RU2776416C1 - Dc key - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, in particular to protective switching equipment. The DC key (DCK) contains a control unit (CU), a pair of counter-serially connected electronic keys (EK) and a mechanical key (MK) installed in parallel, the first and second power contacts of which are connected respectively to the positive first contact and the second contact of the DCK. As a MK, an electromagnetic polarized relay is installed in the DCK, the first and second low-current contacts of which are the contacts of the first winding of this relay, the third and fourth low-current contacts are the contacts of the second winding and are connected to the corresponding outputs of the control unit. In addition, the power inputs of a pair of EKs are interconnected, and the power outputs of the first and second ECs of the said pair are connected respectively to the positive first and second contacts of the DCK, the low-current inputs of the first and second EKs are connected together and connected to the output of the control unit, and the connection of the power inputs of the first and the second EK is connected to the sixth output of the CU, the input of which is connected to the control contact of the DCK to receive control commands.

EFFECT: reducing the power consumed by the key and increasing the reliability of its operation.

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Description

The proposed technical solution relates to the field of electrical engineering, in particular to protective switching equipment and can be used in high voltage direct current distribution systems, in particular in transport power supply systems.

DC key schemes are widely known (for example, in the FDC-2S-2 module, https://micro-pi.ru/bms-%D0%BA%D0%BE%D0%BD%D1%82%D1%80% D0%BE%D0%BB%D0%BB%D0%B5%D1%80-fdc-2s-2-%D0%B7%D0%B0%D1%89%D0%B8%D1%82%D1%8B -2% D1% 85-li-ion /), where with the help of pairs of electronic keys (field-effect transistors Ml and M2) connected in opposite series and controlled by the controller, the load or charger is connected and disconnected from the battery. In the key circuit, the current is limited by resistors (R1 and R2). Such devices are easy to manufacture, have a low cost, but their disadvantage is high energy consumption and heat losses on electronic keys and their failure from overheating with insufficient cooling.

Known DC switch (RU No. 112797, State educational institution of higher professional education Moscow Aviation Institute (State Technical University) (MAI), H01H 75/02, publ. 20.01.2012), containing positive and negative inputs, positive and negative outputs (according to the text - the first power output 3 and the second power output 9, the first 7 and the second 8 output outputs); control device (command device 5) with the ability to independently control two relays (two electromechanical contactors 1 and 2), each of which is connected to one of two spaced electronic keys (first 13 and second 14), one of which opens the circuit in case of a short circuit, the second - discharges the storage capacitor after overvoltage; diode for protection against self-induction of the DC circuit. The disadvantages of this switch: large dimensions of the device due to the presence of two relays to protect the power source from short circuits and surges; own power consumption of the circuit breaker, since in the “on” mode it consumes significant power due to the presence of current on the winding of the first relay (1).

Closest to the claimed technical solution is a bidirectional DC voltage switch (RU No. 2703190, Fig. 2, SIEMENS AKTIENGESELLSHAFT (DE), publ. 10/15/2019), containing the first positive and negative contacts (positive and negative inputs - to the DC source ) and the second positive and negative contacts (positive and negative outputs - to the consumer's network), a mechanical key (MK) (mechanical switch 13), a control device (17) for controlling a pair (two) counter-series (according to the text "anti-series") connected electronic keys (EC) (15 and 25), which are connected by their power outputs (Fig. 2 patent No. 2703190). The switch also contains a protective (extinguishing) diode and controlled electronic keys (152 and 252). The switch circuit allows you to “safely” turn off the MK for all contacts by reducing the current through the contacts below the permissible value as follows: before turning on the MK - turn on (close) 15 and 25, closing the power source to the DC network (1112); before turning off the MC, turn on the EC (152), closing the load current “to the ground” through a transformer (14), to turn off the MC in the opposite direction, use the closure of the EC (252) and the circuit of the load current “to the ground” through a transformer (24).

Disadvantages of the circuit breaker: the presence of three different independent control circuits for turning the MC on and off in two directions with spaced ECs ((15, 25), (152) and (252)), which complicates the device circuit as a whole and the CU operation algorithm, the presence in the circuits inclusion of transformers, which significantly increase the dimensions and weight of the product. In addition, ECs are controlled through their power and low-current inputs, however, when connecting a pair of ECs with power outputs, pairwise connection of their power and low-current inputs for their common control is impossible. Therefore, individual (separate) control of each of the four inputs is required, which also complicates the circuit.

The objective of the proposed technical solution of the DC key is to reduce the size and weight of the device, reduce the power consumption of the key, increase the manufacturability, reduce the cost of manufacturing and operation, as well as avoiding overheating of a pair of EC and their failure, minimizing the energy consumed by the device.

The problem is solved in the following way.

To turn the DC key (CPT) on and off, the mechanical key (MK) is closed and opened during the time interval when two electronic keys connected in series with power inputs are turned on (this connection allows you to connect their power inputs and low-current inputs to simultaneously control these pairs of inputs ), and as an MK, an electromagnetic polarized relay is used that does not consume energy (current) in both stable states (on and off) and consumes energy only at short moments of switching from one state to another due to the presence of two windings. Thus, a pair of EC serves as the only parallel circuit that takes on the current load in the time intervals known and set in the control device, necessary to change the states (closed, open) of the power contacts of the relay and electronic keys.

The CPT contains a control device (CU), a pair (two) of counter-series connected electronic keys (EC) and a mechanical key (MC) installed in parallel, the first and second power contacts of which are connected respectively to the positive first contact and the second contact of the CTP. The first positive and first negative contacts, the second positive and second negative contacts of the CPT are used to connect the CPT to the DC network (connection to a DC source (IP) and the consumer network). The CPT is configured to supply the necessary supply voltage to all its elements that require power.

At the same time, an electromagnetic polarized relay is installed as an MC in the CPT, the first and second low-current contacts of which are the contacts of the first winding of this relay, the third and fourth low-current contacts are the contacts of the second winding and are connected, respectively, to the first and second, third and fourth outputs of the control unit. In addition, the power output of the first EC from the mentioned pair of EC is connected to the first positive contact of the CPT, the power input of which is connected to the power input of the second EC of this pair, the power output of which is connected to the second positive contact of the CPT (the power inputs of the EC pair are interconnected, and the power the outputs of the first and second EC of the mentioned pair are connected respectively to the positive first and second contacts of the CPT), low-current inputs (controlled inputs) of the first and second EC are connected together and connected to the fifth output of the CU, and the connection of the power inputs of the first and second EC is connected to the sixth output of the CU , the input of which is connected to the control contact (input) of the CPT to receive control commands (including switching on and off) of the CPT.

The proposed CPT device can pass current in the forward and reverse directions, which is important when a rechargeable battery (AB) is installed as a power supply, requiring recharging; has a simple and high-tech circuit with a small number of circuits and connections (including due to the presence of only two EC and the possibility of connecting their inputs of the same name for general control), and small size with simplicity and ease of use due to symmetry; allows only by replacing the EC (without replacing the polarized relay) to change the operating voltage of the CPT, since the operating voltage of the CPT is determined by the breakdown voltage of the selected EC and does not depend on the installed polarized relay, and the maximum operating current is determined by the impulse current of the EC and the polarized relay. The proposed functional diagram of the device ensures its reliable operation, without short circuits and failure of a pair of EC. The proposed solution of the CPT allows the use of the CPT in various power circuits. Including in devices and systems with control of charge/discharge modes of batteries of various types, which allow protecting them from critical modes (overcharging, overdischarging, elevated temperatures, short circuits, etc.).

Preferably, the CPT contains a protective (quenching) diode connected in a non-conductive direction to the positive and negative outputs of the CPT to protect against self-induction of the DC circuit (the cathode is connected to the second positive contact, the anode - to the second negative contact of the CPT). In the main embodiment of the proposed technical solution, such a diode can be built into the device on the consumer side.

It is preferable that at least one additional pair of counter-series connected EC power inputs be installed between the first and second positive contacts of the CPT in parallel to the mentioned pair of counter-series-connected EC, the power outputs of the first and second EC of this additional pair are connected respectively to the positive first and second contacts of the CPT, The low-current inputs of this EC pair are connected together and connected to the connection of the low-current inputs of the mentioned EC pair (for general control from the fifth output of the CU), and the connected power inputs of this EC pair are connected to the connection of the power inputs of the mentioned EC pair (for general control from the sixth output of the CU) . Installation of additional pairs of EC allows avoiding EC overload and obtaining a CPT of any required power and for a different operating voltage of the CPT.

It is preferable that the control device has an additional output connected to the control contact of the CPT for transmitting information signals to control the operation of the CPT.

In the proposed technical solution, KPT uses standard products manufactured by Russian and/or foreign companies. For example, field-effect transistors (MOSFET), bipolar transistors, insulated gate bipolar transistors (IGBT), or circuits assembled on lockable thyristors, etc. can be used as electronic switches; as a control unit - a general-purpose microcontroller, FPGA, DSP with appropriate binding, various circuits on logical elements; polarized relay designs can also be different.

In the future, the implementation of the DC key will be considered in one of the preferred embodiments.

In FIG. 1 shows a block diagram of a DC switch in the version with transistors as electronic switches and a protective diode.

In FIG. 2 is a block diagram of a DC key with two pairs of electronic keys.

Shown in FIG. 1 DC key (CPT) with the first positive ("+1") and negative ("-1") contacts for connecting the CPT to a direct current source (SP), the second positive ("+2") and negative ("-2") ”) with contacts for connecting to the consumer's network contains a pair of electronic keys (EC) - the first EC 1 and the second EC 2 - counter-serially connected to each other by their power inputs (emitters). In this embodiment, the CPT as EC installed transistors. In this case, the power output (collector) of EC 1 is connected to the PTS, the power output (collector) of the EC 2 is connected to "+2" of the PTS. Mechanical key 3 (MK) - an electromagnetic polarized relay - is installed in parallel with a pair of EC. The first (1 hp) and the second (2 hp) power contacts of MK 3 are connected respectively to and "+2" of the CTP, the first (1 sl) and the second (2 sl) low-current contacts (contacts of the first relay winding) are connected to the first and second, respectively outputs of control device 4 (CU), and the third (3 sl) and fourth (4 sl) low-current contacts (contacts of the second relay winding) are connected to the third and fourth outputs of CU 4, respectively. In addition, low-current inputs (gates) of EC 1 and EC 2 are connected and connected to the fifth output of CU 4, to the sixth output of CU 4, the connected power inputs of EC 1 and EC 2 are connected, and the input of CU 4 is connected to the control contact of the CPT to receive control commands (on or off signals). The CPT in this embodiment contains a protective diode 5 connected in a non-conductive direction between "+2" and "-2" of the CPT to protect against self-induction of the DC circuit.

In this implementation, the KPT CU 4 is made on a microcontroller and is controlled by commands - "logical 1" or "logical O". It contains the values of time intervals t1 and t2, not less than the time intervals required, respectively, for the operation (closing or opening) of both EC (first and second) and power contacts of relay 3 (determined by its type and design).

The DC switch shown in Fig. 1 works as follows. In the presence of a diode 5, the CPT is connected to the IP (for example, a battery) with the first contacts - and to the consumer's network - with the contacts "+2" and "-2". In this embodiment, only the control unit 4 is supplied with the supply voltage necessary for its operation (not shown in Fig. 1). In the initial state, EC 1 and EC 2 are off, MK 2 is off (contacts 1 forces and 2 forces are open). The CPT is in the standby mode for an external control command and consumes the minimum power (for the functioning of the control unit 4).

Turning on the CPT: when a command to turn on (closing 1 force and 2 forces of MK 3) is applied to the input CU 4 (the control input of the CPT), CU 4 processes it and then simultaneously supplies the voltage necessary to turn on a pair of EC through outputs 5 and 6, respectively, to low-current and power inputs of both EC, including (closing) EC1 and EC2. After the time t1 set in CU 4, after the operation (closing) of the pair of EC, CU 4 from pins 1 and 2 supplies voltage to low-current contacts 1 sl and 2 sl MK 3 (the first winding of the relay) to close its power contacts 1 force and 2 force . Further, after a time t2 - after closing 1 force and 2 forces MK 3, CU 4 relieves voltage at outputs 5 and 6, which turns off (opens) EC 1 and EC 2. Circuit "+1" -MK3 - "+2" is safely closed , because during the closure of 1 force and 2 force, the current flows through the parallel circuit of a pair of closed EC. KPT is on, direct current is supplied from the IP to "+2" and "-2" to the consumer's network. Thus, when turned on, there is no electric arc during chattering and sticking of the power contacts of MK 3, without disabling the IP and MK 3 itself. In this case, relay 4 consumes energy only in the time interval t2, and the EC pair does not overheat during this time.

Switching off the CPT: after processing the shutdown command (disconnection of forces and 2 forces of MK 3) received from the control contact, CU 4, through outputs 5 and 6, supplies the turn-on voltage of the EC to the low-current and power inputs of both EC, closing EC 1 and 2. After a time interval t1 CU 4, through pins 3 and 4, supplies voltage to low-current contacts 3 sl and 4 sl MK 3 (the second winding of the relay) to open the power contacts 1 of the forces and 2 of the forces of this relay. Further, after a time interval t2, CU 4 removes voltage at outputs 5 and 6, which opens both ECs 1 and 2. The CPT is turned off when the power contacts of relay 3 are safely opened without the occurrence of an electric arc and the destruction of the power contacts MK 3 with the parallel circuit from a pair of ECs switched on. In this case, relay 3 consumes energy only during the time interval tl.

Shown in FIG. 2, the DC key (CPT) contains a pair of EC - EC 1 and EC 2, MK 3 - an electromagnetic polarized relay, CU 4, connected as described above, as well as an additional pair of counter-series connected by their power inputs EC (EC 1 * and EC 2*) installed in parallel with a pair of EC 1 and EC 2, power outputs of EC 1* and EC 2* are connected respectively to and "+2" contacts of the CPT, low-current inputs of EC 1* and EC 2* are connected and connected to the connection of low-current inputs of EC 1 and EC 2, and the connected power inputs EC 1* and EC 2* are connected to the connection of the power inputs of the mentioned pair of EC.

The CBT works similarly to the CBT described above (FIG. 1). When commanded from CU 4, the keys of both pairs are closed for the time t1 known and set in the CU - for time t2. In this case, the current is distributed over the EC pairs, reducing the current load on each pair, while it becomes possible to select the EC for any required power and for any operating voltage of the CPT.

Although the DC switch solution proposed as an invention has been described with reference to its specific embodiments, it should be understood by those skilled in the art that various changes in form and content can be made without departing from the spirit and scope of the invention as defined. the attached claims.

For example, in other implementations of the CPT, electronic keys, a mechanical key, a control device for improving the characteristics of the CPT as a whole can have different schemes (with additional elements) and designs.

To change the operating voltage of the CPT, several additional pairs of counter-series-connected ECs can be installed in parallel with a pair of EC. At the same time, the field of application of CPT for controlled networks of direct current consumption is expanding almost unlimitedly. Including in various types of electric transport - land, water, air, in alternative energy - wind, solar power plants, micro hydroelectric power plants, in storage systems, backup and uninterrupted power supply, in DC power plants.

The presented technical solution of the CPT is characterized by high manufacturability in manufacturing, reliability in operation, provides significant energy savings due to power consumption only when the state of the CPT changes.

Claims (4)

1. A direct current key (CPT), made with the ability to supply the necessary supply voltage to all its elements that require power, contains the first positive ("+1") and the first negative ("-1") contacts, the second positive ("+2 ”) and the second (“-2”) negative contacts, a control device (CU), a pair of counter-serially connected electronic keys (EC) and a mechanical key (MC) installed in parallel, the first and second power contacts of which are connected respectively to “+1” and "+2" to the contacts of the KTP, characterized in that an electromagnetic polarized relay is installed as an MC, the first and second low-current contacts of which are the contacts of the first winding of this relay, the third and fourth low-current contacts are the contacts of its second winding and are connected, respectively, to the first and second , the third and fourth outputs of the CU, and the power output of the first EC (EC1) from the mentioned EC pair is connected to the "+1" contact, the power input of which is connected to the power input of the second EC (EC2) of this pair, the power output of which is connected to the “+2” contact, the low-current inputs of EC1 and EC2 are connected and connected to the fifth output of the CU, the connection of the power inputs of the first and second EC is connected to the sixth output of the CU, and the input of the CU is connected to control contact KPT. 2. KPT according to claim 1, characterized in that it contains a diode connected in a non-conductive direction between the "+2" and "-2" contacts. 3. KPT according to claim 1, characterized in that between the "+2" contacts of the KPT in parallel to the mentioned pair of EC, at least one additional pair of counter-series connected power inputs of the EC was installed, the power outputs of the first and second EC of this additional pair are connected, respectively, to " +2" contacts of the CPT, low-current inputs of an additional pair of EC are connected and connected to the connection of low-current inputs of the said pair of EC, and the connected power inputs of the additional pair of EC are connected to the connection of the power inputs of the said pair of EC. 4. KPT according to claim 1, characterized in that the CU has an additional output connected to the control contact of the KPT for transmitting information signals.

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