Power supply fault rapid isolation and protection device with braking load protection function

Abstract

The present invention provides a power supply fault rapid isolation and protection device with a braking load protection function. The common energy-consuming resistor of the load resistor box unit is connected to the converter monitoring unit, and the braking resistor is connected to the braking circuit protection unit. The rectifier inverter module of the converter monitoring unit is used to monitor the status of the generator converter and control the opening and closing of the generator-side circuit breaker and the grid-side circuit breaker based on the status. The generator-side circuit breaker and the grid-side circuit breaker are used to control the on-off of the circuit. The circuit access component of the braking circuit protection unit is connected to the converter monitoring unit. According to the converter monitoring unit, the relay is connected to the circuit access component, the braking circuit breaker is connected to the relay, the main circuit input terminal of the braking circuit breaker is connected to the generator, and the main circuit output terminal of the braking circuit breaker is connected to the braking resistor of the load resistor box unit. In the event of a converter fault, the present invention refuses to connect the power supply and switches to the braking circuit for unloading, making the safety protection more complete and reliable.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system automation, and in particular relates to a power supply fault rapid isolation and protection device with a braking load protection function. Background Art

[0002] As long as the speed of a permanent magnet synchronous generator exceeds the rated speed, its output voltage will exceed the rated voltage. The higher the speed, the higher the voltage. In order to prevent the generator and load from being damaged by excessive voltage, it is necessary to control the speed of the permanent magnet synchronous generator and take measures to respond faster to prevent runaway.

[0003] Existing power protectors can provide some protection for energized circuits in the event of a fault, but they typically employ passive mechanical protection. This means that after the power protector is connected to the load and energized, it uses a current transformer to detect the load or the current in the power line before actuating the power switch. However, the protector's ability to disconnect the system circuits quickly and provide protection is limited, preventing timely protection of system equipment.

[0004] During operation, load resistors must continuously adjust the actual power input according to a preset power value. Their operating status also requires real-time monitoring to ensure prompt repairs when a fault occurs. Therefore, measurement and control equipment is essential to monitor the resistor's real-time operating parameters. Current load resistor measurement and control systems use relays, contactors, buttons, switches, and other components to control the loading and unloading of loads at various levels. These systems only meet basic testing requirements and, due to their semi-automatic control, are inflexible and inconvenient to operate. Summary of the Invention

[0005] In response to the above-mentioned deficiencies in the prior art, the present invention provides a power supply fault rapid isolation and protection device with a braking load protection function, and also provides a power supply fault rapid isolation and protection method with a braking load protection function, as well as a permanent magnet synchronous generator set based on the power supply fault rapid isolation and protection device with a braking load protection function.

[0006] The present invention is achieved through the following technical solutions.

[0007] According to one aspect of the present invention, a power supply fault rapid isolation and protection device with a braking load protection function is provided, comprising a load resistor box unit, a current transformer monitoring unit, and a braking circuit protection unit; wherein:

[0008] The load resistor box unit includes a common energy-consuming resistor and a braking resistor; the common energy-consuming resistor is connected to the converter monitoring unit, and the braking resistor is connected to the braking circuit protection unit;

[0009] The converter monitoring unit includes a rectifier-inverter module, a generator-side circuit breaker, and a grid-side circuit breaker. The rectifier-inverter module is used to monitor the status of the generator converter and control the opening and closing of the generator-side circuit breaker and the grid-side circuit breaker according to the status. The generator-side circuit breaker and the grid-side circuit breaker are used to control the on-off of the circuit.

[0010] The braking circuit protection unit includes a braking circuit breaker, a circuit access component, a relay and a switch. The circuit access component is connected to the converter monitoring unit. According to the converter monitoring unit, the relay is connected to the circuit access component, the braking circuit breaker is connected to the relay, the main circuit input end of the braking circuit breaker is connected to the generator, and the main circuit output end of the braking circuit breaker is connected to the braking resistor of the load resistor box unit.

[0011] Preferably, for the case where the generator is running at high load, when the converter fails, the converter monitoring unit controls the machine-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system; at the same time, the converter monitoring unit controls the circuit access component to be turned on, thereby causing the intermediate relay to be energized, and the load resistor box unit is put back into the circuit system. At this time, the braking resistor in the load resistor box unit is put into operation to absorb the electrical energy of the generator.

[0012] Preferably, the circuit access component is an alarm indicator light.

[0013] Preferably, the brake circuit breaker current is 1250A.

[0014] Preferably, the outer diameter of the cable connecting the main circuit inlet of the brake circuit breaker and the generator is 240 mm. 2 .

[0015] Preferably, the outer diameter of the cable connecting the main circuit outlet of the brake circuit breaker and the brake resistor of the load resistor box unit is 240mm. 2 .

[0016] According to another aspect of the present invention, there is provided a method for isolating and protecting a power supply fault rapid isolation and protection device with a braking load protection function as described in any one of the above, comprising:

[0017] The rectifier-inverter module of the converter monitoring unit is used to monitor the status of the generator converter in real time. When the collected converter status is a converter fault, the converter monitoring unit controls the machine-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system. At the same time, the converter monitoring unit controls the circuit access component to be connected, thereby closing the intermediate relay and re-entering the load resistor box unit into the circuit system. At this time, the braking resistor in the load resistor box unit is put into operation to absorb the electrical energy of the generator.

[0018] According to a third aspect of the present invention, a permanent magnet synchronous generator set is provided, comprising a permanent magnet synchronous generator and any one of the above-mentioned power supply fault rapid isolation and protection devices with a braking load protection function connected to the permanent magnet synchronous generator.

[0019] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0020] The present invention provides a power supply fault rapid isolation and protection device and method with a braking load protection function. Before the braking circuit protection unit closes the power supply, the converter monitoring unit monitors the converter status of the generator to see whether there is overload, excessive speed, or other conditions. If the above hidden dangers occur, the converter monitoring unit outputs a corresponding control signal to the microprocessor to disconnect the machine-side and grid-side circuit breakers, and the braking circuit protection unit is connected. At the same time, a fault display and alarm can be made. Only after the hidden dangers are eliminated can the main switch be turned on, thereby providing a more convenient and safe protection device for the generator set. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0022] Figure 1 This is a circuit schematic diagram of a power supply fault rapid isolation and protection device with a braking load protection function in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following is a detailed description of an embodiment of the present invention. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process. It should be noted that those skilled in the art may make various modifications and improvements without departing from the scope of the present invention, and these modifications and improvements fall within the scope of protection of the present invention.

[0024] One embodiment of the present invention provides a power supply fault rapid isolation and protection device with a braking load protection function. The direct cause of generator overspeed is the failure to safely release the generator's electrical energy. The power supply fault rapid isolation and protection device with a braking load protection function provided in this embodiment can add a braking resistor to the generator to safely release the generator's electrical energy. When the converter is powered on, it can detect the status of the generator to determine whether there is an overload, excessive speed, or other conditions. If so, the converter refuses to connect the power supply and switches to the braking circuit for unloading, making the safety protection more complete and reliable.

[0025] Figure 1 This is a circuit schematic diagram of a power supply fault rapid isolation and protection device with a braking load protection function in a preferred embodiment of the present invention.

[0026] refer to Figure 1 As shown, the power supply fault rapid isolation and protection device with a braking load protection function provided in this embodiment includes: a load resistor box unit, a converter monitoring unit and a braking circuit protection unit; wherein:

[0027] The load resistor box unit includes a common energy-consuming resistor and a braking resistor; the common energy-consuming resistor is connected to the converter monitoring unit, and the braking resistor is connected to the braking circuit protection unit;

[0028] The converter monitoring unit includes a rectifier-inverter module, a generator-side circuit breaker, and a grid-side circuit breaker. The rectifier-inverter module is used to monitor the status of the generator converter and control the opening and closing of the generator-side circuit breaker and the grid-side circuit breaker according to the status. The generator-side circuit breaker and the grid-side circuit breaker are used to control the on-off of the circuit.

[0029] The braking circuit protection unit includes a braking circuit breaker, a circuit access component, a relay and a switch. The circuit access component is connected to the converter monitoring unit. According to the converter monitoring unit, the relay is connected to the circuit access component, the braking circuit breaker is connected to the relay, the main circuit input end of the braking circuit breaker is connected to the generator, and the main circuit output end of the braking circuit breaker is connected to the braking resistor of the load resistor box unit.

[0030] As a preferred embodiment, for the case of high-load operation of the generator, when the converter fails, the converter monitoring unit controls the machine-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system; at the same time, the converter monitoring unit controls the circuit access component to be turned on, thereby causing the intermediate relay to be energized, and the load resistor box unit is put back into the circuit system. At this time, the braking resistor in the load resistor box unit is put into operation to absorb the electrical energy of the generator.

[0031] As a preferred embodiment, the circuit access component adopts an alarm indicator light.

[0032] As a preferred embodiment, the brake circuit breaker current is 1250A.

[0033] As a preferred embodiment, the outer diameter of the cable connecting the main circuit inlet of the brake circuit breaker and the generator is 240mm. 2 .

[0034] As a preferred embodiment, the outer diameter of the cable connecting the main circuit outlet of the brake circuit breaker and the brake resistor of the load resistor box unit is 240mm. 2 .

[0035] like Figure 1 As shown, this embodiment provides a power supply fault rapid isolation and protection device with a braking load protection function. In the event of a system fault, the circuit breaker control unit controls the incoming and outgoing line switches to achieve rapid fault isolation and connect the braking load for protection. This embodiment can quickly isolate the faulty line, effectively improving the reliability and stability of the power supply.

[0036] Among them, in the load resistor box unit, the commonly used energy-consuming resistor is connected to the converter monitoring unit, and the braking resistor in the load resistor box unit is connected to the braking circuit protection unit; in the braking circuit protection unit, the braking protection circuit contactor KA3 is controlled to be attracted and disconnected through the braking circuit converter circuit break alarm output terminals 1 and 2; in the converter monitoring unit, the rectifier inverter module is responsible for monitoring the status of the generator, and the machine-side and grid-side circuit breakers control the on and off of the converter monitoring unit circuit.

[0037] The converter monitoring module continuously monitors the generator voltage. When the generator voltage exceeds the protection threshold, the converter shuts down and illuminates the fault indicator HL1 on the converter cabinet door. Connect the terminals of the converter fault indicator HL1 to the coil of intermediate relay KA1. When HL1 illuminates, KA3 is also energized.

[0038] Use KA1 to control the start and stop of the brake circuit breaker QS3. The reference current of the brake circuit breaker QS3 is 1250A. 2 ) Connect another set of cables to the main circuit inlet of the brake circuit breaker QS3, and the main circuit outlet of the brake circuit breaker QS3 to the on-site load box (reference cable outer diameter 240mm 2 ).

[0039] When the generator is operating under high load and the generator voltage exceeds the protection threshold or the converter fails due to other reasons, the converter immediately disconnects generator-side circuit breaker QS2 and grid-side circuit breaker QS1, illuminates the fault indicator, and removes the load bank from the system. Simultaneously, QS3 is closed, and the load bank is reactivated, but now functions as a brake resistor, rather than a normal load. This entire transition from load bank to brake resistor occurs in less than one second, after which the brake resistor absorbs the generator's energy. The brake resistor maintains the same value as the load resistor at the time of the converter failure, eliminating the need for manual intervention. This allows the generator to continue to discharge energy efficiently and safely. The expander control system also receives the converter fault signal and enters a shutdown state, preventing the generator from accelerating and potentially causing runaway speed.

[0040] When the generator stops, manually reset the converter, the converter fault indicator HL1 will go out, and the braking resistor will be withdrawn, no longer affecting restarting.

[0041] Regardless of whether the generator is running or not, as long as the converter fails, the braking resistor will be put into use. The converter fault must be eliminated before the generator can be started.

[0042] Another embodiment of the present invention provides an isolation and protection method for the power supply fault rapid isolation and protection device with a braking load protection function provided in any of the above embodiments, comprising:

[0043] The rectifier-inverter module of the converter monitoring unit is used to monitor the status of the generator converter in real time. When the collected converter status is a converter fault, the converter monitoring unit controls the machine-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system. At the same time, the converter monitoring unit controls the circuit access component to be connected, thereby closing the intermediate relay and re-entering the load resistor box unit into the circuit system. At this time, the braking resistor in the load resistor box unit is put into operation to absorb the electrical energy of the generator.

[0044] A third embodiment of the present invention provides a permanent magnet synchronous generator set, comprising a permanent magnet synchronous generator and a power supply fault rapid isolation and protection device with a braking load protection function provided in any one of the above embodiments connected to the permanent magnet synchronous generator.

[0045] As long as the speed of a permanent magnet synchronous generator exceeds the rated speed, its output voltage will exceed the rated voltage. The higher the speed, the higher the voltage. In order to prevent the generator and load from being damaged due to high voltage, the speed of the permanent magnet synchronous generator needs to be controlled. The direct cause of the generator overspeed is that the electric energy of the generator is not released safely. The power supply fault rapid isolation and protection device and method with a braking load protection function provided by the above embodiment of the present invention can add a braking resistor to the generator to safely release the electric energy of the generator. When the converter monitoring unit is connected to the power supply, it can detect the converter status of the generator to determine whether the generator is overloaded, the speed is too high, etc. If so, the converter refuses to connect the power supply and switches to the braking circuit for unloading, making the safety protection more complete and reliable.

[0046] It should be noted that the steps in the method provided by the present invention can be implemented using corresponding modules, devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the system to implement the step flow of the method, that is, the embodiments in the system can be understood as preferred examples of implementing the method, which will not be elaborated here.

[0047] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A power supply fault rapid isolation and protection device with a braking load protection function, characterized in that: It includes a load resistance box unit, a current transformer monitoring unit and a brake circuit protection unit; wherein: The load resistor box unit includes a common energy-consuming resistor and a braking resistor; the common energy-consuming resistor is connected to the converter monitoring unit, and the braking resistor is connected to the braking circuit protection unit; The converter monitoring unit includes a rectifier-inverter module, a generator-side circuit breaker, and a grid-side circuit breaker. The rectifier-inverter module is used to monitor the status of the generator converter and control the opening and closing of the generator-side circuit breaker and the grid-side circuit breaker according to the status. The generator-side circuit breaker and the grid-side circuit breaker are used to control the on-off of the circuit. The brake circuit protection unit includes a brake circuit breaker, a circuit access component and a relay, the circuit access component is connected to the converter monitoring unit, and according to the control of the converter monitoring unit, the relay is connected to the circuit access component, the brake circuit breaker is connected to the relay, the main circuit inlet of the brake circuit breaker is connected to the generator, and the main circuit outlet of the brake circuit breaker is connected to the brake resistor of the load resistor box unit; In the case of high-load operation of the generator, when the converter fails, the converter monitoring unit controls the generator-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system; at the same time, the converter monitoring unit controls the circuit access component to be turned on, thereby closing the relay, and the load resistor box unit is put back into the circuit system. At this time, the braking resistor in the load resistor box unit starts working to absorb the electrical energy of the generator.

2. The power supply fault rapid isolation and protection device with brake load protection function according to claim 1 is characterized in that: The circuit access component adopts an alarm indicator light.

3. The power supply fault rapid isolation and protection device with brake load protection function according to claim 1 is characterized in that: The brake circuit breaker current is 1250A.

4. The power supply fault rapid isolation and protection device with brake load protection function according to claim 1 is characterized in that: The outer diameter of the cable connecting the main circuit inlet of the brake circuit breaker and the generator is 240mm².

5. The power supply fault rapid isolation and protection device with brake load protection function according to claim 1 is characterized in that: The outer diameter of the cable connecting the main circuit outlet of the brake circuit breaker and the brake resistor of the load resistor box unit is 240 mm².

6. An isolation and protection method for a power supply fault rapid isolation and protection device with a braking load protection function according to any one of claims 1 to 5, characterized in that: include: The rectifier-inverter module of the converter monitoring unit is used to monitor the status of the generator converter in real time. When the collected converter status is a converter fault, the converter monitoring unit controls the machine-side circuit breaker and the grid-side circuit breaker to be disconnected. At this time, the load resistor box unit is cut off from the circuit system. At the same time, the converter monitoring unit controls the circuit access component to be connected, thereby closing the relay and re-entering the load resistor box unit into the circuit system. At this time, the braking resistor in the load resistor box unit is put into operation to absorb the electrical energy of the generator.

7. A permanent magnet synchronous generator set, characterized in that: The invention comprises a permanent magnet synchronous generator and a power supply fault rapid isolation and protection device with a braking load protection function according to any one of claims 1 to 5 connected to the permanent magnet synchronous generator.

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