specifically, in the normal operation state, the on/off of the external circuit 2 can be controlled by controlling the first semiconductor switch T1 and the second semiconductor switch T2 to adjust the operation state of the external circuit 2. Compared with a relay switch, the semiconductor switch of the embodiment belongs to a semiconductor device, the number of times of use is not limited, and the service life is longer.
At this time, if the voltage value is taken as the electrical parameter, the first voltage value collected by the first input terminal of the switch detection sub-circuit 12 and the second voltage value collected by the second input terminal of the switch detection sub-circuit 12 are different voltage data. When the first semiconductor switch T1 and/or the second semiconductor switch T2 fails, the gate, the emitter, and the collector of the failed semiconductor switch are all turned on, and the voltages of the gate and the collector of the failed semiconductor switch are substantially equal.
Further, in the switching circuit of the present embodiment, the switch detection sub-circuit 12 includes a subtractor U1, a double-limit comparator U2, and a signal converter U3.
As shown in fig. 3, a first input terminal of the subtractor U1 is connected as a first input terminal of the switch detection sub-circuit 12 to the signal terminal of the semiconductor switch sub-circuit 11, and a second input terminal of the subtractor U1 is connected as a second input terminal of the switch detection sub-circuit 12 to the output terminal of the external circuit 2. The output end of the subtracter U1 is connected with the first input end of a double-limit comparator U2, the second input end of the double-limit comparator U2 is used for inputting a first threshold signal U1, and the third input end of the double-limit comparator U2 is used for inputting a second threshold signal U2; the output terminal of the double-limit comparator U2 is connected with the input terminal of the signal converter U3. The output terminal of the signal converter U3 is connected as the output terminal of the switch detection sub-circuit 12 to the control terminal of the external circuit 2.
In a particular embodiment, the first input of the subtractor U1 comprises a negative input and the second input of the subtractor U1 comprises a positive input. The second input of the double-limit comparator U2 comprises a positive input and the third input of the double-limit comparator U2 comprises a negative input.
Specifically, the subtractor U1 is an operational amplifier, the subtractor U1 may calculate a difference between the first electrical parameter and the second electrical parameter, and if the voltage value is taken as the electrical parameter, the subtractor U1 is configured to calculate a difference between the first voltage value and the second voltage value, and send the difference between the first voltage value and the second voltage value to the double-limit comparator U2.
In a specific embodiment, the dual-limit comparator U2 includes two operational amplifiers and two resistors, where the connection relationships between the first operational amplifier S1, the second operational amplifier S2, the first resistor R1, and the second resistor R2, and the first operational amplifier S1, the second operational amplifier S2, the first resistor R1, and the second resistor R2 are shown in fig. 3, and the description of the embodiment is omitted.
Since the voltage itself fluctuates, a person skilled in the art can set the first threshold signal U1 and the second threshold signal U2 according to practical situations, input the first threshold signal U1 to the second input terminal of the subtractor U1, and input the second threshold signal U2 to the third input terminal of the subtractor U1. In one specific embodiment, the first threshold signal u1 is positive and the second threshold signal u2 is negative. When the difference between the first voltage value and the second voltage value is a positive number and is less than or equal to the first threshold signal u1, or when the difference between the first voltage value and the second voltage value is a negative number and is greater than or equal to the second threshold signal u2, it indicates that the corresponding first semiconductor switch T1 and/or second semiconductor switch T2 are/is failed, and the first voltage value collected at the first input terminal of the switch detection sub-circuit 12 and the second voltage value collected at the second input terminal of the switch detection sub-circuit 12 are in a substantially same state.
At this time, the double-limit comparator U2 may output a control signal to the signal converter U3, and the signal converter U3 outputs a PWM control signal, so as to control the output terminal of the external circuit 2 to stop outputting current through the control terminal of the external circuit 2, thereby preventing the components in the external circuit 2 from being damaged.
In one particular embodiment, the signal converter U3 includes a DSP control board.
Further, as shown in fig. 2, the switching circuit of the present embodiment further includes a switch indication sub-circuit 13, the switch indication sub-circuit 13 is connected to the semiconductor switch sub-circuit 11, and the switch indication sub-circuit 13 is used for indicating the operating state of the semiconductor switch sub-circuit 11.
In a particular embodiment, the switch indicator sub-circuit 3 comprises a light emitting diode. The light emitting diodes may be connected to the collector and emitter of each semiconductor switch, respectively, and when a semiconductor switch is turned on, the corresponding light emitting diode emits light, and when a semiconductor switch is turned off, the corresponding light emitting diode is also turned off. The switch indication sub-circuit 13 can indicate the operating state of the semiconductor switch sub-circuit 11, and a user can observe whether the semiconductor switch sub-circuit 11 is operated or not through the switch indication sub-circuit 13.
The switch circuit of this embodiment includes semiconductor switch sub-circuit 11 and switch detection sub-circuit 12, and the first input of switch detection sub-circuit 12 is used for gathering the first electrical parameter of semiconductor switch sub-circuit 11 output, and the second electrical parameter of the output of external circuit 2 is gathered to the second input of switch detection sub-circuit 12. The switch detection sub-circuit 12 determines the operating state of the semiconductor switch sub-circuit 11 according to the first electrical parameter and the second electrical parameter, and controls the output terminal of the external circuit 2 to stop outputting the current if the operating state is abnormal. The technical scheme that this embodiment provided uses semiconductor switch to replace the relay, need not judge whether the relay adheres, has also avoided the relay to take place the adhesion under operating condition simultaneously, and unable detection leads to the problem of unable disconnection, has reduced the complexity of control, in case break down can confirm the fault location fast, and then realizes quick corresponding maintenance processing, has improved the reliability of control.
Based on one general inventive concept, the present embodiment also provides a photovoltaic air conditioning system.
Fig. 4 is a circuit diagram of a photovoltaic air conditioning system according to an embodiment of the present invention.
The photovoltaic air conditioning system of the present embodiment includes a photovoltaic power generation circuit 31, a rectification inverter circuit 32, a rectification circuit 33, an air conditioning circuit 34, and the switching circuit 35 of the above embodiment.
As shown in fig. 4, the switching circuit 35 of the present embodiment includes a semiconductor switch sub-circuit 11 and a switch detection sub-circuit 12. The output end of the photovoltaic power generation circuit 31 is connected with the input end of the rectification circuit 33, and the output end of the rectification circuit 33 is respectively connected with the input end of the rectification inverter circuit 32 and the air conditioning circuit 34. After direct current generated by a photovoltaic power generation circuit 31, namely a photovoltaic panel, is boosted by a rectification circuit 33, a part of the boosted direct current is supplied to a direct current air conditioner in an air conditioner circuit 34 for use, and a part of the boosted direct current is inverted by a rectification inverter circuit 32 and then passes through a switching circuit 35; when the electricity generated by the photovoltaic system is not enough for the air conditioner, the electricity of the power grid is rectified by the rectification inverter circuit 32 through the switch circuit 35 to supply power to the air conditioner.
Specifically, in this embodiment, the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, and the W-phase output end of the rectification inverter circuit 32 are respectively and correspondingly connected to one switch circuit 35, and the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, and the W-phase output end of the rectification inverter circuit 32 are respectively connected to the input ends of the semiconductor switch sub-circuits 11 in the corresponding switch circuits 35, and the output ends of all the semiconductor switch sub-circuits 11 are merged into the power grid 36, so as to obtain R, S, T.
The signal terminal of the semiconductor switch sub-circuit 11 is connected to the first input terminal of the switch detection sub-circuit 12; a first input end of the switch detection sub-circuit 12 collects a first electrical parameter output by the semiconductor switch sub-circuit 12; the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, and the W-phase output end of the rectification inverter circuit 32 are further connected to corresponding second input ends of the switch detection sub-circuits 12 in the switch circuits 35, and the second input ends of the switch detection sub-circuits 12 are used for acquiring second electrical parameters of the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, or the W-phase output end of the rectification inverter circuit 32 to which the switch detection sub-circuits 12 are connected.
The output ends of all the switch detection sub-circuits 12 are connected with the control end of the rectification inverter circuit 32, and the output ends of all the switch detection sub-circuits 12 are also connected with the control end of the rectification circuit 33.
Specifically, each switch circuit 35 is configured to determine a working state of the corresponding semiconductor switch sub-circuit 11 according to a first electrical parameter and a second electrical parameter of a circuit in which the switch circuit is located, determine an abnormal position if the working state of the switch detection sub-circuit is abnormal, that is, determine the switch circuit 35 with a fault, and control the rectification inverter circuit 32 and the rectification circuit 33 to stop working through the control end of the rectification inverter circuit 32 and the control end of the rectification circuit 33.
In this embodiment, the three switch circuits 35 are in one-to-one relationship with the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, and the W-phase output end of the rectification inverter circuit 32, that is, the three sets of PWM control signals output by the three switch circuits 35 are also in one-to-one relationship with the U-phase output end of the rectification inverter circuit 32, the V-phase output end of the rectification inverter circuit 32, and the W-phase output end of the rectification inverter circuit 32. Therefore, when the switching circuit 35 fails, it is possible to locate which switching circuit 35 is damaged.
Generally, the control terminal of the rectifying/inverting circuit 32 is a semiconductor device in the rectifying/inverting circuit 32, and the control terminal of the rectifying circuit 33 is a semiconductor device in the rectifying circuit 33.
By adopting the technical scheme of the embodiment, the semiconductor switch is used for replacing the relay, whether the relay is adhered or not does not need to be judged, meanwhile, the problem that the relay is adhered in a working state and cannot be detected, and disconnection cannot be caused is avoided, the complexity of control is reduced, the fault position can be rapidly determined once a fault occurs, and then rapid and targeted maintenance and treatment are realized, and the reliability of control is improved. In addition, the cost of the network side control switch is reduced, the area of the PCB is reduced, the position of the fault of the switch circuit 35 can be determined, and the maintenance is convenient.
It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.
It should be noted that the terms "first," "second," and the like in the description of the present invention are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present invention, the meaning of "a plurality" means at least two unless otherwise specified.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims (11)

1. A switching circuit comprising a semiconductor switching sub-circuit and a switch sensing sub-circuit;
the semiconductor switch subcircuit is used for being connected with an external circuit; the input end of the semiconductor switch sub-circuit is used for being connected with the output end of the external circuit, and the output end of the semiconductor switch sub-circuit is used for being connected with the load end of the external circuit;
the signal end of the semiconductor switch sub-circuit is connected with the first input end of the switch detection sub-circuit; a first input end of the switch detection sub-circuit collects a first electrical parameter output by a signal end of the semiconductor switch sub-circuit; the second input end of the switch detection sub-circuit is used for being connected with the output end of the external circuit, and the second input end of the switch detection sub-circuit acquires a second electrical parameter of the output end of the external circuit;
the output end of the switch detection sub-circuit is used for being connected with the control end of the external circuit, the switch detection sub-circuit determines the working state of the switch detection sub-circuit according to the first electrical parameter and the second electrical parameter, and if the working state of the switch detection sub-circuit is abnormal, the control end of the external circuit controls the output end of the external circuit to stop current output.
2. The switching circuit according to claim 1, wherein the semiconductor switch sub-circuit comprises a first semiconductor switch, a second semiconductor switch, and a diode;
the first end of the first semiconductor switch and the first end of the second semiconductor switch are connected to form a node; the second end of the first semiconductor switch and the second end of the second semiconductor switch are connected with the cathode end of the diode at the same time, and the anode end of the diode is connected with the node; the node is used as a signal end of the semiconductor switch sub-circuit;
and the third end of the first semiconductor switch is used as the input end of the semiconductor switch sub-circuit, and the third end of the second semiconductor switch is used as the output end of the semiconductor switch sub-circuit.
3. The switching circuit of claim 2, wherein the first semiconductor switch and the second semiconductor switch each comprise an IGBT device.
4. The switch circuit of claim 2, wherein the first semiconductor switch and the second semiconductor switch each comprise a P-channel semiconductor switch;
the first ends of the first semiconductor switch and the second semiconductor switch are both gate electrodes;
the second ends of the first semiconductor switch and the second semiconductor switch are both emitters;
and the third ends of the first semiconductor switch and the second semiconductor switch are collectors.
5. The switching circuit of claim 1, wherein the switch detection sub-circuit comprises a subtractor, a double-limit comparator, and a signal converter;
a first input end of the subtractor is used as a first input end of the switch detection sub-circuit, and a second input end of the subtractor is used as a second input end of the switch detection sub-circuit;
the output end of the subtracter is connected with the first input end of the double-limit comparator, the second input end of the double-limit comparator is used for inputting a first threshold signal, and the third input end of the double-limit comparator is used for inputting a second threshold signal; the output end of the double-limit comparator is connected with the input end of the signal converter;
and the output end of the signal converter is used as the output end of the switch detection sub-circuit.
6. The switching circuit of claim 5 wherein the first input of the subtractor comprises a negative input;
the second input of the subtractor comprises a positive input.
7. The switching circuit of claim 5, wherein the second input of the double-limited comparator comprises a positive input;
the third input of the double-limit comparator comprises a negative input.
8. The switching circuit of claim 5, wherein the signal converter comprises a DSP control board.
9. The switching circuit of claim 1, further comprising a switch indication sub-circuit;
the switch indication sub-circuit is connected with the semiconductor switch sub-circuit;
the switch indication sub-circuit is used for indicating the working state of the semiconductor switch sub-circuit.
10. The switching circuit of claim 9, wherein the switch indication subcircuit comprises a light emitting diode.
11. A photovoltaic air conditioning system comprising a photovoltaic power generation circuit, a rectifying inverter circuit, a rectifying circuit, an air conditioning circuit, and the switching circuit of any one of claims 1 to 10;
the switching circuit comprises a semiconductor switching sub-circuit and a switching detection sub-circuit;
the output end of the photovoltaic power generation circuit is connected with the input end of the rectifying circuit, and the output end of the rectifying circuit is respectively connected with the input end of the rectifying and inverting circuit and the air conditioning circuit;
the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are respectively and correspondingly connected with one switch circuit, and the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are respectively connected with the input ends of the semiconductor switch sub-circuits in the corresponding switch circuits; the output ends of all the semiconductor switch sub-circuits are connected to a power grid;
the U-phase output end of the rectification inverter circuit, the V-phase output end of the rectification inverter circuit and the W-phase output end of the rectification inverter circuit are also connected with the second input end of the switch detection sub-circuit in the corresponding switch circuit;
the output ends of all the switch detection sub-circuits are connected with the control end of the rectification inverter circuit, and the output ends of all the switch detection sub-circuits are also connected with the control end of the rectification circuit.
CN202011313689.5A 2020-11-20 2020-11-20 Switch circuit and photovoltaic air conditioning system Pending CN112532221A (en)

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CN202011313689.5A CN112532221A (en) 2020-11-20 2020-11-20 Switch circuit and photovoltaic air conditioning system

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Application Number Priority Date Filing Date Title
CN202011313689.5A CN112532221A (en) 2020-11-20 2020-11-20 Switch circuit and photovoltaic air conditioning system

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4158150A (en) * 1978-01-10 1979-06-12 Amf Incorporated Solid state relay with zero crossover feature
CN104006479A (en) * 2014-06-17 2014-08-27 珠海格力电器股份有限公司 Photovoltaic air conditioning system and control method thereof
CN108023583A (en) * 2016-10-28 2018-05-11 矢崎总业株式会社 Control apparatus of semiconductor switch
CN110417388A (en) * 2019-08-02 2019-11-05 海宁昱能电子有限公司 A kind of photovoltaic module switching off device and photovoltaic power generation safety system
CN111869029A (en) * 2018-04-30 2020-10-30 Ls电气株式会社 Circuit breaker control module

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4158150A (en) * 1978-01-10 1979-06-12 Amf Incorporated Solid state relay with zero crossover feature
CN104006479A (en) * 2014-06-17 2014-08-27 珠海格力电器股份有限公司 Photovoltaic air conditioning system and control method thereof
CN108023583A (en) * 2016-10-28 2018-05-11 矢崎总业株式会社 Control apparatus of semiconductor switch
CN111869029A (en) * 2018-04-30 2020-10-30 Ls电气株式会社 Circuit breaker control module
CN110417388A (en) * 2019-08-02 2019-11-05 海宁昱能电子有限公司 A kind of photovoltaic module switching off device and photovoltaic power generation safety system

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